Part 24 - cd3wd424.zip - Offline - Proceedings of the Meeting of the Expert Working Group on the Use of Solar and Wind Energy

Part 24 - cd3wd424.zip - Offline - Proceedings of the Meeting of the Expert Working Group on the Use of Solar and Wind Energy
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ECONOiwC
AND SOCIAL COhI~IISSION
FOR ASIA AbiB THE FACIFIC
Bangkok, Thailand
ENERGY RESOURCES DEVELOPMENT
No. 16
UNITED NATIONS
New York, 1976
SERIES
ST/E!XAP/7
Price:
$US 9.00 or equivalent in other currencies
ii
FOREWORD
This publication contains the report and documents of the
meeting of the Expert Working Group on the Use of Solar and
Wmd Energy (2-9 March, 1976), held, as part of the continuing
programme on the utilization of non-conventional energy resources,
by the United Nations Economic and Social Commission for Asia
and the Pacific (ESCAP) at Bangkok, Thailand, with the financial
assistanceof the United Nations Development Programme (UNDP).
It consists of four parts. Part one includes the report of the
meeting. Parts two, three and four contain technical
documents,
presented by the secretariat and contributed by the experts, on
soIar energy, wind energy and integrated systems utilizing solar
and/or wind devices, respectively.
Owing to limitations of space and budget, it has not been
possible to reproduce all the papers contributed by the experts in
full; some papers have been abridged, and selected information
given in the papers has been collated and re-presented.
...
111
f
CONTENTS
Part One
REPORT OF THE MEETING
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Discussion, conclusions and recommendations . .
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Introduction
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AMCXS
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Report of the Solar Energy Sectoral Group . .
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Report of the Wind Energy Sectoral Group . .
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III.
Report of the Solar/Wind
TV. List of experts
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List of documents
Energy SectoraI Group
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Part Two
DOCUMENTATION
OS SOLAR ENERGY
Working paper presented by the secretariat
Solar ener-q: its relevance to developing countries
Information
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papers prepared by participants
Solar energy research in the Philippines
Solar energy in India:
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research, development and utilization
Recent research and development on solar energy applications in Japan
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Solar energy in southeast Asia
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Programme and progress for solar house development in Korea
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The prospects of solar energy utilization:
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The Sunshine Project: solar energy research and development. .
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Solar energy work in Pakistan
Solar energy in Australia
Solar energy and energy conservation in Australian
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Research, development and use of solar energy in Thailand
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the Indonesian case
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Consolidated list of references on solar energy
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Organizations concerned with solar energy
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iv
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Part Three
DOLLJ~IEXI’~TIOS
I.
WorKmg papers presented by the secretariat
Development of wind energy utilization
The design and construction
II.
ON WIND EXRGY
Information
in Asia and the Pacific
of low-cost wi&-powered
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water pumping systems . .
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papers prepared by participants
A review of efforts made in India for wind power utilization
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Research. development and use of wind energy in Thailand
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The utihzation of wind energy in Australia
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A review of renewable enetgy in New Zealand with emphasis on wind power utilization
Wiidpower
studies in Korea
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Research and prospects of wind enera
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utilization
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in Indonesia
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III.
Consolidated list cf references on wind energy
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IV.
Organizations concerned with wind energy
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Part Four
DOCUMEXTATION
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Information
to integrated solar-wind systems . .
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paper prepared by participant
Planning for small-scale use of renewable energy sources in Fiji
III.
SYSTEMS
Working paper presented by the secretariat
An introduction
II.
ON U’JTEGRATED
Consolidated list of references on integrated systems __
V
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Part One
REPORT OF THE MEETING
I.
INTRODUCTION
objectives of the
Es-pert Il’orki~rg
Group
Backpromci
0FZt.i
The ESC.\P programme on energy involves hvo
main streams of activity -a
long-term programme
mvolving the co-or&rated planning of the investigation,
development aud management of energy resources, and
a short-term pro,gamm e aimed at accelerated development of selected non-conventional energy resources
with emphasis on the needs of rural areas. The latter
programme was initiated in December 1974, with a
reconnaissance mission to 14 developing countries to
make a preliminary assessment of energy programmes
and needs, and was completed in September 1975.
Two workshops on the technology and utilization of
bio-gas were also completed in 1975.
The other component of the programme involves
solar and wind energy, under which the original plan
to provide advisoq services to developing countries
was changed to arranging an expert working group
when the reconnaissance mission indicated that a great
deal of research and development had been undertaken
in a number of member countries in the region. In
view of the signihcant interactions between solar energy
and wind enerhq. it was decided to arrange one expert
working group on those two topics. Participants would
comprise mainly experts selected from countries which
were known to have considerable experience in either
or both of the two fields, but some experts from
outside the region were also included.
The objectives of the meeting were to identify the
existing technology and devices for the use of solar
and wind energy which could be recommended for
immediate application, mainly but not exclusively in
rural areas, and to recommend research and development activities likely to yield practical results in the
short term. so as to improve the use of those resources.
It was also intended to issue a publication setting out
guidelines for the use of solar and wind energy in
the variety of situations considered by the Working
Group. With the linancial support of UNDP. the
Working Group was held from 2 to 9 March 1976
at Bangkok.
A ttendame
The meeting was attended by 23 experts from 13
countries, as listed in annex IV.
Opening address
In his opening address, Mr. J. B. P. Maramis.
Executive Secretary, stressed the importance of the
meeting in the context of the decisions of the sixth
and seventh special sessions gf the General Assembly
and those of the Commission, particularly at its thirtyfirst session in 1975. all of which emphasized the need
to develop scientific and technological co-operation in
all sectors of development activity. He referred to the
ESCAP programme in the energy field and the background of the Expert Working Group, and stressed
that the Group had been arranged to make the best
use of the extensive knowledge and experience available
within the region on the use of solar and wind energy.
At the same time it was pleasing to have the participation of some experts from outside the region.
Since the majority of the population in the developing countries of the’ ESCAP region lived in rural
areas, the main objective of those activities was to
foster the small-scale and medium-scale development of
those non-commercial but renewable forms of energy
in rural areas. Following the Expert Working Group
meeting, it was intended to organize in 1977 a roving
seminar on rural energy development under which a
small team would spend about three weeks in each
of the interested countries to assist in the development
of practical measures to improve the availability of
energy in rural areas. That would include consideration of bio-gas, solar and wind ener,v. rural electrification and mini-hydroelectricity.
In the light of those objectives, the Expert Working
Group had before it an important task which, although
related specifically to solar and wind energy, would
contribute to integrated energy development programmes in regional countries in a more comprehensive
way. He expressed confidence that the recommendations to be put forward by the Working Group would
be so specihc and practical that they could be considered for immediate implementation by the ESCAP
member countries.
Election of o&em
Mr. R. V. Dunkle, Chief Research Scientist,
Division of Mechanical Engineering, Commonwealth
Scientific and Industrial Research Organization, Australia, was elected Chairman and Mr. Prapath Premmani. Director of the Technical Division, National
Energy Administration, Thailand, was elected ViceChairman.
Mr. C. L. Gupta, Professor, Applied Science
Group, Sri Aurobindo International Centre of Education. Pondicherry, India, was elected Moderator for
the Solar Energy Sectoral Group and Mr. R. E. Chilcott.
Lincoln College, Canterbury, New Zealand. was elected
Moderator for the Wind Energy Sectoral Group.
Part One.
2
Agenda
(ii) Evaluation of local
determinants
.
The Expert Working Group adopted the following
agenda:
1.
Opening address
2.
Election of officers
3.
Adoption of the agenda
4.
Presentation of summaries of the consultants’
and participants’ papers
5.
Group discussions
(iv) Electricity generating systems: available designs, capabilities, constraints,
recommendations
(v) Analysis of basic components: rotor,
hub shaft, bearings, tower, control
mechanisms, power transfer mechanisms, power utilization devices, storage; recommendations on hybrid
de: i.gns
(i) Small- and medium-scale thermal
applications; design, construction,
socio-economic aspects,
Ovation.
mfurther research and development,
and recommendations: wa*er heating, distillation,
cooking, drying,
rrfrigerarion
and air-conditioning,
Pumping
(ii) Promising fields of application and
research and development
Small and medium-scale conversion to electrical and mechanical
power
Large-scale power production
by photovoltaic and photothermal devices
Other fields: high temperature
furnace. solar house, greenhouse, algal pond
Recommendations
(iii) Solar energy characteristics. measurements and data evaluation, recommendations
(iv) Recommended actions, and priorities
of the report
(b) Wind energy sectoral group
(i) Demands for and limitations
of wind energy
environmenta.)
(iii) Water pumping systems: available
designs, capabilities, constraints, recommendations
(a) Solar energy sectoral group
(Y) fi&piion
Report of the meeting
in use
(vi) Other uses and advanced concepts
acquiring research and development
(vii) Recommended actions and priorities
(viii)
Adoption
of the report
(c) Discussion of solar/wind
interactions
(i) Uses where either is appropriate
(ii) Integrated uses ,
(iii)
Recommended actions and priorities
(iv) Adoption of the report
6.
Consideration of reports and formulation
recommendations by the Working Group
of
7.
Adoption of the report of the Working Group
Organization of work
As a background for consideration of the two main
topics, the papers which had been prepared by the
consultants and participants were presented in summary
by the authors. Those papers are listed in annex V.
The substance of those papers was considered in detail
in sectoral group meetings.
The programme of meetings included field trips to
the Asian Institute of Technology, to salt farms (windmill-pumps) in Samut Songkram province and to Samut
Prakam (windmills).
II.
DISCUSSION, CONCLUSIONS AND RECOMMENDA’I’IONS
Members of the Working Group, meeting both in
sectoral _eroupc and in plenary meetings. had in mind
a number of considerations which influenced their
thinking on pro,gmmmes associated with solar and wind
energy. The principal considerations are st,mmarized
below.
Increased availability of ener”q was an important
factor in any effort to improve the well-being of the
rural poor. who comprised a large sector in the total
population of the region. While manual labour was
likely to remain a significant component in most countries of the region, other forms of eneqg were needed
to avoid drudgery, increase productivity and improve
the quality of life. There was an over-all need for an
increase in the availability of energy per capitti. The
beneEts from improved energy supplies were often
difhcult to measure in strictly economic terms, but
there were generally large social benefits associated
with such developments as provision of adequate lighting, improved water supply or crop-drying facilities.
Rural areas were often the most costly and difficult
to supply with conventional energy forms, whereas nonconventional forms of energy, including solar and wind
energy, were not necessarily subject to the same constraints. The development of those energy forms had
the advantage of aiding decentralization and se!fsufficiency in rural communities. Generally. however,
solar and wind energy were available only intermittently,
so that there was an incentive for integration with
other enery forms, conventional as well as non-conventional. Thus, there was a need for integration of
planning for the development of non-conventional
energy resources in rural areas, in over-all nation31
energy planning.
Because the problems in terms of human need
and enery deficiency tended to be greater in rural
areas, the emphasis should be on meeting the needs
of those areas. However, solar and wind energy could
also play useful roles in contributing to meeting energy
requirements in urban and metropolitan areas in appropriate circumstances.
It was important that any devices and systems
intended for widespread application in rural communities should be simple and rugged, and make the best
use of locally available materials and skills. Involvement of local people as far as feasible improved the
prospects for acceptability and had a variety of significant supplementary beneEts.
In addition to improving living conditions, the use
designed and
of solar and wind ener,gy. if properly
managed, had no significant environmental disadvantages.
Many solar and wind energy devices currently
available tended to be capital-intensive, thus restricting
their widespread application. Their potential value,
however, was such that high priority should be given
to carefully selected and managed programmes aimed
at reducing costs and extending the use of those energy
resources.
The Working Group in plenary session endorsed
the reports of the three Sectora! Groups and the
detailed recommendations made, as given in annexes
I, II and III. Based on those recommendations, the
Working Group put fonvard a number of proposals
in different areas of activity.
National planning and surveys
National energy planning should take into account
the availability of renewable resources and their development to complement any existing ener,y systems.
Energy surveys should be carried out and should
include assessment of:
(a)
Solar and wind energy (and bio-mass where
applicable);
(6)
Energy needs of rural areas to achieve a
reasonable quality of life.
National meteorological networks should be strengthened to bring solar radiation and wind measurements
to at least the World Meteorological Organization
( WMO) standards.
Research and development
Research and development by and for the respective countries of the region should be encouraged and
promoted with particular reference to selected solar
devices (recommendation No. 7 (c) of annex I),
wind-powered pumps and electric units (recommendation No. 8 of annex II), and integrated solar-wind
uses (recommendation No. 2 of annex III).
Efforts
should also be made to stimulate commercial and
industrial involvement in research and development
projects in those fields.
Training
ESCAP should initiate and encourage training in
the Eelds of solar and wind energy use at various
levels, seeking support from international agencies and
countries outside the region as appropriate:
.
Part One.
4
-.(a) At universities and technological institutions
in the region, by assistance in development of courses
and text matPrials. and provision of fellowships;
(b) By further expert technical meetings, and
roving seminars. at intervals as appropriate;
(c) By assisting countries to produce texts and
illustrated material for use in schools and extension
services.
Dernomtratiotz units
I
ESCAP should encourage the setting up in selected ’
locations of demonstrations of selected solar and wind
energy utilization devices, in separate and in integrated
systems, for the purposes of providing information for
potential u-m-s, ensuring the necessary system reliability
under normal conditions and obtaining socio-economic
data needed for local and commercial development
(recommendations NOS.7 (a) and (b) of annex I,
recommendation No. 16 of annex II, and recommendation No. 3 of annex III).
Report of the meeting
Research directory
A regional directory of research institutions and
organizations engaged in work on renewable enern
sources should be compiled and published. The directory should include research programmes and personnel,
and sources of commercially available hardware.
A regional documentation and dissemination centre
on solar and wind energy technologies should be
established, preferably at an existing library or technological institution within the region.
Guide-books
Technical guide-books on the design of solar and
wind energ utilization devices should be compiled
and published in a format appropriate for use by
development workers and Eeld extension agents. The
guide-books should include sufficient information for
the design and construction of those devices by local
workers.
Annex I
REPORT OF THE SOLAR ENERGY SECTORAL GROUP
solar water-heating
The Group noted that domestic solar water-heaters
were currently within the reach of af!luent people in
the developing countries, and, in appropriate circumstances, could provide energy more economically than
conventional energy forms. Reliable designs in the
region were commercially available from Australia,
India, Japan and New Zealand.
With respect to urban and metropolitan areas,
heating of water for industrial as well as domestic use
should be explored further.
ensuring the necessary system reliability, and obtaining
socio-economic data needed for commercial development;
(d) Dissemination of information and feedback
of the experience among regional countries.
Research and development should be undertaken
on the following aspects:
(a)
Use of locally available material and skills;
(b) Building up of criteria for socio-economic
viability of solar water-heating;
There was scope for solar water-heating, par&
cularly in rural areas, for community use, such as for
health centres, tourist hotels and hostels, and for some
cottage industries. Solar energy could also be used
more extensively for heating slurry of bio-gas plants.
(c) Solar water-heating system for multiple uses,
for example, combined solar water-heating and solar
stills and integration of roof and collector systems,
The Group suggested that the following action be
taken in order to foster the development of solar
water-heaters:
The Group considered the application of solar
distillation mainly for two purposes, one for producing
potable water and the other for providing distilled
water for other uses. It reviewed the current status
of solar distillation development, and the experience
developed, in the region.
(a) Selection of appropriate locations and conditions for installation of demonstration plants;
(b) Design of water-heating systems to take advantage of ihe most cost-effective collector panels;
(c)
purpose
Demonstration of selected systems for the
of providing information for potential users,
Solar distillation
Solar stills were being used to provide drinking
water for domestic use in some low-rainfall areas and
isolated areas, such as salt farms. light-houses, and
villages where fresh water was not available.
II.
f
Discussion, conclusions and recommendations
--
5
Solar stills had also proved to be cost-effective in
certain circumstances for providing distiI!ed water for
use in garages, workshops, laboratories and health
centres. and should be promoted for the developing
countries of the region.
With respect to natural solar drying. existing
practices should be studied with a view to improving
the performance and the quality of the product.
Nevertheless, solar stills were satisfactory only in
special circumstances, and there was a need for further
research and development with a view to widening
their applicability and use, particularly by reducing
operational cost and maintenance.
Considerable interest was expressed in the potential
for use of solar energy for pumping. ReEerence was
made to two systems:
S&r
cooking
The Group considered that solar cooking hardware
could be classified in three main types: (a) solar
steam cooker which only boils but cooking can be
done inside; (b) solar hot box which can boil and
bake but needs occasional tracking, although no continuous attendance is required: (c) reflector type cooker
which can bake, boil and roast but needs tracking
and attendance.
The discussion revealed that, within the region,
there was little experience in the field of solar cooking
except in India. However, it was felt that there could
be scope for greater use of solar cookers of types
(a) or (b) for which proven designs were available,
in situations where other forms of energy were not
readily available or not reliable. and the cost was not
prohibitive.
Research and deveIopment were needed to reduce
the cost of cookers and to develop designs involving
storage or auxiliary heating in order to increase the
reliability of the cooker, extend the cooking time and
allow indoor cooking.
Sotar drying
The Group noted that there was considerable
experience in the use of solar drying in the region,
ranging from small-scale cabinet driers to sophisticated
systems incorporating storage, automatic control and
auxiliary power. The availability of radiation during
the wet season in most of the southeast Asian countries
appeared to offer scope for more extensive use of
solar drying.
The Group recommended that demonstrations be
arranged of solar convective driers for drying of
grains in multiple-cropping systems and for cash crops,
such as cashew nut, copra, pepper and tea, and for
timber where other fuels were currently used.
In forced-draft systems, research and development
were needed to develop autonomous systems which
could replace
power-operated blowers by thermal
chimneys, windmills or manual pedalling.
Sob
pumping
(a)
The solar thermal system; and
(b) Using solar cells to produce electricity
drive electrically-powered pumps.
Electricity
conversion
was
to
discussed later.
With regard to the solar thermal system, it was
noted that technological solutions were already available, although the cost was high. It was also noted
that research and development were being carried out
in the region, particularly for low-lift pumping, which
seemed promising.
Developmental trials of existing solar thermal
pumps of about 1 kW that were available commercially
outside the region should be undertaken in order to
determine their techno-economic feasibility in the
countries of the region.
Research and development were needed to develop
economic prototype solar pumping systems, based preferably on flat-plate collectors and stationary concentrators, servicing farm units of about 1 hectare each.
Solar refrigeration
The Group considered that there was a widespread
need for ice and/or cold storage for various purposes
in rural areas. Use of solar energy was technically
feasible, but the economics were not known. Research
and development were needed to determine the
applicability of solar energy for that purpose.
Space heating and cooling
The Group emphasized the importance of care in
building design and selection of materials with a view
to minimizing heating and cooling req,$rements.
Solar heating could be promoted in some colder
of the region, using systems based on solar
collectors which were already available for heating
liquids or air.
parts
Space cooling with solar collectors was also
technically feasible, but the outlook for its application
in developing countries was not promising. Its combination with space heating, which was being pursued
in some countries of the region, could improve its
viability.
Part One.
6
“Passive” heating and cooling, incorporating for
instance roof pools, heat storage elements and panels
designed to allow controlled movement of heat (thermal
diodes), appeared to have considerable promise in the
drier parts of the region. Work being carried out in
Australia and India should be encouraged.
fn the humid tropics, the outlook for passive
cooling systems was not promising, and emphasis should
be on architectural design.
A handbook of data to assist in the thermal
design of houses, and solar heating and cooling systems,
should be compiled.
Sotar energy conversion to etecfricat and
mechanical power
The Group considered solar power systems of the
following xales :
Small-scale
: 100Wto2kW
(Individual
houses, farms, workshops)
Medium-scale
:
20 kW to 100 kW
(Village power supply)
Large-scale
: 200 kW to 1 MW and above
(Power for smaIl industries, small town power
supply)
:
For small-scale power requirements, photovoltaic
direct conversion systems using 5 to 8 W solar cells
which were available in the region had proved successful
in isolated localities in Pakistan. In order to reduce
costs, research and development were needed to develop
new system components, including cells, concentrators.
controlling devices and cooling systems. There might
be scope for heating water with the coolant.
In the absence of experience
medium-scale power production,
for imported solar/thermal units
gion could be conducted in order
under different conditions.
within the region for
developmental trials
from outside the reto determine viability
For large-scale power production, base-line system
studies should be carried out only after some experience
on the medium-scale system had been gained.
PI~oiosynr1~esi.s(bio-mass)
’
While the matter was not examined in detail.
attention was drawn to the potential for energy production from waste organic materials and from “energy
plantations.”
Report of the meeting
Sotar evaporation
The Group noted that solar evaporation of solutions for salt recovery and concentration of waste
liquids represented a significant major use of solar
energy.
Solar ponds
Research and development for solar ponds could
be carried out as a long-term progrrnme, using bittern
(mother liquor 01 ;:i: prod*lction) ir&>rn a salt farm.
The solar pond might be useti r‘or therm31 collection
and energy storage, and for the recovery of valuable
chemicals.
Greenhouses
The technology for greenhouses was well established in colder parts of the region. Research and
development were needed for inexpensive heat storage
and the reduction of heat losses.
Solar radiation n~easmnertt and data evaluation
The networks of solar radiation stations in countries of the region should be strengthened, using the
standards laid down by WMO.
A regional solar radiation data book with specific
reference to the utilization of solar energy should be
compiled.
Recommendations
The following recommendations were made:
1. Surveys of energy availability and requirements
should be carried out in representative rural communities in the countries of the region. Available data
should be published.
2. A handbook of solar radiation data should
be compiled for the region, based on available records.
The data should be specific to solar energy utilization,
including conversion factors for optimum tilted surfaces. solar positions, frequency analysis etc.
3. A handbook of data to assist thermal design
of houses and heating and cooling systems should be
compiled.
4-? The networks of solar radiation stations in
countries of the region should be strengthened, using
.
the standards laid down by WMO.
5. To assist collaborative efforts in this field,
exchange of information and personnel and the planning of non-conventional energy programmes, ESCAP
should publish a regional directory of personnel.
II.
Discussion, conclusions and recommendations
institutions, research programmes and commercially
available hardware. This directory should contain references to directories available for other parts of the
world and also the literature on energy bibliographies.
Updating supplements should be provided biennially.
7
(c) Research and development are required prior
to application of potentially available technology for
the following:
(i) Autonomous drying systems;
(ii)
Solar pumping system for 1 hectare size
farms, primarily based on flat-plate collectors
and stationary concentrators;
(iii)
Systems and components for 100 W - 2 kW
small-scale power, using direct photovoltaic
conversion;
Priority I: Crop drying, water pumping, smallscale electricity generation. solar-assisted biogas generators;
(iv)
Development of criteria for socio-economic
viability and relevance of specific uses of
solar energy;
Priority II: DistillationT!J water-heaters, passive
heating systems, passive cooling systems;
(VI
Multiple use and architecturally
solar water-heating systems:
Priority III:
Refrigeration, cooking, active heating systems, active cooling systems.
(vi)
Reduction of maintenance and operational
problems of solar stills;
6. In view of the needs and socio-economic
priorities, as well as the current state of solar technology
and trends for the future, work on research, development and demonstration for and by the developing
countries of the region should preferably be grouped
according to the following priorities:
integrated
7. The specific research and development work
required in each of these areas as well as the demonstration/developmental trials required for promoting
immediate applications are stated below:
(vii)
Integration of optimized building design with
passive heating/cooling systems in buildings;
(viii)
Economic viability of solar refrigeration for
proven needs of ice or cold storage in rural
areas;
(a) Demonstration trials are required in the
following priority areas to promote immediate application of available solar technology within the region:
(ix)
Reliable cookers which would cook indoors
and do not need continuous attention;
(4
Inexpensive thermal storage in greenhouses;
(xi)
Use of bittern from salt farms for solar
ponds.
(i)
(ii)
Solar convective driers for grains in multiplecropping systems and for cash crops;
Solar water-heating systems for community
uses, such as health centres, tourist hotels,
hostels, cottage industries and heating of
bio-gas plants in rural areas.
(b) Evaluatiorz trials are required in the following to introduce and test the viability of solar technology
available outside the region for priority needs within
the region:
(i)
Solar thermal pumps of 1 kW size;
(ii)
Solar thermal power stations of 20 to 100
kW size for electritication at village level.
The chosen sites should not only be suitable
climatically but should represent the possibility of
economically and environmentally satisfactory solutions.
8. Countries of the region in the initial stages
of solar energy research work should be assisted with
the provision of training fellowships, seminars, workshops and advisory services.
9. The Group recommended that ESCAP take
an immediate lead in organizing short-term courses in
the region on the application of solar-energy devices
for domestic arid commercial buildings and for agricultural and industrial uses.
10. The Group recommended that countries produce attractive and well-illustrated material on the
basics and applications of so1ic.renergy, for secondary
schools. That would probably be the best way to
create intelligent awareness as well as provide future
sources of trained personnel for solar energy work.
Part One.
8
Report of the meeting
Annex II
REPORT OF THE WIND ENERGY SECTORAL GROUP
1. Limitations in the use of wind energy
2. Locd environmental determinants
It was agreed that, for preliminary design purposes,
it was appropriate to use an approximate formula
such as:
It was noted that, for most development projects,
classical economic evaluation criteria were not likely
to be applicable to wind energy utilization at the
village level, where local material and labour might
be freely available, or where a small input of enerc
might result in a significant social impact; socioeconomic considerations require further study.
Useful power output per unit swept area
= 9.1 v3 watts/m2.
where v = instantaneous wind velocity in m/set
That formula included the Betz aerodynamic, mechanical and hydraulic or electrical efficiencies.
.
In estimating the actual energy output, it was
necessary to know the average wind speed over the
desired period and the hourly wind speed frequency
curve.
It was considered that the existing international
practice of hourly wind data collection was adequate,
provided the anemometer height was 10 m above
ground level. In places where insufficient wind data
were available, interpolation techniques for correlating
short-term measurement at the site with the complete
data of a nearby standard meteorological installation
were suggested. In places where no wind data were
available, it was sugested that portable anemometers
might be used for a first assessment of wind power
potential, supplemented by qualitative information obtained by local enquiry. Need was expressed for
simple, cheap and reliable anemometers, such as those
being developed in New Zealand. It was pointed out
that the maximum gust speed was a significant design
criterion for survival.
It was recognized that an important consideration
in the use of wind ener=v was to be able to supply a
given quantity of energy of given quality during stated
periods with a known probability level, and it might
not be necessary to endeavour to provide continuous
supplies of energy. It was emphasized that the determination of rated wind speed depended on the mode
of utilization, i.e. whether maximum energy output or
maximum reliability was required. In practice, there
would generally be a compromise solution which would
involve cost considerations.
The over-all economic evaluation of wind power
utilization should consider capital cost, interest rate,
furcign exchange, depreciation, inflation, maintenance,
~KA materials and operation costs, related to the
(jpri.ms available for each situatjon.
In general, the erection of small structures in a
rural area was not regarded as a terrain disfigurement,
and in many cases might become a tourist attraction.
- Energy production by windmills was a nonpollutant procedure, and as such was preferred to
some other means of energy production.
3. Water pumping systems
It was suggested that water pumping windmills
should be adaptable to the existing pumps and wells
and should not interfere with the traditional power
source, which should be maintained as an alternative.
However, some improvement in the efficiency of the
traditional pumps might be desirable. Greek sail rotor
adaptations or Chinese vertical-axis variations might
be most adaptable to traditional pumps, such as Persian
wheels, rope and bucket lifts, and square-pallet wooden
chain pumps.
In a situation where there was no existing pump.
the ideal installation should have an integrated system
comprising a well-matched rotor and pump. It was
recommended that urgent consideration be given to the
development of design specifications and prototype
testing of wind pumping systems most appropriate for
water lifting in conditions most typical of the region.
particularly for units of 1 kW for irrigation and 0.1
kW for domestic water supply. It was recommended
that a detailed classification of the performance and
construction characteristics of rotors and slow-speed
pumps be urgently compiled in order to facilitate and
optimize the design of suitably matched wind-powered
pumping systems.
The design procedure giveq in the consultant’s
paper was discussed and found to be a reasonable
checklist of design criteria. The importance of careful
preliminary investigations of local design determinan1.
was stressed.
Performance specifications and design requiremcnly
were dra\yn up for wind-powered water pumping ~5.
terns for immediate use in rural development:
II.
Discussion, conclusions and recommendations
Type 1: mechanical power output at shaft: lkW,
to suit existing pumps.
Rated wind speeds:
9
Type I:
250 W delivered to battery;
Voltage output: to suit lead-acid batteries 12-36 V;
Rated wind speed 5 m/set;
low
-
3.5 mlsec
medium
-
5
m/set
Utilization: village lighting and TV, remote communications etc.;
high
-
7
m/set
DC generator or alternator-rectifier.
Rotor diameters: typically 5 to 20 m;
Type 2:
Power transfer: rotary power output near ground:
Voltage rating: 380-440 V AC three-phase;
Starting torque: high torque required;
Load: 12-36 V batteries, or loads such as electric
pumps, resistive heating and small appliances.
Normal operating shaft speed: low;
Fail safe gust protection: the windmill should have
the ability to survive occasional extreme wind
speeds;
Operational control: the windmill should have the
ability to be occasionally manually adjusted
from ground level.
Type 3:
Minimum cost would be most easily. realized by
using labour-intensive construction and local materials
and skills; for instance. where almost constant attendance was feasible, construction cost may be reduced
by simplification of control mechanisms.
4.
Eiectricity generating systems
Available designs were reviewed and found to ‘be
expensive and generally not practical for rural use.
It was considered that a real need existed for low-cost
plants suitable for the relatively low average wind
speeds characteristic of much of the region. It was
agreed that 5 m/set should be taken as a reasonable
rated wind speed applicable to the region.
Development of a series of three types of windelectric generators with rated capacities of 0.250, 1-2
and 5-6 kW was suggested as a practical means of
supplying power for remote areas. Critical uses included lighting, educational ‘TV, radio, microwave repeaters. various agricultural uses, and food refrigeration.
At or above 1 kW it was agreed that three-phase/
AC 380-440 volt generation appeared to be the most
economical. It was considered that. for wind-electric
generating systems, over-all efficiency was a more
critical consideration than in water pumping systems.
Performance specifications and design requirements
for wind-electric generating systems were drawn up
for immediate development in the region:
5-6 kW at load;
Voltage rating: 380-440 V AC three-phase;
Load: 12-36 V batteries or loads such as electric
pumps, resistive heating, and small appliances;
Rated wind speed 7 m/set.
Type 2: as above, but with matched high, medium
and low head pumps.
Type 3: 0.1 kW as type 2.
1-2 kW at load;
5. Analysis of basic components
It was considered that regional development of
wind energy was restricted because of a lack of appropriate design informaiion for the guidance of technicians
and decision-makers, and that priority should be given
to the compilation and dissemination of suitable
technical reference material, including aerodynamic
design data, performance estimation and guidance on
construction using available technology.
Rotors
It was agreed that optimum rigid aerofoil designs ,
were best for practical wind-electric generation, but
simple and less efficient rotors were satisfactory for
water lifting by wind power. It was considered that
wind-powered water pumping systems comprising highspeed rotors matched with appropriate pumps had
considerable potential for future development. For
immediate application in water pumping, the Greek
configuration sail rotor was considered the most appropriate. Cambered metal plate rotors seemed well
suited to applications where greater du.rability and
increased efficiency were desired, provided the greater
cost and weight could be tolerated. The Darrieus
and Savonius rotors were not recommended for water
pumping use, but the classic Chinese vertical-axis rotor
might have some potential for low-cost water pumping
in rural areas. A guide to application of the various
types of rotors is given in figures 1-7. In general,
down-wind rotors were considered desirable from the
viewpoint of elimination of the tail cost and the
elimination of the danger of the rotor hitting the
tower in high winds.
Part One. Report of the meeting
10
2. Medium-speed
I. Slow-speed
A up to 2
3. High-speed
A 2-5
lo. Greek soil rotor
2 o. 4-blade combered
met01 plote rotor
30.3-blade
I b. Multi-vone rotor
2 b. Princeton soil- wing
rotor
3 b. Dorrieus
@I
4. Very-high-speed
A 5-10
A obove IO
rotor
40. 2 -blade
rotor
rotor
4 b. I- blade rotor
A
= Swept ore0
n
=
Rev/set
C
-
Chord length
u
=
Tip speed
c,, Z
Axial force coefficient
v
-
Wind velocity
CD =
Drog coefficient
vrel
=
Relative
CL I
Lift
A
-
Tip speed
CM =
Torque
coefficient
P
-
Air density
cp z
Power
coefficient
6
=
Solidity
FA
:
Axiol
M
= Torque
P
= Power
R
:
Re
= Reynolds
Vk
= Kinematic
rotio
A
.u
Power coefficient
cp
=
Torque coefficient
2M =‘p
%l = pv2R
X
Axial
CA
I C. Sovonius
rotor
Id. Chinese verticoloxis rotor
Tip speed
force
coefficient
ratio
factor
force
Units -
m, kg, set,
kW
Radius of rotor
number
viscocity
_ 2nnR
V
z
coefficient
oir velocity
V
2p
p v’A
Re
=
Vrel
Vk
P
=
0.5
Vk
=
I5 x 10-6m2/sec
- 2 FA
p v2A
tJA -
M
=
kg/m2
Frontal
blade Oreo
meosured
along chord
P
2Tln
Figure 1. Basic rotor characteristics
C
.
IL
Discussion. conclusions and recommendations
0.6
11
-l
Practical
maximum
0.5
E
2u
;f
w
0)
3
c'
I
IF
0.4
0
0.3
0
/I
/
0.2
0
Al
00
0
AM
,A
0
1
I
I
2
0
/0
3
/
0’
0
of good performance
0
,’
[email protected]
dN
/ /’
5
4
1
6
Tip
e
7
speed
I
9
IO
‘
II
r
12
13
ratio
Figure 2. Power coefficient
0.6
Note : Starting torque without
pitch adjustment
0.5
.
w
0
m=
m
Region of good performance
2
?234?
VW
2
-x ,,,\\
Jf<
0.1
= Upto0.2
039
= up to 0.5
03b
=
0
x0.2
0. I
0
r
0
r
I
,
I
I
I
2
3
4
5
Tip
I
r
1
6
7
6
9
speed
ratio
Figure 3. Torque coefficient
I
IO
I
II
I
12
I3
12
Part One.
RCJMJ~-1of the meeting
I.0
‘\
0.9
3
0.6
/
0'
B
2
4
\
/
/
‘\
Region of good
performance
0.7
1’
\
\
,
/
/
0.6
//
/I
//
1’
0.5
1’
/
0.4
/
.
/
0.3
0
0.2
,/
-- R/R
0. I
a
-
I
0
I
2
0
/
/
1’
Note
/
: At zero speed,
CA may
be token as (j
/’
0
/
3
4
6
5
Tip
7
speed
6
9
IO
II
I2
I
13
f
14
13
II
12
I3
14
ratio
Figure 4. Axial force on spinning rotor
100
c
:
”
2
0.
IO
c
..-0
+
0,
3
F.-
:
G
ul
0.
I
0I
02
I
I
-
2
3
4
5
Rated
6
tip
7
a
speed
ratio
9
Figure 5. Solidity ratio for optimum perfornnnce
It.
Discussion, conclusions and recommendations
13
Best obtainable
% ratios
CD
-
Re
I
L
IO6
/
near
i
I
I
0
I
number
tip
/-
,--I0
IO7
Reynolds
,
Aerofeoils
,
I
I
I
I
I
9
IO
II
I2
I3
I4
I Sail wing
-I
i
Sails,
Metal plates
bamboo mats
.
Tip
speed
rotio
Figure 6. Lift/drag
Hub a?rd shaft
Use of hand-crafted wooden hubs sezmed to be
quite suitable for slow-speed rotors. Wooden main
shafts had been widely used in some countries and
might find wider applications in new hybrid slow-speed
designs. Solid steel or pipe main shafts would provide
equal performance and longer life than wooden shafts.
“Teetering hubs” were useful for relieving bending
loads on high-speed rotor shafts as a result of unequal
disc .ioading.
Bearings
Oil-soaked wooden bearings had been used successfully in the past and were preferable to steel ball
and metal bearings for many slow-speed applications.
Orientation mechanism
The options for orienting the rotor into the wind
included tail vane, down-wind rotor, manual orientation
by tail rope or A-frame support, fan-tail rotor and
ekctric servo-mechanisms. In situations where the
wind direction was fairly constant. such as along
ratio
coastlines and many equatorial regions, signikant construction savings might result from tixed alignment of
the rotor. Where change of wind direction was infrequent, manual orientation might be most economical.
Servo-orientation was best adapted to large windelectric generators. Xn construction of the tower-head
bearing, the use of simple greased plates was adequate.
Use of a hollow post for the tower-head bearing might
result in decreased cost and simpliied construction.
Towers
Tower height range was usually 5 m to 20 m.
depending on the shape of the rotor, the need for
appropriate ground clearance and the proximity of
nearby wind obstructions. Selection of tower design
depended primarily on the local materials available,
which might be:
Angie iron, using traditional
lattice structure.
bolted or welded
Tubular steel, using a triangular base and geodetic
(octahectron module) structure, with bolted
joints.
Part One. Report of the rwcting
Fabrication
technology
TYPE
Initial
con
Mainzenonce
Confrol
Lye
Typical
applicafion . i
Rated
uindqccd
1. Slow-speed rotors
la.
Greek sail rotor
.
Local
LOW
RCgUlSS
Manual
Medium
wqer
pumph
Low,
medium
up IO
10 m
local
lb.
Multi-vane
rotor .
Medium
(as now made)
Medium
Trained
personnel
Automatic
L-g
Water
.
pump&z
I--,
medium
up 10
8m
Gould be
local
LOW
Local
Semiautomatic
Medium
Water
pumping
LOWS
medium
UP to
6m
lc
Savonius rotor
.
Local
LOW
Local
Nil
Medium
Water
pumpb
Medium,
high
up to
3m
Id.
Chinese
vcrticalaxis rotor
. .
Local
LOW
Regular
local
Manual
Medium
Water
pumph
Lo-5
medium
up to
10 m
Medium
technology
or local
Medium
Low,
trained
personnel
Automatic
or semiautomatic
Lwz
Water
pumph
Medium
up to
6m
Local, medium
or high
Low,
medium
Regular,
trained
personnel
Automatic
Medium
Water
pumping,
electricity
Medium,
high
UP to
8m
Local wood
or metal
LOW
Regular
local
Automatic
Medium
Electricity,
water
pumph3
high
up to
5m
Fibrcglass
reinforced
plastic
Medium
I--,
trained
personnel
Automatic
Electricity
Medium,
high
up to
10 m
.
Extruded aluminum or fibrcglass
reinforced
plastic
Medium
I--,
trained
Automatic
Electricity
High
up to
24 m
.
Metal or fibreglass
reinforced
pIa&
High
Low,
Automatic
Electricity
High
Greater
than
10 m
Metal or fibreglass
reinforced
plastic
High
Electricity
High
Greater
than
10 m
2. Medium-speed
rotors
2~. 4-blade cambered
metal plate rotor
2b. Princeton sailwing
romr . . . .
3. High-speed
Medium
rotors
3a. 3-blade rotor .
3b. Darricus
:
rotor
4. Very-high-speed
rotors
4~. 2-blade rotor .
4b. I-blade rotor
.
.
Long
trained
personnel
L-J,
personnel
Automatic
Figure 7. Practical aspects of some rotors
II.
Discussion, conclusions and recommendations
15
Mzlriple woo&pole structure with cross-bracing of
wood or tensioned cable, with base bolted to
foundation.
Concrete pipes stacked end to end, with central
tensioning behveen end plates against the top
and bottom of the column of concrete pipes.
Concrete fill might be used. The upper end
plate was incorporated for mounting of the
windmill. The entire column might be stabilized by guy wires attached to a ring at
maximum height to allcw rotor clearance.
Si&e wood-poles, which might be self-supporting
or hinged at the ground and guyed.
Approved local building practices should be followed in regard to foundation construction. Ease of
erection and lowering, for maintenance of the rotor, was
essential. The single column. with three stays, was
convenient, particularly for electricity generation. In
the case of a water pumping windmill, the pump shaft
(whether reciprocating or rotary) could be led down
one side of the column. with the vertical axis of the
windmill offset to the side accordingly.
Confrol mechanisms
Allowance should be made for either manual or
automatic control of starting, stopping, overspeeding
(governing) furling or reefing of sails, and protection
against unexpected high wind speeds (fail safe device).
Maximum use of manual control devices would lead
to savings in construction cost. Automatic controls
were necessary for unattended operation. The dynamics of variable-pitch control of rigid aerodynamic
rotors was not well understood and required more
detailed technical study. Adjustment of piston stroke
in water pumps could be provided by a horizontal
lever arm.
Power transjer mechanisms
It was agreed that the use of rotary power transfer
was most desirable for optimal matching of rotortorque characteristics with many types of pumps. That
transfer might be accomplished by long vee-belts,
chains, shaft and gears, chains and cowhide belts.
Electric transmission should be considered only for
loads greater than 1 kW.
Power utilization
Any load must be able to accept a variable shaft
speed and power input. There was an immediate need
for a comprehensive design selection manual on water
pumps in the range of 0.1-10.0 kW for high, medium
and low pumping heads. Special attention should be
paid to ascertaining the performance and construction
characteristics of lesser-known pumps that were currently confined to limited areas of use. Some information is given in table 1.
Table 1. PUMP CHARACTERISTICS
.
Range
Pump type
Piston
. . . .
Turbine
. . . .
Ladder
. . . .
Wood chain
. .
Steel chain . . .
screw
. . . .
T-pump
. . . .
Inertia
. . . .
Piston
. . . .
Diaphragm
. . _
Rope and bucket
.
Double-acting piston
Pui5taltic
. . .
Paddicwhccl . . .
Persian wheel
- .
Spiral wheel . . .
~ropdlcr . . . .
Surfion
fm)
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
-
-
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
-
.
.
.
.
.
.
-
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
,
.
.
.
.
a
.
.
.
7
5
0
0
0
0
7
0
10
7
0
7
1.5
0
0
0
0
of head
DiThl;rgc
m
100
100
3
4
30
5
0
4
30
30
50
100
10
0.5
50
1
7
Eficiency
(percentage)
80
90 max.
35
50
50
60
60
80
90
85
70
20
50
60
60
Starring
torque
speed
(reu/min)
high
low
medium
medium
medium
low
low
low
high
high
high
high
low
low
medium
low
low
30
1,400-2,000
80
80
80
30-400
400
80
30
30
2
30
100
80
4
60
4OC-2,000
Typical marerial
metal
metal
wood
wood
metal
wood
metal
metal
metal
metal, leather
cloth, leather, metal
metal, plastic
5-12 cm plastic, rubber
wood
met31
wood
mcml
16
-
Part One. Report of the meeting
Electric gcneralors
7. Field trips
It was suggested that in order to formulate proper
rotor matching guidelines, torque-speed characteristics
of alternators and generators should be compiled. It
was agreed that brushless low-speed 380-440 V AC
three-phase alternators were most appropriate for use
in wind-electric generation. Generators from trucks,
railway carriages and automobiles might be adapted
to wind-electric generation.
During the field trips, preliminary performance
measurements were made on a Thai bomboo-mat sail
rotor in Samut Songkram and a Thai high-speed
wooden rotor in Samut Prakam. Each machine \vas
coupled to a wooden-pallet chain pump for lifting salt
water to salt-production ponds. Time did not allow
a complete analysis of those observations.
Storage
The Group felt that reliable measurement of the
performance characteristics of local windmill systems
should be encouraged throughout the region.
Wind energy utilization was most economical
where storage was not required. Storage requirements
might be minimized by adopting changes in usage
patterns. Secondary use of water-storage tanks for
bathing, washing and fish culture might be considered.
Pumped water storage for energy conversion by a
small water turbine and generator might be practical
in some limited situations. Compressed air production
and storage might be feasible in some cases.
Hybrid designs
Development of new hybrid windmill designs was
considered. Some suggested possibilities were the use
of ciassical Greek and Chinese slow-speed rotors for
electricity generation, Thai high-speed wooden: rotors
for electric generation, high-speed rotors I?< water
pumping and Thai sail rotors with A-frame manual
orientation.
6. Other uses and advanced concepts
It was considered that there was potential for
further development of wind-generated energy supply
for grain grinding, cane crushing, oilseed pressing, air
circulation in crop driers, refrigerator operation, wood
sawing, water aeration for sewage oxidation and
aeration of intensive aquaculture ponds. Maximum
windmill economy might be achieved by multipurpose
use.
Several advanced concepts suggested for development in the region were: large-scale wind-electric
generators f.or supply to an electric distribution grid;
regional manufacture and use of high-efliciency solid
state inverters for use with variable DC wind-electric
generators; regional manufacture and use of variable
speed input, constant frequency output alternators;
de\-elopment of special rotors, such as the single-blade
high-speed type; and development of regional batch
and mass production of aerodynamic rotor blades using
available materials.
Continuing research and development outside the
r-$n should be monitored by ESCAP and information
c’n J:l:vant dcvclol>ments disseminated to appropriate
cKsnizations in the region for regional adaptation.
8. Conclusions and recommendations
It was concluded that the current level of expertise
and technology available in the region was sufficient
for immediate implementation of selected wind-energy
utilization devices. However, additional activities must
be initiated to further expand its use.
The following recommendations were made :
1. A systematic survey of existing wind velocity
data in the region should be made with a view to
its use for standard wind energy analysis.
2. A variety of simple cheap anemometers should
be developed and produced within the region.
3. Standard methodology should be developed for
the analysis and extrapolation of incomplete wind
speed data.
4. A detailed classification of the performance
and constr:iction characteristics of all wind rotors
should be compiled in order to facilitate and optimize
the design of properly matched wind-powered systems.
5. A detailed survey of component characteristics
should be undertaken on an international scale in order
to provide an illustrated “catalogue” of proven components which could be used in the design of new
hybrid wind-powered systems.
6. A detailed classification of the performance
and construction of all water pumping devices between
0.1 and 10 kW should be compiled in order to facilitate
and optimize the desip of properly matched windpower pumping s\‘stems.
7. A guide-book on windmill design processes
should be compiled and made available to development
workers.
8. Efforts should be made to encourage research,
development and trainin: in universities, technical
colleges and rcscarch institutes. including fellowships,
development of COUJSCS
and text material.
II.
Discussion, conclusions and recommendations
17
9. Efforts should be made to stimulate immediate
utilization of proven wind-energy technology via existing industry and non-governmental organizations, rural
development and extension services.
10. Efforts should be made to stimulate commercial and industrial involvement in production and
promotion of wind-ener,T utilization devices.
11. Expert engineering advice should be made
available for optimization of water pumping and
electric generating windmiils currently available in the
region.
12. Socio-economic considerations should be further studied where local labour and renewable materials
may be freely available.
13. Continuing research and development outside
the region should be monitored by ESCAP and information on relevant developments disseminated to
appropriate organizations in the region for regional
adaptation. This may take the form of a regional
wind-energy documentation centre.
14. ESCAP should follow up this meeting by
further expert technical meetings to report and evaluate
current progress in the field.
15. An effort should be made to ensure that the
wind energy section in the proposed regional technology
transfer centre be adequate for the needs of the region.
16. ESCAP should encourage and co-ordinate the
setting up of field demonstrations of wind-energy
utilization devices in the region.
Highest priority should be given to recommendation number 16, which implies that work related to
some of the other recommendations would have been
initiated.
Annex III
REPORT OF THE SOLAR/WIND
Discussion revealed that, while attention had been
given to the integration of both solar and wind energy
into other energy systems, there was little experience
in the integration of those two energy forms.
The Group considered that, given the variability
in availability of both solar and wind energy in any
location, the potential for use of bio-gas in many rural
situations, and the possible use of each of those energy
forms to complement each other, and in conjunction
with other forms of ener=T. there was a need to explore
ways in which the use of various types of integrated
energy systems might be stimulated.
Accordingly,
1.
the Group recommended :
ENERGY SECTORAL GROUP
availability of both conventional and non-conventional energy resources, singly or in combination;
in representative rural communities in various
countries of the region, to assist in planning the
development of energy resources in rural communities.
2. That research and development be carried out
on integrated ener,v systems for small rural communities with a view to:
(a) Establishing technological and environmental feasibility in favourable circumstances;
(b) Making the best use of materials an;l
skills available in various local environments; and
That studies be made of:
(a)
Meteorological
data;
(b) Availability of the appropriate materials
and skills for construction, operation and maintenance;
(c) Present and potential demands for energy
in its various forms; and
(d) The ways in which these demands might
appropriately be met, having regard to likely
(c) Optimization of systems performance
with due regard to energy balance and costeffectiveness.
3. That demonstrations of selected integrated
energy systems be carried out in selected localities
for the purposes of providing information for
potential users, ensuring the necessary system reliability under normal operating conditions, and
obtaining socio-economic data needed for commercial development.
Part One. Report of the meeting
18
Annex IV
LIST OF EXPERTS
R. V. Dunkle, Chief Research Scientist, Division of
Mechanical Engineering, CSIRO, Highett, Victoria
3190. Australia
Jong Hee Cha, Head, Thermal-Hydraulics Laboratory,
Korea Atomic Energy Research Institute, Seoul,
Republic of Korea
N. R. Sheridan, Reader in Mechanical Engineering,
University of Queensland, Brisbane, Australia
Chung-Oh Lee, Professor, Department of Mechanical
Engineering, Korea Advanced Institute of Science,
Seoul, Republic of Korea
P. Johnston, Energy Unit, Central Planning Office,
Government Buildings, Suva, F!ji
C. L. Gupta, Professor, Applied Science Group, Sri
Aurobindo International
Centre of Education,
Pondichcrry 605002, India
S. K. Tewari, Scientist, National Aeronautical Laboratory, Bangalore 560017, India
Filino Harahap. Director, Development Technology
Centre, Institut Teknologi Bandung (ITB), Bandung, Indonesia
Harijono Djojodihardjo, Lecturer, Mechanical Engineering Department, Institut Teknologi Bandung
(ITB), Bandung, and Head, Aerospace Technology Centre, the National Institute of Aeronautics
and Space (LAPAN), Djakarta, Indonesia
T. Noguchi, Chief, Solar Research Laboratory, Govemn&t Industrial Research Institute, Hirate-machi,
Kita-ku, Nagoya, Japan
P:‘ T. Smulders, Steering Committee Wind Energy
Developing Countries, c/o Physics Department,
Wind Energy Group, University of Technology,
Post Box 513, Eindhoven, Netherlands
R. E. Chilcott, Department of Agricultural Engineering,
Lincoln College, Canterbury, New Zealand
Prapath Premmani, Director, Technical Division, National Energy Administration, Bangkok, Thailand
Sompongse Chantavorapap, Chief, Design and Energy
Research Section, National Energy Administration,
3
Bangkok, Thailand
Chalermchai Suksri, Chief, Power Resource Research
Unit, Agricultural Engineering Division, Department of Agriculture, Kasetsart University Grounds,
Bangkhen, Bangkok-g, Thailand
Pllthin Nopparat, Agricultural Engineering Division,
Department of Agriculture, Kasetsart University
Grounds, Bangkhen, Bangkok-g, Thailand
P. A. Cowell, Chairman, Division of Community and
Regional Development, Asian Institute of Technology, P. 0. Box 2754, Bangkok, Thailand
R. H. B. Exell, Division of Community and Regional
Development, Asian Institute of Technology, P. 0.
Box 2754, Bangkok, Thailand
Ray Wijewardene. Farming Systems Engineering, International Institute of Tropical Agriculture, Oyo
Road, P.M.B. 5320, Ibadan, Nigeria
Masoul Anwar, Principal Scientific Officer,
Pakistan Atomic Energy Commission, Islamabad,
Pakistan
R. L. Datta, Central Salt and Marine Chemical
Research Institute, Bhavnagar, Gujarat, India
(consultant)
Ernest0 N. Terrado, Supervising Nuclear Technologist,
Philippine Atomic Energy Commission, Diliman,
Quezon City, Philippines
M. M. Sherman, New Alchemy Institute-East, Box
432, Woods Hole, Massachusetts, 02543, United
States of America (consultant)
Mian
II.
Discussion, conclusions and recommendations
Annex V
LIST OF DOCUMENTS
Title
Symbol number
Provisional agenda
Secretariat
NR/ERD/EWGSW/2
Annotated provisional agenda
Secretariat
NR/ERD/EWGSW/3
Development of wind energy utilization
the Pacific
NR/ERD/EWGSW/4
An introduction
to integrated solar-wind systems
Secretariat
NR/ERD/EWGSW/5
Solar energy; its relevance to developing countries
Secretariat
NRIERD/EWGSW/Ci
The design and construction of low-cost wind-powered
water pumping systems
Secretariat
NR/ERD/EWGSW/CR.l
Solar energy research in the Philippines
E. N. Terrado
(Philippines)
NRjERD/EWGSW/CR.2
Solar energy in India: research, development and
utilization
C. L. Gupta (India)
MRIERDIEWGSWICR.3
A review of efforts made in India for wind power
utilization
S. K. Tewari (India)
NR/ERD/EWGSW/CR.4
Recent developments in solar energy research and
application in Japan
T. Noguchi (Japan)
NR/ERD/EWGSW/CR.S
Research, development and use of wind energy in
Thailand
National Energy
Administration,
NR/ERD/EWGSW/CR.6
Recent research and development on solar energy
applications in Japan
.
T. Noguchi (Japan)
NR/ERD/EWGSW/CR.7
Solar energy in Australia
R. V. Dunkle (Australia)
NRIERDIEWGSWICR.8
Solar energy in southeast Asia
R. I-I. B. Exell, Asian
Institute of Technology
NRIERDIEWGSWICR.9
Solar energy and energy conservation in Australian
buildings
N. R. Sheridan (Australia)
NR/ERD/EWGSW/CR.lO
Research, development and use of solar energy in
Thailand
National Energy
Administration,
NR/ERD/EWGSW/CR.ll
Programme and progress for solar house development
in Korea
Jong Hee Cha
(Republic of Korea)
NR/ERD/EWGSW/CR.12
Solar energy as a natural resource
N. R. Sheridan (Australia)
NRlERDlEWGSWjCR.13
The utilization of wind energy in Australia
Department of Science,
Autralia
NRIERDIEWGSWICR.14
The prospects of solar energy utilization:
the Indonesian case
F. Ha&hap (Indonesia)
NR/ERD/EWGSW/
.
Source
1
in Asia and
Secretariat
Thailand
Thailand
Part One.
20
~ Title
Symbol number
Report of the meeting
Source
NR/ERD/EWGSW/CR.lS
A review of renewable energy in New Zealand with
emphasis on wind power utihzation
R. E. Chilcott
(New Zealand)
NR/ERD/EWGSW/CR.16
Windpower studies ‘in Korea
Chung-Oh Lee
(Republic of Korea)
NR/ERD/EWGSW/CR.17
Research and prospects of wind enera utilization in
Indonesia
H. Djojodihardjo
(Indonesia)
NR/ERD/EWGSW/CR.18
The Sunshine Project: solar energy research and
development
.
r
Agency of Industrial
Science and Technology,
Japan
NR/ERD/EWGSW/CR.19
Solar energy work in Pakistan
M. M. Anwar (Pakistan)
NR/ERD/EWGSW/CR.20*
.
Planning for small-scale use of renewable energy
sources in Fiji
P. Johnston (Fiji)
l
Dclaycd in transit and not distributed.
Part Two
DOCUMENTATION
ON SOLAR ENERGY
21
I.
WORKING
SOLAR ENERGY:
PAPER PRESENTED BY THE SECRETARIAT
ITS RELEVAXE
TO DEVELOPIXG
INTRODUCTION
Over 1.000 million people live in underdeveloped
economic conditions around the world behveen latitudes
35”N and 35%; that area also receives the highest
concentration of solar radiation. Most of the developing countries in the BSCAP region he between those
latitudes; the relatively high population densities in
rural
areas, and high exposure to the sun, suggest
that the use of solar energy should be .explored when
considering ener=v problems in the region.
In planning applications for solar energy, a distinction must first be drawn between the enerDT
requirements in rural and in urban areas. The rurai
population needs energy primarily for cooking, lighting,
irrigation and household water supply, water purification, processing of agricultural products and recreation.
Solar power devices to serve those purposes might
include cookers, pumps, driers, and solar stills.
In small-to-medium urban areas, the most important uses for energy are in agriculture, household
maintenance, industry, and transportation, among
others. Those needs might someday be met with
mini-generators powered under the “energy plantation”
concept or by photothermal devices (use of selective
surfaces), but, in the meantime, available solar energy
devices include those for water and space heating,
cooking, refrigeration and distillation.
Energy consumption in metropolitan areas follows
an entirely different pattern. with industrial and manufacturing plants taking a major share of available
power; the commercial, transport and domestic sectors
consume varying but smaller percentages. Solar devices appear to have a relatively less significant role
in metropolitan areas, being used mainly for heating
of water and space, and cooling. In time, direct conversion processes for large-scale power generation,
either photovoltaic or photothermal, may be developed.
Promising fields for further research and development
also include solar ponds for small-scale power production, high-temperature furnaces, thermoelectric and
thermo-ionic conversion processes, algal ponds, and
such integrated systems as solar houses.
l Prepared by Mr. R. L. Datta,
consultant on solar energy, at the
rqumt of the ESCAP secretariat. The views cxprascd in thii paper
are the author’s own and do not necessarily reflect those oE the
s~ctariat or the United Nations.
COUNXIJ3
(NR/ERD/E\VGSW/S)*
Solar energy characteristics
In general, the greatest amount of solar energy is
found in two broad bands around the earth between
latitudes 15” and 35” north and south (references S 1.
S 2). In the best regions, there is a minimum monthly
mean radiation of 500 calories per square centimetre
per day (cal/cmT/day).
These regions are on the
equatorial side of the world’s arid deserts. They have
less than 25 cm of rain in a year. In some countries,
more than two thirds of the area is arid, and there
is usually over 3,000 hours of sunshine per year, over
90 per cent of which comes as direct radiation. These
areas are well suited for applied solar energy.
The next most favourable region for the purpose
is in the equatorial belt between latitudes 15”N and
15”s. There the humidity is high, cloud cover is
frequent, and the proportion of scattered radiation is
high. There are about 2,500 hours of sunshine per
year, with very little seasonal variation. Radiation is
from 300 to 500 cal/cm”/day throughout the year.
Between latitudes 35’ and 45’. at the edge of the
desert areas, the radiation can average 400 to 500
cal/cm”/day on a horizontal surface throughout the
year, but there is a marked seasonal effect, and the
winter months have low solar radiation. The seasonal
variation can be greatly minimized by tilting the
receiving surfaces to face the sun. The regions beyond
latitudes 45”N and 45”s are limited in their year-round
direct use of solar energy.
Several types of instruments are known for
measuring and recording solar characterilics.
Some
instruments give instantaneous readings and others give
integrated readings over periods of an hour or a day.
Some measure the total radiation and others measure
only direct radiation on horizontal, vertical, normal or
inclined surfaces. The principles used in the operation
of differer:! types of instruments include thermoelectric
measurement of the rise of temperature on a black
soiar receiver: balancing the heat with measured
electrical Peltier cooling; direct calorimetric lmeasurements; evaporation of a measured volume of liquid;
photovoltaic measurements, photographic measurements; and photochemi’cal actinometers. Examples
are the Eppley phraheliometer, the Mall-GocVrski
solarimeter, the integrating solarimeter developed in
Australia, and the Campbell-Stokes sunshine recorder.
There is ample scope for development of very
much simpler and portable types of solarimeters
Part Two.
22
sufficiently accurate (within -C 5 per cent or So) for
planr&g the development of solar energy. Evaluation
of solar radiation is a prerequisite for sound plans for
solar energy use.
A number of solar radiation stations exist in a
few countries of the ESCAP region. In India, there
are more than 26 stations, operated by the Indian
Meteorological Department, and there are some 60
stations measuring duration of sunshine with CampbellStokes recorders. Indonesia currently has 15 radiation
stations, most of which are operated by the Meteorological and Geophysical Institute, and others by
educational and research institutions. Each of the
ESCAP countries involved in solar energy applications
might well have a chain of solar radiation stations
selected on the basis of geog-raphical/meteorological/
cliiatic peculiarities; these stations could be the control
points for solar radiation data collected by portable
solarimeters. ESCAP should therefore co-operate with
the World Meteorological Organization (WMO) in
assisting countries to set up radiation stations, and to
prepare solar maps for each country.
I. TECIIIL’OLOGY
OF SOLAR DEVICES
There are three broad approaches to the utilization
of solar devices and processes: (a) low-grade solar
heat, (b) direct conversion to electric energy, and (c)
photosynthetic and biological conversion processes.
Of these, the technology of low-grade heat devices
has been developed to such an extent that they have
immediate applications, particularly in rural and small
urban areas. However, a realistic assessment on a
continuous basis is required regarding the impact of
these devices on social and economic conditions;
moreover, the need for research and development to
improve these devices should be kept under review.
although
the technology has been developed for
direct conversion and biological processes, extensive
research and development is required to put these on
a satisfactory basis for general use.
A.
PRODUCTION
OF LOW-GRADE
HEAT
Devices for conversion of solar energy for the
production of low-grade heat include water-heaters,
solar stills, cookers, driers, refrigerators and pumps.
Most of these devices use a collector or concentrator
of solar energy, utilizing the energy produced to &eat
a working fluid with varying degrees of efficiency.
The status of these devices should be reassessed with
reference to rural areas in the region; technological,
economic and social constraints; potential uses; and
feedback of problems.
1.
Documentation on solar energy
Solar water-heaters
Basically, a solar water-heater comprises a black,
metal flat-plate collector (absorber) containing water
channels, facing the general direction of the sun, together with an insulated storage. There can be one or
more transparent covers for the collector at intervals
of about 2 cm above the plate, and thermal insulation
at the. rear. The higher the number of covers, the
higher is the temperature reached in the collector, but
the less is the energy that reaches the plate. Materials
for collectors diier around the world: copper is mainly
used in Australia, and galvanized iron in India and
Israel. The heating selective surface of the collector
should have durable coating with a high ratio of
absorbtivity to emissivify; for example, Australian
selective surface coatings have a ratio of 6. The three
basic types of solar heaters are described below.
(a) Domestic water-heaters consist of a flat-plate
collector and a separate water storage tank connected
to the public water supply either directly in pressurized
units, e.g. as found in Israel and Australia, or through
a float valve such as developed in India. The water
circulates by convection. Normally, the absorber is a
sheet of copper or galvanized iron to which is soldered
or brazed a continuous zigzag tube, the main direction
of the tubing being slightly off the horizontal to prevent
air-locks at the bends. Water flows either by gravity
or from a pump into the lower end of the tube, and
back and forth across the surface of the sheet, issuing
at the upper opening. The spacing between the bends
of this tubing may vary, and in some designs may be
15 cm. In some versions, the collector is in the form
of a sandwich which consists of corrugate2 galvanized
iron sheet backed with a plain sheet of the same
material, the two being secured by rivets: the edges
along the length are hammered together with an
overlap, and sealed with soft solder. The openings
along the width at the two ends are formed into pipes
by folding the plane sheet over the corrugated sheet,
then welding or soldering. In this manner, header
pipes are formed at the two ends. The corrugated face
is blackened and the whole assembly can be put in
a wooden box containing insulating material. The
upper face of the box is glazed with a sheet of window
glass, with an air gap of perhaps 5 cm. Water from
an insulated cylindrical reservoir is allowed to enter the
collector from its lower header, and flows up through
the channels formed by the corrugations out to the
upper header, and then on to the upper end of the
reservoir. In this manner, closed-cycle thermosyphon
circulation is established and the water temperature
rises in the reservoir. This corrugated type of flatplate collector has good heat-exchange eficiency, of
about 50 per cent, and heats water to 50°C to 60°C.
Alternatively, the collector may consist of galvanized
tubes fitted at IO cm centre-to-centre spacing on two
I.
Working paper presented by the secretariat
pipe headers; aluminium sheet is wrapped around the
pipe nehvork; each tube is kept in good thermal
contact with this sheet; the collector is encased in an
airtight, mild steel box having insulation on the rear
side and ordinary window glass on the front side.
The water level in the storage tank is maintained by a
Boat valve, the storage tank being insulated by thick
mineral wool which is protected from the weather by a
cover box of mild steel sheet. Figure l1 shows a
domestic heater with natural water circulation.
(b) Built-in storage-type heaters, with an integrated
storage and absorber facility, consist of a galvanized
iron, rectangular tank placed in a rectangular, mild
steel sheet tray with ordinary window glass on the
front and an insulating layer (5 cm) of glass wool on
the back and sides. Tank bulging under pressure is
reduced by using steel sections bolted to the sides of
the tray. The front face of the tray is blackened.
The hot water is removed at the top by opening the
gate valve from the inlet pipe at the bottom. A vent
pipe is also provided at the outlet pipe of the heater
for safety purposes. A large funnel (bucket-size) can
be fixed at the top of the heater and connected to
the inlet tube so that this type of water-heater can
be used in rural areas where there is no regular water
supply. The efficiency of this type of heater may
rise to 80 per cent conversion of solar energy to heat.
In this heater, hot water is not normally available in
the early morning.
(c) Large-size water-heaters for hotels, hospitals
and other public uses. involve a number of absorber
tanks and can heat water in quantities larger than
600 litres at temperatures up to 55°C in winter. This
typo also has an auxiliary heating system. The mean
water temperature in the storage tank is controlled
by a differential circuit. Efficiency of such heaters
can be 55 per cent or higher. Australian scientists
have developed multistage, high-temperature solar
water-heaters which can possibly supply water commercially at as high a temperature as 95’C. This
multistage type of solar heater uses different types of
absorbers with d&rent selective coatings as high-,
medium- and low-temperature absorbers.
In a number of countries, including Australia.
Israel. Japan and the United States of America, solar
water-heaters are manufactured commercially. Certain
factors must first be considered for critical evaluation
of the different types of water-heaters: (i) a per-unit
capacity which may be 0.01 mz/litre; (ii) provision
of supplementary electrical heating, controlled by
thermostat: (iii) the life of the heater: (iv) water
supply: except in the case of the built-in storage design;
(v) ease of operation: (vi) application in multistorey
buiIdings; (vii) cost per unit of thermal energy; (viii)
adaptability for customers’ specifications; and (ix)
product design, incIuding finish.
’ FiSurcs ar end of paper.
23
-One of the inhibiting factors in the utilization of
solar water-heaters is high capital costs. Reference
S 3 indicates a number of factors upon which feasibility
of solar water-heaters depends, e.g. cost, availability
and cost of alternate sources of heating, efficiency of
collection, and local cost of materials, and suggests
that solar water-heaters generally prove competitive
with fuel plants for small and medium-sized installations, e.g. for hotels and schools. Certain types of
heaters, e.g. built-in storage type, may be more
economic even with a relatively short life. I-“xs for
solar heating exist in such industries as foods ai:4
pharmaceuticals, where the range of temperature
required may reach 90°C or more; the development
work on high-temperature water-heaters is significant
in this context.
Technical/economic studies should be undertaken
to improve the efficiency of solar water-heaters by
(i) use of reflectors, (ii) selective coatings, (iii)
modified collector design, and (iv) architectural
integration. There is also scope for research and
development on heaters for different temperatures and
capacities, and on improving the durability of sealants.
paints and other materials used in manufacture.
2.
Solar distillation
Solar distillation can produce fresh water in
isolated areas where natural water is too saline for
ordinary use, for instance, salt farms, lighthouses and
remote rural areas. Pure water is needed for lead-acid
accumulators, engineering and chemical laboratories
and pharmaceutical preparations. Solar stills have
been known for a long time; design features are now
well established. and desirable materials for construction are available. Figure 2 indicates the variety
of uses of water so derived.
Currently. not more than about 30 per cent of
the total solar energy can be used in distillation. The
disadvantages of current models. with respect to the
extent of useable solar energy and the high space
requirement, are substantially reduced through the use
of the humidification/dehumidification
(HD) technique.
(a) in solar stills for distillation of sea or saline
water, the water to be distilled is kept in black-bottom
stills covered with airtight glass or plastic enclosures.
Incident solar rays pass through the glass cover and are
absorbed on the black bottom and heat the water.
Vapour is formed and moves upward towards the
covers which are relatively cool, condensing on the
underside of the glass sheet. This condensed water
slides on the sloping glass sheets and is collected in
the channels provided at the lower edge of the cover.
This technique depends on steady availability of highintensity solar energy.
24
The first plant of large capacity based on this
was built at LAS Salina~, Chile, in 1874. with
a surface area of 4,757 m2 and a daily production of
22.5 m3 per day of fresh water, and operated for
Some 40 years. Research contributions, mainly from
the United States of America, the USSR, Algeria,
Australia, Greece and India in recent years, are
responsible for popularization of this method in
locations lacking both potable water and power, but
rich in sunshine and saline ground water or seawater.
Production from the solar stills depends mainly on
solar radiation intensity, and humidity has no effect
on production. A gentle wind is favourable. and production increases with ambient temperature. Depth of
saline water in the still and the angle of inclination of
the glass cover affect production. Smaller angle and
smaller depth increase productivity (expressed as litres/
m2/day). Either glass or plastic can be used as
material for the cover, although glass is often preferred
for durability and ease of cleaning. A glass cover with
diameter smaller than about 2 m is convenient to
reduce breakage. PVC and polythene are not very
desirable as covers on account of their shorter life and
decreasing transmittivity. With a radiation intensity of
550 cal/cm2/day. the annual average productivity of a
solar still can be 3 litres/m2/day, the productivity being
higher in summer and lower in winter.
principle
Many solar stills have capacities in the range of
5 to 10 litres per day. The construction materials
required include wood, asbestos cement sheet, aluminium sections, and glass or plastics. For the
bottom of the still, a thick, black polythene film
spread on an insulating layer is used as liner, and a
water depth of 2 to 3 cm can be maintained. In
permanent, higher-capacity stills, cement and similar
construction materials, including sealant materials (e.g.
silicone/tar plastics), are required.
Clean glass covers offer a good surface for rainwater collection, and if sufficient storage is provided,
the collected rainwater can supply additional water
for use. Places with low rainfall distributed throughout
the year are more suitable for such units than areas
with heavy rainfall concentrated in certain parts of the
year. A few units have been installed in lighthouses,
and their satisfactory performance suggests a potential
for wider use.
Generally, two types of design have been adopted
for the basins of large solar stills: (i) a single, large
waler basin covering the whole still area (i.e. pond ape,
as adopted in the pilot plant at Dayton beach); (ii) the
plant is divided into many units with varying lengths
having uniform width (bay rype construction in
Australia, Greece and India). Pond construction is
the cheaper type. Although cotton adhesive tape is
reasonably durable for about a year or so for glass-
Part Two.
Documentation on solar energy
to-glass joints, tar plastic (a product of coal tar
distillation) has been found to be more suitable for
Silting on the surface and algae growth
the purpose.
sometimes cause maintenance problems. In the absence
of availability of butyl rubber sheets at a reasonable
price, and in view of the short life of jute-impregnated
asphalt mat-liners and black plastic film. it is necessary
to adopt complete concrete or brick masonry flooring
with black asphalt coatings for the bottom of permanent
installations. In some plants, precast items were used
for the top ridge, and bottom supports were combined
with rainwater gutter and ridge-supporting pillars.
Water vapour leakage is one of the major problems
affecting the performance of solar stills during
operation. Use of silicone sealant in Australian solar
stills has proved to be a solution, but silicone, apart
from its very high cost, is not available in many
countries.
Costs vary with the types of stills constructed.
Generally, for estimates, the efficiency of solar energy
utilization is assumed to be 30 per cent, and with
the value of average annual radiation intensity, the
calculated productivity is taken as the basis for
calculation of surface area required for solar stills.
The investment cost can be calculated on the basis
of cost of construction of unit surface area of stills
that collect rainwater and have a water supply tank.
The operating cost of the plant can be calculated on
the basis of 20 years’ life, an appropriate interest rate,
1 per cent of investment as annual operation and
maintenance cost, and an additional 100 man days per
year per 930 m2 area. It may also be assumed that
80 per cent of the rainwater is collected. In any
given situation, of course, these assumptions may
require modification. Since the solar energy is freely
available, the interest on capital costs contributes the
major portion of the product water cost. The output
is independ<:nt of salt concentration in the feed water.
Regarding increases in labour and materials costs. the
capital cost per m2 increased in India from NJS 7.50
in 1966 to $US 11.50 in 1975, including the cost of
storage tanks.
Attempts have been made to improve the yield of
product water per unit area with the use of green dyes
for evaporation enhancement in India, and with the
use of industrial waste heat in Australia and Canada.
Further development should enable these results to
be applied in stills under different conditions.
Solar radiation is the principal energy source for
salt farms, which treat seawater/inland brine. in three
stages to produce common salt: (i) reservoir (3’
to 6O Baume) wherein seawater in taken in, (ii)
condensers wherein brine is concentrated to precipitate
out calcium salts, and (iii) crystallizers (24’ to 29”
Baume)
wherein common salt is precipitated. The
I.
Working paper presented by the secretariat
area required in the manufacturing process is high,
e.g. nearly 35 per cent of the area will be used for
reservoirs, 45 per cent for condensers, and 10 per
cent for crystallizers. The exact area requirements
are determined by the rate of evaporation and reduction
in volume at various concentrations of seawater/brine.
For every ton of salt produced, 45 m3 of water must
be evaporated. Evaporation depends mainly on the
intensity of solar radiation, meteorological variables
like air temperature and humidity, direction and
velocity of wind, number of cloudy and rainy days,
and total rainfall. The evaporation rate decreases at
higher densities of brine; this rate is increased by
operational variables such as decreased brine depth
and addition of green dyes. The mother liquor
(bittern) can be processed to obtain fertilizer-grade
potassium chloride or pure potassium chloride for
industrial uses, as well as bromine and magnesium
salt.
(b) The humidification - dehrmidificarion (HD)
rechnipe of solar distillation offers significant advantages over the solar still in terms of efficiency in use of
solar energy, and space requirements. The principle
consists in using solar energy (or waste heat) to heat
the feed water, spraying the heated water through a
packed tower against an airsirii~dill biown up from *&c
bottom of the tower, stripping off the vapour from
the airstream at the top of the tower by means of a
condenser, and recovering the condensed water. HD
requires power for blowing the air and for spraying
heated brine at the top of the packed tower. The
solar energy collector consists of a shallow, rectangular
tank containing feed water over which a transparent
plastic sheet is laid, and the heated seawater
is pumped to the top of the packed tower; feed
water heated by other means, such as imlu~trial waste
heat, can be fed directly to the top of the packed’
tower. There is scope for reducing the cost of initial
investment by design improvements in the tower,
selection of common construction materials, use ,?f
the multiple-tower system for high capacity, and alw
with higher operating temperatures.
3.
cooking
Efforts to design and introduce solar cookers have
for many years concentrated on two main types: the
cooker with a fixed-plane collector, and the cook-r
with a spherical/parabolic mirror of average precision.
Operating temperatures can exceed 400°C. A number
of materials can be used, namely, glass plastics,
aluminized plastics, steel or aluminium. Taking into
account the conditions of use and aiming at a cooker
of reasonable working life (five years or more), and
adequate versatility for the types of cooking which are
feasible. research has tended to favour the cooker with
a parabolic mirror of polished aluminium. the detailed
25
design being subject to variation (moulded in plastics
or artificial resin or constructed entirely from metal).
In India, a concentrator-type solar cooker was
developed which essentially consists of a parabolic
disc of about 1 m diameter made of aluminium sheet
with a reflectivity of 75 per cent, a stand being provided
at the focus for the cooking pot. An Israeli version
used mirrors of very pure (99.98 per cent) aluminium
electrolytically polished and anodized as recommended
for streetlight reflectors, with a life or more than five
years, but at a higher cost. As the cost of these units
was too high to be used economically in developing
countries, a great deal of work has been done in the
United States of America and Israel in an attempt to
reduce the per-unit cost by substituting less expensive
materials. Recent efforts have been directed toward
making an umbrella-type solar cooker using aluminized
plastics; these can be folded and kept indoors when
not in use. Figures 3 and 4 illustrate the box and
parabolic mirror types of solar cookers.
Units with an area of 1 to 3 rn” for solar radiation
co!!ection with diameter 1 to 2 m and power ranging
between 0.7 and 2.0 kW seem well suited for family
cooking and pose no insurmountable problem in
production. Different investigators give cost prices for
mass production ranging from $US 10 to 20. Another
estimate for a parabolic cooker of diameter 1.5 m is
about SUS 30. which could be brought down to $US 22
if mass produced.
The effectiveness of a solar cooker can be enhanced
by coupling with a heat storage system. The heat
storage must be provided in a volume small enough
so as not to shadow an appreciable part of the solar
collector, and of weight small enough to be supported
on the grill. Insulation must be sufficient to prevent
serious loss of heat during solar exposure. It must be
capable of storing heat equivalent to one kWh or more
at a temperature high enough to permit effective cooking
later. It is desirable to be able to regulate the rate
of heat release for cooking. These requirements are
not easy to meet.
Although quite a few designs are functionally
satisfactory, there are not very many solar cookers
in use. The main reasons stem from (a) social
habits, (b) technical drawbacks, and (c) inadequate
promotional efforts. Among the socio-economic factors
inhibiting the large-scale utilization of solar cookers.
initial investment cost is one obstacle to the purchase
of a solar cooker. Families in rural areas can gather
wood and cow dung for fuel for conventional cooking.
Furthermore, solar cooking involves alteration in the
household routine, since the housewife must prepare
the evening meal during daylight, well before the
traditional time, which incurs the additional problem
of keeping the food hot. Secondly. the housewife
must remain in the hot sun while cooking. As the
.
Part Two.
26
community becomes able to acquire kerosene or
electric facilities. solar cooking might not be considered.
ne application of solar cookers appears to be limited
mam]y to the low-income group and poor communities
with no alternative fuel and who are prepared to have
their midday meal as the major meal. Nonetheless,
considerable promotional and extension work is involved, preferably undertaken by government and local
authorities. A promising approach to overcome the
difficulties is to combine the introduction of solar
cooking with other programmes for rural development
(e.g. education. public health, cultivation techniques
and home economics). Such an integrated approach
should help to bring solar cooking into general use in
countries with a tropical climate: the resulting advantages appear so extensive in social and geographical
terms as to justify the necessary effort.
- 4.
Solar drying
Solar drying has been used for agricultural and
other products since time immemorial. The traditional
techniques, though cheap, often yield inferior products,
and cleanliness cannot be ensured. By applying
modem technology to solar drying, substantial improvements can be made. Products traditionally dried by
solar energy include various kinds of vegetables and
fruits, pahn nuts. copra, soya bean, meat and fish.
The systematic application of modem solar drying to
carefully selected, high-value goods for export or for
consumption by high-income people should lead to
clean and refined materials, substantial reduction in
weight, and improved preservation and taste. These
factors can have a major influence on marketing.
Documentation on solar energy
United States of America and the West Indies, and a
number of products in Turkey and Middle Eastern
countries.
Convective driers have separate areas for collection
of solar energy and for drying the product. Heat can
be transferred from one area to the other by air or
by water. In the latter case, a heat exchanger is
used, and storage or supplementary heating may or
may not be provided. The collectors, mostly the flat
type, have features in common with solar heating.
A two-stage drier, using an inflatable collector coupled
to a mobile van has been field-tested at Barbados by
the Brace Research Institute of Canada. A solar kiln
for seasoning timber, using separate air heater and
rockbed thermal storage, is under development in
Australia; a similar kiln, without storage, is under
trial at the Forest Research Institute, India (see also
reference S 4).
Where other supplementary power is not available,
a windmill can be added to a drying system for
circulating air. Thermal chimneys are also possible,
with the difference in density of the heated air inside
and the cooler air outside creating an upward movement of the enclosed air, but they must be tall to
obtain sufficient difference in air temperature, and
large in cross-section to prevent undue resistance to
the flow of air.
Extensive developmental efforts are required for
heat-storage devices, collector-drier combinations and
flat-plate air-heaters to supply hot air to driers.
5.
-Solar drying systems can be classified mainly on
the basis of the mode of heat transfer employed. i.e.
radiation or forced convection (free convection is
present in both cases). The type of heating collector
employed. the availability of thermal storage during
sundown hours, the transport medium and its circulation, and the rate of drying are important for
operational and cost efficiency.
Radiation driers have a common space for collecting solar energy and for drying the product (figure 5).
There are holes in the bottom and top of the space to
allow for ventilation of evaporated moisture. The
materials for drying are spread thinly in trays. usually
at one level, and exposed to direct radiation from the
sun. There are no controls beyond adjusting the
orientation. The area per unit weight of the product
mav be calculated from the heat-balance equation for
different products, but often the average area per unit
weight is calculated and used in the design. Such
driers are easy to manufacture on a small scale, and
have been used for drying copra in Fiii, grapes in
the USSR. France and Australia, corn and yam in the
Pumping
Among the possible uses of solar energy. the
lifting of water for drinking or irrigation purposes is
of interest in dry regions and other rural areas,
particularly where underground water is available at
a depth not exceeding 30 m. Requirements of smallscale irrigation and domestic purposes will be well
within the reach of solar energy pumps in the fairly
near future. A pair of bullocks working continuously
can raise 1 ms of water per hour from a depth of
30 m. The equivalent of this work can be done by
an electric motor pump rated at 0.8 kW, for which
a solar pump can be designed.
Solar pumps can be operated with solar energy
directly converted into electricity, or by using thermal
energy itself to heat a working substance which may
operate the engine. The direct conversion of solar
into electrical enem does not at this stage seem to
be an economic proposition. However, solar pumps
run by thermal energy from the sun have been
constructed in France, the United States of America,
the USSR and Israel. In these pumps, flat-plate
I.
Working paper presented by the secretariat
27
collectors have been used for raising the temperature
of the working substance. A solar pump developed
at the .University of Florida in the United States oJ
America has two check valves with no moving parts.
A boiler is connected by straight and U-shaped tubes
to a chamber with check valves at the inlet and
outlet. The liquid in the boiler is vaporized by
pushing the liquid out of the system; when the vapour
reaches the bottom of the tube, it suddenly streams
into the chamber filled with cold liquid where the
steam rapidly condenses. While the steam is produced,
the top check-valve is open and the liquid is pushed
out. When the vapour condenses, the valve closes due
to the low pressure created, and the bottom check-valve
opens to let in more liquid to be transported. The
SOFRETES Company of France has developed a
solar pump which consists of the heating circuit where
the water is heated with the help of solar radiation,
and the fluid circuit wherein the hot water passes
through the tubular heat exchangers where beat is
given to a volatile liquid. The colder water then
returns to the heating circuit. The working fluid,
in gaseous form at high pressure, leaves the heat
exchanger and expands in the piston motor, and passes
into a condenser cooled by the pumped water. The
gaseous fluid is liquefied and is returned to the heat
exchanger by a reinjection pump driven by the engine
itself. In the final phase, the pumped water circuit,
the engine drives a hydraulic press which operates
Nadie
Collector
area (ma)
Rate of pumping
Height
(m)
.
Speed (rev/min)
.
.
.
(m3/hour)
.
.
.
.
.
.
.
.
.
.
12
1.2
15
180/150
Availability
of small and medium-sized units
(corresponding to a fraction of 1 kW to several kW)
at reasonable production costs, e.g. $US 1,000 to 1,500
per kW installed, could provide the basis for economic
and social changes, but it does not seem possible
that this goal can be achieved unless the developing
countries themselves participate in the process of
research, development and industrial production.
6. Refrigeration and air-conditioning
In many tropical and developing countries, a
substantial quantity of foodstuffs cannot be preserved
and spoils. For some foods, refrigeration is required;
and. for areas without electricity, solar refrigeration
and/or solar cooling may well be the answer.
The coldness from night-time air can be stored
and. in some areas, produced by radiation to the night
sky. In dry climates, cooling can be effected by
evaporating water from cloth wicks. In moist climates,
:L pump immersed in the water in the well.
SOFRETES pump is illustrated in figure 6.
The
The working fluid is low-boiling point methyl
chloride. Several different models of the solar pump
have been made and tested. Some of the main
characteristics of these pumps, and test locations,
appear in the following table. In addition to these,
further exhaustive trials in the village areas of the
Republic of Chad show that such pumps can lift
water up to a height of 60 m or more. One of the
main features of SOFRETES solar pumps is that the
components can be manufactured in the user country.
This type of pump has been in service at the laboratory
of Dakar University, Senegal, since 1969, and has
functioned without any trouble. Similar solar pumps
have been used by farmers in Israel. In addition to
methyl chloride, a wide variety of fluorinated organic
compounds including freons can be used at lower
temperature ranges (reference S 5). The average cost
of the SOFRETES pump is about $US 22,000 for
0.3 to 0.5 kW. Solar engines of the Thermoelectronic
Corporation of the United States of America cost
$US 20,000 in 1972 yielding 2 to 5 kW. Undoubtedly,
mass production. could reduce prices considerably.
Nearly 50 per cent of the cost is the collector. Another
type of pump, based on the Stirling cycle, is described
in reference S 6. Solar pumps for lift irrigation are
under development in India (see reference S 7).
onmat
60
sencgat
88
Qrma
30
Chingnetti
88
10
6
2
10
12
25
20
20
LOO/150
100/150
100/150
100/150
Secra
6
0.6
14
80
the moisture in the air can be partially removed, and
the dried air cooled by evaporation of water. Most
cooling systems depend on the evaporation of a liquid
in a closed system. The household refrigerator works
on the principle of alternate vaporization under reduced
pressure, and condensation under increased pressure,
of a fluid such as ammonia or freon. Vaporization
extracts heat from the surrounding environment and
cools the refrigerator cabin, or freezes water to ice;
the system is regenerated by compressing the vaporized
working fluid to liquid, the heat produced being
dissipated to a stream of circulating air or water;
the two operations of cooling and regeneration are
combined into continuous operation.
Solar energy could be used to operate a heat
engine, which in turn can operate a compression-type
refrigerator or air-conditioner. The solar engine has.
however, low efficiency for producing power. It is
usually simpler and cheaper to use the sun directly
in an absorption-desorption cycle for the purpose. A
Part Two.
28
number of systems (e.g. ammonia/water, ammonia/
sodium thiocyanate) could be used. Figure 7 shows
refrigeration
using an ammonia/sodium thiocyanate
system.
For the purpose of refrigeration and producing
ice, the weight proportions of ammonia and water
are in the ratio of 1:1.3. and the maximum heating
temperature is about 130°C with a special valve
separating the water from the liquefied ammonia; the
over-all coefficient of performance (COP), i.e. the
heat absorbed by vaporizing coolant, divided by solar
heat incident on collector, is about 0.10. Flat-plate
collectors can also be used for the system, in which
case the COP is further reduced. The ammonia/water
system has the disadvantage that some of the water
vaporizes with ammonia, requiring a rectifying arrangement for separation, and at intervals the water must
be returned to the larger vessel containing ammonia/
water solution. It is desirable to eliminate water,
which can be done by using very concentrated
solutions af salt in liquid ammonia. The vapour
pressure of liquid ammonia can thus be reduced at
room temperature from 10 atmospheres to less than
1 atmosphere, and the salts have negligible vapour
pressure even at high temperatures. Ammonia/sodium
thiocyanate solutions have suitable thermodynamic
properties with very high solubility. low vapour
pressure, and high heats of vaporization; they are
chemically stable and inert, comparatively inexpensive
and can be used in steel vessels; they have high heat
conductivities and low viscosities. The COP of this
system is approximately three times that of the
ammonia/water system. Although solar refrigeration
is normally more expensive than refrigeration with
ordinary fuel or electricity, it can be considered where
electricity and fuel are very expensive or unavailable,
as in many rural areas of the developing countries.
Large industrial refrigeration plants can have a
COP as high as 0.7, but smaller plants are less
efficient. If household labour far domestic cooling
is considered free, small solar cooling units may be
viable, but operation of a solar cooling machine is
fairly complicated, requiring experience and skill in
mechanical operations. In view of this, solar cooling
and ice production as a village industry may be more
practical than individual hand-operated domestic solar
refrigerators in homes. One of the difficulties in ice
production is the slow growth of ice crystals, and it
may be advisable to operate several regeneration units
while the sun is shining, and carry aut the freezing
operations at night,
There is great demand for air-conditioning in hot
climates. and air-conditioning
by solar enerG is
tcehnie+ feasible. In a typical flat-roofed, one-storey
[email protected] much of the roof area would be covered with
Solar
CdeCtOrS,
Documentation on solar energy
and capitrd investment would therefore
be high.
The characteristics of water make it satisfactory
for cooling and air-conditioning.
A Ii&mm bromide!
water system can be used for cooling in that the
absorption of water vapour by concentrated lithium
bromide solutions produces cooling in the same way
as the ammonia/sodium thiocyanate system. nb
system is well suited to solar operation because it
can be regenerated with hot water above 77”~ but
below the boiling point of water. With indirect heating
through a heat exchanger, it is possible to have extm
heat storage for cloudy weather. The average COP of
such a system is about 0.18. At very low temperatures,
lithium bromide may crystallize, but this can be
prevented by temperature control. The general trend
of results with such a system is such that, an a bright,
calm day, a solar collector of 20 m2 should produce
one ton of refrigeration. Improvement in collection
efficiency by a selective surface like nickel black may
reduce the collector area.
Dehumidification in moist hot climates is almost
as important as cooling. Removal of moisture from
the air is much easier to achieve than cooling the air.
and dehumidifiers operated by electricity are cheaper
than air-conditioners. Active silica gel has been used
for the purpose, followed by regeneration. In hot,
dry climates, air can be cooled by evaporating water.
and it is common practice to blow air through coarse
cloth saturated with water. Even in humid climates.
considerable cooling can be effected by dehumidification
of the air followed by evaporation of the water
and restoration of part of the humidity. Such dehumidification can be effected by an ethylene glycol!
air/solar collector system, as proposed by the University
of Wisconsin, United States of America, whereby
moisture in the air is absorbed by passing it through
a spray. tower of falling drops of ethylene glycol. the
non-volatile glycol absorbing water and giving drier
air, and the glycol being regenerated with a stream of
hot air heated by the sun.
Cooling of houses can be achieved in hot. clear
climates by radiation to the sky during the night. usmg
a black cloth radiator; such a radiator may act as a
solar collector for heating during day-time. Large
buildings, such as hospitals, factories and schools, may
be fitted economically with roof-mounted, combined
solar heating and radiative cooling systems, in which
the same panel operates as a collector during day and
a radiator at night, using separate storage.
As a supporting activity to space ‘heating and
cooling, considerable work has been done on the stud!
of indoor temperature as a function of architecture,
orientation of the building, insulation, shading and
selective paints. A detailed consideration of these
I.
Working paper presented by the secretariat
factors can considerably reduce the load on the heating
and cooling system that may be developed. One
alternative system for residential heating and cooling
is illustrated in figure 8. A number of experiments
involving the absorption cooling cycle have been conducted in the United States of America, Australia,
the USSR, France, Japan and other countries, and
have shown that the concept is fully feasible, but
considerable design engineering works will have to
be done before the system can be used widely.
A convective coaling system, using lower wet-bulb
temperatures at night and coupled to rockpile thermal
storage, is under development in Australia and India
as a component of a hybrid heating-cum-cooling system.
Comparative studies of economics and reliability of
the rockpile and natural air-conditioning systems need
to be undertaken for hot, dry climates, and their
areas of application specified.
B.
GENERAL CONCLUSIOiVS AND
SUGGESTIONS
There has been considerable work in many
countries of the world on low-grade thermal devices,
such as solar water-heaters, solar stills, driers, space
heating, refrigeration and air-conditioning, and pumping.
Except for water-heaters and solar stills, which are
commercial propositions in some developed countries,
other devices have not found any large-scale utilization
mainly because of their high cost and low efficiency.
(a) Solar water-heaters : Data on commercially
available solar water-heaters of small, medium and
large capacities should be widely disseminated with a
view to selection of appropriate types.
Steps
should then be taken to encourage their production
and use. Governments might assist in setting up
demonstration units in representative locations.
(b) Solar stills: Similar approaches should be
made for solar distillation, including small, portable
equipment. In addition, there is scape for improved
means for trapping the water vapour which escapes
during salt production (the I-ID principle can be used
for this purpose).
(c) Solar driers: Programmes might be developed
to make solar driers useful for drying agricultural
products through demonstration units and other
promotional efforts.
A recommended design for a solar timber kiln
should be developed, and a few such kilns fabricated
for typical locations.
(d) Cooking: Extensive promotional activities
should be initiated in rural areas; simultaneously,
suitable storage device and heatpipe systems need to
29
be evolved for coupling with the cooker to remove
certain short-comings.
(e) Solar space heating and coolitzg : A pilot
programme for introducing solar heating in a few
selected villages and at high-altitude areas should be
undertaken.
For preservation of food materials, a few prototype
ammonia/water solar refrigeration units should be
set up in remote rural areas for developmental
investigations. More extensive developmental investigations should be carried out for use of the lithium
bromide/water system in solar air-conditioning.
The SOFRETES solar pump
(f) Pumping:
should be tried out in selected rural areas, and
developmental investigations for its adoption tmdertaken, using indigenously available materials.
II. SMALL- AND MEDIUM-SCALE CONVERSION
TO ELECTRICAL
AND MECHANICAL POWER
The possibilities which have been explored, and
which have proved rewarding for small-scale and
medium-scale applications, are solar engines, and turbines working on the Rankine cycle, producing
mechanical power, and various solar photobatteries
and thermobatteries for conversion into electrrc power,
and solar ponus.
A solar thermal power umt 1s sunuar IO any
conventional, external heat engme. except that the
heat is provided by solar collectors. High-temperature
units use focuskg collectors that have to follow the
sun, and in general such collectors are expensive and
diflicult to maintain. To avoid the complications
of sun-following devices, many types of stationary
collectors have been proposed: the tlat type as
used for water heating, or very low-concentrating
mirrors limited to a concentration factor of 2 or 3.
Such collectors generally produce relatively very
low temperatures, thereby resulting in much lower
thermodynamic efficiency of the heat engme; but me
system is simple. Apart from the cost of the coilectors,
and the preparation of the ground site on which these
are erected, the absence of a satisfactory and cheap
solution to the problem of solar heat storage greatly
increases the capital cost of installation.
1.
Solar engines
Many designs of solar engines, both piston and
turbine types, have been proposed, and several have
been demonstrated. but they have not yet been
produced commercially. Investigations are currently
being carried out in Israel, Italy and the United States
of America.
:
Part Two.
Documentation on solar energy
cells. A chlorophyl
mising.
semiconductor photocell is pro-
30
2. Thermoelectric conversion
Thermoelectric conversion methods may be used
for converting solar energy into electricity directly.
Thermobatteries with semiconductors of antimony.
bismuth tellurides, selenium tellurides, etc., are being
produced on a large scale, and have an efficiency of
thermal energy conversion of 6 to 7 per cent. This
thermoelectric process requires concentration of normal
solar radiation, and thus requires development of a
cheap concentrator; a heat storage device is also
required. Solar thermobatteries have a number of
small-scale and medium-scale applications with production of power in the range of a few watts to a
few kilowatts, particularly for power communication
apparatus.
3.
Photovoltaic power
.
In photovoltaic power generation, a voltage is
produced at a metal/semiconductor junction. Arsenicdoped silicon and boron-doped silicon semiconductors
can be used to form a good junction for the purpose.
Currently, silicon cells have an efficiency of about
10 to 12 per cent, but this can be improved by special
processing and increasing the purity of the material,
and an efficiency of conversion in such cells as
high as 30 per cent has been predicted. Conversion
efficiency of a solar cell is a function of the geometry
of the cell, and increases with its thickness. Silicon
cells are used in space ships, but the cost is at present
prohibitive for terrestrial applications.
Cadmium sulphide (CdS) is a good photovoltaic
material, and efficiency up to 7 per cent has been
attained; this seems to be more attractive for relatively
high-temperaturs photovoltaic cells, but it appears
that there is some amount of degradation at higher
temperature. Nevertheless, efforts are in progress to
use it in combination with other materials. A crosssection of a typical cadmium sulphide/copper sulphide
solar cell is displayed in figure 9. The main advantage
of the CdS cell is that it can be made from microcrystalline thin film rather from single crystals; the
cells are capable of being manufactured continuously
by vacuum deposition of the materials on plastics.
Gallium arsenide is also a good photovoltaic material,
but it is not abundant. Cadmium telluride is another
good photovoltaic material with potentially a much
higher efficiency, but its manufacture and availability
pose problems. Technological developments are in
progress to prepare cells of this from both single
crystals and thin films.
In recent years, organic semiconductors have been
investigated in development of photovoltaic cells.
Or,nanic dyes and such materials as magnesium
Pbthalocyanine have been used in organic photovoltaic
4.
Solar pond
h1 principle, the solar pond is a convenient device
for collection and storage of solar heat. It comprises
half a hectare or more in area, with a blacken4
bottom overlain by layers of concentrated salnvater,
above which is placed, without mixing, a layer of
pure water. The lower salt solution is heavier than
the upper water and does not mix with it; when the
bottom layer becomes heated. it does not rise to the
top. Thus, the upper layer of water remains coo]
while the lower layer heats up to 90°C or more. A
low-temperature steam turbine is operated by a boiler
placed at the bottom of the pond.
As a collector for low-temperature heat, the pond
is very much cheaper per unit area than the conventional solar collector used for water heating, since
no metal, plastic or glass is used in its construcrion.
Despite low efficiency, a low-temperature turbine can
be used to produce small power. Depending on the
investment needed in the construction of the pond and
its plumbing. the estimated cost of power produced
would be about 2 US cents per kWh. Thus, for the
supply of power from smaller sources, especially in
remote rural or coastal areas, the solar pond appears
to be a feasible proposition. The solar pond can be
coupled with production of common salt from seawater,
particularly in areas of heavy rainfall. Israel, Australia
and Canada have done extensive work in that field.
Although the heat extraction problem in solar ponds
has substantially been solved, there remains the mixing
problems of the layers of the pond: chemical engineering studies need to establish for each case the proper
design to yield the desired amount of low-temperature
heat, power and salt.
III.
LARGE-SCALE
1.
POWER PRODUCTION
Solar power via satellite
For any practical use of solar energy for largescale power production, the two main and basic hurdles
to be overcome are (a) atmospheric reduction of the
intensity of solar radiation, and (b) storage of the
solar energy. A concept evolved in the United States
of America to overcome both those hurdles. ~JKJV~
as the Satellite Solar Power System, envisages that a
satellite synchronized with the earth’s movement ouKidc
the geosphere would transmit solar power to reccivinf
stations on earth for conversion into electrical PoLVcr
(see figure 10). In such an orbit, solar radiation
would be received continuously and would bc tif
c
an intensity on an’ ayerage six times that yn
earth’s surface. Solar batteries would convert It inlo
I.
Working paper presented by the secretariat
31
electricity, I which in turn would be converted to
microwaves for transmission to earth where it would
fmally be reconverted to electric power. The tentative
cost estimate for a system of 5,000 MW is $US 1040
per kW.
2.
Photothermal conversion
3.
Use of selective surfaces of high absorptivity (very
thin film of silicon and silver) and low emissivity, on
the exterior of steel pipes in evacuated glass envelopes
and operating at elevated temperatures, has been
proposed as a concept of thin-film photothermal
conversion of solar energy for power production.
This concept mainly comprises a solar collection area,
a thermal storage, a heat exchanger, a boiler, and a
power plant. Liquid sodium has been suggested as
the thermal fluid, but some organic fluids and salt
eutectics could also serve the purpose. Concentrating
collectors in the solar farm with high absorptivity/
emissivity ratios of 10 to 15 could give temperatures
in the range of 350” to 550°C; or flat-plate collectors
with no concentration but with high ratios of 20 to 40
could give a temperature of 250” to 350°C. Economic
projections have been carried out for a collector area
of 1 lcn?. to produce 80 MW.
IV.
OTHER FIELDS OF SOLAR ENERGY
USE
A number of other applications or suggested
systems have not been elaborated here, either because
they are not as yet directly relevant to the conditions
in developing countries or because they are as yet
theoretical.
1.
Energy plantation
The recent concept of an energy plantation covers
the planting of fast-growing, woody plants or trees
which have a high photosynthetic efficiency. The trees
would be harvested, cured in direct sunlight. and burnt
to produce power. Investigation is still required on
technical and non-technical aspects.
2.
Pinasco (Mexico) greenhouse experiment, designed on
the same basis, produces similar results. The experiment has now been extended to Abu Dhabi, and
has started operation. Such greenhouses have real
possibilities for many developing countries.
Controlled environmental greenhouses
At the Environmental Research Laboratory of
Tucson in the United States of America, vegetables
are grown in the controlled environment of an airinflated, plastic greenhouse. The large-scale Puerto
Algal ponds
Fuel derived from pond-grown algae can drive
gas turbines and reciprocating heat engines. The
potentid of algae for fuel is about the same as
for higher plants. When growing in conditions in
which ample carbon dioxide and suitable nutrients are
provided, the process of repeated subdivision provides
large quantities of organic matter. When the energy
potentially available in the dried algae is related to
the solar energy incident upon the growth tanks, it
has been shown that up to 8 per cent can be recovered.
4.
Solar furnaces
Solar furnaces which give a very high concentration
of focused radiation have been used for scientific
investigations. Those with high optical precision give
temperatures of over 3,OOO”C and may cost over
$US 1.000 per m2. Such furnaces have been constructed and studied in France (reference S 8). Japan,
the USSR, the United States of America and Algeria.
V. CONCLUDNG
REMARKS
In each country, there is a need to identify the
future role of solar energy. Many solar devices depend
heavily on the collector system, and there is a continuous need for testing and scientific assessment of
collectors with a view to using local materials for
construction.
There is scope for immediate transfer of technology
on small-scale special purpose uses of direct energy
conversion processes, and this will assist future transfer
of technology on larger-scale processes.
For effective utilization of solar energy in the
region, a broad spectrum of activities will be required;
involving existing and new research and development
institutions, scientific training, educational and promotional activities, and dissemination of information, and
ESCAP is well qualified to lead and co-ordinate national
and regional efforts in these respects.
Part Two.
32
Sun’s
Documentation on solar energy
rays
pour
\
-Ho, IO,@
OutIct
AZ
\
~~..Y--s.
_ .-“1
amount
f0
-ADro,EW(tilt:
_I
. - 1 .
.
/
Product
Salt water or some
of soline woter
- f-L-----‘1’-1
I.mitudc+15°1
Drinking
Figure 2.
Figure 1. Domestic solar water heater
,-
. .‘M
I
woter
water
Distilled
woter
Solar still for water desalination
WOP
forlid
-7
-
Figure 3. “Hot box” type of soliar cooker
&
Adjur!ment
.L
Figure 4. Solar cooker with parabolic mirror
Figure 6. Solar pump (SOFREJES type)
I
VCnrllDt.0”
no:er lrl”lmlOn
Legs--GL-,J
Figure 5. Tray-type solar drier
I.
Working paper presented by the secretariat
33
Summer
oDeration
Winter
aaeration
5edanlY
. ..~..
.- -
L-----l.
1
cad
\ Lower
header
line
during
Hat
!
/ system
1
GI
Automoticvolve
Hot
water
not
water
”
<,‘I
retrigeratian
Figure 7. Refrigeration system
(ammonia/sodium thiocyanate refrigerant)
-
Fw!watd
“.Oter SuPPlY
7
Figure 8. Residential heating and cooling
j;unction
n-type
Negative
Receivinq
electrode
Figure 9. Cross-section of typical
cds/cu,s
solar cell
Control
antenna
station
Cooling
l aoiament
Figure 10. Satellite solar power system
34
II.
INFORMATION
PAPERS PREPARED BY PARTICIPANTS
SOLAR ENERGY RESEARCH IN THE PHILIPPINES(NR/ERD/EWGSW/CR.l)*
by
Mr. E. N. Terrado (Philippines)
In spite of the amiouncement that the national goal
of the country for future power development would
centre around nuclear reactors, geothermal and hydroelectric potential, alternative sources of energy, such as
solar energy and wind energy, were given an important
place in national energy planning. However, the
absence of pertinent survey data makes it difficult to
determine the exact role to be played by these sources
in the energy picture for the next 25 years or so.
Extensive survey work is therefore necessary in the
Philippines, as in other countries of the region.
Low-grade heat derived from solar devices has
considerable and immediate possibilities in the region.
Such devices comprise: (a) refrigeration for the preservation of vegetables, fish and other materials on a
sub-community scale; (b) water heating for schools,
hotels, hospitals, etc.; (c) pumping for irrigation; (d)
drying of agricultural products; and (e) distillation for
potable water and other specialized uses such as water
l
Summarized.
SOLAR ENERGY ~-N~IA:
for lead-acid batteries. Developmental efforts are to
be made for adoption of the devices in many of the
countries of the region. In the long term, the develop
ment of large-scale power production from solar energy
will benefit both the developing and the advanced
countries, and collaboration should be established on
regional and international levels.
At present there are four ongoing research projects in the country, related to: (a) solar engine for
agro-industrial purposes, water heating, distillation,
and refrigeration, work on which commenced in 1974;
and (b) flat-plate collectors and ammonia absorptiondesorption system for the development of an ice-making
machine. The National Science Development Board
is considering financing for other projects, namely, a
drier for lumber, solar-powered open-cycle gas turbine,
and silicon cells. It plans to establish a National
Energy Institute in order to co-ordinate all research on
non-conventional energy sources. The country is in
need of a chain of &jar radiation stations to -record
solar radiation data.
RE~EARCH,DEVELOPMENTAND
(NR/ERD/EWGSW/CR.2)*
UTILIZATION
Mr. C. L. Gupta (India)
A.
DEVELOPMENT
IN INDIA
OF SOLAR ENERGY
Systematic efforts to harness solar energy were
initiated in the early 1950s.
Since then, the various
laboratories have concentrated on low-grade thermal
processes, such as solar water-heating, solar distillation,
space heating, solar drying and solar cooking. From
such research, useful data have been made available for
indigenous flat-plate collector design and technology
However, social non(references S 9 to S 11).
acceptance of the technically successful solar cooker
developed by the National Physical Laboratory
practically closed all financial and scientific slipport to
solar work until 1962. This scepticism remained until
l
Abridged.
the 1972 Stockholm United Nations Environmental
Conference. Since that time, an expert panel has been
constituted in the Ministry of Science and Technology
(reference S 12), and open, enthusiastic support has
been given by the Prime Minister in an attempt to find
a place for solar energy in the country’s energy
economy. Solar water-heaters and solar stills are now
manufactured and sold commercially.
Specific fields of investigation have now been
detied by the Government as priority sectors which
are to be developed at least to the demonstration stage
(reference S 12). In addition, work in the areas of
solar cells is being funded. The greatest stress is on
power for domestic use, cottage industries and agricultural areas, being developed according to the scheme
below.
II.
I&ormation
(a)
Rural sector (villages with a population of
less than 1,000)
.
(b)
(c)
B.
PRESEiVT STATE OF SOLAR ENERGY
IN INDIA
(i)
Water pumping
(ii)
Drying of agricultural produce (e.g.
food grains, forest products)
Eight institutions are currently WGrking in this
topmost priority area.
(iii)
Conversion of brackish water into
potable water
(iv)
Use of solar slurry heaters for integrated hio-gas plants
(a) I kW and 4 kW solar pumps using flat-plate
collectors and orgafiic-fluid Rankine cycle (Auroville
Centre for Environmental Studies, Pondicherry).
A 1
kW pump is being designed as-the intermediate stage
of a project to be completed in 1978. In addition to
pumping, solar collectors are meant to be used as part
of farm building roofs which could heat air to dry
agricultural produce. Also, the solar pump is meant
to be coupled to a low-speed generator/compressor to
produce power/cooling on non-pumping days.
Urban sector (small towns with a population
of 1,000 to 10,000)
(i) Mini-power plants (10 kW - 50 kW
size)
(ii)
Solar water-heaters (domestic size)
(iii)
Space heating and cooling, mainly
for health centres, tourist bungalows,
etc.
(iv)
Solar ice-making for fisheries, health
centres, etc.
Metropolitan sector (cities with a population
exceeding 0.5 million)
(i)
Solar cells for television, radios, etc.
(ii)
Bioconversion of waste into transportable fuels
(iii)
Process steam
(iv)
Factory heating and cooling
(v)
Solar water-heaters (large size for
cafeterias, hotels, etc.)
During 1974, in the wake of the oil price crisis
and the publication of the report of a solar energy
expert panel, the idea that large industrial concerns
should sponsor or conduct in-house research and
development projects became policy, and the Govemment permitted all expenses incurred on solar applications in industry to be treated as research expenses.
_-.
3s
papers prepared by participants
Solar research and development in India is supported by a network of radiation stations run by the
[email protected] Meteorological Department (reference S 13).
There are-26 such stations, 13 of which ‘are principal
stations measuring global,[email protected], normal beam radialThe remainder are
tion and hours of sunshine.
ordinary stations measuring global radiation and hours
of sunshine only.
Most principal stations use MollGoczynski pyranographs, Eppley pyroheliometers and
Campbell-Stokes sunshine recorders, while most
ordinary stations use bimetallic pyranographs and
CampbellStokes sunshine recorders.
All these instruments are manufactured in India under licence or
with indigenous designs.
1. Solar pumping
(b) Low-temperature direct-contact vapour pump
for lift [email protected] (Birla Institute of Technology, Pilani).
The vapour pump uses flat-plate collectors and an
organic-fluid vapour (immiscible with water) in direct
contact with water. Feasibility studies and cost
analyses for heads up to 30 m with a capacity of
100 m3/day have been completed.
Prototypes are
being developed for both air-cooled and water-cooled
types of pumps. Except for the valves, there are no
movable parts in this pump design.
(c) Medium-temperature 4 kW pump using
compound parabolic/wedge stationary concentrators
and steam Rankine cycle (Punjab Agricultural University, Ludhiana) . Theoretical and optimization studies
have been completed on generating and tracking requirements of compound parabolic/wedge stationary
concentrators, designed for a concentration factor up
to 3 with monthly adjustment. A small steam engine
operating with a head of 5 kg/cm2 pressure has been
fabricated and operated off this concentrator.
(d) Medium-temperature 200 W hot-air engine
using tracking concentrators and Stirling cycle (Central
Salt and Marine Chemicals Research Institute,
An indigenous version similar to the
Bhavnagar).
Philips hot-air engine is planned, to be completed by
July 1977.
(e) I kW solar pump using medium-temperature,
flat-plate collectors and organic-vapour turbine or expander (National Physical Laboratory, New Delhi).
Flat-plate collectors will be developed to operate at
12OT, with an instantaneous efficiency of 70 per cent.
Selective windows, selective black-on-copper substrates,
and convection suppression by honeycombs will be
coupled to a once-a-month adjusting reflector hinged to
a double glass flat-plate collector. On the power side,
the freon group of organic liquids would be used as
working fluids in an indirect system using thermic fluid
as a transport medium from the solar collectors and an
expander.
Part Two.
36
(f) Solar pump using Cds/silicone solar cells
(Indian Institute of Technology and National Physical
A long-term project is
Laboratory, New Delhi).
intended to develop direct conversion of Solar energy
to electricity by indigenously-fabricated cheap and reliable solar cells encapsulated for long life.
(g)
Fluidyne engine with liquid piston operating
on SrirZirzg cycle (Metal Box (India) with Atomic
Energy Research Establishment, Harwell, United
Practical commercial development is
Kingdom).
envisaged for lift irrigation in the field, from small
laboratory models pumping 300 litres/hour already
developed at Harwell.
(h) I kW pump using cylindrical, parabolic,
stationary concentrator and steam Rankine cycle (Jyoti
Ltd., Baroda).
A leading pump manufacturer of
India has undertaken development of a solar pump
using conventional solar principles, with a view to mass
production.
2.
solar drying
Work on small cabinet driers of 5 to 10 kg
capacity using a combined radiation/natural convection/storage principle has been in progress in many
institutions (reference S 14 to S 20). However, for
any signiticant input to post-harvest technology, the
minimum size needed is 100 kg/day for cash crops and
a metric ton/day for grain-drying, even for small
farmers (reference S 21).
(a) One ton/day capacity solar paddy drier
Laboratory
(Annamalai University, Chidambaram) .
studies and pilot plant studies in a rice mill have been
completed. The pilot plant dries 10 kg/h of paddy
by blowing solar-heated air from an air-heater of area
4.25 m2 with an electrical blower. A prototype is
being fabricated.
(b) Solar kiln for timber drying (Forest Research Institute, Dehradun).
A kiln was designed and
developed in 1971-1972 for air-seasoning of timber
sections (10 cm x 7.5 cm) used for frames of windows
and doors (reference S 22). The kiln is of nearly
10 m2 area. Drying can be done in 40 per cent of
the time taken for normal air-drying, and with 40 per
cent of the operating cost of a steam-heated kiln at an
initial capital cost of only 20 per cent.
3.
Conversion of brackish into potable water
Many
institutions
have experimented
with
domestic models of solar stills having 5 to 7 litres
capacity and 1.5 to 2.0 mz area, primarily for supplying
distilled water. Recently, figures were published (reference S 23) for explicit multiple correlation of distillate ouput with three climatic variables: solar
radiation, dry bulb temperature and wind velocity.
Documentation on solar energy
The major work on supplying potable water has been
done by the Central Salt and Marine Chemical Research
Institute, Bhavnagar, during the last decade (reference
S 24).
A 1,000 litres/day pilot plant was built on the
ground in masonry of 1.7 x 2.5 m bays covering a
total area of 350 m2 with glass covers at varying angles.
For sealing materials, tar plastic, commercially available
in India, was found reliable. The bottom liner was
made of masonry plaster covered with black asphalt
coating or black cement. For top ridges, bottom sup
ports combined with rainwater gutters and pillars
supporting ridges, factory-fiuiihed precast items were
found best. It has been found (reference S 25) that,
if the freshwater source is more than 24 km away and
the community requirements are less than 22 m3/day.
solar distillation is competitive and in some cases even
economical. Costs of solar stills-cum-rainfall collection
systems are dominated by storage costs because of the
prevalent monsoon type of rainfall. In areas of rainfall
less than 200 mm/year, solar distillation alone is
economical.
4. Mini-power
plants.
There has been a recent emphasis on developing
mini-power plants in the 5 kW-50 kW range suitable
for supplying electricity to existing tube-well pumps and
to villages with populations of 500 to 1,000. A
baseline study (reference S 26) for choosing an initial
concept for further development of a solar plant has
highlighted the need for developing hybrid planar
collectors in the range 120’ to 150°C and stationary
concentrators up to 3OOOC. Two recent feasibility
studies have been carried out (references S 27 and
S 28). A 10 kW power plant is being assembled on a
collaborative basis with the Republic of Germany.
5.
Solar water-heaters
Research began in India in 1955 at the National
Physical Laboratory (reference S 29).
A mathematical model to predict the performance
of a natural circulation system, using a corrugated
NPL-type collector or wire-wound pipes with a plate
CBRI-type collector, was developed in 1967 (references S 30 and S 31). Both gave comparable performance, but they are costly for an average-income
household. In spite of some drawbacks, the industry
took up the sale and manufacture of the CBRI design.
A recent innovation has been the use of aluminium
tubGn-strip panels with built-in headers in coliector
sk:: Ti 1.5 x 0.4 m.
Rema$ng problems in water-heater design and
production appear to be solvable (references S 32, S 33,
s 34).
IX. Inform&on
6.
37
papers prepared by participants
Building heating and cooling
Buildiig heatin,= for high altitudes was tried in
1963 (reference S 35) as a simple extension of the
solar water-heater, in which a flat storage tank formed
the heating panel inside a high-capacity, well-insulated
room, and the results were very encouraging. The use
of forced air circulation and a rock pile storage were
also tried.
For sophisticated, active cooling systems, the
University of Roorkee has developed a one ton capacity
absorption air-conditioning system (reference S 36),
using ammonia/water as the refrigerant and water from
The Indian
Institute
of
collectors.
flat-plate
Technology, Madras, (reference S 37) has developed
an inexpensive system which combines the dehumidiication of room air by an absorbent, foilowed
by adiabatic evaporative cooling with the solar desorption of the absorbent in a flat-plate collector open to
ambient air.
The systems described above are either for heating
or for cooling. But in latitudes between 25” and 35”N,
both summer cooling and winter heating are required. A
high utilization factor makes such a system practicable,
if collectors can form the buildiig roof and ducting can
be avoided. This may be achieved in pond-type, lowcapacity sheet roofs with movable shades. A thermal
design model for this system has been developed (reference S 38) to optimize the operating and design
Another composite system (reference
parameters.
S 39) uses rock beds for heating and cooling.
7.
Solar ice-making
Recently, an ammonia/sodium thiocyanate system
capable of producing 75 kg of ice per day has been
developed (reference S 40) with a high design
coefficient of performance.
8.
Solar cells
Thin, wafer-type silicone solar cells from imported
silicone crystals were developed with efficiency of 8 to
10 per cent in 1972, but these were very costly. Production of thin-film CdS solar cells, which are reliable,
efficient and cheap, is now the major field of development.
9.
Process steam
Development of suitable collectors is of prime importance in thii field, and several institutions are
engaged in this activity. Industry supplies the major
fhmial support.
(a) Medium-temperature
flat-plate collectors
(National Physical Laboratory, New Delhi).
Stagnation temperatures up to 200°C have been obtained
with flat-plate collectors (reference S 41), using
a selective black on copper absorber, a honeycomb of
glass tubes and a selectively coated collector window
(tin dioxide) to reduce radiation losses. Work has
also been started on evacuated-tube collectors which
could be mass produced if successful technically and
viable economically.
(b) Medium-temperature planar collectors (Tata
Energy
Research Institute
Unit, Pondicherry) .
Truncated, compound parabolic collectors (reference
S 42), with a concentration of 4 and a height of 10 cm
for receiver size of 3 cm have been designed to achieve
15O*C within three hours of the solar noon, when
bimonthly adjustments are made. Selective surfaces,
coated windows and plastic honeycombs are contemplated to increase the efficiency from the current value
of nearly 15 per cent.
(c) Compound wedge/stationary concentrators
(Punjab Agricultural University, Ludhiana) .
Compound wedge/stationary concentrators (reference S 43)
have been produced as discretized versions of compound
parabolic collectors. Efficiencies of 56 per cent have
been achieved with a concentration factor of 2.8, and
steam has been produced at pressures up to 5 atmospheres. Work is continuing on these concentrators with
absorbers in the range of 30 to 40 cm and corresponding
heights of the aluminium reflector panels exposed
directly to the atmospheric elements.
10. Factory heating and cooling
No special problems arise as distinct from building
heating and cooling. However, large roof areas of thii
elements must be designed as energy generators. A
large engineering company has installed a system in
which water’ can be heated by solar energy and air can
be blown past hot-water coils mounted on the walls
below windows. Water pumps as well as blower fans
are needed.
11.
Industrial
drying
Drying of palm jaggery juice, drying of coal fines
and spray-drying of baby milk have been explored.
12.
Solar ponds
Temperatures up to 80’ to 90°C have been
obtained in shallow ponds; use of this process in salt
flats for preheating the water for process steam or for
very hot water may soon be undertaken.
13.
Solar cookers
Step-type reflector cookers have been experimented
with, along with steam cookers which can O~Y do
limited types of cooking. Solar hot-boxes and ovens
Part Two.
38
.
have been developed in many parts of the country; the
compound wedge/conical type is original and probably
the most successful in terms of lowest cost-per-unit
efficiency.
C.
FUTURE PROSPECTS OF SOLAR ENERGY
APPLICATIONS
In the national solar energy plan (reference S 12),
some of the targets have been explicitly stated. The
author estimates, in the light of the last two years execution of this pl:an, that most of these targets will be
achieved during the period 1978-1983. the likely
first achievements being the installation of a solar
desalination system for potable water supply in 100
villages, the production of solar water-heaters for bio-
RECENT RESEARCH AND DEVELOPMENT
(NR/ERD/EWGSW/CR.4
Documentation on solar ener-mp
gas plants as a village handicraft, a 10 kW
thermal power plant and 1 kW solar pumps.
SOI=
Solar energy research efforts are being COordinated by the National Committee on Science and
Technology. Funds are provided to research laboratories, universities, industrial associations and other
voluntary organizations by the Department of Science
and Technology, by government-supported research
councils and by the Tata Energy Research Institute.
For co-ordinated work, it may be desirable to have a
single, over-all planning, funding and evaluating unit
to cover the whole field of renewable energy or onh
that of solar energy. A single research institute fo;
solar energy research would be useful if the current
groups become constituent regional units for field-testing
and centres of excellence in one specific field each.
ON SOLAR ENERGY APPLICATIONS
and NR/ERD/EWGSW/CR.6)*
IN JAPAN
by
Mr. T. Noguchi (Japan)
During the lo-year period ending in 1971, research and development in the solar energy field was
related to agricultural applications, water-heating,
space heating and cooling, small-scale power generation, solar furnaces and investigation of materials.
Subsequent developments have been fairly fast because
of the oil crisis, and the budget of the “Sunshine
Project” (see document NR/ERD/EWGSW/CR.18)
includes 874 million yen for research and development
on solar energy. The work programme includes major
investigations on thermal and photo-voltaic conversion,
water-heating, space heating and cooling, solar furnaces
and solar process heating.
During the earlier period, solar radiation measurements and their statistical correlation, assessment of
turbidity coefficients, intensities on titled surfaces, and
studies of the relation between sunshine hours and solar
radiation were carried out in considerable detail.
Work on agricultural applications of solar energy
included: establishing the relationship between the
quantity of ripening rice, sunshine hours and ambient
temperature [critical air temperature is found to be
about 22OC for ripening rice); warming cool irrigation
water for paddy fields by means of a solar pond;
lowering the temperature of water for paddy fields by
dispersin_e carbon black or white plastic film or
polystyrene flakes; study of an open-cycle algae pond;
production of cattle feed; mulching in fruit orchards
to prevent the growth of weeds; investigation of in* Summarized.
expensive greenhouses with plastic films; snow melting
by the use of calcium silicate and development of a
solarimeter for the measurement of photosynthetically
active radiation.
Solar water-heating is a large and growing industry
in Japan, with some six companies manufacturing solar
heaters of the closed-cycle type or natural-circulation
type. For some 15 years, silicon-cell solar batteries
have been used in large numbers for microwave rel.:y
stations, unattended navigation lighthouses, buoys, aTd
robot rain gauges. Solar furnaces giving very hi$
temperatures of the order of 3,000°C have mainly been
concerned with temperature and emissivity measuiements of metal oxides, freezing points of ceramic
oxides, high-temperature phase diagram studies, for
obtaining single crystals, and for studies on sintering
of ferrite compacts. A feasibility study of the use of
a large-scale solar furnace as a heat source for industry
is under way.
Architectural glass materials (heat absorbing and
reflecting glass, combined with aluminium-sputtered
Xecently
polyster film) are commercially available.
constructed solar houses in Japan use flat-plate
collectors with selective surfaces of copper oxide on
copper sheet, and black chrome on stainless steel sheet,
and are operated with lithium bromide wate; absorption
units for heating, cooling and hot water supply.
Energy demands in many of the developing
countries have not been assessed, and comprehensive
II.
1
39
Information papers prepared by participants
cesses in order to be able to assist the developing
countries by transfer of technoIo,v.
surveys are essential to find the areas in which solar
.energy can play a part. It seems likely that there will
be requirements for extensive applications of solar
energy for salt production, water desalination, and crop
drying, with possible requirements for food and timber
processing, heating and cooling and thermal and photovoltaic conversion.
Part of the research and develop
ment facilities in Japan will be devoted to these pro-
Reliability criteria of solar devices, availability
and cost problems require investigation under interregional co-operative research and development, and it
is suggested that a world research and development institution for solar energy be set up as well as a local
regional centre for training and education.
SOLAR ENERGY IN AUSTRALIA
(NR/ERD/EWGSW/CR.7)*
by
Mr. R. V. Dunkle (Australia)
A.
RESEARCH AND DEVELOPMENT
Solar energy research in Australia was initiated
nearly 30 years ago, mainly in the fields of low-grade
Since 1973 there has been a
thermal applications.
sharp increase in interest in solar energy utilization.
Current research and development covers the following
fieIds: (a) preparation of radiation standards, and of
solar tables and diagams; (b) thermal performance
and behaviour in dwellings and plastic greenhouses; (c)
integrated system design for solar house-heating; (d)
selective surfaces; (e) cost reduction in water heating
through use of aluminium instead of copper; (f)
drying kiln for timber; (g) energy plantation; (h)
generating high temperatures (60” to 8OOC) for the
food-processing industry; (i) small power systems (up
to 20 watts) for remote telecommunications; (j)
swimming-pool heating; (k) air-conditioning; (1) use
of reversible chemical reactions to transfer ener,T from
solar radiation collection systems; (m) heat pipe studies;
(n) linear concentrators; (0) photothermal conversion;
and (p) solar-operated water pumps.
Funds are
mostly provided by the Australian Government either
directly, or through statutory bodies, such as the
Australian Research Grants Committee (which supports
universities) and the A.ustralian Industrial Research and
Development Grants Roard (research in industry).
(a) Commonwealth Scientific and lndrtstrial Research
Organization (CSIRO)
During the 195Os, pioneering work was carried
out in the Division of Mechanical Engineering on a
prototype solar water-heater (reference S 44) which
led to the development of a solar water-heating industry
in Australia.
A simple solar still (reference S 45)
was developed, but this did not reach the commercial
stage. Other work. included crop drying and solar
ponds. In 1959, the Division expanded its programme
to include the fields of thermal radiation and solar
l
Abridged.
energy research. Work was carried out on selective
surfaces, solar distillation, solar air-conditioning, waterheaters and air-heaters.
The Division of Atmospheric Physics has tackled
solar measurement problems and developed excellent
calibration facilities for both solar and long-wave
radiometers, and several new types of radiometers.
The Division of Irrigation Research has investigated solar measurements in connexion with their
field-work in irrigation evaporation and plant growth,
and developed a useful evaporated tilm thermopile and
pyranometer (reference S 46).
(b) Australian universities
Australian universities have lagged somewhat
behind CSIRO in commencing solar energy research,
concentrating on basic rather than applied research.
Most programmes were initiated in the 196Os, but
there has been a recent sharp upsurge in activity.
University of New South Wales. Primary concern has been with solar measurements, and the use of
silicon cells for this purpose.
The most signilicant
University of Queensland.
work has been in the area of solar air-conditioning, and
this has involved development and testing of a solar
air-conditioned dwelling using solar-heated water with
a lithium bromide absorption system (reference S 47).
Primary concern has
University of Melbourne.
been with heat transfer mechanisms in solar systems,
and this has included such problems as asymmetric duct
heating (reference S 48), free convection in inclined
cells, entrance effects in air-heaters, and the theoretical
and experimental evaluation of the heat loss from flatplate absorbers (reference S 49).
40
-
~~~~~~~~university.
The most relevant research
has been fundamental work on heat and mass transfer,
for example on heat transfer in asymmetrically heated
triangular ducts (reference S 50). More recent studies
on energy storage using desiccant beds (reference S 51)
a:ld problems of regenerator design for a system with
coupled heat and mass transfer in porous beds (references S 52 and S 53) have also been directed towards
understanding the performance of components of solar
systems.
University of Western Australia. Although located
in the centre of the greatest concentration of manufacturers of solar water-heaters, and in the area where
solar energy is most competitive, the only significant
work has been on a theoretical and experimental study
of solar stills (references S 54 and S 55).
(c) Zndutry
The solar water-heating field represents the only
industry of importance in
solar manufacturing
Australia.
Several manufacturers commenced production between 1955 and 1960, large firms already
producing conventional hot-water systems and also
small firms which have built up successful and growing
businesses over the years. Although based on the
original copper tube and plate CSIRO developments,
significant innovation has taken place and many varied
designs are on the market.
Sales have been mainly
within Australia and the islands to the north, but one
company has recently licensed a Japanese manufacturer
to produce hot-water systems based on the Australian
design.
(d) Department of Housing and Construction
An experimental solar system was installed late in
1956 in Coolgardie, Western Australia. The success
of this installation, and economic analysis of solar relative to other water-heating systems, led to the decision
that the installation of solar water-heating should be
recommended in both homes and institutional buildings
in the Northern Territory of Australia and most
locations in Papua New Guinea. Users are generally
satisfied with both the amount and temperature of hot
water available; boosters are not normally called upon
except where systems serve large families.
B.
INDUSTRIAL,
COMMERCIAL
DOMESTIC UTILIZATION
AND
The current status of solar energy utilization in
Australia for industrial, commercial and domestic purposes has been summarized in reference S 56.
Australian per capita consumption of energy is
h!gh by world standards, about 50 per cent of the
tolal being supplied by petroleum productS, with transportation becoming increasingly dependent on liquid
fuels.
Part Two.
Documentation on solar enera
The percentage contribution of petroleum is expetted to decrease significantly as indigeneous 03 reserves are limited, while the use of natural gas (which
is present in some abundance) should increase ve-,.
rapidly.
Coal reserves are very large, and co~
provides the primary energy for about 75 per cent of
the country’s electric power production, the remainder
being hydroelectricity.
The major contribution of solar energy in industry
currently is in salt production. In 1972/73, the total
salt production in Australia was 3,774,OOO tons,
essentially all produced by solar evaporation of sea
water.
The energy input required to evaporate the
water to produce this much salt amounts to about I2
per cent of the total annual Australian energy consumption. This large amount of energy is neglected
by government statistic’ans as it is not bought, sold or
metered. Similarly, agricultural solar enerm used does
not appear in any energy input tabulation.
Solar water-heating is growing rapidly in Australia,
although the total energy supplied -is negligibly small in
terms of the total energy consumed in Australia. The
majority of the installations are in private homes, but a
significant number supply hot water to schools,
hospitals, mote!s and hostels.
The total solar water-heater area installed in
Australia can be approximated by summing the annual
production figures since 1969, which total 58,000 m2.
Although some of the water-heaters have been exported, this estimate is likely to be somewhat low as
the production figures before 1969 are not available.
Moreover, many collectors have been home made and
there is no way to estimate their area. However, this
figure can be used to approximate the solar energy used
for water-heating in Australia at about 0.0047 per cent
of the total energy consumption. Although this present
contribution is negligible, it could become important if
current growth rates continue.
Another, and even more rapid!y increasing use, is
in swimming-pool heating. Largely as a result of the
increasing affluence and leisure time in Australia, home
swimming pools are becoming very common. Because
of the low temperature needed, 20’ to 27OC, the solar
heaters can be very simple and yet highly efficient, and
a great many home made solar swimming-pool heaters
are being installed. No figures are available, but it is
likely that this application will soon exceed other solar
water-heating in terms of solar energy utilized.
C.
FUTURE
TRENDS
A very large amount of low-grade thermal energy
is used by industry at temperatures below 120°C (reThis is a promising area for solar
ference S 56).
energy utilization in the future.
II.
Information
papers prepared by participants
41
good engineering design, solar space heating should
become important in Australia, but economical solar
air-conditioning could prove to be a more difficult
problem. It is likely that most installations, at least
initially, will be on new dwellings specifically designed
for solar heating.
A significant and rapidly growing use of energy
in Australia is for the heating and air-conditioning of
homes. This is an area wherein a viable solar-energy
industry can develop similar to the water-heating
industry. Both solar space heating and air-conditioning
can be achieved (references S 47, S 57, S 58, S 59,
S 60), but the economic question is unresolved. With
SOLAR ENERGY IN SOUTHEAST
ASIA (NR/ERD/EWGSW/CR.8)*
by
Mr. R. H. B. Exell, Asian Institute of Technology
As Thailand occupies a central position in the
southeast Asian peninsula, the solar energy data of this
country can be extended, with some amount of
approximation, to other neighbouring countries of the
region. Although a network of solar radiation stations
is necessary for a comprehensive assessment of the
available solar intensity in a country or a region, it is
possible to calculate approximately, with the help of
the Angstrom regression equation, the intensity of
solar radiation from data on the duration of sunshine.
This relationship has been used to calculate the solar
data for a number of areas in Thailand from the
radiation data obtained in Bangkok and Chiang Mai,
where the average values of global solar radiation are
from 450 to 350 cal/cm?/day.
Nevertheless, it is
desirable to set up at least a few measurement stations
in Thailand for making accurate and detailed measurements of solar radiation on a continuing basis, following
the pattern of standards set up by the World
Meteorological Organization.
Inexpensive devices for solar data measurement,
such as simple portable solar water-heaters of standard
design can be used to obtain data in individual locations
and rural areas with reasonable accuracy. Survey and
analysis of such data for the region would be of great
assistance in choosing sites for solar installations and
in the design of suitable collecting systems.
In the Asian Institute of Technology, there are
four ongoing research projects of relevance to the
region:
(a) Solar-power water pump to be used for lowlift irrigation, with a lift of about 3 m. With average
rolar radiation of 400 cal/cm2/day, and an estimated
’ Summarized.
over-all efficiency of 5 per cent (2 per cent at present),
a collector area of 3.5 m2 per hectare will be required
for 100 m3 of water per day.
(b) Solar ice-maker to be used for cold storage
of food and for ice making. An intermittent ammonia/
water system with a collector area of 2 m2 is being
used to obtain preliminary data and practical experience; the future prototype design will be for 100 kg
of ice per day.
(c) Solar stills for producing potable water for
rural areas. Several solar stills of wooden construction
One unit, equipped
have been experimented with.
with external mirror attachments, is capable of producing 3.2 litres of fresh water per square metre per
day. Another of the units, of concrete design with a
glass surface area of 3.5 m2, has a stirring device
(powered by a windmill) to facilitate investigation of
the effects of seeding the feed water with varying
dosages of carbon particles. There is also provision
for rainwater collection on some units.
(d) Solar drying units for drying agricultural
At present, one unit, with a
and marine products.
moving bed and a total glass surface area of 7 m2 is
under study for residence time, drier configuration, mass
feed rate, etc.
ESCAP is well suited to give a lead to the countries of the region in the promotion of utilization of
The establishment of an information
solar energy.
and service centre at ESCAP is suggested, to act as a
clearing-house for dissemination of information on
solar energy publications and projects, to organize short
courses, workshops and conferences, and to assist ~JI
arranging finance for the various countries of the region.
Part Two.
42
SOLAR ENERGY
AND ENERGY CONSERVATION
(NR/ERD/EGWSW/CR.9)*
Documentation on solar energy
IN AUSTRALIAN
BUILDINGS
by
Mr. N. R. Sheridan (Australia)
A.
A DISTINCTIVE AUSTRALIAN
OF COLLECTOR
DESIGN
The Australian domestic water-heater has evolved
from an original design of the Commonwealth Scientific
and Industrial Research Organization (CSIRO). With
a single pass through several parallel tubes, the absorber
plate has changed little with development. It is usually
fabricated from copper tube and sheet by soft and/or
hard soldering. Specialized materials, such as “tubein-strip” and “roll-bond”, have been used, but the
market is hardly large enough for the production investBesides, both these
ment of these special materials.
materials have corrosion problems resulting from
carbon inclusions in copper tube-in-strip and pinholing
of aluminium roll-bond.
Originally, black-painted absorbing surface was
However, the copper
used with two glass covers.
oxide selective surface, produced by chemical treatment, has been simple to produce in the small plants,
is reliable in service and achieves with only one glass
cover a similar performance to the original design. It
is usually used. The radiation properties of the
selective surface are absorptance 0.89 and emittance
0.17 and are stable up to a temperature of 15O”C,
which is about the equilibrium temperature for the
collectors when dry.
An analysis of energy use per household shows a
considerable difference between two cities at the
extremes of the well-populated region, though this
difference is due mainly to the heating load.
Lowgrade energy defined as heat energy up to a maximum
temperature of 12O”C, is a large part of the energy
demand, 2,400 kWh (49 per cent) in Queensland, and
10,000 kWh (67 per cent) in Victoria.
Energy costs for Australian residences have not
risen dramatically in the last decade as the proportion
of energy supplied by high-cost petroleum is relatively
Natural gas has not been available until resmall.
cently, so that electricity, which is mainly generated from
coal, has obtained a major share of the load. Electrical
energy is sold on an incremental cost basis at off-peak
hours for domestic hot water and thermal energy stores,
which are used in space heating.
The discount from
regular prices is 25 to 40 per cent. Control of off-peak
power is by time clock or audio-frequency switching
with a signal superimposed on the power circuit.
C.
(a)
ENERGY NEEDS OF AN AUSTRALIAN
RESIDENCE
The Australian people are concentrated on the
coastal fringe between Brisbane in the north and
Adelaide, with Melbourne being the most southerly
major city.
In this area, about 10 per cent of the
Australian land surface, live 90 per cent of the population. The &mate is mild throughout. Only a small
amount of heating is required, and there is little real
need for summer air-conditioning.
l Abridged,
and including
I~R:ERD/EG\~S\~/CR.12).
“Solar
energy
ar a natural
resource”
CONSERVATION
IN BUILDINGS
Energy conservation in buildings has many aspects,
including the use of solar energy. The various systems
may be classified as follows:
Simplicity has been a basic design criterion, so
the systems generally have thermosyphon circulation of
the potable water at low pressure. The resulting
advantages include no circulation pump, a minimum of
controls, no heat exchanger, and no risk of contamination of potable water with heat transfer fluid. Against
this must be weighed the disadvantages of the tank
location, which must be above the collectors and high
enough to supply pressure to the water outlets.
B.
ENERGY
(b)
Non-solar
(i)
Thermal conductance: insulation,
centage glass
(ii)
Thermal capacitance
(iii)
Layout: area of outside wall per unit
floor area, zoning
(iv)
heat exchange
Infiltration:
ventilation and exhaust air
(v)
Heat pump, total energy, etc.
(vi)
Evaporative cooling: roof sprays, roof
pool, natural wind coolers, forced
ventilation coolers
(vii)
techniques
on
Operational
conditioning and water systems
(viii)
Performance of equipment
Passi~r solar
(i)
Orientation:
(ii)
Aspect ratio
sun control
per-
between
air-
II.
(c)
43
Information papers prepared by participants
(iii)
Thermal conductance:
ductance, roof pool
variable
con-
(iv)
Thermal reflectance: wall surface, glass
(v)
Radiant transmittance: variable
mittance, south wall collector
(vi)
Shading: parasol roof, roof overhang,
louvres
(vii)
Wind: attic ventilators, Altenkirch
humidification system
trans-
de-
Active solar
(i)
No-utility energy: electricity generation,
heating and cooling.
(ii)
Low-utility
energy:
D.
Unlimited
pump
utility
energy:
AUSTRALIAN
CONTRIBUTIONS
ENERGY CONSERVATION
1.
2.
solar heat
TO
Tropical house design
In the underdeveloped tropical north of Australia,
refrigerated air-conditioning for residences can be
justified on currently accepted comfort standards, but
it costs more than the inhabitants can afford.
cost
factors include: the high number of cooling degree
days, the high cost of electricity generated in relatively
small diesel plants, the inadequate buildings for retrofitting of equipment, and the high cost of maintenance in a remote area. One study showed that the
cost of air-conditioning a.residence was as much as 20
per cent of the family income.
In the past, the houses have been built of lightweight, uninsulated construction on stilts, high stumps
which allow the underneath section to be used for
laundry, storage, garage, etc. Shading, reflection,
orientation and other energy-saving ideas have not
generally been considered.
It has been shown that,
since the ground temperature at 1 m depth is always
below the comfort temperature, a concrete slab on the
ground acts as a heat sink Coupled with an insulated
envelope and masonry partitions to increase the thermal
caPacitance, a slab will considerably reduce day-time
temperatures. Such houses would also be satisfactory
Heat pump
The heat pump cycle has been used in window
air-conditioners for many years, and has been used in
the air-conditioning of several large buildings. In the
mild Australian climate, the outdoor coil has little
trouble with icing, especially if arranged for solar
assistance. There have been problems with the compressors under the higher temperature of operation, but
they will be overcome as equipment designed for the
purpose becomes more readily available.
3.
a. Domestic hot water
b. Swimmmg-pool heating
forced
air,
c. Space heating:
hydronic
d. Space cooling: nocturnal radiarefrigeration,
absorption
tion,
Rankine refrigeraticn, ejector refrigeration, open-cycle systems
(iii)
for future air-conditioning.
Proposed standards for
thermal performance for Australian government houses
are g&n in reference S 61.
Evaporative processes
Evaporative cooling should be applicable to energy
conservation, as it is capable of providing space cooling
with much less ener,T than refrigerated systems. Such
systems need to achieve a room air change every one or
two minutes to utilize the small available temperature
drop between supply air and room temperature. The
resulting relatively high air quantities must be delivered
by properly sized registers to insure good distribution
and satisfactory noise levels.
Further, to achieve a
saturation efficiency of 80 per cent as is desirable, the
evaporative system must be carefully designed.
Several compound or staged cycles can be
developed, which improve the cooling capabilities of
evaporative processes, or extend their usefulness to
areas of higher wet-buIb temperatures.
These cycIes
make use of heat exchangers and dehumidification
devices in addition to the evaporative cooler.
The aim of much CSIRO research has been to
improve the efficiency or effectiveness of the comA target of 80 per cent for saturation
ponents.
efficiency of evaporative coolers, effectiveness of heat
exchangers and effectiveness of dehumidifiers seems
reasonable.
(a) Use of rock piles. The rock pile, a
reasonably inexpensive heat exchanger and heat storage
device, can be used in several ways as a component of
evaporative systems.
As a long-term storage device, it can be cooled
down over-night by evaporatively cooled air. In the
day-time, outside air can be drawn through the pile to
Subsequently, it can be evaporatively
pre-cool it.
cooled for supply to the room.
CSIRO has developed a rockbed regenerative
cooler which consists of a rockbed heat exchanger and
a rockbed evaporative cooling matrix, each in two
parts. These are used alternatively: one being cooled
I’:\ . Two.
44
by evaporation, while the other is cooling the supply
The heat exchanger consists of two beds, each
The rocks are
yg mz in area and 127 mm thick.
6’ mm screenings which are treated with bitumastic
material to restrict the absorption of moisture.
Associated with each heat exchanger bed is an
evaporating matrix of area 3.9 m2 and 38 mm thickness.
Untreated 6 mm screenings are used for the matrix.
A motor-driven damper reverses the direction through
the heat exchangers every five minutes, and the
evaporating bed is sprayed for 12 seconds every second
cycle. In appropriately
insulated .buildings, the
systems produce satisfactory conditions, with an air
change every 2 minutes in areas where the design wetbulb temperature at the 2.5 per cent level is 24OC or
With limited batch production, the units cost
less.
about 20 per cent more than equivalent refrigerated
units, but the energy cost is about half.
(b) Delum~idijkation
cycles. The basic dehumidification cycle uses an adsorbent or absorbent
Subchemical to dry the air at constant enthalpy.
sequently, it can be cooled to approach the dry-bulb or
wet-bulb temperatures and then evaporatively cooled.
The chemical can be regenerated by solar-heated air.
Lithium chloride solution is a suitable absorbent, while
adsorbent cycles use silica gel or alumina (reference
s 57).
4.
Roof pool
The thermal capacitance and the evaporative
effects are two properties of water that can be exploited in the roof pool. For heating, the Pool can be
covered by a transparent cover, and acts like a solar
collector which stores its energy in the water. Circulation through a slab floor further enhances the storage.
For cooling, the pool should be covered with an opaque
material in the day-time and uncovered at night to lower
its temperature by radiation and evaporative cooling.
A research project is being undertaken and preliminary
results are encouraging.
5.
Isolated homestead
In Australia, there are perhaps 50,000 residences
which are so far from electrical supply lines that it is
uneconomical to supply them. Thus, it appears that a
solar generating plant could be a desirable alternative.
It would be convenient if the device could supply
heating and cooling as well as electricity. A study has
commenced at the University of Queensland on the
Possibility of meeting the required load from a concenWater for
trating collector using photovoltaic cells.
Cooling the cells would supply the heating and/or
cooling loads. As the concentration ratio is 40: 1, the
cost of the cells should be reasonable. However, it is
Probable that gaIIium arsenide or some similar high
tcmpcrature cell will be needed.
6.
Documentation on solar energy
Domestic hot water
Researc:, of interest to domestic water-heaters is
continuing ;l: several establishments. Materials research aims : I improving selective surfaces as regards
their optical 1‘x.+, ormance, their corrosion resistance and
their ability i,k 1JCapplied to different materials. There
is also the P:\‘Ncrn of corrosion on the heat-transport
fluid side of I::,. plate. Much effort is being expended
on a chromilv ::I oxide coating for mild steel, a product
that is in c\\:llmercial use as a corrosion-protection
coating. Th,. :Gm is to improve its selective properties.
For snN forced-circulation systems, only a few
watts of Pumlr Ilower are needed and would seem to be
within the C:l\‘.\hility of photovoltaic cells. CSIRO has
developed a hula11centrifugal pump driven by a solar
battery. Tht* system has the advantage that it is selfcontrolling, t I\ c pump starting to operate when solar
energY is ayilil;lble, and has a mass flow rate related to
intensity Of il\holation.
The cost is comparable with
the combined cost of available pumps and controllers.
Plane rl-llcctors can improve the output of flatplate coilecIoI s. Provided they are simple to install,
they may bv r’ust-effective.
Their use has been investgated fol llrisbane at latitude 27.5%. It has been
shown that \‘(-I tical specular reflectors mounted behind
the absorber Ijtnte and with three times its area will
increase winIt. output about 15 per cent.
7. Swimming-pool heating
A study !.howed that the desirable features for the
collector WI’I c : an area k as large as the pool
area, an iln*lination equal to the latitude plus
15O, an cl!>crating collector
temperature only
3OC above JNJOItemperature, and a simple, cheap
construction.
The experimental collector was made
from black-]);linted corrugated aluminium roofing with
the water running down the corrugations.
A threemonth exten:;illn to the swimming season was obtained
(reference S (,2).
Plastic pool-covers made from ultra-violet
stabilized, CIC.IY PVC film are sold commercially. They
need to be cfl..tom-made to ensure a good fit and to
reduce convc’ lion losses.
8.
Space heating
Very ft I/ solar space heating systems have been
applied to h .;Irlings in Australia. CSIRO reports the
use of a SL:.: heater with an area of 56 in* on a
building in !.?,:hourne in association with a rock pile Of
32 ml.
VI’: ;n the outlet air temperature from the
collector is r.ljntroJled to 55”C, an average daily
efficiency of ‘:‘i per cent is claimed (reference S 63).
LT. Information
9.
Space cooling
A solar air-conditioned house was operated in
The
Brisbane for several years (reference S 64).
system used a lithium bromide water absorption refrigerator supplied with water at temperatures up to
95°C from a flat-plate solar collector. Water storage
was provided for the hot water and a rock pile was used
in the conditioned air circuit. The system was shown
to be technically feasible.
E.
45
papers prepared by participants
POTENTIAL FOR SOLAR ENERGY
DEVELOPMENT IN SOUTHEAST ASIA
The changing pattern of the world energy resource
base must inevitably affect countries in the region.
The developing countries have a relatively low per
capita energy usage, but this will increase with
Commercial energy production is
industrial growth.
not as centralized as in more developed countries,
leading to relatively high per unit cost, which has enThe arguments
couraged conservatism in utilization.
for energy independence are equally applicable as in
any other part of the world, and the advantages of
having diverse sources of energy also apply, while the
developmental options might not be restricted by
previous major commitments.
There is a need to consider alternative sources of
energy, especially those that are locally available, and
solar energy is attractive, particularly iu tropical areas
RESEARCH,
where the solar radiation is relatively uniform on a
seasonal basis, subject to some reduction due to clouds
and the water-vapour content of the atmosphere during
heavy rainfall periods.
In any country, the contribution of solar energy is
unlikely to exceed 6 to 8 per cent of total energy by
the end of the century, and most of this will come from
high technology devices which still require considerable
developmental work.
Considering the high risk and
long-term aspects of research and development of such
devices, and the capital intensive nature of the likely
products, it is doubtful if such work is warranted in the
developing countries.
Solar domestic hot water is a possible application
of social significance, but of limited benefit as a means
of reducing non-renewable fuel consumption; there is
little need for further basic research in this field. Lowenergy devices for “comfort conditioning” are suitable
for widespread application; considerable local research,
development and demonstration would be needed to
achieve any reasonable level of market penetration.
The limited funds available locally for solar energy
and related research and development would probably
be best channelled into those projects which can be introduced in the short term. Domestic hot water and
low-energy comfort conditioning are two candidate
systems.
DEVELOPMENT
AND USE OF SOLAR ENERGY
(NR/ERD/EWGSW/CR.lO)*
.
by
The National Energy Administration
Owing to the increasing demand for energy and
the rise in the price of oil, solar ener,y is now considered as an important alternative source of energy in
the country. Some solar radiation data for Bangkok
and Chiang Mai are available (average values 410 and
432 cal/cm’/day
respectively) from meteorological
stations. Data for other areas, particularly rural areas,
would be necessary for a realistic assessment of the
possible uses of solar energy, and a network of solar
radiation measuring stations has been planned by the
National Energy Administration which is responsible
for the over-all planning of energy. A comprehensive
survey is planned, followed by analysis, and it is expected that substantial use will be made of this
abundant non-polluting source of energy.
l
Summarized.
IN THAILAND
(Thailand)
Solar energy is already in use in the country in a
fairly primitive way for drying foodsmffs and industrial
raw materials, and for common salt production. The
King Mongkut Institute of Technology has recently
carried out some investigations on small-scale solar
water-heating and steam-generation; flat-plate collectors
(1.2 mz) of aluminium and copper have been used.
The Asian Institute of Technology is carrying out investigations on solar distillation, drying of crops, water
pumping, and refrigeration.
As investigation on solar energy is at an early
stage in Thailand, technical assistance will be useful for
the development of solar devices for urban and rural
areas; particularly for cooling of houses and *large
buildings, heating of water and air, and small po\<er
generation.
Part Two.
46
pROGRAblME
Documentation on solar encrgj
AND PROGRESS FOR SOLAR HOUSE DEVELOPMENT
(NR/ERD/EWGSW/CR.ll)*
IN KOREA
by
Mr. Jong Hee Cha (Republic of Korea)
With increasing demand for commercial forms of
energy, and the rise in the price of oil, the planners
considered possible uses of alternative sources of
ener,y, such as solar energy and wind energy. From
a brief survey of heat insulation practices in the country,
and the available materials for building construction, it
was possible to visualize effective use being made of
solar ener,T for space heating of residences and large
buildings. More comprehensive, surveys of a similar
nature will be needed before the status of solar
energy in the spectrum of sources of energy can be
firmly established.
The plan of action for development of a solar
house includes an exhaustive survey of geographic
chmatolo,~, experiments with solar collectors using
both water and air as the heated medium, studies of
l
Summarized.
available construction materials, consideration of
maintenance problems, the design of a prototype house.
investigation of a suitable solar heating system for large
buildings, economic evaluation of solar heating of
houses and large buildings and collaboration with industrial firms for design and manufacture of heating
systems.
The results of initial experiments in the prototype
solar house indicate that solar energy can meet about
85 per cent of the heat load, the rest being met by the
auxiliary heating system. In the cost structure of the
solar heating system, the investment cost of the solar
collector accounts for about 75 per cent of the total,
with a cost of $US 46 per m2. In order to obtain
optimum technical and economic benefits from the
heating system, further developmental investigations are
planned, particularly on the selectivity of the heatcollecting surfaces.
THE PROSPECTS OF SOLAR ENERGY UTILIZATION:
(Rn/ERD/E~~‘GS~~‘/CR.14)*
THE INDONESIAN
CASE
by
Mr. F. Harahap (Indonesia)
Indonesia is characterized by archipelago conditions, dispersed and sometimes inaccessible population, abundant labour and limitations on capital, and is
faced with high investments for conventional power
stations and electrica transmission.
There is great concern in the country at the substantial use of non-commercial forms of energy, particularly wood, and commercial energy (mainly oil
products) accounts for only about one third of total
energy consumption. On the other hand, the sale price
of oil available for export is high, and it is not desired
to increase local usage of oil products. At the same
time, energy requirements are increasing, especially in
the rural areas.
Solar energy is an abundant resource, and may be
able to meet a sigrmihcant part of the energy requirements. The Center for Meteorology and Geophysics
measures solar radiation only at its main stations at
Based on
Jakarta, Bandung, Medan and Kupang.
g Sammxizcd.
measurements at these four stations, the estimated solar
For the
radiation data is about 402 cal/cmz/day.
tital area of the country of 1.9 million square km, the
total incident solar radiation is the equivalent of
3.2 x lOI kWh per year, which is 42,000 times the
rate of energy consumption in the country in 1972.
The possible uses of solar energy under consideration relate to:
(a) Space heating and cooling, water-heating,
food preservation and solar pumping;
(b)
The drying of agricultural products;
(c) Biochemical conversion in methane gas
plants to produce fuel for cooking and/or lighting.
At present, the ongoing research and development
projects in the country are the development of a solar
rice-drier: a bio-gas-powered ice-machine, and a waterheater at the Institute of Technology, Bandung, and
investigation of direct conversion of solar energy at the
National Institute of Physics and Electronics.
II.
Information
47
papers prepared by participants
THE Sb%SHIhX
PROJECT: SOLAR ENERGY RESEARCH
(hX/ERD/EWGSW/CR.lS)*
AND DEVELOPMENT
by
‘The Agency of Industrial Science and
Technology (Japan)
The Sunshine Project was announced by the
Government of Japan in 1973 and commenced in July
1974. It covers research and development for several
energy sources, with an initial budget of 2,200 million
yen, of which 874 million yen is set aside for solar
Susmarizcd.
l
energy.
The total budget, for work up to the year
2000, is estimated to be 430,000 million yen.
The solar energy programme includes major investigations on several devices and processes. Initial
activity has been directed towards space heating and
procedures by which this can be applied to existing
houses and larger buildings.
SOLAR ENERGY WORK IN PAKISTAN
(NR/ERD/EWGSW/CR.19)*
by
Mr. M. M. Anwar (Pakistan)
Introduction
Pakistan must import coal and oil as sources of
heat and power, which is mainly consumed by industry
and in urban areas. The rural population, which comprises more than 80 per cent of the total, meets its heat
energy needs from cattle dung, farm wastes and wood;
the power requirements are met by human and animal
muscular energy. In the province of Punjab, 40,000
villages lack electricity.
In a span of three years,
Electric
about 1,000 villages have been electrified.
power has become a basic need, bringing new life and
education to villages.
Looking to new sources of cheap energy, those
which offer promise are nuclear energy, wind energy
and solar ener,7.
In Pakistan, research and development on various
problems of solar energy was first taken up by a few
scientists at the Atomic Energy Centre at Lahore in
1964. The success of “solar-lights” in remote villages
aroused much interest.
Solar energy work in Pakistan has been carried
out at the Atomic Energy Centre (Lahore), the Seawater Desalination Project (Gwadar), and the Engineering and Technology Universities of Lahore and
Peshawar. A brief account of the fields and progress
Of the work follows below.
A.
WORK DONE AT A.E.C., LAHORE
(a) Solar-lights for rural areas
In experiments on new lighting systems, silicon
solar cells were used with nickel-cadmium storage
l
Abridged.
batteries. After a number of trials, a system of solarcell lighting with a small panel of 5 watt rating was
developed (references S 65, S 66).
The system
provides lighting, and can also be used for operating
Sixteen solar lighting
transistor radios at all hours.
kits were installed in various regions of Pakistan. Their
performance over a period of 10 to 11 years has been
encouraging. One house was supplied with a television
set which operated for three years. Another has been
operating for the last five years (reference S 67).
(b)
Fabrication of silicon solar cells
During 1970-1972, a small laboratory was set up
to develop solar-cell processes. Cut-wafers of silicon
were used as starting material, yielding solar-cells of 8
It
per cent Iefficiency at a cost of $US 30 per watt.
was estimated that the choice of silicon rods as starting
material would bring the cost down to about $ 20 per
watt.
(c)
Solar water-pump
A solar water-pump was designed (reference S 68)
which utilized an 8-m diameter paraboloid fitted with
flat mirrors, a boiler and a steam engine. The complete system was made with locally available material,
and it provided 1.5 kW to the water-pump. In order
to study smaller portable units, 1.5-m diameter mosaic
mirrors were constructed and connected to a steam
engine and bolier.
(d)
Solar water-chillers
The purpose of this project was to produce chilled
A rectangular paraboloid
water by solar energy.
mounted with flat mirrors was used to concentrate the
4s
___. ---sol;lr radiation on a water/ammonia container of an
The system
ab.\orption machine (reference S 69).
Later
models
produced 22 litres of cold water (5OC).
used fiat-plate absorbers of the water-heater type.
(c)
Solar water-heaters
In December 1969, three solar water-heaters were
installed on the roof to supply hot water in the washrooms (reference S 70). One model was supplemented
\vith an electric element to keep the water hot (at 40°
to 45%) on cloudy days. The other models supplied
water at 60” to 70°C to be mixed with cold water.
The efficiency of the solar water-heaters was 80 per
cent, and the cost of the model with a 1 m* face was
Several large and small models were
$US 20.
fabricated, including some which supplied steam.
(f)
Family-size water stills
In numerous areas of l,ckistan there is a shortage
Solar
of water for human and animal consumption.
stills were developed, 5 m x 1 m, to supply about
15 litres of water per day for a small family (reference
S 71). The demand for such stills is very large, and
the laboratory cannot meet it. Development of prefabricated stills would be most desirable.
(g)
Solar driers
The customary technique of open drying exposes
the products to dust and contamination, and the drying
A well-designed solar
process takes several days.
drier cuts the period of drying and results in highquality products. Solar driers (reference S 72) were
fabricated from locally available material, with a tray
size 2.5 m x 0.6 m, costing $US 10.
B.
DESALINATION
PLANT AT GWADAR
Gwadar lies about 300 miles west of Karachi
along the Arabian seacoast and has a population of
20,000. For this remote but important fishing village,
the Government approved a scheme for the construction
Part Two.
Documentation on solar energy
of a solar desalination plant with a capacity of 70 m3
The plant (reference S 73) has 250
per day.
still units, each 20 m long with a rectangular frame
structure of aluminium alloy, and a reinforced concrete
supporting structure. The plant currently supplies 36
to 45 m3 of water per day at a cost of $US 0.3 to 0.5
per m3. Previously, the cost of fresh water brought
from Karachi was $US 10 per ma.
c.
WORK IN THE UNIVERSITIES
The Engineering and Technology Universities at
Lahore and Peshawar have been taking a great interest
in harnessing solar energy by -giving problems in this
The problems
field to students for thesis material.
that have been tackled are: a portable, 1.5-m mosaic
paraboloid mirror as concentrator; a 2 m mirror for
use with a boiler and turbiue; a solar ice-machine and
water-chiller; a solar-operated model aeroplane; a
solar-operated flat-plate thermoelectric generator; and
solar cookers and water-heaters.
D.
FUTURE
WORK
Considering the above review of solar energy research and development, it should be possible to start
a programme in solar energy on a more organized basis.
Instead of scattered attempts and duplication of work,
it would be desirable to establish an exclusive institute
of solar energy in Pakistan.
A roving seminar should be held in Pakistan in
order to arouse the interest of large sections of the
Government and the public, teachers ‘and students.
Universities and research institutes in Karachi, Sind,
Lahore, Peshawar and Islamabad could serve as hosts
to the seminar.
Funds should be allocated to building working
models, thereby enabling engineers and industrialists to
acquire a first-hand knowledge of how a solar energy
device looks, its size, portability, and construction
material.
49
III.
CONSOLIDATED
LIST OF REFERENCES ON SOLAR ENERGY
1.
s 1.
J. i. Duffie, C. Smith and G. 0. G. Lijf,
Bulletin 21 (Engineering Experimental Station,
Wisconsin University, 1964).
s 2.
N. Robinson, Solar Radiftion
s 3.
H. Tabor, Report of the UNESCO Working
Party on Solar Energy (Paris, 1973).
(Elsevier, 1967).
s 4.
S. Akyml and K. Selcuk, Solar Energy, 14, 3/3,
1973.
s 5.
United Nations Conference on New Sources of
Energy, Rome, 1961; report in two volumes.
S 6.
Research Establishment
Atomic
Energy
(Harwell) Report, R. 6775, 1971.
s 7.
Solar Use Now -A
Resource for People, Solar
Energy Congress, Los Angeles, 1975.
S 8.
Proceedings of the International Conference on
Solar Energy, Maryland, 1971.
s 9.
H. P. Garg and C. L. Gupta, “Design of flatplate solar collectors for India”, Journal of Institution of Engineers (India), XLVIII
(9),
MES, 1967.
S 10. H. P. Garg and A. Krishnan, “Solar energy
utilization potential in India,” Sun in the Service
of Markind, International Solar Energy Society,
Congress paper E12, Paris, 1973.
S 11. C. I;. Gupta, “Field design methods and data
for solar energy applications”, Sun in the
Service of Mankind, International Solar Energy
Society, Congress paper E45, Paris, 1973.
S 12. V. G. Bhide, Report of the National Committee
for Science and Technology Expert Panel on
Solar Energy (New Delhi, Government of India,
Department of Science and Technology, 1974).
S 13. S. Rangarajan and V. Desikan, ‘A review of
solar radiation measurements in India”, preprint
for 7th National Solar Energy Convention,
Punjab Agricultural University, Ludhiana, 1975.
S 14. R. K. Bhardwaj, “Solar drying in foodprocessing industry”, JYth meeting of the Solar
Energy Working Group, Roorkee, 1972.
S 15. I-I. P. Garg and A. Krishnan, “Solar drying of
agricultural products, Pt. I: Drying of chillies in
I.
a solar cabinet dryer”, Annals of Arid Zone,
13(4), 1974.
S 16. V. R. Muthuveerappan and others, “Design of
solar paddy dryer”, VIth meeting of the Solar
Energy Working Group, Allahabad, 1974.
s 17. B. Kemp+Gowde, “Grain drying by solar
heated air”, VIIth meeting of the Solar Energy
Working Group, Ludhiana, 1975.
S 18. R. Lawlor, “Algae research iu India”, Alternative Sources of Energy, No. 16, 1974.
s 19. A. K. Bhatia and S. L. Gupta, “Drying of
apricots in Ladakh by solar energy”, VIIth
meeting of the Solar Energy Working Group,
Ludhiana, 1975.
s 20. C. L. Gupta and H. P. Garg, “Performance
studies on solar air-heaters”, So/w Energy,
II (l), 1967.
s 21. C. L. Gupta, ‘Action plan for solar drying”,
ACES occasional report No. 5, 1973.
s 22. S. N. Sharma and others, “A solar timber kiln”,
3ournal of Timber Development Association of
India, 17(2), 1972.
S 23. H. P. Garg and H. S. Mann, “Effect of climate,
operational and ylesign parameters on the yearround performance of single-slope and doubleslope solar stills under India arid-zone conditions”, International Solar Energy Society
Conference, Los Angeles, 1975.
S 24. R. L. Datta, “Solar energy utilization in
developing countries”, Appendix B in Solar
Energy in Developing Countries: Perspectives
and Prospects (Washington, D.C., National
Academy of Sciences, 1972).
S 25. R. L. Datta and others, “Evaporation of seawater in solar stills and its development for
desalination”, Proceedings of First Institute
Symposium on Water Desalination, Washington,
D.C., 1967.
S 26. C. L. Gupta, “A baseline concept for Solar
power generation in India”, Proceedings of the
National Seminar on Energy Conservation.
Paper N-l, Madras, 1975.
50
s 27. H. C. Agarwal Ad B. S. Sandhu, “FeasiLtity
of running a large-scale power plant using \+,?er
lenses”, VIIth meeting of the Solar En*=3
Working Group, Ludhiana, 1975.
s 28. Raju Kanaka, and others,, “20 kW s-.!ar
dynamic power system - a feasibility sty:;“,
VIIth meeting of the Solar Energy Wor::ng
Group, Ludhiana, 1975.
S 29. K. N. Mathur and M. L. Khanna, “S..qe
observations on a domestic solar water-hez,.x”,
Proceedings of the UNESCO Symposiuti. on
Wind a
S&r Energy, New -Delhi, 1X6,
pp. 202 ff; also United Nations Conferenc+. on
New Sources of Energy, Rome, 1961.
s 30. C. L. Gupta and H. P. Garg, “System desi;::. in
solar water-heaters with natural circulati-.2”,
Solar Energy, 12, 1968.
s 31. C. L. Gupta and others, “Solar-cum-ele.?ic
water-heater”, Indian and astern Engineer,
III (l), 1969.
Part Two.
Documentation on solar energy
S 40. R. L. Datta, “Solar energy; its relevance to
India”, Invention Intelligence, 9, 1974.
S 41. V. G. Bhide, “Solar energy utilization in India
and abroad”, Proceedings, Seminar on Industrial
Applications of Solar Energy, Madras, 1975.
S 42. S. C. Mullick and C. L. Gupta, private communication.
S 43. K. D. Mannan and L. S. Cheema, “Hightemperature water-heater using a new stationary
concentrator”, VIIth meeting of the Solar
Energy Working Group, Ludhiana, 1975.
S 44. R. N. Morse, “Solar water-heaters”, Proceedings, World Symposium on Applied Solar
Energy, Phodnix, Arizona, 1955.
S 45. B. W. Wilion, “Solar distillation in Australia”,
Trans. Conference on the Use of Solar Energy,
Tucson, Arizona, 1955; 3: Thermal Processes,
II, 1958.
S 32. A. Pandya, “Experience with solar erlqy
utilization”, IVth meeting of the Solar Er,qy
Working Group, Roorkee, 1972.
S 46. D. J. Norris and E. S. Trickett, “A simple,
low-cost pyranometer”, Solar Energy, 12 (2),
1968.
s 33. T. A. Reddy and C. L. Gupta, “Solar WIlterheater, Design and Cost Optimization Studrrs”,
higher course project report (Pondicherry, Sri
Aurobindo International Centre of Education,
1975).
S 47. N. R. Sheridan, “On solar operation of absorp
tion air-conditioners”, Ph.D. thesis, University
of Queensland, 1968.
s 34. H. P. Garg and others, “Design and performance prediction of a built-in, low-cost !.olar
water-heater”, Research and Industry, 17, l’~72.
s 35. J. P. Gupta and others, “Solar space-heatiq: at
high altitudes”, IIIrd meeting of the Solar
Energy Working Group, Kanpur, 197 1.
S 36. V. Charan and others, “Development of a room
air-conditioner using solar energy”, Vth met-ting
of the Solar Energy Working Group, Madras,
1973.
s 37. S. C. Mullick and M. C. Gupta, “Solar desorption of absorbent solutions for air-conditioning”,
Solar Energy, 16, 1974, pp. 19-24.
S 48. H. M. Tan and W. W. S. Charters, “Effect of
thermal entrance region on turbulent, forced
convective heat transfer for an asymmetrically
heated rectangular duct with uniform heat flux”,
Solar Energy, 12(4), 1969.
S 49. A. D. Rankine and W. W. S. Charters, “Combined convective and radiative heat losses from
flat-plate solar air-heaters”, Solar Energy,
12(4), 1969.
S 50. P. C. Bandopadhayay, J. B. Hinwood and C. W.
Ambrose, “Turbulent heat transfer in isosceles
triangular ducts of small apex angle”, Fi-st
Australasian Conference on Heat and Mass
Transfer, Monash University, Melbourne, 1973.
s 38. C. L. Gupta, “A thermal design model f\>r a
natural air-conditioning system”, Proceetlirqs,
International Solar Energy Society Conference,
Los Angeles, 1975.
S 51. D. J. Close and R. V. Dunkle, “Energy storage
using desiccant beds”, paper No. 7/24, International Solar Energy Society Conference,
Melbourne, 1970.
5 39. P. Chandra and others, “Performance of rockpile storage in cooling of buildings”, \‘IIth
meeting of the Solar Energy Working Group,
Ludhiana, 1975.
S 52. R. V. Dunkle and I. L. MacLaine-Cross,
“Theory and design of rotary regenerators for
air-conditioning”, iklech. Chem. Engng. Trans.,
Instn. Engrs. Aust., 6( 1 ), 1970.
III.
Consolidated list of references on solar enew
51
s 53. I. L. MaClaine-Cross and P. J. Banks, “Coupled
heat and mass transfer in regenerators: predic.tion using an ax&o,7 with heat transfer”, Znt. J.
Heat Mass Transfer, 15 (6), 1972.
s 66. M. M. Anwar, “Role of silicon solar celIs for
providing lights in rural areas of Pakistan”,
paper No. 2/28, International Solar Energy
Society Conference, Melbourne, 1970.
s 54. P. I. Cooper, “Digital simulation of transient
solar still processes”, Solar Energy, 12 (3))
1969.
S 67. M. M. Anwar, “Silicon solar-cell generator for
operating transistorized television”, PAEC/Sol-5
(Lahore, Atomic Energy Centre, 1973).
s 55. P. I. Cooper, “The absorption of radiation in
solar stills”, Solar Energy, 12(3), 1969.
S 56. R. N. Morse, P. I. Cooper and D. Proctor,
“The status of solar energy utilization in
Australia
for industrial,
commercial and
domestic purposes”, report No. 74/l, CUR0
Solar Energy Studies, 1974.
s 57. R. V. Dunkle, “A niethod of solar airconditioning”, Me&. Chem. Engng. Trans.,
Instn. Engrs. Aust., l(l),
1965.
S 58. D. J. Close, R. V. Dunkle and K. A. Robeson,
“Design and performance of a thermal storage
air-conditioning system”, Mech. Chem. Engng.
Trans., Instn. Engrs. Aust., 4(l), 1968.
s 59. D. J. Close, “Solar air-heaters for low and
applications”,
Solar
moderate-temperature
Energy, 7(3), 1963.
S 60. R. V. Dunkle, “Design considerations and performance predictions for an integrated solar airheater and gravelbed thermal store in a
dwelling”, International Solar Energy Society,
AN2 Section, Symposium on Applications of
Solar Energy Research and Development in
Australia, Melbourne, 1975.
S 61. F. Wickham, “Programs of the Australian Department of Housing and Construction”, Proceedings, United States-Australia Joint Seminar,
Durham, N. C., 1975.
s 68. M. M. Anwar, “Final technical
lopment of solar-powered
operating a small irrigation
PAEC/Sol-3 (Lahore, Atomic
1967).
report on deveequipment for
water pump”,
Energy Centre,
S 69. A. L. Taseer and others, “Solar water-chiller”,
PAEC/Elect-25,
(Lahore, Atocic
Energy
Centre, 197 1) .
s 70. G. Nabi, “A technical report on the performance
of solar water-heater”, PAEC/Elect-27 (Lahore,
Atomic Energy Centre, 1972).
s 71. M. Saif-ur-Rehman and others, “A technical
report on the family size solar still”,
PAEC/Desai-I (Lahore, Atomic Energy Centre,
1971).
S 72. A. M. Cheems, “Solar dryer for agricultural
(Lahore, Atomic
products”, PAEC/Sol-29
Energy Centre, 1972).
s 73. M. Saif-ur-Rehman, “Solar desalination, performance, comparison and cost analysis of concrete-base and wooden-base solar stills”,
PAEC/Desal-2 (Lahore, Atomic Energy Centre,
1972).
Ottter useful references
S 62. N. R. Sheridan, The Heating of Stvimming
Pools, Solar Research Notes No. 4, (Brisbane,
University of Queensland, 1972).
The Sun in the Service of Mankind, Proceedings of the
UNESCO-International Solar Energy Congress,
(Paris, UNESCO, 1973).
S 63. D. J. Close and others, “Design and performance of a thermal storage air-conditioning
system”, Mech. Gem. Engng. Trans., Instn.
Engrs. Aust., 4(l), 1968.
G. 0. G. Liif, J. A. Duffie and C. 0. Smith, GVorId
Distribution of Solar Radiation, (Solar Energy
Laboratory, University of Wisconsin, 1966).
S 64. N. R. Sheridan, “Performance of the Brisbane
solar house”, Solar Energy Journal, vol. 13,
1972.
S 65. M. M. Anwar, “Rural electrification utilizing
Si-solar cells”, PAEC/Elect-8 (Lahore, Atomic
Energy Centre, 1966).
F. Daniels, Direct Use of the Sun’s Energy, (New
Haven, Yale University Press, 1964).
B. J. Brinkworth, Solar Energy for Man, (Compton
Press, 1972).
A. Zarem and D. Erway, Zntroduction to the Utilization
of Solar Energy, (McGraw-Hill, 1973).
Part Two.
52
solat EncrSy in DeVelOphg countries: Perspectivesand
Prospects, (Washington, D. C., National
Academy of Sciences, 1972).
S. G. TaIbert, J. A. Eibling and G. 0. G. Liif, Manual
of Solm Distiktion (Columbus, Ohio; Battelle
Memorial Institute, 1971).
S&r
Distillation (United Nations Publication, Sales
No. E.70.11.B.l).
J. A. Duffie and W. A. Beckman, Solar Energy Thermal
Processes, (Wiley International, 1972).
Proceedings of Intemational Conference on Phoiovoltaic Power Generation, Hamburg, 1974
(UNESCO).
Documentation on solar energy
Periodicals
Solar Energy, International
Solar Energy
Pergam Press, Oxford, UK.
Society,
Solar Energy Digest, Solar Energy Digest, San Diego,
California, USA.
Heliotechmlogy, Russian language periodical translated
by USA Ikpartment of Commerce, National
Technical Information Service, USA.
CompZes,Co-opkation MediterranCenne Pour I’Bnergie
Solaire, Service De La Comples, Marseille,
France.
Synergy Access, 21st Century Media, New York,
USA.
53
.
IV.
ORGANIZATIONS
CONCERNED WITH SOLAR ENERGY
(Preliminary List)
Organization
A.
Oficcr
concerned
Fields
of work
Research Centrrz in the ESCAP Region
1.
Auflfalia
R. N. Morse
Co-ordination
in Australia
Mechanical Engineering Division, P.O. Box 26,
Highctt, Victoria 3190
R. V. Dunklc
Solar collectors, selective surfaces,
water heating, space heating, storage,
solar stills, timber kilns
Division of Atmospheric Physics, P.O. Box 77,
Mordialloc, Victoria 3195
B. G. Collins
Radiation standards
Division of Buildiig Research, P.O. Box 56,
Highett, Victoria 3190
E. R. Ballautyne
Solar tables, thermal performance
dwellings
Division of Mineral Chemistry, P.O. Box 124,
Port Melbourne, Victoria 3207
A. F. Reid
Selective surfaces
Division of Irrigation Research, Private Bag,
GriEith. N.S.W. 2680
K. V. Gartoli
Plastic greenhouses
Division of Plant Industry, P-0. Box 1600,
Canberra City, ACT. 2601
R. M. Gifford
Plant conversion
A. L. Holderness
Small power systems
P. 0. Cardew
Reversible chemical reactions
W. W. S. Charters
Air heaters, heat pipes, heat pump,
mirror,
boiler, honeycomb, gram
drying
D. R. McKenzie
Sclectivc
surfaces, photo-thermal
conversion, plant conversion
L. W. Davies
Photo-voltaic
School of Mechanical Engineering
C. hi. Sapsford
Air heaters, water-heaters,
School of Physics
L. B. Harris
Refrigeration, hydrogen production,
thermoelectric
generation, photoIysis, linear concentrators, concentrators for industry
N.S.W. Institute of Technology, School of Physics and Mater&,
P.O. Box 123, Broadway, N.S.W. 2007
T. M. Sabine
High-temperature
absorber,
mium sulphide cells
University of Queensland, Department of Mechanical Engineering,
St. Lucia, Queensland 4067
M. IL Peck
Thermo-electric
module, climatic
control, building heating and cooling
James Cook lJniversi.ty of North Queensland, Department of
Engineering, P-0. James &ok University, Queensland 4811
D. J. Close
Air heating, cooling, storage, timber
drying
Caprieornia Jnstitute of Advanced Education, M.S. 76,
Rockhampton, Queensland 4700
J. W. Bugler
Insolation
Univasity of Adelaide, Mechaaical Engineering Department,
Adelaide, South Australia 5001
R. E. Luxton
Computer-based
energy system
T. 1. Quickendcn
Photo-elcctro-chemic51
Directorate
of Solar Energy Studies, Melbourne
Commonwealth
(CSIRO)
Scientific and Industrial Research Organization
Postmaster-General’s Department, Building Branch,
140 Bourkc Street, bfelbournc, Victoria 3000
Australian National University, Department of Engineering
P.O. Box 4. Canberra, ACT. 2600
University
of solar energy studies
Pnysics,
of Melbourne, Parkvihc, Victoria 3052
Ur$e$~;f$ssydney,
. . .
Energy Research Centre, Sydney,
of
University of New South Wales, P.O. Box 1, Kensington,
N.S.W. 2033
School of Engineering
University of Western Australia, Department of Physical and
Inorganic Chemistry, Ncdlands, Western Australia. 6009
conversion
building
radiation
cad-
thermal
effects
Part Two.
54
Orgonizotion
Documentation on solar energy
Officer concerned
Fields
of work
2. hdio
Meteorological Department,
New Delhi
National Physical Laboratory,
New Delhi
Solid State Physics Laboratory,
Central Salt and Marim
Chemicals Research Institute, Bhavnagar
Defencc Science Laboratory,
Ccntd
Delhi
Jodhpur
Building Rcscarch Institute, Roorkcc
University of Roorkce, Roorkec
Sri Aurobindo Ashram, Pondichcrry
2
Silicone cell
R. L. Datta
Desalination
J. P. Gupta
Space heating
Dinesh Mohan
Water-heaters
C. P. Gupta
Air-conditioning
C. L. Gupta
Mini-power
plants
Indian
Madras
M. C. Gupta
Space heating and cooling
Kanpur
H. C. Agarwal
Power, using water lenses
V. R. Muthuvccrappan
Rice drying
K. D. Mannan
Stationary concentrators for power
H. P. Garg
Agricultural
S. N. Sharma
Timber kiln
Khadi and Village Industries, Allahabad
A. Pandya
Slurry heater
Regional Engineering College, Ahmcdabad
B. K. Cfupta
Large fresnel lenses
Biila
D. P. Rao
Pump
B. Kempe-Govdc
Drying
K. Prasad
Small engines
S. Deb
Cadmium sulphide cells
Space Technology Centrc, Trivandrum
M. R. Mukherji
Cells
Bhabha Atomic Rcscarch Centrc, Trombay
M. R. Srinirasan
Concentration
Tata
G. Swarup
Ray tracing in dish-type
concentrators
of Tahnology,
hdNtc
Forest Research
University,
hstiNtc,
Chidambaram
Ludhiana
Jodhpur
htiNtc,
Dehradun
of Tahnology
InStiNtc
Bangalorc Agricultural
and Scicncc, Pilani
University,
Bangalorc, Kornataka
Indian Institute of Science, Bangalore, Kornataka,
Jadavpur University,
of Fundamental
hstitutc
560012
Calcutta
Research, Bombay
uses
of wastes by heating
Indonesia
Bandung
hstitutc
of Technology
F. Harahap
Refrigeration,
drying
National
hstitutc
of Physics and Electronics
F. Harahap
Direct conversion
water heating, grain
T. Noguchi
High-temperature
furnace. heating
and cooling, power production
K. Kimura
Heating, cooling, solar house
Y. saito
Collectors
Science, Toyonaka,
H. Tsubomura
Cells
Shiijuku,
Y. Nakajima
Storage tanks
S. Sawata
Sclcctivc surfaces, thcrm:J power
K. S. Ong
Water-heater
Rajcsh Prasad
Water-hcarcr
fopon
Government Industrial Research hISdNtC,
Solar Rescarch Laboratory, 1 Hirati-Machi,
Wascda University,
Osaka
IuStiNtC
of Architecture,
l-24 Nishi-shiijuku,
Laboratory,
K&-Ku,
Nagoya
Tokyo
5-16-I Omiya, Asahi-ku, Osaka 535
Faculty of Engineering
Kagakin University,
Electrotcchnical
Department
of Tahnology,
Osaka University,
Tokyo
Tokyo
Tanashi, Tokyo
n¶olaysio
University
6.
1. C. Mathur
CCIIS
Central Arid Zone Research
5.
Flat-plate medium-tcmpcrature
collectors
K. L. Chopra
Punjab Agricultural
4.
V. G. Bhidc
Delhi
Annamalai University, Annamalai,
3.
Radiation, mcasurcmcnts
Indian Institute of Technology,
. Indian Institute of Technology,
-.
A. Mani
of Malaysia, Engincaing
Faculty, Kuala Lumpur
22-l 1
h’epal
Balaju Yantra Shala, Plumbing
Division,
Kathmandu
IV.
Organizations concerned with solar energy
55
Oficer
Organiz;:ron
7.
Water-heaters
J. C. V. Chinappa
Pump, rcfrigcrator
Atomic Energy Research Centrc, Lahorc
M. hL Anwar
Lighting, cells, pump, heating, cooling, drier, solar still
Sea Water Desalination
M. &if-ur-Rchman
Dcsahnation
Papna brew Guinea
Po&ton
Project, Gwadar
Engineering and Technology University,
Engineering
I 0.
and Technology University,
Lahorc
-
Various student projects
Pcshawar
-
Various student projects
Philippines
National Science Development Board, Bieutau, Taguig. Rizal
V. Jose
Water hcatine
University
L. Abis
Desalination
Martinez
Engine for agro-industriaJ
E. Terrado
Rcfrigcration
Korea Atomic Energy Research hStiNtC.
Thermal-Hydraulics
Laboratory, P-0. Box 7. Cheong Ryang, Seoul
J. H. Cha
Flat-plate collectors
Korea Advanced Institute of Science, P.O. Box 150,
Cheong-Ryang-Ri, Seoul
S. Bat
Solar house
P. A. Cowcll
Pump, ice-maker, grain driers, solar
of the Philippines, Quezon City
De La Salle University,
Manila
Project Santa Barbara, Sanglcy Point, Cavitc City
1 I.
I
12.
of work
R. F. Benscman
Papua New Guinea Univcrsi~ of Technology,
Dcpartmcnt of Mechanical Engineering, P.O. Box 793, Lae
9.
Fields
New Zealand
Department of Sdcntific and Industrial Research,
Physics and Engineering Laboratory, Private Bag, Lower Hutt
8.
concerned
Republic
purposes
of Korea
Thailand
Asian Institute of Technology,
P.O. Box 2754, Bangkok
St&
of Tahnology,
The King Mongkut htiNtC
Department of Mechanical Engineering, Thonburi
B.
C. Rithipuk
Water-heater.
J. L. Gncrrero
Solar devices
steam generation
Other Organizations
1.
Argenlino
Division Hdioenergctica, Commission National de Estudios
Gco-hcliofisicos, Av. Mitrc 3 100 San Miguel, Pcia dc Buenos Aires
2.
Belgium
Section of Radiometric,
3 Avenue Circulairc,
lnstitut Royal hlftCorologiquc
1180 Bruxclles
de Bdgique,
R. Dogniaux
Brazil
J. C. Ometto
Solar dcviccs
R. J. Florov
Solar dcviccs
Brace Research htstitutc, MacDonald Collcgc of McGill University,
P.O. B 900, Stc. Anne dc Bellevuc 800, Quebec H9X 3Ml
T. A. Lawand
All solar technologies
University
K. G. T. Hollands
Solar devices
R. K. Swartman
Rcfrigcration
J. R. Bolton
Solar devices
Fisica ESALQ, Caixa Postal 9, 13400 Piiacicaba
SP
Bulgaria
Ecolc Sup&icurc
de Sylviculturc.
Sofia
Canada
of Waterloo, Waterloo. Ontario
Faculty of Engineering Science, University
London, Ontario N6A 589
Department of Chemistry, University
London, Ontario N6A 587
of Western Ontario,
of Wcstcrn Ontario,
Part Two.
56
Oficer
Organizxztion
6.
of Tccnica, Casilla II0 V,
Institute of Experimental Endocrinology,
Slovak Academy of Science, Bra&lava
hl. Fatranska
Solar devices
Institute of Botany, Department of Hydrobotany,
Czechoslorak Academy of Sdencc, 37982 T&on
D. Dykyjora
Solar devices
T. V. Esebcnsen
Solar devices
I. A. Sakr
Solar devices
F. Hollwich
Solar devices
Solar Energy Laboratory, Ccntre National dc la Rccherchc
Scientifiqur, 66, Oddlo
F. Trombe
Solar devices
Laboratoirc de MagnCtisme ct de Physique du Solide du CNRS,
Bellcvuc
hf. Rodot
Solar devices
Laboratoirc des Ultra-RCfractaircs,
Ccntre National dc la
Rcchcrchc Scientifique, b.p. 5, 66120 Odcllo-Fontromeu
hi. Focx
Solar devices
Laboratoire de La Roquette, 34, St. Bauzille de Putois
R. D. Fox
Solar devices
Association Fran&se Pour I’dtude et la Divcloppemcnt de
I%nergie Solaire (AFEDES), 28 Rue de la Source, Paris
I. Pryches
All solar technologies
Laboratoire d’Htliophysique,
13-Marseille
G. Peri
Solar devices
UniversiG dc Paris VI, Geophysiquc Spatiale Option Environnemcnt, 2 Place Jussicn, 75005 Paris
M. Cabanat
Solar devices
Centrc UniversitC, d’fitudes
hl. P. Vasscur
Solar devices
hf. Ducrcy
Solar devices
R. Ortavant
Solar devices
of Denmark,
Egypt
Solar Energy Laboratory,
Dokki, Cairo
National
Research Centrc, ShBl-Tahrx.
Federal Republic of Germany
University
of Eye Clinic, Munster
UnivcrsitC de Provencc,
Spatialcs
Station de Sylviculture et de Production,
Rccherchcs Forest&es, INRA, Nancy
La Station de Physiologic
37389 Nouzilly
Centre National de
de la Reproduction,
INR4,
Office Franpis de Rccherchcs de Bioclimatologic and So&d
MCtCorologique de France, 196 rue de l’Universit&, 75007 Paris
Station de Bioclimatologie,
INRA,
Solar devices
Solar devices
’ J. L. Plazy
Solar devices
P. Char&r
So!ar devices
R. Bonhommc
So!ar devices
In&rut dcs ttudes AvancCs Sur Les fincrgies Solairc ct Eolienne,
Athens
.%. Spanidcs
Solar devices
rni\ersity
A. A. Delxannis
So!ar dcviccs
9. G. Knumoutsos
Solar dc\-ices
A. Spyridonos
Solat devices
INRA, Route dc Saint-Cry,
78000 Versailles
French Wcri lndirs
IhTRA Bioclimatologie.
13.
J. Damcrgncz
84 Montfavet
Observatoirc Leon Tcisscrcnc de Bort, 78190 Trappers
12.
Solar devices
Solar devices
Physics, Slovak Technical University,
Thermal Insulation Laboratory, Technical University
Building 118, DK-2800 Lyngby
10.
J. R. Hirsman
Czcchoslor~a&a
Dcpartmcnt of Building
Bra&lava
9.
Ficldr of work
Chile
Solar Energy Laboratory, University
Fed&co Santareira, Valpar-iso
7.
concerned
Documentation on solar energy
97170 P&t-Bourg,
Guadaloupe
Greccc
S.&onal
S&r
of Athens, P.O. Box 1199, Omonia, Athens
Technical University,
Athens
En:rgy Research Centrc, N.R.C. Dcmocritos,
Athens
IV.
Or,gnization
57
concerned with solar energ
Oficer
Org~nixtion
l-l.
H. Tabor
Medium-temperature
B. Givoni
Research, semiconductors, space
heating and cooling
B. Nebbia
Solar devices
V. Stordli
Solar devices
C. Pisoni
Solar devices
V. Balzani
Solar devices
.A. hloumouni
Solar devices
J. Lewinka
Solar de.
College of Petroleum and Minerals, Dhahran
A. Kcttani
Solar devices
College of Engineering,
E. Xi. A. El-Salam
Solar devices
P. Blanco
Solar devices
P. Bcucr
Solar devices
E. Grandjean
Solar devices
N. S. Liderenko
Solar devices
Y. N. Malevsky
Solar devices
V. A. Baum
Solar devices
A. A. Shakhov
Solar devices
R. K. Baranova
Solar devices
M. Archar
Solar dcviccs
Martin Ccntrc for Architectural anl Urban Studies,
1 Scroopc Terrace, Cambridge
1. G. F. Littler
Solar devices
Department of Architecture,
J. K. Page
Solar devices
Department of Mrchanical Engineering and Production
Engineering, Brighton Polytechnic, Brighton, BN2 4GJ, Sussex
J. C. McVcigh
Solar devices
Department of Building
Liverpool
hi. G. Davies
Solar devices
J. R. Clarke
Solar devices
R. G. Harrison
Solar devices
P.O. Box 3745, Jerusalem
Department of Building Climatology, Building Research Station,
Tcchnion. Israel Institute of Technology, Haifa
ttaly
Direttoirc Instituto di Mcrcmlogia, Univcrsita
Large A. Fraccacreta-1, l-70122 Bari
Solar Energy Laboratory,
Napoli
University
degli Studi,
of Naples, Via. F. Crispi-72,
Institute de Fisica Tccnica e Impianti Termotechnici,
Facolta d’Ingegneria - Universita dcgli Studi,
di Geneva via all Operapia 11, l-16145 Geneva
Institute Chimico “G. Ciamician”.
16.
19.
Poland
Division
of Hydrology
and Meteorology,
Krakow
University
of Riyadh
Spain
des Energies Spicialcs, Madrid
Switzerland
Physikalisch Meteorologischcs, Obscrvatorium Davos,
Weltstrahlungszentrum.
7270 Davos - Platz
d’Hygienc et de Physiologie du Travail, Ecolc Polytcchnique
Fcdcrale, Clausiusstrasse 25, CH-8006 Zurich
hStiNt
21.
USSR
on the Source of Electricity,
All Union hstitute
Academy of Sciences, Moscow
Solar Energy Laboratory,
Moscow
Kryzhanovsky
Institute
of Energy,
Physical Institute, Academy of Sciences of the Turkmcnian
Ashkabad
SSSR,
of Plant Physiology, Academy of Sciences,
Botanitcheskaya 35, Moscow I-273
hstitutc
Kryxhanovsky
22.
es
Saudi Arabia
La Commission National
20.
Bolonga
of Solar Energy, Niamcy
PIHM 18.
de I’Univcrsita,
Niger
hStiNtc
17.
Fields of work
lsraei
The Scientific Research Foundation,
15.
roncerncd
Institute of Energy, Avenue Lenin 19, Moscow
United Kingdom
Royal htiN&XI
of Great Britain, 21 Albcmarlc
London, WIK 4BS
University
Engineering,
Department of Agricultural
of Sheffield, Sh&ield
University
Science, University
Department of Photobiology,
Homcrtonc Grove, London
Institute
Street,
of Liverpool,
of Oxford, Oxford
of Dermatology,
collectors
Part Two.
58
Oficer
Organizz?ion
23.
Documentation on solar enerm
Fields oi work
concerned
United States of dmerica
L. 0. Hcrwig
Solar devices
NASA Goddard Code 322, Goddard Space Flight Center, Greenbdr,
Maryland 20771
M. P. Thckackara
Solar devices
Lewis Research Center, NASA, 21000 B:ookpark
Ohio 44135
H. B. Curtis
Solar devices
E. R. Streed
Solar devices
H. Hintenberger
Solar devices
W. H. Klein
Solar devices
Mid West Research Institute, Kansas City, Missouri
hf. C. Noland
Solar devices
Solar En’crgy Systems Division 5717, Samba Laboratories,
Albuquerque, New Mexico 87115
R. W. Harringan
Solar devices
~ncrgy Research and Drvclopmrnt Administration,
Division of Solar Energy, 1800 6th Street, Washington,
DC.
205-E
Road, Clcvdand,
Thermal Engineering Section, Center for Bui1dir.d Technology,
National Bur. of Standards, Washington, DC. 20234
Fermi National Accelerator
Laboratory,
Batavia, Illinois
Smithsonian Radiation Biology Laboratory,
Rockville, Maryland 20852
Franklin
Institute, Philadelphia,
60510
12441 Parklawn
Pennsylvania
Drive,
.
-
19101
Solar devices
G. 0. G. L6f
Solar devices
J. A. D&e
Solar devices
Solar Energy and Energy Conversion Laboratories,
University of Florida,.Gaincsvillc,
Florida 32611
E. A. Farber
Solar devices
Environmental Rcscarch Laboratory, University
Tucson Air Port, Tucson, Arizona 65706
C. N. Hodges
Solar devices
A. hlcinel
Solar devices
F. H. Morse
Solar devices
Mechanical Engineering Department, Collcgc of Engineering
Science and College of Architecture, Arizona State University,
Tcmpe, Arizona 85281
I. I. Ycllot
Solar devices
Department of hlaterials Science and Engineering, Hearst Mining
Building, University of California, Berkeley, California 94720
M. F. hlcrriam
Solar devices
Department of Animal Physiology and the Institute of Ecology,
University of California, Davies, California 95616
R. G. Schwab
Solar devices
Institute of Energy Conversion,
Delaware 19711
K. W. Boer
Solar de-vices
D. 6. Edwards
Solar devices
Solar Energy Applications Laboratory,
Fort Collins, Colorado 80523
Solar Energy Laboratory,
Wisconsin 53706
University
Optical Science Center, University
Ariiona 85706
Colorado StAte University,
of Wisconsin, hladison,
of Arizona,
Department of Mechanical Engineering,
College Park, Maryland 20742
of Arizona,
Tucson,
University
University
of Maryland,
of Delaware,
Energy and Kinetics Department, University
Los Angeles, California 90024
Newark,
of California,
Dcpartmcnt of Mechanical
Peoria, Illinois 61625
Engineering,
Bradley Unircrsity.
Y. B. Safdari
Solar devices
Drpartmcnt of Mechanical
hlinncapolis, Minnesota
Engineering,
University
E. R. G. Eckcrt
Solar devices
School of Mechanical Engineering, Georgia Institute of Trchnology,
Atlanta, Georgia 30332
G. hf. Kaplan
Solar devices
City Cobcgc, University
H. Luatig
Solar devices
V. N. Smilcy
Solar
of hfinncsota,
of New York, New York, N.Y. 10031
Laboratory of Atmospheric Physics, Desert Research Institute,
University of Nevada System, Reno, Nevada 89507
dcG?s
Iv.
59
Organizations concerned with solar enera
Ofirer
Organization
23.
Texas A and M University,
Solar Energy Laboratory,
Texas 77004
University
Purdue University,
of Houston, Houston,
Massachusetts Institute of Technology, Department
Engineering. Cambridge, Massachusetts
Massachusetts Institute oE Technology,
Lexington. Massachusetts 02173
Solar drviccs
R. R. Davidson
Solar devices
R. M. Peart
Solar devices
A. F. Hildebrandt
Solar devices
H. C. Hottel
Solar devices
P. 0. Jarvinen
Solar devices
of Pennsylvania,
M. Wolf
Solar devices
S. Satcunathan
Solar devices
M. R. Saric
Solar devices
J. Xl. K. Dake
Solar devices
IVest Indies
Department of Mechanical Engineering,
Indies, St. Augustine, Trinidad
University
of the West
Yugoslavia
Department of Plant Physiology,
Akademska Street 2
26.
of Civil
Lincoln Laboratory,
Institute for Energy Conversion, University
PhiIadelphia, Pennsylvania
N. Lior
19174
College Station, Texas
Department of Agricultural Engineering,
West LaEayette, Indiana 47907
25.
Fields of work
United States of America (continued)
National Center for Energy, Managemenr and Power,
University of Pennsylvania, Philadelphia, Pennsylvania
24.
concerned
University
of Novi Sad,
Lambia
Department oE Civil Engineering,
University
of Zambia, Lusaka
Part Three
DOCUMENTATION
ON WIND ENERGY
61
.
I.
WORKIXG
DEVELOPJIE?iT
PAPERS PRESENTED BY THE SECRETARIAT
OF WIND ENERGY UTILIZATION
(NR/ERD/EWGSW/3)*
IXXRODUCI-ION
About 10,000,000 MW is continuously available
in the earth’s winds, and attempts have been made
from time to time to use some of this power.
It is
mentioned in reference W 1 that the Babylonian ruler
Hammurabi planned to use wind pumps for large-scale
irrigation in the seventeenth century B. C. The raising
of water by contrivances worked by wind power is
mentioned in a Hindu classic (reference W 2) dated
400 B. C.
By the fourth century A. D., windmills
were widely used in Persia, and applications spread
widely through the Moslem civilization and into China.
From 1,100 A. D. onwards, wind energy utilization
developed in Europe and, by the nineteenth century,
was a significant source of industrial power, especially
in the Netherlands.
Approximately 80 per cent of the population of
the developing countries of the ESCAP region is
engaged in agricultural production in rural areas, and
uses mainly non-commercial sources of energy, such as
human and animal muscle power, firewood and
charcoal, cow dung and agricultural waste, and, to a
limited extent, wind energy and solar energy (see reference W 3).
In any evaluation of energy utilization patterns in
rural areas, it is noted that wind and solar energy have
*Prepared by Mr. hi. hf. Sherman, consultant on wind energy, at the
request of the ESCAP secretariat. The views expressed in this paper are
the author’s own and do not necessarily reflect those of the secretariat or
the United Nations.
IN ASW ASD THE PACIFIC
several important characteristics that make them well
adapted to rural utilization: they are renewable sources;
they are widely distributed and do not require a distribution network; they are under the direct control of
the user; and their !l:velopment and use can be based
largely on local resources.
I.
A.
POTENPIAL INCREASE IN
ENERGY UTILIZATION
LOCAL ENERGY NEEDS
Assuming that an increase in energy utilization is
desirable in a particular rural area where transmitted
electricity or energy based on oil products is not freely
available, the first requirement is to quantify the present supplies and uses of energy and then to determine
the additional uses and the minimum increase in energy
required. Demand data should preferably be arranged
in a form similar to the hypothetical examples of figure
1 and figure 2.
When the amount of increased energy supplies required has been determined, all available energy sources
should be evaluated for their ability to satisfy the demand, proceeding in turn from increased efficiency in
the ust: of currently-used sources to increased usage of
locally available energy supplies, including biological
fuels, solar energy and wind energy, before considering
the use of transmitted electricity or oil products.
g 2,000
!?
c
1
a
400
4
300
;
0’
200
z
;
2
it
=
ii
a
%
1,600
1,200
.c
z
i
BOO
0’
:
100
0
~/V~/V’V~/~‘V’~/~‘V’V’l
Jan.
Jul.
Months
Figure 1. Monthly energy demand for
electric lighting (50 families)
Dec.
400
Jan.
Months
Figure 2. Monthly demand for irrigation pumping
Part Three.
62
B.
CALCULATION
OF WZND ENERGY
The wind velocity is continually varying in both
magnitude and direction, but is broadly predictable
over significant periods of time, and the power in the
windstream is proportional to the cube of the velocity.
The equation for total available wind power is
P =K A v3 where A is the cross-sectional area of the
windstream and v is the velocity.
The value of the
constant K is 0.0000137 where the units used are kW,
m2 and km/h. (See reference W 4).
Theoretically, 0.5926 per unit of the available
wind power could be extracted by a wind rotor, but
allowance must also be made for the practical efficiency
of the rotor, transmission and power utilization device,
which is normally in the range of 0.3 to 0.7 per unit.
Expressing the over-all efficiency as E, the practical
equation becomes:
P = 0.0000137 A v3 x 0.5926 E
C.
RELEVANT WZND MEASUREMENT
INSTRUMENTS
Much valuable work has been done by the World
Meteorological Organization on standardization of wind
data collection for meteorological and navigational purposes. Preliminary efforts have been made at wind
energy assessment (reference W 5 j, and it is hoped
that further work will be carried out on standardization
of instruments and methods of analysis of data for
wind energy.
The most complete information on wind velocity
behaviour is gained from anemometers giving continuous records of speed and direction.
The Dines
pressure tube anemograph is widely used as the standard
wind-measuring device in many permanently established
meteorological stations, but determination of average
hourly wind velocities from the charts of this type of
anemograph is diBicult and time-consuming.
The electric cupcontact recording anemometer is
extensively used for accurate determination of average
hourly wind velocities.
This device incorporates
rotating cups which drive a device which makes a contact in an electric circuit once for some selected value
of wind run, preferably 1 km.
The circuit causes a
pen to mark a continuous chart recorder, thus making
it possible to determine the hourly run of the wind by
counting the marks on each hourly segment of the chart,
However, instruments of this kind are expensive to
purchase and install and need skilled daily maintenance.
In a variant, a narrow paper tape is moved forward a short distance for each contact produced by the
anemometer. A time switch is used to operate a pen
or marker SO that a mark is made on the tape at hourly
intervals, and the distance between successive marks
Documentation on wind energ)
represents the run of the wind. This type of instrum
ment is designed particularly for economy and for
simplicity in operation and chart interpretation.
An inexpensive method of wind recording used at
some stations is a Robinson cup or propeller type of
anemometer which is connected to a cyclometer type
of digital indicator. The difference behveen any two
readings indicates the run of the wind during the time
interval, and hourly averages can be readily obtained.
Anemometers which give “instantaneous” wind
speeds are used at many minor observation stations, including airports. These are indicating instruments, not
recorders, and their readings are noted at certain
specified times in the day, usually once per hour. The
wind speed values thus measured are useful as a general
guide, but do not give a good basis for an accurate
statement of hourly average wind velocities.
There is a great need for a standardized, simple
and inexpensive wind recording device specifically
designed for the purpose of wind energy estimation.
It has been reported (reference W 6) that a batterypowered energy sampling unit has recently been
developed which counts the numbers of hburs of duration of each wind velocity and also records solar energy
intensity.
This device is intended for use in remote
locations and is expected to be commercially available
in 1976.
D.
COL LECTZON OF WIND VELOCITY
DATA
It is highly desirable to determine accurately the
total hourly duration of each wind velocity during each
month of the year at the proposed windmill sites for a
period of at least three years, in order to quantify the
wind energy potential and to provide a basis for windmill selection and design. However, recording at the
exact location and height of each proposed windmill is
usually practicable only for the siting of large electric
generating windmills.
When undertaking a comprehensive wLd survey
covering a large area with a similar weather pattern
throughout, a reasonable procedure is to locate one
continuous recording anemometer at a fully exposed
primary &e in conjunction with simple run of the wind
unattended di_rital recording anemomeiers at severzil
secondary locations where windmills are needed. Cornparison of the average tveekly or monthly wind velocity
at the primaq site and each secondary location will
yield correlation factors which can be applied to the
secondarv site data to estimate the detailed wind
charactehstics. If data are available from ‘a station
\vhich has a similar \iind regime to a proposed site, a
similar correlation procedure can be applied by making
accurate hourly average measurements with a portable
instrument at the propsed site for a fixed period and
I.
comparing the results with the recording station hourly
Such a
average measurements for the same period.
method has limitations, as the correlation factor may
vary widely with different wind directions according to
terrain differences between the primary site and the
secondary recording station.
If adequate data are not available, an approximate
assessment of wind patterns may be made by taking
short-period observations of wind velocity with a portable instrument, in conjunction with individual disSuch discuscussions with several local inhabitants.
sions should seek to determine the relative windiness
on a month-to-month basis (especially the months, with
most and least wind), the periods and times of day
when the wind is most and least and the direction and
relative velocities of these winds, the maximum velocity
during the year and the maximum length of time with
no wind. This method is easy to undertake and may
be the most appropriate for immediate widespread implementation of low-cost hand-crafted windmills.
E.
63
Working papers presented by the secretariat
ANALYSZS OF WIND VELOCITY
DATA
Using the average monthly or annual wind velocity
for determining the energy potential of a site may not
give an accurate result, because some of the velocities
included in the average may be above the rated wind
velocity of a windmill and because (A -l- B f C)l does
not equal (As) + (B3) -l- (Cs).
A duration curve should be prepared as a graph
of (P), which is proportional to power, against time
as shown in figure 3. It is also useful for determination
of the optimum rated wind velocity of a windmill
to plot a graph of wind velocity against time, as shown
in figure 4.
For a particular wind pump at a particular location, the following basic data are required in order to
predict the monthly and annual water output:
(a) Hourly average wind velocity records processed to become monthly and annual power duration
Curves of the type shown in figure 3;
(b) Water pumping rates of the wind pump
under consideration within the range of minimum and
maximum operating wind velocities when working
against any fixed gross head, corrected for the actual
gross head. These output rates may be depicted as
in figure 5.
Multiplication of the number of hours duration
Per month at each wind velocity by the relevant hourly
Output rate will give a series of quantities which, when
summed, will yield the total monthly output.
The
result of calculations for each month of the year may
then be shown as in figure 6. A comparison between
figure 6 and figure 2 will indicate the seasonal correlations between water pumping demand and wind
pumping capacity. It should be noted however that it
may also be necessary to consider minimum outputs for
shorter periods in order to assess storage requirements.
For estimates of wind-electric generator output, it
is usual to assume that the total windmill efficiency is
constant for all wind speeds. For a given tentative
design, the wind velocity for starting, rated wind
velocity and maximum allowable wind velocity are
assumed, and figure 7 can be constructed from figure 3.
Referring to figure 7, the shaded area (bcfgh) represents the actual output of energy, which will be some
proportion of the rectangle (adeo) which represents the
output if the windmill were running at full rated power
throughout the period, the proportion being the load
factor. Using data on a month-by-month basis, figure
8 may be constructed, indicating monthly production
of wind energy.
IL
STATUS OF WINDMILLS
WATER PUMPING’
FOR
Priority consideration should be given to utilization of windmills for water pumping to supply the
increasingly critical needs of domestic consumption,
animal husbandry, agriculture and aquaculture.
Water pumping windmill systems can be broadly
classified into three major categories: manua!ly produced, mechanical drive;
industrially
produced,
mechanical drive; and electric pumps powered by windgenerated electricity.
A.
MANU.4LLY PRODUCED, MECHANICAL
DRIVE TYPES
Several different types of simple hand-crafted
water pumping windmills have been developed and are
now in seasonal use in various parts of the world.
However, construction of each of these non-commercial
types has tended to be localized because of communication barriers. These wind pumps have several common
characteristics: they are constructed of locally available
materials (often wood) and are produced with local
skills, using simple hand tools; they may operate at low
wind velocity; they require daily attendance when in
operation; they require frequent but low-cost
maintenance; and they are generally used for irrigation or
drainage requiring relatively low lift.
1 Illustrations OF the basic types of windmills
second secretariat paper in this s&on.
m,ay bc found in the
.
Part Three.
64
Documentation on wind energy
C
G
:
:
0
C
3
40,000
30,000
2O,GOO-10,000
30
Wind
Figure 3.
Power duration curve
Figure 4.
45
velocity
60
in km/h
Velocity distribution
-
6
_:
3
6
9
Wind
Figure 5.
12
15
uelocity
10
21
24
-
21
in km/h
Wiid pump performance
IA
i
I
I
I
000,I
Figure 6.
/
Jon.
I
i I
r/y/v
t%Cti
so
(annual or monthly)
:
,” e
;
“E
7s
I-
JUI.
Months
T
/’iz
Monthly output of water per wind pump
Hours
ODOVC
maximum
oprrntinq
velocity
-d
0 h
Figure 7.
e
l’b~rs
in lhe
yeor
Estimate of energy output
8760
Figure 8. Monthly distribution of energy in the wind
I.
Working papers presented by the secretariat
1. The wind pumps of Lz&thiou,
(a)
Crete (Greece)
Usn,oe
In the Mediterranean region, large stone tower
mono-directional windmills with triangular cloth sails
were historically used for grinding corn and pressing
olive oil. Shortly before 1913 this traditional design
was adapted in Crete to smaller lightweight structures
for pumping water for seasonal irrigation of intensively
cultivated plots of vegetables and grains.
At least
6,000 of these devices are now in use in the broad
fertile plain of Lassithiou which is isolated in the
mountains, and some hundreds are also in use in other
parts of Crete (see references W 7 and W 8).
(b )
Componenis
Viewed from a distance, all Cretan wind pumps
look alike, but large variations in construction become
apparent upon close examination.
The components
described here are generally accepted by the local
farmers as being the most successful. The Lassithiou
windmill design consists of 11 basic elements; sails,
spars, hub, crankshaft, main bearings, tail, carriage,
turntable, tower, storage tank and base-well.
triangular cloth sail measuring 2.6 m x
Sails -A
1.2 m x 2.4 m is attached to each of the radial spars.
The loose comer of each sail is secured by a rope to
the tip of the adjacent spar, thus forming a strong
uniform surface for catching thl wind. The sails can
be wrapped around the spars to control the amount of
sail area exposed to the wind.
Spars-Commonly, eight wooden spars, each 2.7 m
long, radiate out from the hub to form a total windmill
diameter of 5.4 m. Stones are attached to the tips of
some spars for balancing if required. An axial spar
of angle iron extends 2 m out in front of the hub along
the main axis of the crankshaft. Steel wires radia:ing
back and out from the end of the axial spar to the tips
of the radial spars provide bracing against strong
winds, and steel wires between the tips of all the radial
spars provide additional bracing.
A 60-cm diameter
tlat steel ring around the hub is bolted to each spar to
keep them secured tightly within the hub.
Hllb -The front end of the crankshaft is inserted
through a 30-cm diameter, E-cm thick wooden hub
with eight S-cm square holes chiselled in the perimeter
to receive the squared ends of the spars. The hub is fixed
to the end of the shaft by a bolt passing through both.
An improved hub made of two 30-cm diameter, OS-cm
thick steel discs separated 5-cm apart by 16 small
rectangles of IO-cm x OS-cm steel plate welded to form
eight square holes has recently been adopted.
65
Crankshaft -The
crankshaft is made of a S-cm
diameter, 160~cm long mild steel rod incorporating a
U-shaped crank.
The U-shape, which was formerly
fashioned by bending, but more recently by welding,
has an inside width of 7 cm and a height of 7.5 cm,
giving a stroke of 15 cm. A 2-cm diameter steel connecting rod attached with two bolts to a wooden crank
bearing transfers the rotary motion of the crankshaft
into vertically reciprocating motion of the pump piston.
Main bearings - Two 34-cm wide, 15-cm high,
8-cm thick blocks of hardwood, each with a 5-cm
diameter hole in the centre of the large surface, are
bolted to the front and rear of the carriage to support
the crankshaft.
,
Tail -A
triangular tail of corrugated sheet steel
1.5 m x 1.5 m x 1 m is supported by two 2-m long
pieces of angle iron from the rear of the carriage.
(Some units have a manually-operated tail pole with no
vane).
Carriage - The carriage is a rectangular angle iron
frame 35-cm wide and 140-cm long, connected by four
bolts to two 35-cm long pieces of angle iron riveted to
a 45-cm diameter flat steel ring which rotates on the
bottom inside surface of the turntable ring.
This
arrangement keeps the carriage firmly attached to the
top of the tower, while, at the same time, allowing it
and the attached shaft, sails, etc. to rotate when the
wind direction changes.
Turntable -The
turntable, riveted to the top of
the four tower legs, is made of a i60-cm long piece
of 5-cm mild steel angle iron bent into a 50-cm
diameter ring to form a flat horizontal greased bearing
surface for the carriage.
the four-legged S-m high
Tower -Normally
tower is made from S-cm mild steel angle iron, with
flat steel riveted cross bracing, and is bolted and wired
(In some of the coastal
to the 1.5-m square base.
villages several wind pumps are mounted on stone
Projecting stones or
towers offset from the well.)
stepping holes in the tower give access to the sails and
top mechanism.
Storage tank - A 13-cm diameter, 15-cm stroke
piston pump, made from a discarded cannon shell and
fitted with a leather foot valve and a leather-sealed
piston, is mounted on the base in the centre of the
tower.
Base-well - A 15-cm thick concrete slab covering
a 2-m diameter, 7-m deep well forms the base of the
windmill.
.
Part Three. Documentation on wind energv
66
(c)
constractior2 materials and skills
m the wooden bearings and spars are Of kid
[email protected]
The metal shaft and lengths LIEangle iron are
fabricated using ordinary blacksmith’s tools and SkiiS.
Recently, some electric welding has been utilized for
construction of improved crankshafts and hubs.
(d)
Operation and maintenance
To decrease sail area during periods of high wind,
the operator wraps each cloth sail one or more times
around its spar. During periods of very high winds,
and when the operator is not in attendance, the sails
The windmill
are fully wrapped around the spars.
can be stopped during operation by pulling the tail cord
so that the surface of the sails is parallel to the wind.
The sails are fully removed from the spars and stored
during seasons when the wind pump is not required for
irrigation.
All bearings are greased twice a month.
Sails and pump valves are normally replaced every two
Spars and main bearings are replaced every
years.
five years.
(e)
Performance
The Cretan windmills start pumping at a wind
velocity of 8 km/b and reach optimum performance of
The wind pump will in25 rev/min at 13 km/h.
crease speed up to about 40 rev/min in higher winds
before it controls itself through excessive tip drag and
sail fluttering, although the sails are usually reefed at
Lifting water as much as
speeds above 25 rev/min.
5 m, this type of windmill pumps 3,000 litres per hour,
lo-12 hours per day, 4-5 months per year, and has an
expected lifetime of about 20 years.
(f)
Economics
Each wind pumping system costs about $US 480
(windmill $US 320, storage tank $US 120, pump
$US 40). The cost of water pumped is approximately
one US cent per m3. The widespread success of the
Cretan windmill design can be attributed to several
factors, namely: the use of lightweight and inexpensive
cloth as efficient aerofoils, the use of simple wooden
bearings, availability of skilled local carpenters and
blacksmiths for construction, large rotor diameter in
relation to tower height, favourable local winds, high
water-table, intensive agricultural production of cash
crops and high cost of petroleum fuels and electricity.
In the ‘O-year period up to 1973, many of the
original lO,OOO-12,000 windmills on Crete were retired
otting to increased availability and low cost of oil products and clcctricity. Recently, however, many of the
“r&cd”
windmills have been put back in service.
2.
Adaptatiws
(a)
of the Greek windmill configuration
United States of America
A 7.6-m diameter sail windmill with six triangular
sails of the classical Greek configuration has been
designed by Windworks (reference W 9) and tested by
the Brace Research Institute, Canada (see reference
W 10). This adaptation incorporates durable sails of
dacron polyester fibre, mounted on wooden spars. The
rotor is mounted on a used automobile differential gear
drive which transfers rotary motion with a speed increase ratio of 4: 1. A vertical drive shaft delivers this
rotary motion to the ground where it can be used for
a variety of mechanical tasks, including water pumping.
A unique steel octahedron truss tower design, with very
high strength to weight ratio, is used. The complete
unit costs about $US 600 for materials plus 400 hours
of skilled labour, and may be constructed by the owner.
(b)
lndin
A 10-m diameter sail windmill with eight
triangular cloth sails of the Greek configuration was
constructed and tested by the Madurai Windmill Committee for irrigation pumping in low winds in southern
This design utilizes a maximum of local
India.
materials and skills in an effort to keep the price within
reach of common farmers. The eight sails, of khaki
canvas, are fitted to bamboo spars which are clamped
A
to a central hub adapted from an oxcart wheel.
steel crankshaft mounted in ball bearings transfers re
ciprocating motion, via a wooden connecting rod and
a variable-stroke lever arm, to a lo-cm bore piston
pump with a stroke of 30 cm. 6,000 litres of water
per hour can be lifted 10 m at a rated wind velocity of
16 km/h. The welded steel turntable carriage, sup
porting the crankshaft and bamboo-mat tail, rests upon
a turntable base made from a steel truck tyre rim
which is bolted to the top of a tower made from six
8-m long teak poles. The total construction cost of
this windmill was $US 400. Construction plans are
available from the TOOL Foundation (reference W 11).
Further design optimization and testing is currently
in progress at the Agricultural Engineering Division of
the Indian Agricultural Research Institute.
A 6-m diameter, six-sail adaptation of this wind
pump has been constructed for second crop rice irrigation, and is currently undergoing trials with a 20-cm
&ameter piston pump at the Sarvodaya Educational
Development Institute, Sri Lanka (see reference W 12).
(c)
Ethiopia
The American Christian Mission at Omo, near
Lahe Rudolph, Ethiopia, has established a project
called Food from \Yind and is selling 6-blade Greektype sail rotor wind pumps at a subsidized price to
I.
Working papers presented by the secretariat
local farmers for lifting river water for irrigation. In
August 1975, 19 of these windmills were being operated
by the local villagers and five more were being operated
by the misSion.
This project, sponsored by the
British charity organization OXFAM, intends to build
a total of 100 wind pumps for use in the area. This
adaptation may be utilized in areas where there is a
shortage of wooden construction materials, and metal
working facilities are available. A detailed report and
drawings of the design are available from the Intermediate Technology Development Group, United
Kingdom (see reference W 13).
3. Wind pumps of China
(a)
Lufing-sail
type
Simple hand-crafted windmills have been used in
China for many centuries (see references W 14, W 15
and W 16).
Reportedly the first of these were the
hand-crafted Ming-sail vertical-axis wind pumps which
are still extensively used along the eastern coast north
of the Yangtze River, particularly near Tientsin, for
lifting salt water into evaporating ponds. A minutely
detailed study of these pumps has recently been made
(reference W 17). The windmill has a central vertical
wooden drive shaft from which radiate hvo sets of eight
equally-spaced wooden poles, to give a total diameter
of about 9 m. Eight vertical masts suspended between
the tips of the 16 poles support eight 3 m x 1.8 m sails
similar in construction and rigging to those on Chinese
junks. When being pushed down-wind, each sail presents its full surface to the wind, being held in position
by a rope. When returning against the wind, the sail
turns automatically on the mast so that it presents only
its edge, and no surface, to the wind. At the base of
the vertical shaft, a 3-m diameter drive wheel with 88
wooden teeth engages a &tooth pinion gear mounted
on one end of a horizontal shaft. At the other knd of
the horizontal shaft is 3 wheel with nine ar,ms which
drives the wooden chain of a square-pallet ladder
pump. The whole unit is simple aud inexpensive.
Further developments, including a more compact
and economical arrangement, were shown at the
Agricultural Machinery Exhibition at Peking in 1958.
Prototype construction of adaptations of this
design has recently been undertaken in Thailand by the
Division of Agricultural Engineering, Department of
Agriculture.
(b)
Adaptation of Greek design
In northeastern China, Greek-type windmills of
wooden construction, with 12 cloth sails, are connected
to paternoster pumps to lift irrigation water (reference
W 18). These windmills use an eight-blade automatic
fan tail for directional control, and each windmill is
fitted with a simple wooden anemometer.
67
(c)
Oblique-axis type
In some of the eastern provinces, especially
between Shanghai and Hangchow, oblique-axis wind
pumps similar to the Tjasker type. (Netherlands) have
been used for water lifting (reference W 19). These
devices are fitted with six mat and batten type sails at
the top end of the shaft, pointed into the wind.
A
steel wheel with 19 or 20 steel teeth, fitted to the
bottom of the shaft, engages a similar toothed wheel
fixed to the top of a vertical drivs shaft supported by a
short wooden four-legged toi?t;.
L&C vertical drive
shaft is connected to a square-pallet ladder pump.
The rotor can be pivoted around the vertical drive shaft
to point into the wind by changing the position of the
two wooden poles which form an A-frame supporting
the top end of the shaft.
4.
Hand-crafted wind pumps of Thailand
Several types of low-cost wind pumps are used in
Thailand for pumping water for rice irrigation and salt
production. These devices are explained in the paper
presented by the National Energy Administration of
Thailand.
(See also reference W 20).
5.
(a)
Wiid
pumps of the Netherlands
Hollow post type
The wipmolen or hollow post type of wind pump
(reference W 21) was developed in the fifteenth century
and used extensively for drainage, Tt consists of four
cloth-covered wooden lattice frames up to 10 m long,
lixed to a wooden main shaft. The main shaft carries
a large drive wheel with wooden teeth, driving a
wooden toothed wheel lixed at the top of a vertical
driveshaft, which extends down through a large hollow.
wooden post to the bottom, where its weight rests on a
thrust bearing. At the lower end of the vertical shaft,
a small wooden gear wheel meshes with the teeth of a
large gear wheel which is tixed to the pump shaft on
which the pump is mounted.
In the second half of the sixteenth century, the
relatively simple hollow post units evolved into very
large smock and cap tower units used extensively for
Although proportionately
land reclamation projects.
larger than the hollow post units, the internal machinery
is similar. Each of these units could pump as much
as 57 m3 of water per minute to a height of 1.5 m.
The Archimedean screw, consisting of a wooden spiral
enclosed in a wooden casing, was adapted to drainage
lJsi.ng such a device, it was
wind pumps in 1634.
possible to increase the lift to 5 m.
(b)
Meadow type
The meadow type with a 4-m diameter, four-blade
rotor, is an adaptation of the hollow post type, and is
still widely used in the northern area. This unit has a
Part Three.
68
wooden body resting on a concrete foundation. Steel
ball bearings are used on the shafts of the traditional
power transfer system of wooden gearing. At the rear
of the movable cap is a large tail vane which incorporates a spring-operated control mechanism for turning
the rotor out of the wind during periods of very high
wind. The base of the structure encloses a largediameter, slow-speed, centrifugal pump.
(c)
Tjmker type
The Tjasker type is the simplest and smallest of
the Netherlands water pumping windmills, It consists
essentially of a long wooden shaft mounted at an angle
of 30° to the horizontal, the upper end of the shaft
carrying four cloth sails on a wooden framework, 6 m
in diameter, and the lower end terminating in a closed
Archimedean screw.
The shaft is supported by a
wooden A-frame and the assembly can be moved in a
circle around a central pivot pole to point the sails into
the wind.
6. Tanzanian design
A low-cost locally-constructed windmill suited for
deep borehole water pumping has been developed by a
team in co-operation with the Ministry of Lands, Settlement, and Water Development, Tanzania (reference
Twelve of these windmills are being conw 22).
structed for use in Tanzanian villages, and one unit will
be displayed in June 1976 at the UNICEF Appropriate
Technology Centre, Nairobi.
The 5-m diameter rotor consists of six 0.9 m x
0.7 m corrugated, galvanized metal sheets mounted
with a root pitch angle of 45’ and a tip pitch angle of
30” on six steel spars. Each blade is cambered along
its chord to a 2.7-m radius, and blade pitch control is
incorporated into the hub mechanism. The tail vane
is of sheet steel. The tower is constructed from three
6-m long galvanized steel pipes, Power transfer by an
adjustable eccentric wheel permits adjustment of the
reciprocating stroke for dilIerent pumping conditions.
7.
French design
A low-cost multi-blade windmill intended for
local construction has been developed by a group of
French engineers and tested over a period of 30
months. Prototypes have been on trial at Ougadougou,
Upper Volta, and at Agades, Niger, since the end of
1973. A pilot series of 20 windmills was manufactured
in 1974 and 1975 and sent for trial and demonstration
to Chad, Cape Verde Islands, Niger, Haiti, Laos,
Democratic Yemen, Mali and Senegal.
The 3-m diameter rotor has 16 canvas vanes
mouutcd on wooden spars with a variable pitch and
self-feathering control mechanism, and a canvas and
Documentation -on wind energ!
bamboo tail vane.
A steel crankshaft mounted in
metal/teflon bearings converts the rotary motion to
Vertically reciprocating motion, which is transferred by
a wooden connecting rod to an adjustable balance arm,
At the starting wind velocity of 7 km/h, with the rotor
turning at 10 rev/min, the unit will lift water 6 m at
the rate of 120 litres per hour.
The maximum
rotational speed in higher winds is 60 rev/mm
The
simple wooden guyed pole structure is 4 m high. The
cost of this windmill is somewhat greater than $US 400.
Details of construction and assembly are available (see
reference W 23).
8. Savonius rotor
The Savonius rotor has been widely publicized as
being appropriate for use in developing countries (reference W 24). This vertical-axis rotor incorporates
two semi-cylindrical surfaces, mounted on a vertical
shaft so that the view from above presents the shape of
the letter S. Typical models of this design are made
from hvo halves of an oil drum split longitudinally.
The potential advantages of this system are that it will
accept the wind from any direction, and the rotor is
simple and inexpensive to build. Many organizations
and individuals throughout the world have experimented
with this design and found it to be generally unsatisfactory for practical application (reference W 25).
The disadvantages are small collection area, large
weight/surface area ratio, low aerodynamic efficiency,
vibration problems and difficulty in making a connexion
to a pump. Potential is seen for this design only in
applications requiring very little power, such as the
stirring of algae cultures and the starting of Darrieus
rotors.
B.
INDUSTRIALLY
WIND PUMPS
PRODUCED MECHANICAL
1. Multi-vane wind pumps
(a) Usage
The most commonly used and widely ditributed type of wind pump is the slow-running multiOriginally
vane metal fan driving a piston pump.
developed in France, the multi-vane windmill first
attained widespread use in the United States of America
in the late 1800s for domestic and livestock water
supply. Use and manufacture have gradually spread
to many parts of the world, especially the United
figdom,
Australia, South Africa and South America.
Local adaptations of this design have been developed
in the Philippines, India, Syria, Indonesia and Thailand,
but have not been widely used in those countries because of the high cost of all-metal construction and
economic and technical limitations on the capability of
the owners to undertake proper maintenance. Many
multi-vane wind pumps made in the United States of
America and Australia have been exported to
developing countries throughout the world, often on a
I.
Working papers presented by the secretariat
69
subsidized basis, but these units often cease functioning
within 10 years because of the lack of skilled maintenance.
The main shaft is often offset slightly from the
centre of rotation of the turntable, so that in higher
winds the rotor is automatically turned partially out of
the wind by the unbalanced distribution of wind
pressure at the centre of rotation.
Pump - Pumps are commonly of the single-acting
reciprocating piston type.
The piston cylinder is
usually of brass or PVC plastic 5-15 cm inside diameter.
The piston incorporates a single or double leather seal
and a one-way valve. A steel ball or leather flap valve
is fitted at the base of the cylinder and a third one-way
valve may be fitted at the bottom of the inlet pipe.
Storage tank-Water
is usually stored in an
elevated steel tank for domestic water supply and in a
ground-level tank or pond for stock watering.
(c) Construction materials and skills
Multi-vane windmills are shipped from the manufacturer complete and ready for assembly, with ordinary
mechanic’s wrenches and screwdrivers, by semi-skilled
workers. Considerable skill and dexterity are required
to lift up the tower, the gearbox assembly and the rotor,
which are each quite heavy.
(d ] Operation and maintenance
Once assembled, the only normal maintenance
required is annual replacement of the oil in the
After several years, the replacement of
gearbox.
damaged rotor blades, worn bearings and worn pump
valves and seals may ‘.te required. These tasks may
present some difficulty in rural areas, especially when
the new part must be obtained from the manufacturer.
(e) Performance
The standard types start working with a
wind velocity of 6-8 km/h and have a constant
operational speed and output for wind velocity of 28
(It should be noted that the
km/h and above.
rotational speed decreases as the rotor diameter increases, so that selection of a rotor larger than that
required to supply the necessary torque to the pump
to start operating may have a negative effect on
pumping rate).
Table 1 gives an example of the performance of a
typical multi-vane wind pump (Comet) operating at a
mean hourly wind velocity of 12.4 km/h.
(b) Components
Although there may be variations between
different manufacturers, the basic components are as
follows:
Rotor - The windwheel or fan consists of 8 to 24
galvanized sheet steel vanes which are cambered to
provide optimum aerodynamic efficiency. The vanes
are carefully balanced, and fastened to two concentric
steel rings which are supported by five or six tensioned
steel spokes connected to a cast steel hub.
This
assembly is mounted on a shaft which runs in
automatically-oiled ball or babbitt bearings, or wooden
bearings. The diameter of the rotors available ranges
from 1.8 m to 9 m.
Gearbox -The
shaft is mounted in a cast iron
head unit incorporatin g a reciprocating crank system.
In smaller models, a speed reduction gearing of ratio
2: 1 to 4: 1 permits the rotor to turn with a relatively
low torque load and deliver a longer stroke to the pump
connecting rod than if it were connected directly to a
crankshaft.
Turntable -The
gearbox is mounted on a turntable, through which passes the reciprocating steel
connecting rod and the tail pullout chain.
Tower -A
three-legged or four-legged angle iron
lattice tower is used, varying in height from 5.5 to 18 m.
The large quantity of steel used for the towers is a
major expense. The tower is mounted directly above,
or adjacent to, the water supply, on a concrete
foundation.
Control devices -The
rotor is po‘inted into the
wind by a galvanized sheet steel tail vane. The rotor
may be turned parallel to the wind, when necessary
during exceptionally strong winds (above 60 km/h),
by means of a cable winch or lever fitted at the base of
the tower and connected to the tail pullout chain. In
some models, a brake on the rotor operates simultaneously with the tail pullout mechanism.
Table 1.
PERFORMANCE
OF COMET
Roror
Pump
diomstrt
?.c)
WIXD
dlmrrcr
4.89 m
r-3
PUMP
7.32 m
9.14 m
(4
L/C
(ml
5.08 .
7.62
10.16
15.24
20.32
30.48
45.72
.
.
.
.
.
O:,Ip‘f
/nJ
;.-r dq)
hff
(ml
oerpw
Cm3 prr Jay)
.
.
.
38
5.8
167
9.6
.
.
.
.
.
.
.
,
.
I
.
.
_
.
.
.
I!,
I1
5
-
13.1
13.2
47.7
-
83
49
21
11
-
21.8
38.2
86.4
154
-
.
Lift
fm)
237
136
58
34
15
7
7urpur
(m3 prr dq)
23.4
41.4
93.4
163
366
832
Lift
(ml
236
109
61
28
12
o”!FI”
fm3
prr
dayJ
37.6
84.3
149
336
746
Part Three.
70
2. Lubing wind pump
The Lubing company in the Federal Republic of
Germany manufactures a highly reliable precision-made
wind pump, which has three aerodynamically-shaped
high speed rotor blades mounted down-wind in a coning
augle. Speed control is achieved through radial
feathering of the rotor blades by centrifugal weights
mounted on each blade shaft. The single guyed steel
pole tower is hinged at the base so that the complete
unit may be easily lowered to the ground by means of
a winch at the base of one of the three guy cables,
which is a useful feature in typhoon areas. This wind
pump will operate unattended for long periods of time
but it is very expensive.
3.
generator may be used to operate several pumps; (c)
several generators may supply a single pumping station,
e.g. in Germany a 64 kW pumping station is supplied
by eight Allgaier wind power plants; (d) the manufacture of wind-electric generators may be carried on
independently of the manufacture of the pumps or the
intended application; (e) the efficiency of high-speed
wind rotors and high-speed centrifugal pumps is greater
than the efficiency of slow-speed wind rotors and piston
pumps; (f) energy may be used from time to time for
other purposes.
Despite these advantages, the method has not been
widely used, because of the high capital cost of large
wind-electric generators.
Sparco wind pump
The Sparco wind pump, manufactured in
Denmark, is intended for cattle watering.
It is
mounted on a single guyed steel pole tower, and has
curved plate steel alloy blades individually mounted on
steel shafts, and self-regulating, with a tail for
directional orientation. All moving parts are mounted
in sealed ball bearings.
4. Bosman wind pump
The Bosman wind pump is manufactured in the
Netherlands for small-scale drainage pumping on farms
and grazing land. It consists of four flat steel plates,
twisted to achieve a low pitch angle at the tip and high
pitch angle at the root, and Axed to four steel arms to
give an effective diaml ter of 3 m. The rotary motion
of the horizontal main shaft is transferred through 90°
by a sealed oil-bath geLr system to a vertical shaft,
which runs down the centre of the 4-m high steel
lattice tower to a submerged centrifugal low-lift pump.
A unique control system incorporates two tails mounted
90” apart and capable of simultaneous radial twist, so
that only one tail is vertical at any time, the operation
being controlled by the water level.
Detailed studies are being made at Eindhoven
University, Netherlands, on the potential for further
development of plate blades such as those used on the
Sparco and Bosman wind pumps.
c.
Documentation on wind energy
ELECTRIC PUMPS POWERED BY
WIhrD-GENERATED ELECTRICITY
High-speed wind-electric generators can be used
to pump water by transmitting power to electric motors
connected to centrifugal immersion pumps (reference
vb’ 26). This method has several advantages: (a) the
p’-‘nlp and wind motor need not be mounted at the
s~nle location. e.g. the generator may be located on a
l’,-md> hill and the pump on a river flat; (b) one
III.
STATUS OF WI>D-DRIVEN
GENERATORS
ELECTRIC
The first wide-scale use of wind-generated
electricity occurred in the 193Os, following the develop
ment of medium-speed generators for automobiles, and
using the increased knowledge available of aerofoils
and aircraft propellers.
Wind-electric generators can be broadly classified
as suitable for small-scale generation for localized use,
or large-scale generation for supply to a distribution
grid.
A.
SMALL-SCALE
GE,‘VERATION
During the late 1930s more than 300 companies
around the world were producing various types of
small wind-electric generators with rated output as
high as 3 kW. Following the rapid development of
fossil-fueled central electric-generating stations and the
development of distribution systems, wind-electric
generators tended to become uneconomical. At present
there is a much smaller number of manufacturers, but
many new developments are taking place (see reference
W 27).
1. Elecktro wind generators
The Elecktro company in Switzerland, established
in 1938, manufactures a large range of DC windelectric generators with specifications as summarized in
table 2.
Most models are available with special dust-proof
bearings, and insect-proof wiring for use in tropical
areas. A DC/AC inverter is also available.
These highly reliable windmills are used around
the world in all extremes of climate to supply power
for communications relay stations and navigation aids.
I.
Working papers presented by the secretariat
Table 2.
ELECKTRO BIND-ELECTRIC GENERATORS
Rzrd
Model
ou;.ht
(uultts)
*
Rxed u+d
WlOC$
i%m/h)
_
.
.
W 250
_
\wo5
.
\W 156 .
.
.
.
.
.
.
50
250
600
1,200
-
IW256
.
\W356
.
WVG506
\WlSW
WV250
.
IW35D
IWGSOD
.
.
.
.
.
.
.
.
.
.
.
.
.
.
2,200
4,000
6,000
1,200
2,000
3,500
5,000
35
38
42
37
35
38
42
m50.
71
37
Rcrd
: [email protected]
(;‘I
DC 6’1’ -, “-I
DC 12/2:
DC 12/2?;36
DC 12/24/36/48/65/
110
DC 24/36,‘tS/65/110
DC 48/65/ 110
DC 65/110
AC 110, I-phase
AC 110,3-phase
AC 110/220,3-phase
AC 110/270,3-phase
2. Aerowatt wind generator
The Aerowatt company in France manufactures
several models of exceptional wind-electric generators
especially adapted for long periods of unattended reliable operation in severe environments. Specifications
are summarized in table 3.
Table 3.
GENEILATCXS
AEROWATT WCND-ELECTRIC
Starting wind
Model
Rated wind
speed
(b/h)
24FP7
.
l’jOFRF’7
3ooFP7
.
11ooFP7
41ooFP7
.
.
.
.
.
.
.
.
.
.
14
11
II
11
14
Rated orrr~ur
Racd
(warts)
25
25
25
25
27
28
130
350
1,125
4,100
uolrage
W)
24
24
110
110,220,380
110,220,380
These units are frequently used to supply power
for critical remote installations, such as communications
relay stations and navigation aids.
3. Dunlite wind generator
The Dunlite company in Australia manufactures
two models of high quality reasonably-priced windelectric generators. These have been used in remote
places in Australia and the ESCAP region for the past
30 years for domestic power supply as well as power
supply to communications relays and navigational aids.
Specifications are summarized in table 4.
Table 4.
DUNLITE WIND-ELECTRICGENEUTORS
4. Wince battery charger
The Wince-Dynatechnology
company in the
United States of America manufactures a wind-electric
battery charger model No. 1222 H. This device has a
starting speed of 11 km/h and a rated speed of 37 km/h
and delivers 14 amperes at 15 volts DC.
5. Lubing battery charger
The Lubing company in the Federal Republic of
Germany manufactures a wind-electric battery charger,
based on 25 years of experience in the design and
construction of wind-electric generating units.
The rotor consists of a propeller with three
aerodynamically proNed blades made of epoxy resin
reinforced with glass fibre, and a centrifugal governor
is provided to limit rotor speed to approximately 600
rev/mm
Three additional smaller blades provide a
starting facility at a wind velocity of 12-14 km/h.
Transmission of power from the shaft to the special
brushless AC generator is by means of a two-stage
oil-bath gearbox.
The resulting .4C output is transformed to 24 V,
rectified and stored in batteries.
Electronic controls
regulate the charging of the batteries automatically and,
when the battery voltage reaches 28.5 V, the charging
current is automatically switched off.
The designed
output for various wind velocities is:
Wind v&city
output
(km/h)
(watts)
-
14
22
29
36
43
-
24
136
325
400
400
6. Bucknell wind generator
The Bucknell company in the United States of
America manufactures a 12 V 200 watt wind-electric
generator. 1
7. Enag wind generator
The Enag company in France manufactures three
models of wind-electric generators:
Eolienne, 400 watts, 24/30 V
Super Eolienne, 1,200 watts, 24/30 V
Super Eolienne, 2,500 watts, 110 V
swring
Modct
speed
(b/h)
L.....
Y.
.
.
.
.
Rated speed
14Wd
-
-
16
40
Rarcd ouyvr
(waus)
14
2,000
Rmd
votrqr
(VDC)
32,36
2% 32,48,
115
8. USSR wind generators
The USSR Institute for Farm Electrification is responsible for several wind-electric generators rated from
0.5 to 25 kW.
Part Three.
72
9. NOAH wind generators
This type of unit has been especially designed for
developing countries and a prelin&ary
economic
anqlysis (reference W 28) indicates that this design
has an economic advantage over some other machines.
company in the Federal Republic of
Germany has recently tested several pre-production
prototype wind-electric generators with maximum outputs up to 90 kW with variable voltage and variable
frequency AC, suitable for electrical heating and
cooling, water pumping and hydrogen production.
NOAH
10.
11. Sencenbough wind generator
The Sencenbough company in the United States of
America provides a complete kit for construction of
Model 750-14 wind-electric generator. This 790 watt,
14.4 V DC device has a starting velocity of 12 km/h
rated wind velocity of 29-32 km/h and maximum
operating velocity of 48 km/h, and is equipped with a
3.7-m diameter propeller.
DAF wind generators
The DAF company in Canada is currently undertaking the manufacture of two models of vertical-axis
Darrieus rotor wind-electric generators.
Selected
characteristics are given in table 5.
Table 5.
Average wind vdocity
CHARACIHLISTICS
per month
OF
(km/h)
.
17.6
GENERATORS
20.8
24.0
28.8
110
210
360
560
1,000
Average monthly kWh output at 24 V
(4.6-m diameter) . . . . . .
.
.
110
190
290
420
680
Average monthly kWh output at 24 V
(6-m diamctcr)
. . . . . .
.
.
210
400
680
1,070
1,900
wind velocity per month
(km/h)
(kWh)
16
19
22
26
R6
150
236
350
Considerable time, skill, specialized power equip
ment and some special materials are required for construction of this unit.
13. Brace wind generator
The Brace Research Institute in Canada has
designed and tested a 9 kW 110-230 V AC windelectric generator for use in developing countries (reference W 10).
This design, intended for local
assembly, utilizes automobile and truck components and
a 9.8-m fibreglass rotor manufactured in Canada. The
estimated electrical output is as follows:
Avcragc wind velocity per month (km/h)
.4vcragc monthly output (kWh)
14.
14.4
WIND
.
The Windworks company in the United States of
America has prepared a plan for a 12 volt DC windelectric generator (reference W 9).
The estimated
power output is as follows:
.4rcra,-c monthly output
DAF
Average monthly kWh output at 110 V
(4.6-m diameter) . . . . . . .
12. Windworks battery charger
Arcragc
Documentation on wind energy
16
19
22
26
740 1,278 2,030 3,030
Kcdco battery charger
The Kedco company in the United States of
America has begun production of a simple, reliable
wind-electric generator. Model 1200 produces 1,200
watts, 85 amps at 14.4 V DC at a rated wind velocity
of 34 km/h, the starting wind velocity being 11 km/h.
15. Models no longer manufactured
hjany of the wind-electric generators previouslv
in the United States of America were if
simple reliable construction, and several of these units
are still providing reliable service. A detailed study
of the components of these units is recommended prior
to finalization of any design of wind-electric generators
for manufacture and use in the region.
iiiaiiLii&ZiliiTj
B.
LARGE-SCALE GENERATION
TO DISTRIBUTION
GRIDS
FOR SUPPLY
From 1930 to the late 195Os, many large proto%pe
wind-electric generators, the largest of which was r3icd
at 1,250 kW, Lvere constructed and tested in a numb=r
of countries, including Denmark, the United Ki.ngdLT%
France, Germany, the USSR and the United States of
America. Although technically successful, they I\ cre
not generally adopted because they were not c.>y:competitive \vith large-scale fossil-fueled genern:l.‘n.
New activities in this field have occurred recently (I-”
ference W 29).
I.
Working papers presented by the secretariat
1.
rotor
ERDA projects
In 1973, considering recent technological developments in .related fields, the United States National
Aeronautical and Space Administration (NASA) and
the National Science Foundation undertook a major
wild enerH development programme which :vas
followed up by the Energy Research and Development
Adm%stration (ERDA) in 1975.
The first ERDA prototype wind-electric generator
commenced operation in November 1975. The general
specifications of this Model 0, 100 kW experimental
unit were:
Cut-in wind speed (first load applied)
13 km/h
Rated wind speed (100 kW at busbar)
28 km/h
Maximum operating wind speed
95 km/h
In 1976, ERDA is planning construction of two
prototypes each rated 200 kW, and commencement of
a significant programme for development of small
wind-electric generators.
2.
Danish wind-electric
generators
In 1941-1943, the Smidth company in Denmark
manufactured twelve 60 kW and six 70 kW DC windelectric generators which supplied a local electricity
grid for about 10 years. In 1957, the same company
installed a 200 kW AC wind-electric generator, which
supplied electricity to the national distribution grid for
10 years.
In 1974-1975, the Danish Academy of Technical
Science re-examined the possibilities of large-scale
wind-electric generation and concluded that wind energy
could supply 10 per cent of the country’s electricity.
Large Darrieus rotors supported on icosahedron frames
were proposed as an appropriate design.
3. French wind-electric
73
generator
In 1957 an 800 kW 3,000 V wind-electric
generator was constructed and operated for 5,000 hours,
including 600 hours connected to the distribution grid.
In the early 196Os, the NEYRPIC organization constructed a 1,000 kW, 3,000 V asynchronous AC windelectric generator which supplied a maximum output of
220,000 kWh in November 1963.
A reduction in
petroleum prices discouraged plans for widespread use
of these machines.
4. Canudian wind-electric generator
The Canadian National Research Council is proceeding with a plan for erection of a 200 kW Darrieus
supply
wind-electric generator which is expected to
500,000 kWh per year to a local distribution
grid.
5.
New Zealand study
The New Zealand Aerospace company is studying
a 10 kW version of the Darrieus rotor design as a
model for a larger unit intended to be connected to the
national grid.
IV.
WINDMILLS
FOR OTHER USES
In many countries, windmills have been
traditionally used for grinding grains, oilseed pressing,
sugarcane crushing, wood cutting and other semiindustrial tasks. Construction and performance details
of some of these machines are available in the literature
and present some potential for adaptation for use in
the region.
A.
MULTIPLE
USAGE
Considerab!e potential appears to exist for
adaptation of wind rotors already used in the region
for water pumping, such as the Greek sail configuration
and the Thai high-speed type, to tasks able to use
variable intermittent mechanical power, including grain
threshing, winnowing and grinding, concrete mixing,
load lifting and compost grinding.
It would be desirable to consider development of
wind utilization systems that can be used for several
purposes, thus allowing the windmill to be used whenever wind is available, and this would depend largely
on the proper selection cr development of the utilization devices. Some activity in this field has been
initiated by the Social Work and Research Centre at
Tilonia in India, and some commercial applications
are being developed by the L)harat Heavy Electricals
company in India.
B.
CHINESE
WIND-POWERED
PLOUGH
The use of a wind-powered cable plough in China
has been reported in reference W 30. This device incorporates a wind-powered winch consisting of an upper
and a lower capstan and a coupler capable of changing
direction. A bi-directional plough is connected to a
continuous cable which passes through a pulley at the
end of the field. The system is operated by two persons, one person operating the windwheel and winch
and the other person operating the plough, and can
plough 0.25 to 0.8 hectares of land per day, depending
on wind velocity.
.
Part Three.
74
V. SELECTION AND MATCHING OF
TRADITIONAL COMPONENTS FOR DESIGN
OF NEW HYBRID WINDMILLS
Components may be broadly classified as follows:
The rotor consists of a surface area for receiving
the pressure of the wind and a support structure which
converts the horizontal pressure of the wind to rotary
motion.
The hub connects the rotor to the main shaft.
The muin shaft and bearings support the weight
of tbe rotor and carry the rotary motion to a power
transfer mechanism.
The power transfer mechanism carries the rotary
motion of the shaft to tbe power utilization device.
The power utilization device converts the
mechanical power delivered to it into some form of
useful work.
The tower supports the rotor above the ground at
a height where it can receive a useful amount of wind
and in most cases rotate free!y.
The orientation system consists of a turntable,
shaft carriage and sometimes a tail. It is required on
horizontal axis devices to maintain the plane of rotation of the rotor perpendicular to the direction of wind
flow.
The control system is required to match the performance of the windmill to the available wind and the
energy demand, and to prevent structural damage in
high winds.
The primary factors determining the design of
each component are: function, physical stress related
to wind speed and load demand, materials available and
the skills and tools required to work with these
The matching of individual components
materials.
into a system should aim to have all components able
to withstand similar maximum stress loads and to require a minimum number of di.tIerent materials, skills
and tools for assembly of the system.
A large number of successful components is
described in detail in the literature. The construction
and performance characteristics of an appropriate
selection of these, and others not reported, could be
carefully documented for each major use (mechanical,
electrical) for two power ranges (less than 5 kW,
greater than 5 kW). Such documents would be most
useful for the development of hybrid whd-energ
systems for specific applications.
Documentation on wind enerev
VI. CURRENT INTERNATIONAL
ACIXVITIES
several international organizations are involved in
the development and promotion of small-scale wind
utilization devices.
A.
UNITED NATIONS
The Centre for Natural Resources, Energy
and Transport of the Department of Economic and
Social Affairs in New York has an expert adviser on
non-conventional resources on its staff. In 1974, an
economic evaluation of ‘nd-power systems was made.
The Economic and Social Commission for Asia
and the Pacific will conduct a roving seminar on rural
energy development in 1977.
The Economic Commission for Africa
is
sponsoring the Second African Meeting on Energy in
This meeting will include discussions on the
1976.
future role of wind energy utilization in Africa.
The Economic Commission for Latin America is
undertaking a study, and experts are being hired to
undertake
the implementation
of wind-electric
generators in rural areas of Paraguay.
The Food and Agriculture Organization of the
United Nations is, currently updating reference W 4.
The United Nations Environment Programme is
undertaking the establishment of a few demonstration
centres which will integrate solar, wind and bio-mass
energy sources into self-sufficient energy systems for
communities in some of the typical rural areas of Asia,
Latin America and Africa. Sri Lanka has been chosen
as the site of the Asian centre.
Although the United Nations Industrial Development Organization is concerned primarily with industrial development, it has several programmes related
to energy, and is supplying expert advice to the Govemment of the Sudan on the utilization of wind energy.
A small production unit for the manufacture of water
pumping windmills is being set up in Kenya.
The United Nations Children’s Fund is establishing
a village technology demonstration unit in Nairobi that
is expected to be completed by the end of May 1976,
and is sponsoring a seminar, commencing 10 June
1976, that will include demonstrations of local renewable energy resources, including two types of windmi&
and simple technolo,y for the rural family.
The United Nations Educational, Scientific and
Culturai Organization has been supporting activines
related to non-conventional energy resources including
l.vind energy and has established a committee to COordinate this activity.
I.
B.
Working papers presented by the secretariat
UNITED STATES OF AMERICA
The New Alchemy Institute-East is developing a
6 kW wind-electric generator to be demonstrated as
part of the United Nations Human Settlement Programme in Canada. They have also been involved in
the clevelopment of low-cost wind pumps in India.
Volunteers for International Technical Assistance
publishes details on the construction of several varieties
of windmill appropriate for construction and use in
developing countries and has several voluntary windenergy experts who respond to enquiries regarding
wind energy utilization.
75
their impIementation in developing countries for several
years, and has issued several relevant technical
publications.
E.
UNITED KINGDOM
The Intermediate Technology Development Group
has provided direct technical assistance on wind pumps
in Africa and has prepared a technical report on this
work. It is currently building a prototype wind pump
with a 6-m diameter rotor with three metal aerofoil
blades, a fail-safe governing device and an improved
pump, primarily for irrigation.
The
Energy
Research and Development
Administration is actively collaborating with several
countries in the development of large-scale wind-electric
generating devices.
The Oxford C?rmlittee
for Famine Relief
(OXFAM) has been acti,.. in promoting and financing
the development of windmills in India and Africa.
The Technical Assistance Information Clearing
House has recently devoted some effort to international
co-ordination of work on small-scale wind energy
utilization.
F.
The Wind Energy Society of America is concerned
with dissemination of wind energy information within
the academic and research community.
The Society
has several international members.
C.
REPUBLIC
OF GERMANY
The Foundation for International Development
organized a conference in September 1975.
A Wind Energy Research Institute has recently
been established at the University of Stuttgart. This
institute will consider problems of wind energy utilization and will hold regular classes in wind energy
techniques,
NETHERLANDS
The Netherlands development foundation TOOL
publishes an international newsletter with the aim of
increasing communication between technical workers.
TOOL is providing direct technical collaboration on
wind energ development projects in India, Indonesia
and Sri Lanka and has published technical information
on windmill construction for use by rural development
workers.
G.
CA i<A DA
The Brace Research Institute has been actively
involved in the development of windmill designs and
MALA YSIA
The Malaysian Agricultural Research and Develop
nlent Institute has recently developed a 6-m diameter,
tail-less (down-wind)
Greek type sail rotor and
peristaltic pump suitable for rural construction, and use
for irrigation and drainage of rice fields.
H.
nu.
FEDERAL
SWITZERLAND
The World Council of Churches publishes original
information on windmill construction for use by
development workers.
76
Part Three. Documentation on wind energy
THE DESIGN AND CONSTRUCTION OF LOW-COST WIND-POWERED
WATER PUMPING SYSTEMS (NR/ERD/EWGSW/6)*
INTRODUCTION
Recently ihere has been an increasing demand for
information on designs of water pumping windmill
systems suitable for construction with low-cost locallyavailable materials and skills, and it appears that the
general unavailability of. properly-documented technical
information on indigenous wind pumps is a major
factor limiting more widespread implemecration of
wind pumps in rural areas.
Because of the complex interrelationships of the
variables of wind characteristics, water supply, materials
and skiis at each difIerent locality, adaptation of lowcost wind pumps to new areas without modification or
redesign has had limited success in the past. However,
such interrelationships
may be identified
and
rationalized, and the design process presented as a
sequential flow of information analysis, rational decisions, and calculations, as in the flow chart figure 1.
I.
A.
PRELIMINARY
INVESTIGATIONS
SURVEY OF LOCAL WIND
CHARACTERISTICS
A reliable determination
of local wind
characteristics is required, especially for the period
when water pum$ig is most needed.
Summarized
average hourly wind velocities (figure 2) are required
for preparation of velocity and power frequency curves
(figure 3) and power duration curves (figure 4). The
maximum wind velocity, and directional distribution of
winds (figure 5) should also be determined.
B.
SURVEY OF LOCAL WATER PUMPING
NEEDS
A survey of local water pumping needs should be
carried out to determine the total pumping head and
the daily water demand on a monthly basis for each
likely agricultural and domestic requirement.
C.
CLASSIFICATlOh’
OF WIND ROTORS
Several different $pes of wind rotors are wellknown, but their construction and performance
characteristics have not been comprehensively classified
in a format suitable for design purposes.
Complete
information for comFxaCve analysis of rotors sJ>ould
include: starting velocicq-, rated velocity, maxi;:\um
operating velocity, tip speed ratio, rated effich.cy,
-’ P;cparc.d by Mr. M. X. 5’-.zxxn, consultant on wind enc:gy, at the
rrqur 4 r.: I!!5 ESCAP sccrc-2:;:.
The views cxpressrd in this pager XC
the ao:h~,‘- awn and do L.: rt;:r.-xily
reflect thost of the sccrc!sijat c’r
Ihr Vn~tri Nations.
range of diameters, construction materials, rotor solidity
(total swept area divided by total frontal area of blades),
control mechanisms, velocity/power graph, and, where
relevant, root chord, tip chord, root angle, tip angle and
aerofoil section. Compilation of these parameters for
existing wind rotors would greatly assist the design and
development of new hybrid wind-pumping systems.
1. Horizontal-axis rotors
(a) The classic Greek type sail rotor (figure 6)
is widely used in Greece (references W 7, W 8, W 3 l),
and adaptations are widely used in Thailand (figure
7 and reference W 20) and China (reference W 18).
It is suitable for wind pumps because of its high
starting torque, low stalting speed, low weight and
cost, and its ability to be easily adjusted on the
occurrence of higher wind velocities. It consists of 6
to 12 triangular cloth sails, each attached to a wooden
spar along its longest edge and held tight by a rope
leading from the free corner to the adjacent spar tip or
circumferential wire between spar tips. Radial wires,
leading from the tip of each spar -to the tip of a
central axial spar, brace the spars against wind pressure.
Maximum rotor solidity is about 45-50 per cent. Sail
area can be reduced by wrapping each sail one or more
times around its spar. This type of rolor appears to
be the most appropriate design for use in areas with
limited resources of materials and skill.
It has been
further developed by several organizations for use in
India (figure 8 and references W 11, W 32), Malaysia
(figure 9), Sri Lanka (reference W 12), Ethiopia (refcrence W 13) and other developing countries (figure
10 and references W 9 and W 10).
(b) The steel .multi-vane fan rotor (figure 11)
consists of 8 to 24 curved sheet metal blades mounted
on two concentric steel rings supported by 5 or 6
tensioned steel spokes. Rotor solidity is 90-100 per
cent. Local adaptations of this design have been
developed by the National Aeronautical Laboratory in
India, the General Administration for the Development
of the Euphrates Basin in Syria, a private company in
Thailand, the Bandung Institute of Technology in
Indonesia (reference W 33) and USAID (reference
w 34).
A cloth multi-vane rotor has also been
developed (reference W 23 ) .
Multi-vane rotnrs :::e characterized by a very low
starting wind ve!o&z of 6-8 Erm,/h: and high starting
torque, and xc; ::o:A:..:~~ used in conjunction with a
piston pump. They 1:: xost appropriate for industrial
manufactuic 4~.~’ I:‘~; :Y/ areas \vhere the necessity for
long-time dt: 7’:i!ii !t;’ r:~i reliable unattended operation
can justify ttz P:g:, capital expenditure required.
I.
Working papers presented by the secretariat
4
-w--e
c”
0
%
‘S
0
.c
i?
.-z
E
‘Z
L
P
ci
S i I
Part Threes Documentation on wind energy
78
v’(
knots)
0
Y- I, km/h I
I
0
hnura
duratiani
391
. . ..__._
--.-..- .~ __.
tf
I
v3xt
0
VI ( knots)
v ( km/h)
v311
L
t
IO
293
1,86l,lt37
Figure 2.
1.85
1
33
--
1
3.70
1
619
-.-
I
31,354
202
18.52
t (hours duration)
1
2
II
3
4
5
6
7
8
5.55
7.41
9.26
II.11
12 96
14.81
331
857
387
56,585
340,607
307,287
I2
13
20.37
22.22
24.07
23
104
25
194,401
l,l40,943
348,631
604
828,281
I4
I5
I6
25.93
27.78
29.63
I4
5
244,081
107,193
219
5 I7
92
476,714
1,679,402
426,180
17
31.48
I
26,013
1
I8
’ ‘33.33
0
2
0
74,052
Summary of M hourly wind velocity readings at Don Muang airport,
Bangkok, for March, April and May 1975
900
IMaximum
Wind
Figure 3.
velocity
Rated velo
ity
power
in km/h
Velocity and power frequency curves
Figure 4.
Shape of power duration curve
9
I6 1.67
I.
79
Working papers presented by the secretariat
/
a11 rind
blows
qreo?erthan
from
SE,
!i Or
SW
\
/
.Wooden
Corriope /
olremw”
p”ll-Q”l
rim
I
i
Figure 5.
Wind rose, Bangkok, March, April, May
Figure 6.
Greek sail rotor water pump
Bamboo
ma1 soil
Wooden
Figure 7.
Thai sail rotor water pump
main 1ho0
\
80
Part Three.
Documentation on wind energy
adaptation for water pumping are available (see re
ferences W 35 and W 36).
(e)
High-speed propeller-type rotors are not
usually considered for water pumping, but they are
successfully used for this purpose in Thailand (figure
15) and they may be adapted to high-speed centrifugal
pumps. A rotor of this type for use with a wind pump
is proposed in referent, W 37.
These rotors are
characterized by high starting velocity, high rotational
speed and low starting torque. Most high-speed rotors
are carved from wood, although some are made from
aluminium by casting or rib construction (reference
W 38) or fibreglass (references W 39 and W 40).
High-speed rotors for pumping applications would
normay be used in conjunction with pumps requiring
low starting and constant operating torques, such a~
square-pallet chain pumps, centrifugal pumps, chain
pumps and archimedean screws.
Figure 8. Madurai prototype sail rotor water pump
(c) A very simple and durable rotor consists of
four rectangular cambered steel plate blades twisted to
give low pitch angle at the tip and high pitch angle
at the root (figure 12).
Rotor solidity is about
, 35 per cent. It is commonly used in the Netherlands
and Denmark for small-scale drainage and cattle
watering, and has also been used on low-cost wind
pumps at some salt works in France (figure 13).
Optimization investigations are being carried out at the
Technical University, Eindhoven, the Netherlands. A
6-blade cambered metal plate rotor has been developed
in Tanzania (reference W 22).
This type of rotor
seems to have considerable potential for use in low-cost
water pumping systems because of simplicity of contruction, durability and good aerodynamic efficiency.
(d) The Princeton sail wing rotor (figure 14)
was developed in 1960 at Princeton University, United
States of America.
It consists of two blades, each
having a double thickness of sailcloth supported by a
rigid straight leading edge, rigid tip and root chord
sections and a trailing edg,e cable stretched between the
tip and root sections. The ratio of root chord to tip
chord is about 3: 1. The sail is cut with a catenary arc
trailing edge, which allows equal chord tensions to be
developed along the length of the sail as a function of
the tension at the trailing edge cable. The aerodynamic
performance of this rotor is similar t’o that of conventional rigid rotors, but the weight, cost and complexity of construction are all substantially reduced.
Detailed plans of the original Princeton design and an
(f) The classic Netherlands type of rotor, consisting of four spars supporting a wooden lattice covered
with cloth sails, is best adapted to very large machines
where high power output at low rotational speed and
high torque are required. Recent use of this type of
rotor for water pumping is rare, and its use in new
hybrid designs will be limited primarily by the large
amount of skilled carpentering required to construct the
lattice structure.
(g) Several other horizontal-axis rotors have
been used that incorporate four to eight fixed rectangular blades of wood or fibre mat construction;
their cost, efficiency and durability are each quite low.
Generally speaking, a rotor blade can be made from any
Bat thin material, including metal, cloth, wood, plastic,
bamboo and fibre mats, with appropriate supports.
2. Vertical-axis
rotors
Many different varieties of vertical-axis wind
machines rotating in a horizontal plane have been reported (reference W 41). The primary advantage of
these rotors is that they can accept wind from any
direction and thus do not require any orientation
mechanism, but their construction is usually very bullry
and requires a large, quantity of material in relation to
the effective collection area. These rotors have maintenance difficulties as a result of the large weight resting
on one thrust bearing at the base of the main shaft.
AerodJxamic efficiency is low because the rotor turns
as a result of direct wind pressure which is a function
of the square of the wind velocity, unlike horizontalaxis rotors which extract wind energy as a function Of
the cube of \vind velocity. Also, only about half of
the rotor blades are doing work while the other half are
However, two classic vertical-axis
returning up-nind.
rotors \vhich may have some practical importance for
modem applications, because of their light coW.ructiOn.
I.
Working papers presented by the secretariat
81
Lm
0
I. dl r- i&y
P-
Figure 10. Brace Institute-Windworks sail
rotor with octahedron module tower
Figure 9. Malaysian Agricultural Research and
Development Institute down-wind sail rotor water pump
Figure 11.
Multi-vane metal rotor
Figure 12.
4-blade metal rotor
Part Three.
82
Alternative
4 sheet-iron
-4m
surface
Documentation on wind energy
crankshaft
sails,
I m*,
span 3 m
Wind shaft
-3m
Direction of
rotation
-Counterweight
( when fitted)
-Pm
Fixed
Support
for
Wooden or iron
-0 rn.
Stole
-H Access ladder ( when fitted)
sub-structure
pipe
//
At-l
11 1 I/-Staves
i..
c. ..
/ ,’ -.
Figure 13.
4-blade metal rotor water pump at lle de Noirmoutier, France
I.
83
Working papers presented by the secretariat
Axed
unloaded
-‘.- e
,
Loaded
rigid tip
profile
orof eile
Wire cable,trailing
Rigid leoding*,;
edge. (soar
. 1
,
-
/
5-h
‘Rigid
/
root
Figure 14.
to ground
Princeton sail wing rotor blade
stake
support
‘*\\‘,\
\\b ‘,\
\\‘$--;.
frame
I
Figure 15.
i
I
Wooden pole
Thai high-speed rotor water pump-wooden
mounting assembly
.
Part Three.
84
are the Chinese type (figure 16) and the Turks and
Caicos Islands type (figure 17). These rotors may be
particularly adaptable to Persian wheel and bucket
types of water lifts in addition to continued traditional
use with square-wooden-pallet chain pumps.
(a) The rotors used in the Turks and Caicos
Islands, British West Indies, for pumping salt water to
evaporating ponds consist of six triangular cloth jib
sails supported along their long edge by a vertical pole,
and held by a rope tied from the loose corner to the
adjacent vertical pole. Each vertical pole is supported
by two horizontal wooden poles which radiate out
from the central vertical main shaft. A similar jib-sail
rotor utilizing eight sails has been proposed for use in
Thailand (figure 18).
(b) The Savonius rotor (figure 19) has been
well documented (reference W 25).
Its use for
practical water pumping and electricity generation has
met with limited success only.
(c) The Darrieus rotor (figure 20) consists of
two or three constant-chord aerofoil blades bent into a
catenary curve and fixed at each end to a vertical axis
which is supported by guy wires at the top and connected to a power utilization device at the base (reference W 42). The advantages of this rotor are that,
unlike other vertical-axis rotors, a minimal support
structure is required, the proportion of materials to total
swept area is very low (solidity about 5 per cent), and
efficiency is high. The main disadvantage is that it. is
not self-starting, and construction of the blades from
fibreglass reinforced plastics or extruded aluminium is
Although it has only recently been
quite expensive.
developed for electricity generation (reference W 43),
it may have some potential for water pumping. Experimental work with a Darrieus rotor powered water
pump has recently been undertaken at the National
Aeronautical Laboratory in India.
(d) The gyro vertical-axis rotor (figure 21 and
reference W 44) is similar to the Darrieus rotor in that
it has a high efficiency of about 60 per cent, a very
low solidity factor and minimal support structure requirements. This rotor consists of two or three straight
symmetrical aerofoil blades supported vertically from
horizontal support arms fixed to a vertical central
power shaft.
Orientation of the blades is reversed
twice during each rotation so that maximum lift is
High-speed small-diameter designs have
achieved.
Fur:her develcpment of this
considerable vibration.
rotor is currently in progress at the Cranfield College
of Technology, United Kingdom.
3. Threfz novel conwpts
Three novel concepts for utilizing wind power for
water pumping have recently been proposed. Although
these ideas have not yet been given full-scale demonstra-
Documentation on wind energ!
tion, their simplicity of operation and low-cost construction makes them worthy of further consideration.
(a) The flapping-vane wind pump (figure 22
and reference W 45) has beeen designed for use with
deep well piston-type water pumps, although it mav be
adapted to diaphragm pumps,or to a crankshaft fi~~\‘heel
to produce rotary motion. This device consists of a
long lever arm with a cloth vane mounted on a
horizontal axis at the outer end and a vertical reciproeating power rod at the fulcrum end. The vane ,-a,,
swing freely about its axis within the range of an upper
and lower angular stop.
Action of the wind on the
vane alternatively depresses and lifts the lever arm
with resultant power applied to the reciprocating rod.
The lever fulcrum is mounted on a pedestal which can
rotate on top of the tower in order to allow the vane
to automatically orient itself to the direction of the
wind. This device is expected to pump 100 m3 per
day from a depth of 40 m with a wind velocity of 16
km/h when the vane area is 29 rn” and the lever arm
With increasing wind velocity, the
is 20 m long.
amplitude of the up and down motion of the lever arm
decreases and the frequency increases, so that the
system is self-regulating.
(b) A tree pump has been proposed that
converts the horizontal motion of a tree trunk swaying
in the wind to reciprocating vertical motion of a piston
pump, via cables and pulleys. In this device, the only
cost is for the power trausfer mechanism and pump.
This method is limited to sites with tall unsheltered
trees.
(c) A parachute pump (figure 23) has been
proposed as a low-cost method of supplying
power to traditional animal-powered bucket pumps.
This system comprises a large parachute Lvhose
circumference ropes are tied to the lift rope.
The force of the wind on the parachute pulls the
bucket to the top of the well, at which point a rope
attached to the centre of the parachute becomes
tightened and collapses the parachute so that it may be
returned to the starting point by the operator, and the
bucket can return down to the base of the well. The
parachute is then again allowed to fill with wind to
begin another lifting cycle. With this system the only
expense is the wind collection device (parachute).
The pump and transfer mechanism exist and there is
no need for a support structure.
D.
CLASSIFlCATION
OF WATER PUMPS
A comprehensive international classification of all
types of small pumps used for water pumpicg is
urgently needed. Such a classification could ticll:de
the following information regarding each VFL of
pump; typical schematic diagram, normal rm?e of
suction and discharge heads, normal range cf ou;?llt*
construction materials and skills required, usllal mode
of power supply, efficiency, range of operat%
sIkcd
and torque.
I.
Working papers presented by the secretariat
85
Spoke
;,(“““1
A.1
r,._
_a
-.--__A--’
‘\
‘\.I 1---__
‘\
,*
‘Ykbf~
I /’’
i
+?--i
r9
u
Figure 16.
I
View fromabove
Chinese vertical-axis rotor
wind
View
Figure 17. Turks and Caicos islands vertical-axis rotor
from above
86
Part Three.
Documentation on wind energy
4.9/
Figure 18. Thai jib-sail rotor
Plywood
template
Sheet
met01
Figure 19. Three-tiered Savonius rotor
Gyrorotor
Figure 21.
Figure 20. Darrieus rotor
blade modulation
Gyro rotor
I.
Working papers presented by the secretariat
87
I. Canvas soil
I
2. Lever arm, wood
3. Lever fulcrum
\
4. Wooden frame tower
\
5. Sail fmmework
6. Swivel stop
\
7. Balancing weights
.
6. Universal
joint
9. Pump rod
\
a
C’
2
”
4
”
Scale
6
’
!
0
”
IO m
’
II
I
I
I6
Figure 22.
/2
Flapping-vane rotor water pump
Wind
i
Figure 23.
Parachute-type water pump
9
Part Three.
88
1. Reciprocating pmnps
Most reciprocating pumps have the disadvantage
that the torque load is not constant, thus requiring a
higher wind velocity for starting, and variable stresses
on the system when in operation.
(a) The single-acting cylindrical piston pump is
most frequently used in wind-powered . pumping
systems. It consists of a cylinder with an inlet pipe
and valve at the base, a leather-sealed piston with a
one-way valve and a water outlet at the top, water
passing through the pump only on the lifting stroke of
the piston. This type of pump is used to pump water
from any depth, with an operating speed of up to 40
strokes per minute.
(b) A square wooden single-acting piston pump
is commonly used by fishermen in eastern Canada
(figure 24) and has recently been adapted to wind
A square wooden pump
power (reference W 46).
powered by the wind has been proposed for use in
The height of lift is
Thailand (reference W 47).
limited by the amount of water pressure that can be
sustained by the wooden joints, although the simple
construction is well adapted to basic carpentering
skills.
(c) The double-acting piston pump (figure 25)
is similar to the single-acting pump, except that
there is no valve or passage of water through
the piston, the water by-passing the piston cylinder
through pipes and valves under pressure during
both the upstroke and the downstroke.
The
advantage of this pump over the single-acting pump is
that the load on the power source is more constant, but
it is not usually used in wind pumping systems because
any compression load during the downstroke could
buckle the long piston rod leading from the top of the
tower: this problem could be avoided if a very short
piston rod were connected to an immediately adjacent
rotary power transfer mechanism powered by a long
belt leading directly from tbe rotor shaft.
(d) The diaphragm pump (figure 26) consists
of a cylinder closed at the lower end, with a circular
diaphragm of rubber or some other flexible material
fixed at the top end. A reciprocating connecting rod
is fixed to the centre of the diaphragm and, upon
vertical movement, causes volumetric displacement in
the cylinder. An arrangement of valves allows water
Imovement in only one direction through the cylinder.
‘fbe difhculty with thii type of pump is the high rate
of wear on the diaphragm at its connexions with the
cylinder and connecting rod. A diaphragm pump has
been developed for use with a Savonius rotor (reference W 24).
(e) The inertia pump (figure 27 and reference
W 48) is a very simple and efficient device that depends
Documentation on wind energy
upon the vertical inertia of a body of water in a re
ciprocating pipe to expel water at the end of the
upstroke of the pipe.
A one-way flap valve in the
pipe is closed during the upstroke, and inertia is imparted to a fresh volume of water by the lifting force
on the pipe. This pump must operate at a constant
frequency which is dependent upon the mass of water
in the pipe and the pipe itself. This recently popular&d
pump has probably not yet been used with wind power.
2. Rotary-motion pumps
Continuous rotary-motion pumps are well adapted
to operation by wind power because they require a
constant torque load and generally operate at a variable
low speed.
(a) The square-wooden-pallet chain pump
(figure 28 and reference W 49) is commonly used in
China and southeast Asia for lifts up to 3 m and
consists df rectangular wooden pallets or paddles
mounted on a continuous wooden chain that runs up
an inclined square-section open wooden trough. The
paddles and chain pass around a large wooden driving
gear wheel at the top and around a small passive gear
wheel at the base of the trough which is submerged in
water.
This type of pump is commonly used with
Chinese vertical-axis wind pumping systems and with
Thai high-speed wooden rotors and Thai sail rotors.
(b) The round-steel-washer chain pump (figure
29 and references W 12, W 15) is used in conjunction
with human and animal power, and consists of a continuous steel chain upon which are mounted ;:eel discs
with rubber or leather washers. The chain passes
around an upper gear wheel, down the well, under the
water source, around and then up into the bottom of a
pipe with inner diameter the same as the washers.
Water is lifted up within the pipe and expelled at the
A square wooden adaptation of this pump is
top.
shown in figure 30.
(c) Large-diameter slow-speed centrifugal pumps
(figure 31) have good potential for low-lift pumping.
The meadow type wind pumps of the Netherlands
are fitted with centrifugal pumps 1 m in diameter and
0.2 m high, with four wooden blades, am! have an
efficiency of 30 per cent and an output of up to 100 m3
per hour in a strong wind. Further design development and quantification of design variables of these
pumps could be undertaken.
Another type of centrifugal pump is the centrifugal
reaction pump (figure 32) which consists of a- vertical
pipe with a T-joint at the top, from which extend two
pipes whose length is dependent upon the rate of
An orifice at
rotation of the assembly in operation.
the end of each pipe arm points, 90’ away from the
When the assembly is f%d with water and
arm.
I.
Working papers presented hy the sxretariat
a9
-
Wooden rod
connected ot top
to crunkshcft,
1
V’. .
&y
;
I
l
1’:
&
l
.
i
: .
f
I.
I
i
I
:
/
.
’
Piston
-
i
to leather
.
flap
l
/
Foot valve -
F,pxe 24.
Square wooden piston-type water pump
!I
Connecting
II
rod
Rubber
or leather
e
Figure 26.
Revtirsed
I’-+t
valve rernovcd
lowe: washer
Diaphragm-type v;ater pump
Part Three. Documentation on wind energy
90
-
_-.--.-.-.-----If
output
Flap
valve
15-20 cm amplitude
80 strokes/min
PERFORMANCE
Pipe
dia.
Lit?
OF INERTIA
.
I&W
m
I/h
7.6
4
6.640
c.09
10.2
2
9.060
0.06
15.2
I
1.704
0.06
cm
)
PUMP
‘+
b
a
%
Spout-J
-IO cm dia.
pipe
Figure 27. Inertia-type water pump
t.
Working napers presented by the secret&&t
0
1
0.5
I
Scale
1.0
m
I
Figure 28.
Wooden-pallet-type water pump
rotated in the direction opposite to the orihces, the
water is forced out through the orifices by centrifugal
force and replenished by water coming up through a
valve in the bottom of the vertical pipe. This pump is
well adapted to variable low speeds, and construction
is simple. One of these pumps, connected to a 3-m
diameter high-speed wind rotor, pum-ped 30 ms per
hour at a head of 4.5 m in a 29&n/h wind (reference
w 50).
(d) Axial-flow pumps have good potential for
low-lift pumping because of their relatively simple construction and high efficiency. No use of these pumps
with wind rotors is recorded, but it has been suggested
that axial-flow pumps would be appropriate for highvolume pumping of sewage wastes in oxidation ponds
(reference W 51).
Theoretical studies of windpowered axial-flow pumps are being carried out at the
National Aeronautical Laboratory in India.
(e) Archimedean screws are very simple, and
have efficiencies up to 80 per, cent. They have been
used in the Netherlands for large-scale drainage requiring a lift of up to 5 m. Three basic versions are
known (reference W 48):
(i) The type with a rotating cylinder made
of strips of wood and having a spiral partition inside
(figure 33), as in the Tjasker type of wind pump in the
Netherlands, requires a footstep bearing below the
water level, and demands a fairly sophisticated level of
construction skill. It can be made large in diameter
Such a
and so suitable for slow-speed operation.
screw, 2.7 m long, 0.56 m diameter and lifting through
1.3 m at a speed of about 30 rev/min, gives an output
of 32.4 m3 per hour.
(ii) The type in which the outer casing is
stationary and the helical rotor is supported on bearings
at either end, &tar&d
tg th_p ra&.g,
ore gorma!ly
nf
smaller diameter and run at a high speed, e.g. 12-cm
diameter up to 200 rev/mm, 40-cm diameter up to 127
rev/mm. An advantage of this type is that the casing
and rotor form a self-contained assembly which does
not require external bearings but only simple supports
to maintain it at the correct angle and axial position.
The screw is made by rolling a flat steel strip between
rollers set at an inclination to each other to squeeze
one edge of the strip and hence cause it to curl into
a helix, which is then welded to an inner cylindrical
pipe.
(iii)
A third method of constructing an
Archimedean screw is to coil a section of pipe into a
cylindrical helix. A particular type has recently been
evolved for field drainage in which the tubing is corrugated with a fine pitch to strengthen it and to allow
coiling to a small radius. This could form the basis
of a simple low-cost pump, since most of the construcFor example, a stout
tion could be done locally.
bamboo could serve as the main axle, and the coils of
pipe could be held in place by lashing with rope, wire
or any suitable local fibre, using longitudinal strips of
bamboo or other wood to form a supporting cage on
the inside of the coils.
Part Three.
92
Documentation on wind energy
I II Ml IAM-Steel
Figure 29.
Steel-washer chaintype water pump
Figure 30.
Square wooden enclosed
chain-type water pump
L Working papers presented by the secretariat
93
I
hlttet
-Pipe
Z.Scmdia.
.Drive wheel
/
Aais
of rotation
-
/.
Slidinq shutter
u
Figure 31.
Large-diameter slow-speed centrifugal-type water pump
\
Orifice
in slidinq
shutter
Figure 32.
Centrifugal reaction-type water piimp
Discharge
--B---B---_
j
I
I
Wheel for turning
the mill into the wind
Figure 33.
Netherlands “Tjasker”-type rotor and water pump
Part Three. Documentation uo wind energy
94
(f) The peristaltic pump (figire 34) consists of
a flexibly hose with a series of rollers rolled along the
length of the hose in order to squeeze water through
the hose. This type of pump has reportedly been
adapted to a Greek sail wind rotor at the Malaysian
Agricultural Research and Development Institute.
mind that the precise characteristics of the main types
of iow-cost locally-constructed rotors are not readily
available. A reasonable compromise must be made
between high reliability, durability and maiutenancefree operation on the one hand, and low construction
cost on the other hand, taking into account’ that increased labour input will generally result in lower
capital input.
Selection of a rotor is also dependent upon the
type of pump to be used. To maximize the eficiency
of power transfer, the torque, speed and power characteristics of the rotor and pump should be as similar as
possible.
inlet
C.
SELECTION
OF PUMP
Selection of the type of pump depends on the total
pumping head, the type of rotor and the local materials
and skills available for construction. The use of
traditional local pumps, whenever possible, will reduce
the problems of introducing a new technology.
Figure 34. Peristaltic-type water pump
D. DETERMIN.ATION
(g) A simple water pump operated by compressed air (figure 35 and reference W 46) is currently
being tested. The advantages of this pump are that it
can be located some distance from the compressor, two
or more pumps could be operated by one compressor,
or one large pump could be operated by two or more
smaller compressors.
(h) A hydraulically operated water pump (figure
36) is currently under development by the Ministry of
Lands, Settlement and Water Development in Tanzania.
This pump was designedto solve the problems of using
piston pumps in very deep and narrow borehole wells.
The starting, rated and maximum operating wind
velocities of the rotor must be known to determine the
Division of the daily water
load factor (figure 4).
demand by the load factor will yield the desired rated
output of the pump. If this rate is greater than the
maximum output of the type of pump selected, the
need for a pump with greater output or the use of more
than one pump is indicated if the total demand is to
be met.
E. DETERMINATION
REQUIREMENT
III. DATA ANALYSIS AND CRITICAL
DECISIONS
A.
B.
SELECTION
OF ROTOR
The selection of the type of rotor requires careful
consideration of local skills and materials as well as
operating and performance characteristics, bearing in
OF THE RATED POWER
OF THE PUMP
The rated power requirement of the pump may
be obtained from the following relation:
Desired output in m3/sec X hezd in m X 9.8
DETERMINATION
OF RATED WIND
VELOCITY AND WATER DEMAND
For the months of greatest water pumping demand, graphs such as those in figures 3 and 4 should
be prepared on a monthly basis. If continuity of wder
,zupply is important, the rated wind velocity choseI,
would be somewhat lower than if maximum output
were the only goal. Daily water demand should be
summarized on a monthly basis.
OF DESIRED PUMP
OUTPUT
Power (kW) =
Pump efiicicncy in per unit
F.
DETERMINATION
OF THE NEED FOR AN
ORIENTATION
MECHANISM
The need for an orientation mechanism may be
determined by analysing the frequency of each wind
direction as in figure 5. In many tropical, and especially
coastal, areas, the wind blows mainly in either of two
opposite directions. In such cases, the we of a tiedaxis rotor can save considerable constnction expense.
If an orientation mechanism is required. the choice of
manual or automatic orientation will &pend on the
number of changes in wind direction.
L Work+
papers presented by the secretariat
Reciprocating
drive rod
95
piston
Pressure
Hydraulic prissure
delivery’ pipe
Compressed
air inlet
1 continuous)
n
Air exhaust
-7
Ii
/
.Valve
..*-.
waler
11,
. . -4
-=&GJ+$fJ
Water table
-\
-
Water inlet boba
(closed position)
Non-return valve
Figure 36. Hydraulic-drive water pump
Figure 35. Water pump driven by compressedair
.
96
Iv.
A.
COMPONENT DESIGN ANb hATCHING
CONTROL MECHANISMS
Mechanisms to step the rotor and to control rotorb5de pitch angle, blade area and pump stroke should
he incorporated in *he design in order to allow operation under a maximum range of wind velocities, without
damage. The pitch angle of rigid blades may be controlled by centrifugal governors or blade coning. The
pitch angle of non-rigid sails may be controlled by
manual or spring adjustment of the trailing edge tension.
The area of sails may be controlled by furling. Pump
stroke may be adjusted by changing the fulcrum point
of a lever.
B.
ROTOR RADIUS
The required radius of the rotor in metres depends
on the power output required in kW, the rated wind
velocity in km/h, and the rotor and power transfer
efficiency according to the relation:
Power =
whae:
0.0000255 R* v3 (eff, X efft)
eff, =
&ciency
efft =
efficiency of power transfer in per unit
of rotor in per unit
The maximum size of the rotor may be limited by
the maximum length of spar material available or by
the type of tower materials.
C.
PUMP SIZE
The size of the pump is a direct function of the
desired rated output, speed of operation and efficiency.
Materials or power available will usually determine
the maximum pump size.
Part Three. ~cumentation on wind &ncg
--c -rod from being twisted when the carriage assemblv~
rotor shaft turn in response to change in wind 6
It is desrrable Jo keep the stroke of a cranu
small as possrble m order to minii
turnhz
diameter but, with commonly available piston punx
it is desirable to m.ake the stroke as long as m%
This apparent confhct can be resolved by using a kz-rt
arm as shown in figure 8.
E. ORIENTATION
The orientation mechanism can take the form d
a classic tail vane for automatic orientation or, a-h-tfc
changes in wind direction are not frequent, a mad,.
operated tail rope as in Thai wooden-blade w-&j&
(figure 15) or manually-shifted A-frame a~& supm
as in the Netherlands Tjasker type (figure 33) a4
Chinese diagonal-axis type (figure 37).
The function of the turntable is to allow the dor,
main shaft and carriage assembly to rotate only ah
a fixed point in a horizontal plane on top of the fiw
tower and to prevent any vertical or horizontal mm*
ment. Vertical power transfer usually [email protected]
the centre of the turntable, but a considerable saving
in turntable construction cost may be achieved b
having the power transfer outside the turntable.
Multi-blade wind pumps incorporate a ball-bearing
turntable, bu- :i :.k+!t: &eased circular steel ring has
proved adequate for Greek type wind pumps. The
Thai wooden-rotor wind pump (figure 15) uses a
tapered wooden post inserted into a wooden hole in the
carriage assembly, with thr pwer going down oufdc
the post.
F.
D. ,POWER TRANSFER MECHANISM
The function of the power transfer mechanism is
to transfer the rotary motion of the rotor to the pump,
and the design depends upon. the type of pump used
(reciprocating or rotary motion) and the type of rotor
(horizontal- or vertical-axis).
For rotary pumps, difEerencesin speed between
rotor and pump up to a ratio of 4:l can be compensated for by a single-step pulley or a gear transfer.
Rotary motion of a horizontal shaft can be converted
to vertical rotary motion by gears and transferred to
ground level by a rotating power shaft, or horizontal
rotary motion at ground level can be obtained by the
use of large diameter upper and lower pulleys and a
steel chain or cowhide belt,
Vertical reciprocating motion is usually obtained
from a crankshaft, and passed down through the centre
of the turntable to the pump by a steel or wooden connecting rod which incorporates a swivel to prevent the
MECHANISM
HUB, MAIN
SHAFT, BEARINGS
‘l-he selection of hub, main shaft and bearinp b
most important because rotor load stressesare ConcCatrated on these components.
The function of the hub is to connect the root c=J
of the rotor spars firmly to the main shaft. The hub
must withstand the centrifugal force of the rotor, d
bending loads of the rotor spar causedby wind Pram
and rotor torque. These forces (indicated in fiFut
38) are quantified in the following formulae:
Centrifugal force (kg) = O.OOZg \I’ t; \z
-x-Torque (m - kg)
=367
Wind pressure (kg)
=
0.00142
l3.P
tv
v- R:
for a spinning rotor, and is increxd t?’ ‘sxz
the solidity factor for a Stationa? r”‘o;
L Working papers presented by the secretariat
Figure 37. Chinese diagonal-axis rotor water pump
97
Part Three. Documentation on wind energy
98
-J+5,
Crnlrtfupal lood lc )
rt
wires, when possible, will significantly increase over-all
tower strength at little cost.
The minimum tower height should be at least
equal to the rotor radius plus 1.8 m (for safety of personnel). Efforts to make the tower much higher than
this should be avoided because the additional cost is
likely to be greater than the increase in benefit, except
in locations with nearby wind obstructions.
Wind
H.
CARRIAGE
ASSEMBLY
The carriage assemblyprovides a firm but movable
foundation for the main shaft bearings upon the tower,
and may be of wood or steel. It must be fastened to
the turntable in such a way that it may turn in response
to changing wind direction. The tail is fastened to the
carriage assembly.
I.
Figure 38. Loads on rotor
where: P
R
RI
t
t1
V
W
= power in kW
= radius of rotor blade in m
= radius to centre of gravity of rotor
blade. in m
= tip speed ratio at tip
= tip speed ratio at centre of gravity
of rotor blade
= wind velocity in km/h
= weight of the blade in kg
The main shaft must bear the weight of the rotor
and withstand the torque and bending forces applied
by the power transfer mechanism. The shaft may be
made from wood, steel rod or steel pipe.
Simple wooden bearings or steel ball or thrust
bearings may be used. If steel bearings are used,
adequate protection must be provided against dust and
rain. Wooden bearings should be capable of easy replacement. Provision must be made for lubrication.
G.
TOWER
Determination of the type of tower is primarily a
function of the materials and skills available. The
Windworks octahedron module design (figure 10) has
the highest strength-to-weight ratio of any non-guyed
tower, but construction is complex and must be precise.
Lattice steel towers (figure 6) are strong and well
proven but quite expensive. Single wooden pole
towers (figures 7 and 15) are the cheapest, but
can only be used when it is not necessaryto have the
power transfer down the centre of the tower. Multiple
wood pole towers (figure 8) are cheap, strong and
easy to construct, and use is limited primarily by
resistance to wood ants and termites. The use of guy
STORAGE TANK
The maximum capacity of the storage tank is
determined by multiplying the longest period of wind
less than starting velocity by the daily water demand.
Overhead storage is not economical unless pressurized supply is required. A ground-level tank may
be constructed of stone masonry about 1 m high.
Possible additional uses of the storage tank for bathing
and fish culture should be taken into consideration.
J.
WORKING DRAWINGS, MODEL
After preliminary sketches of each component
have been prepared, the final working drawings should
be made, showing the details of and ccnnexions
between each component.
A l/S scale model should be made and tested in
order to gain familiarity with the construction process
and to carry out design optimization trials.
OdY
after a model has been tested to full satisfaction should
construction of a full-scale prototype proceed.
V. A HYBRID ASIAN WIND-POWBRED
WATER PUMP
In this section, an example is given of the design
of a low-cost wind-powered water pump according to
the sequential flow design process suggestedin figure 1.
An effort has been made to base the design on conditions common to many parts of Asia.
A.
PRELIMINARY
INVESTIGATION
1. Survey of local wind characteristics
The average wind velocity at Don Muang Airport,
Bangkok, for 5 minutes of each half hour is recorded
by the Meteorological Department of Thailand. As
noted, the data for the months of Mcrch, April, May
1975 had been summarized and analysed as shown in
figures 2,3 and 4. Data from the airport were selected
because of its exposed location in a rice-growing area
99
I. Working papers presented by the secretariat
and its proximity to the Asian Institute of Technolo,v
and the proposed National Energy Administration
windmill test location.
2.
Survey of loca! water pumping needs
March, April and May were chosen as the period
when irrigation pumping wou!d be most beneficial
because tbe tist crop of rice is already harvested by
February and, in the virtual absence of rain, the fields
are norma.Uynot used until the onset of the monsoon
in June.
3.
Classification of wind rotors and pumps
As a complete classification of wind rotors and
pumps is not available, reference will be made to
previous sections of this report.
starting velocity of 6 km/h and an optimum rated
velocity of 20 km/h in order to obtain maximum
output.
(b) The raw wind data indicate that the longest
period of wind below optimum starting velocity of 6
km/h is 6 hours.
(c) Study of the wind power rose (figure 5)
indicates that an orientation mechanism would be
useful but not necessary; but, for the benefit of other
areas with more variable wind direction, it is assumed
that there is a need for an orientation mechanism.
(d) Analysis of the power duration curve (figure
4) yields a load factor of 0.30.
2.
B. DATA ANALYSZS AND CRZTZCAL
DECISIONS
1. Wind data analysis
(a) Consideration of the velocity and power
frequency curves (figure 3) indicates an optimum
Selection of rotor
Based on the widespread success, low cost and
light weight of the Greek sail rotor, thii configuration
was selected (figure 39). An alternative configuration
that may be used in areas of higher wind speeds is
based on the Princeton sail wing (figure 40).
Bamboo
Wire loop,,
‘stick
soil Rope\
Circumference
sail
Figure 39. Greek cloth sail rotor configuration
Part Three. Documentation on wind energy
Figure 40.
Hybrid Princeton - Greek sail rotor configuration
3. Selection of pump
For generalized design purposes, a total head of
10 m is assumed. Owing to its simplicity of construction and adaptability to variable low-speed rotary
motion, the steel-washer chain pump was selected
(figure 29). However, the square-pallet chain pump
(figure 28) may be best for areas where this pump is
traditionally used and only a low lift is required,
4.
Determination
of desired pmnping rate
Assuming a daily requirement of 6.5~mm depth
per day for rice cultivation and a desired irrigated area
of 2 hectares, the daily water demand is 130 m3 per
day. Multiplication by the reciprocal of the load factor
indicates that the rated capacity of the pump should
be 18 m3 per hour.
5. Determination
of rated power requirement
of the pump
Assuming 0.70 pump efficiency, the rated power
requirement of the pump would be 0.703 kW (section
III. E).
C.
COMPONENTDESZGNANDMATCHING
1.
Control mechanism
Assuming frequent presence of the operator,
furling of the sails would be the primary control
mechanism. An emergency sail-release mechanism
similar to that used on Thai sail rotors would be incorporated (figure 39).
2.
sii
of rotor
Assuming 0.25 and 0.50 for the efficienciesof the
rotor and power transfer respectively, the required
rotor diameter from section IV. B would be 10.5 m.
This size is within the range of bamboo spars
available in Thailand and most Asian places. Sail
rotors have been operated successfully up to 10-m
diameter so this size is acceptable.
3.
size of pump
Given the rated output of 18 m3 per hour and
pump efficiency 0.70, the basis of calculation is 25.7 m3
per hour. Assuming a rated rotor speed of 12 rev/min
101
I. Working papers presented by the secretariat
with a 2:l speed increase and a 0.5-m diameter pump
drive wheel, the size of the. pipe within which water is
lifted by the washers on the chain should be 12.0 cm.
The size of the pipe may be decreasedby increasing the
speed of the chain, which may be effected by providing
a higher drive speed ratio or by increasing the diameter
of the pump drive wheel. The optimum speed of
chain pumps is not known.
4.
Orientation mechanism
Orientation of the main shaft by manual relocation
of an A-frame suppore structure (figure 41) supporting
one end of an extended shaft is suggested because of
its simplicity and proven feasibiity on the Netherlands
Tjasker type (figure 33) and Chinese diagonal-axis type
The opposite end of the shaft rotates
(figure 37).
about a tied, guyed turntable post (figure 42).
5. Power transfer mechanism
Because horizontal rotary motion is required to
operate the chain pump, only a simple direct pulley
drive to ground level is required. Pulley wheels made
of several laminations of wood boards are suggested
(figure 42). Chains are widely used in Thailand as
the transfer connexion and would be suitable.
(c) Simple wooden bearings have been well
proven on Greek and Thai sail rotors and Australian
Comet wind-powered pumps. An improved version
of Greek wood bearings with increased bearing surface
and provision for lubrication has been designedfor both
main bearings (figures 41, 42).
7.
Tower
The tower in this case consists only of the two legs
of the movable A-frame at one end of the shaft and the
turntable post at the other end. The turntable post is
guyed to the ground and the A-frame is guyed to the
base of the turntable post so that it is stabilized but still
free to move.
8.
Carriage assembly
The large wooden bearing blocks also function
as the carriage assembly.
9.
Storage tank
Because the longest period of wind below starting
velocity is only six hours, a storage tank is not considered necessary, although it would be useful for
irrigation control.
6. Hub, main shaft and bearings
(a) A laminated wooden hub was selected
(figure 43) because of its simplicity of construction
and successfuluse on Thai sail rotors.
(b) An extended square wooden main shaft is
successfully used on Thai sail rotors and has been
selected for this hybrid design (figure 43). The shaft
is rounded only at the point where it rests in the bearing
(figures 41, 42).
10.
Fii
drawings
An over-all sketch of this hybrid design (figure
44) is proposed as the basis for construction of models
for testing only. For further development of this
design, model test results should be evaluated and
design modifications incorporated into final working
drawings for prototype construction and testing.
102
Part Three. Documentation on wind energy
-i
,KoW;w
i
/y-f-
7iz
‘Alignment
Isometric
view
‘?
peg
Isometric
view
-
Steel friction
discs,
,Rubber
-
surface
Drive
wheel
I &.^I^
Vertical
wire
20 cm
t
/
10 tigh;
\
cross-section
Figure 41, Double leg support bearing block
Turntable
post’
Vertical
cross-
section
Figure 42. Turntable post bearing block
, Working papers tresented by the secretariat
m.
[email protected]
I
part Three. Documentation on wind rmrl;t
il
104
Cloth or bamboo
Circumference
wires
Radial
wires
.I.0
m dio
laminated
Bamboo spars
5.2 m long
/
/
.I
-wy
w
/0.5
wlrrs
.,v”k
\
m dl0
\
,-.,, I , ‘. -.v
/‘,’ 8’
Figure 44, Hybrid Asian wind-powered water pumpiug system
1
i
i
3
-1
4J
i
(!j
:‘i
:d
;f
105
II.
INFORMATION
PAPERS PREPARED
A REVIEW OF EFFORTS MADE IN INDIA FOR WND
(NR/ERD/EWGSW/CR.3)*
BY PARTICIPANTS
POWER UTILIZATION
by
Mr. S. K. Tewari (India)
Introduction
A systematic approach to wind power utilization
in India began with the formation of the Wind Power
Sub-Committee in 1952 under the Council of Scientific
In
and Industrial Research (see reference W 52).
1955, a conference on large-scale utilization of wind
Subsequently, the
power was held at New Delhi.
Ministry of Health procured 160 imported windmill
pumping sets under an Indian-United States agreement.
The windmills were Southern Cross type No. IZ-D,
with rotor diameter 3.7 m.
By 1959, designs of a local water’ pumping windmill type No. WP-2 were standardized, and the manufacture of an initial batch of 200 was initiated by the
Wind Power Division of the newly formed National
Aeronautical Laboratory (NAL), at Bangalore. This
type of windmill was considered suitable for lifting
water for small-scale irrigation purposes and domestic
water supply in rural areas. It was designed to start
at low wind speeds of about 8 km/h and had facilities
for automatic furling of sails in heavy winds. (For
details refer table 1).
Table 1. DETWS OF TYPE WP-2 WIND PUMP
Rotor:
Wind speeds:
Tower:
Pump:
Performance:
A.
4.9 m diameter, 12 blades
8 km/h cut-in, 16 km/h rated, 48 km/h furling
Lattice steel, 4 legs, free-standing
Reciprocating, 12.5 cm stroke, single-acting
Pump diameter
(cm)
25
20
15
7.5
FEASIBILITY
Lit
(4
3.0
7.6
15.2
30.4
output
(m3/hour)
13.5
6.7
3.4
1.8
STUDIES
Studies were made to determine the adaptability
of some European designsof windmills for use in India.
About 1960, the Government of the Federal Republic
of Germany presented an “Allgaier” wind-electric
This windgenerator for trial and testing at NAL.
electric generator was capable af producing 6 kW,
’ Abridged.
220 V DC at a wind speed of 32 km/h.
It was
installed and studied at Porbandar, Saurashtra (latitude
21”38’ N, longitude 69O37’ E). Table 2 provides
some information related to this study (see also
reference W 53). It was clear that the rated design
speed of 32 km/h was too high even for a relatively
windy location in India.
Table 2.
DETAILS OF ALLGAIER WIND-ELECTRIC
Rotor:
10 m diameter, 3 blades
Wind speeds:
11 km/h cut-in, 32 km/h
Tower:
Tubular steel, one leg, guyed
Generator:
6 kW, 220 V DC at 1,500 rev/min
Performance:
GENERATOR
rated, 54 km/h furling
Wind speed
(km/h)
11
output
(W
0.3
18
2.0
25
4.8
32
6.0
A study was made to assessa Dowsett Holding
type 25 kW wind-electric generator (see reference
W 54). This machine was found to have very limited
potential for utilization in India owing to its high rated
speed.
By 1965, a 250 W, 12 V wind-electric generator
was designed, to have a rotational speed of 400 rev/mm
with a rated wind speed of 25 km/h, and intended to
supply the power requirements of solid state microwave
radio links, using rechargeable batteries. This design
was not developed further (see reference W 55).
B.
WIND DATA ANALYSIS AND SELECTION
OF DESIGN WIND SPEEDS
During 1960-1963, a programme for the analysis
of available records of wind speed was carried out by
the staff of NAL. Several reports were prepared,
tabulating the data in relation to wind power utilization.
A study of the data was recently carried out to enable
some conclusions to be drawn for the country as a
whole (see reference W 56).
Part Three. Documentation on wind emw
106
A report (reference W 57) was published in
1963, in which an, attempt was made to derive the
optimum rated speed for maximum energy output and
minimum cost. Minimum cost criteria were based on
an earlier empirical study (reference W SS), according
to which the capital cost of wind power installations
increases in proportion to the design wind speed.
There is some doubt about the general applicability of
such an observation.
C.
UTILIZATION-ORIENTED
STUDIES
An urgent need for the supply of water for
drinking and minor irrigation purposes in widely distributed villages was identitied. It was considered that
cheap water pumping windmills, starting at wind
speeds as low as 8 km/h, and capable of being constructed indigenously, could readily meet this need (see
reference W 59).
-A report published in 1963 (reference W 60)
showed that distribution of rainfall and wind speeds
during the year was such that peak wind speeds occur
one to two months prior to the peak rainfall, and
another report (reference W 61) showed that, for arid
and semi-arid areas, the peak of wind power precedes
the peak of rainfall by nearly two months. Another
analysis (reference W 62) indicated that some villages
in acute need of drinking water during summer could
utilize wind power.
The possibility of extensiveutilization of windmilldriven water pumping for irrigation has also been
studied. The wind energy distribution during the year
is such that about 58 per cent is available during the
kharif crop when the need for water pumping is low,
and about 22 per cent is available in the rubi season
when the need for water pumping is at its maximum
(see reference W 62).
Incorporation of wind power into the electricity
grid on a substantial basis could add reliability and
consistency to the electricity generated from hydroelectric stations (see reference W 63).
By 1973, about 26 per cent of the nearly half a
million villages in India had been electrified. Most
villages, not yet electrified, are scattered, and distant
from the existing main load centres. An analysis is
in progress at NAL to determine the feasibility of
wind-electric generators located to meet the local
energy requirements in these villages. The economics
of wind-electric systems, compared with existing
methods, are also being assessed. The preliminary
estimates are in favour of uitilizmg wind power for this
application.
-
D. ECONOMZCS
The question Ff economics is fairly involvti
b
is necefsary to. consrder capital cost, interest rota, dtpreciatl?n,
mamtenance and operating costs, and ;rluo
to consider the rehabiity of energy supply in ej,
to the demand for energy for a given application.
'I&
latter relation is difficult to calculate.
An analysis was recently published in whl& -D
cost was plotted against the maximum FnnbX
investment
for a variety of hypothetical win&n& iar
reference W 62). The conclusion of the and\+ art
that wind energy utilization at selectedwind,. &, foa
centralized generation of electricity appeared to bc b
best proposition. The analysiswas not vet e*m&x
and-did not include any forecasts about rises in pri,=
of materials, labour, fuels and rate of inflation A
more exhaustive study along similar lines b k%
attempted at NAL.
E. RECENT DESZGN AND DEVELOpMEji~
EFFORTS
1. Dan-ieus rotor
A design and developmentproject was commmd
in 1975 at NAL for a Darrieus rotor type windmill (a
reference W 64).
The investigation aimed at OEBstrutting a prototype to develop about 1 kW at a aired
speed of 25 km/h. The purposes of the cxcr~&
were to understand and try to overcomethe dcsipr and
fabrication problems, and to test directly in the ai&
normally prevailing in India. Abridged spccifica~
are given in figure 1. A self-priming, comnrcrciall~
available, centrifugal pump rated 1 hp at I.440 r#i
min was coupled to this windmill through a specd-raia%
mechanism of ratio 1:9.3.
The design and operation of this experimraU
prototype has provided some very useful informah
(see reference W 64). Attempts are being made TV
reduce the friction in the bearing system,to [email protected] a
automatic clutch for coupling with electric Faflam
aud pumps, and to improve compatibility bctwm the
starting device and the main rotor.
A simplified method for calculating mean v
coefficients was developed at KAL. A thd
uniform induced velocity1 was restated a a 1a
function for high tip speedlatios, and a slmPir:fmh
was obtained. It was also $ound that prcdiaionr b&
on the uniform induced velbcity theoc VPfcd 1Db
optimistic
when compared with cx~~mcn*~l wa
The discrepancy
to peak power
was greater
output,
and
at tip SPccd m"y'
r'"'M
was considcn% ryfMz’
by applybg
a simple non-uniform
indscd vrarC?
theory (see reference W 65).
II.
Information papers prepared by participants
107
sails, supported by wires in tension. A prototype
windmill 4 m high and 3 m diameter has been constructed costin? Rs. 1,500, excluding pumps. It is
estimated that its efficiency is about 16 to 20 per cent,
and that it produces 0.1 hp with a 15 km/h wind.
3. Permanent magnet genemtor
Bharat Heavy Electricals Ltd. have designed a
5 kW, 400 V, 3-phase, 50 Hz, 1,500 rev/min generator
for windmills. The salient feature of this generator is
the absence of a field winding on the rotor, thus
avoiding slip rings, exciter and voltage regulator.
The performance tests indicated that the permanent
magnet generator was more efficient and inherently
better regulated than a conventional AC generator (see
reference W 66).
4. Further development of the WP-2 windmill
‘__.
-;c--l&zTL-:
,
1_-
2.
- _ ..
.
.-
I
,_-
__
- _--
- .--_
A
Figure 1.
Prototype vertical-axis wind-electric generator
17.2 m*
Frontal area
Blades
The Central Power Research Institute, Bangalore,
has recently made some studies on the early WP-2
windmill. Some operational problems were identified,
such as the frequent loosening of the pump rod,
leakage of lubricating oil in the head mechanism and
rather high sensitivity of the tail vane, and remedial
measures are being incorporated. It was also found
that this windmill had an over-all efficiency of 48.9
per cent for a 6 km/h wind, which was reduced to 6.4
per cent for a 16 km/h wind. For a lifting head of
5.8 m, the quantity of water pumped was 1,000 and
2,400 litres per hour with wind speeds of 6 and 16
km/h respectively.
-
5-m diameter catenary
NACA 0012 25cm chord aerofoil
Starters
-
2 Savonius rotors, 1 m x 1 m
Output
-
1 kW at rated wind speed25 km/h
2. Modified Savonius rotor
At the Indian Institute of Science, Bangalore, a
low-cost modified Savonius rotor type windmill has
been developed for rural application. The rotor uses
5. Low-cost windmill
A 10-m diameter sail-wing type windmill was
erected at Madurai as a demonstration of low-cost
windmills (see reference W 3 1). This windmill had
eight blades and used bamboo for the arms and canvas
for the sails. The quantity of water pumped was
estimated to be 1,635 litres per hour from a depth of
9.2 m, in low wind speeds of the order of 6 to 8 km/h.
It was felt that this windmill could pump more water
if a better-matching reciprocating pump were available.
108
Part Three. Documentation on wind encrEb
I
RESEARCH, DEVELOPMENT AND USE OF WIND ENERGY IN THAILAND
(NR/ERD/EWGSW/CRS)*
The National Energy Administration (Thailand)
IlMJdUCtiOIl
Several types of windmills are commonly used for
water lifting in some parts of Thailand. Most are
locally constructed, using simple wood, bamboo and
cloth materials and ordinary carpentering skills and
tools, but some multi-bladed windmills are fabricated
of metal in Bangkok.
Considerable developmental
work on improved windmills has recently been initiated,
and international ColIaboration is sought for development of a medium-scale wind-electric generator
appropriate for manufacture in the country.
.
A.
WZNDMZLLS USED IN THAILAND
The locations of windmills in Thailand are
indicated in figure 1. Locally-constructed windmills
have been used for brine pumping along the Gulf of
Thailand tid for rice irrigation in the Chao Phraya
delta for at least 40 years. Some details on these have
recently been reported in reference W 20. Several
types of windmills no longer in use ve been reported
by the Royal Irrigation Department 7 reference W 47).
Since the introduction and large-scale adoption of
small diesel and gasoline engine pumps by farmers, the
construction and use of traditional windmills continues
at a reduced rate. With some technical modifications
and improvements, it is hoped that these windmills will
be used more widely by farmers.
There is no evidence, at present, that any windmills are used in Thailand for electricity generation,
although some people have tried to connect two-bladed
wood rotor windmills to DC generators.
from a 30-cm diameter wooden hub mounted b ~)rt
centre of a 5-m long lo-cm square main shaft h
apex of each sail is held tight by a nylon cord fmp
connected to a l-cm diameter nylon rope ~K},-J, h
stretched around the rotor circumference betim ti
tips of each spar. A manually-activated, quick-Rl=
sail-feathering device is incorporated at each imn
connexion (see figure 3). The tips of each SPX &
braced by steel wires to points near the opposite 6
of the main shaft. Each end of the main shaft k
rounded to fit in a notch (journal bearing) cut in h
top of each of the two verticd wooden supporting pol#
The stationary support structure of two wood=
poles is set in the ground in a fixed direction to fcccivc
the winds of the southwest monsoon from one side and
the winds of the northeast monsoon from the O&T
side. Power is transmitted 12 m diagonally by a steel
chain of 2.5cm long open links from a 0.7-m dhmctcr
wooden pulley mounted at one end of the main shalt
to a 0.5-m diameter wooden pulley near the ground
which drives the power shaft of an [email protected]
wooden-pallet chain pump (reference W 49).
The results of two series of performance trials 03
one of these traditional Thai wind-powered uxcx
pumping
systems is summarized in table 1 below.
Table
1. Slow-speed sail rotor type
Several hundred 7 to 8-m diameter bamboo-mat
sail rotors (fig&e 2) are used for brine pumping at
the salt farms along both sides of a 10&m section of
the highway near Samut Songkram. Each of the six
sails of these windmills consists of a triangular mat
woven from split bamboo and reinforced with nylon
cord.
Each sail is fastened by wooden slats and
nails along its long edge to a bamboo spar radiating
l
Abridged.
RESULTS
Number
01nialt
Scricsl..
scrics2
At present there are three basic types of windmills
in active use for water pumping; the slow-speed sail
rotor type, the high-speed wooden rotor type, and the
multi-blade steel rotor type.
1.
.
.
OF PERFORMANCE
Avnogc
rrial period
kJ
dfrrrrgr
wind rprrd
(km/h)
I’umpct
hd
fm:
TRIALS
llrrrp
drr.tip
fr,rnr,
10
39.1
17
0.55
If3
6
35.0
13
0.60
!I.&
m.
Detailed technical drawings of this type of windmill have been prepared by the Agricultural Engincctig
Division, Ministry of Agriculture and Co-opcrativtThese bamboo-mat sail windmills are cans~ruc!~
0x1site by their owner/operators, using a minimum cd
carpentry skills and tools. The lifetime and coFl d
the components are enumerated in table 2.
Assuming that a Thai bamboo-mat sxil @ix%
powered pump operates 8 hours per day, 20 da>> F
month, 8 months of the year at an average f?“rV%
rate of 15 litres per second, the cost of waicr p.;F?z:
is 0.0167 baht per cubic metre, lvhich is cq-ir J!S: L
$US 0.83 per 1,000 m3 (at the exchange r3:: (-! :L i ’
baht per $US 1.00).
.
.-J
I
-..rl.\
o Ciif3ngroi
o Chiangmoi
‘1..
1
=\
i
f
.,
i’--‘.\
..- -I
‘6i
~../.’
Nong Koi
\
%
Khon Kaen
L..I
0
i
i
-1..
o Nokom Sowon
I
r-j
--\
‘-1
4 Nokom Phoncm
-y
?
rr
i*,.
See
inset
00
(
0
f-j
f
Nokorndchosima
..-“Y..-s-c\.
oSoroburi
,i
-*.
5
o Ubo? Rachothonee
.
!
/’ >
0
\
-.
I
b
\
ykor
n’pathom
(I
__. I
b
&Ban
Laem
Guf f
.
L BANGKOK
of
Thailffnd
Figure 1. Map of Thailand indicating windmill locations
110
part Thr=-
bcumen&dOn
Table 2. TYPICAL COST AND LIFETIME OF
COMPONENTS OF BAMBOO-MAT SAIL WINDMILL
Inirial
roti
(baht)
.
Rotor-sail, bamboo mat .
6 @ 23
TM
_
year COII
(bah!)
ldctimc
fY=-l
138
1,380
1
85
170
5
88
880
1
140
1,400
I
300
5
Wood slats
.
.
.
6 and nails
Nylon cord
.
.
.
2.5 kg @ 35
Nylon rope
Steel wire .
.
.
.
.
.
4.0 kg @ 35
.
5.0 kg @ 30
150
Bamboo spars .
.
.
6.0 kg @ 5
30
100
3
wood main shaft .
.
lOcmXlOcmX5m
200
200
10
Woodhub.
.
.
1
100
200
5
.
.
2 @ 250
500
500
10
.
.
chain 24 m
800
800
10
Supporting
.
poles
Power transmission
Upper pulley
.
.
.
1
200
666
3 6
Lower pulley
.
.
.
1
200
666
3
3,000
--
4,286
5,631
--
11,548
Wooden-pallet
Total
chain pump
.
.
.
.
1 .
.
.
.
.
.
.
.
.
On wind -
*
7
About 30 cloth sail windmills are used for h
pumping at three salt farm areas near Chol Buri, dq
the Bangkok-Chol Buri highway. This type of aamill is also known to have been used at Ban La=
Petchaburi, the largest salt-producing area in ThaiIan&
but they have been replaced with diesel and gasoline
engine pumps because of the advantagesof portabilixy
and greater control over water pumping. ~hc chd
Buri sail windmills vary from those near Gamut
Songkram in that the 7-m diameter rotor consists d
eight trapezoidal cloth sails (see figure 4). The OUR
of the cloth sail variation of the bamboo-mat windmi5
is about 5,000 baht including the wooden-pallet cbaia
Pump.
2. High-speed wooden-rotor type
High-speed wooden-rotor type windmills ut
commonly used for water pumping in the cn%Ia!
provinces of Chachoengsao and Samut PnLn
southeast of Bangkok. These windmills are USedfa
lifting brine at the salt farms near Bang PakonE d
for water lifting for rice irrigation in the Chao Phm?a
delta, especially in the paddy arcas Surromdh#
Chachoengsao (see figure 5).
Figure 2. Bamboemat sail windmill
The rotors of these windmills consist of ~0 *
four wooden blades. Two blades arc _rcncrZI~!’d
nearest the coast in higher winds, while four h!adfs ST
used inland where lower wind speedswould czusc Ki’):cwz
starting problems for the two-blade rotoK
blade rotors are sometimes used near tic @ ti’
II.
I
f
111
Information papers prepared by participants
)
---
-‘.
-i .‘-
. -.
-
., - ,
.?
Figure 3. Quick-release sail-feathering device
Figure 4. Cloth sail windmill
Part Three. &xumentation on wind encte_\
112
-
on the lower shaft of the wooden-pallet chain pump s
cowhide rope or chain transmission can he &M
through. 180’ in response to changing wind The horrzontal top and bottom planks of the frame each
have a round hole about 10 cm in diameter to maib
a short to-cm diameter section cut at the top of the
25-cm diameter and 5-m tall single wooden pole tm=.
The approximate cost and lifetime of the mmponents of this wooden-rotor pumping systemare summarized in table 3. A performance test of 10 pump’rr\m
trials on one of these pumping systemswith 0.9-m &
indicated that an average of 25 likes per second is
pumped in an average wind speed of 21 Irm %.
Detailed drawings of this type of windmill have kai
by the Agricultural Engineering Division.
Table 3. APPROXIMATE COST AND
LIFETlME OF COMPONENTSOF A S-BLADE \\'Is~J~IJ~
Rotor - hvo 3-m long blades and
one S-cm diameter steel shaft
with roller and taper bearings
2,800
1,400
20
Supporting structure - 3 wood
poles 25-cm diameter X 10-m
long
. . . . . . .
600
600
10
belt
.
_
.
.
.
-
-
5
Ladder pump
.
.
.
.
.
2,000
2,850
7
Cowhide
These windmills are manufactured upon order 31
a carpentry shop in Chacheongsao. Before thr
introduction of small gasoline pumping units, this shop
produced and sold more than 200 windmills per year.
Figure 5. High-speed wooden-rotor windmill
3. Multi-blade steel rotor type
higher lift, higher torque loads. Each pair of blades
Multi-blade windmills were introduced to ‘D&tnd
more than 10 years ago, and more than 20 have hccn
sold in several areas of Thailand. There have hcca
few recent sales because of the high initial co%
Eight 4.9-m diameter “Demster” multi-blade (waler
pumping) windmills were imported by the Division d
Agricultural Economics, Ministry of Agriculture and
Co-operative (see table 4), and two replicas PCY:
manufactured by the Division.
is carved from a single hardwood plank 8 m long, 20 cm
wide and 5 cm thick so that it forms a crude but effective
aerofoil, including some twist.
In some places, four triangular cloth sails fitted to
wooden spars are used to replace the high-speed
wooden rotor on this device so that the mechanism
will operate in lower wind speeds.
Each rotor is fastened in the centre by four bolts
to a small steel plate hub welded to the end of a 3-cm
diameter, 60-cm long steel main shaft. The steel main
shaft rests in two steel ball bearings mounted in the
front and rear vertical members of the wooden sup
Older high-speed windmills simply
porting frame.
utilize a g-cm square wooden main shaft rounded at
each end to turn directly on a wooden bearing surface.
Power is transferred by a twisted cowhide rope or steel
chain from a 0.35-m diameter wooden pulley attached
to the shaft directly to a l-m diameter wooden pulley
Simpler 2.4-m diameter multi-vane windmilfr
have been designed and made by a small-scale xnanufacturer in Bangkok (see figure 6). These are [email protected]
to the American fan mill, except that the Thai v;lrW~~
(known as Sanit) uses a crankshaft instead of a IV’
mechanism to transmit power from horizontal rol3n
motion to vertical reciprocating molion. This J+$
mill is used with a 7.6-cm diameter piston purr,? ~~~~~
10.2 cm stroke. The output of this windmill 21 Lk
starting wind speed of 6 km/h is 500 hues SJCrhG*
and output at 10 km/h is 800 litres per hoar. [email protected]
II.
113
Information papers prepared by-participants
of these windmills have been distributed to several
locations (see table 4) withii the past five years
(including . some provilzd to the villagers in the
northeast provinces by 752 Military Mobile Development Unit), and the manufacturer hopes for further
sales. It is probable tilt expert design optimization
could result in sign&am cost reduction of this device.
B.
It was reported by tie manufacturer’s representative that 300 Southern Cross multi-blade windmills
have been sold in Thailand in the past 15 years but the
location of these mills has not been determined.
Development of improved water pumping windmills within the Ministry of Agriculture and Cooperative is actively patronized by his Majesty King
Bhumipol.
.
:
-..:--
-.-.
..--
.-..
“.li,_.
I’--.
-.
-‘-
CURRENT ACTIVITIES
After the energy crisis, much attentioti has been
given to harnessing wind energy in Thailand.
The
simple traditional windmills have been re-examined,
and other types are being developed for both pumping
water and DC electricity generation. Several organizations are concerned in these developments.
1. The Agricultural Engineering Division, Ministry
of Agriculture and Co-operative, has a programme
under way for experimental wind-powered water
pumping units. One of the experimental windmills is
a variation of the Chinese vertical-axis type constructed
from a combination of metal, wood and bamboo mats.
It is the intention to develop this type of windmill for
low-cost operation on farms.
:
.
*
2. The Division of Agricultural Economics, Ministry
of Agriculture and Co-operative, has conducted
economic trials of windmill pumps for farms in four
provinces, using ten Demster windmill pumps (eight
imported and two copies made by the Division). The
results, analysed from data collected over four years,
indicated very successful operation. The cost of each
locally-made windmill can be recouped out of the incremental agricultural production in about four years.
The Division strongly suggests that more farmers use
these windmills.
3. The Royal Irrigation Department, Ministry of
Agriculture and Co-operative, has recently installed an
improved four-bladed water pumping windmill at Wat
Bang Chak, Ang Tong province, for lifting water from
the Noi River to irrigate a bean crop of 16 acres to
replace a crop lost in the floods.
The Meteorological Department, Ministry of
Communications, has more than 50 weather stations
throughout Thailand, from which wind velccity data
based on hourly readings are available, for preliminary
evaluation of wind energy potential. These existing
weather stations can be modified to record wind data
continuously, as required for comprehensive wind
energy evaluation prior to extensive windpower
development in the country.
4.
Figure 6. Locally-rz3de multi-vane windmill
Table 4.
LOCATION ANDNUMBEROF
DC??ZItW
NC--y hi (4)
Pc:~LGxlri (1)
ss-?wi
(3)
Xi;.-rn
Phanom (2)
MULTI-VANE WINDMILLS
Sad
Others
Udorn Thance (2)
Burirum (1)
Grin (1)
Bang Sarac, Chol Buri (1)
Bang Khcn, Bangkok (3)
Ban Dan, Samut Prakarn (2)
Pattaya (1)
Hua Hin (1)
‘1
.>’
Part Three. Documentation on wind encw
114
The National Energy Administration (NEA),
Office of the Prime Minister, is interested in the
development of small-scale renewable energy sources,
and, in September 1975, established an Energy
Research and Development Unit. NEA has gathered
much relevant literature concerning wind energy and
other renewable forms of energy, and has assessedwind
data obtained from the Meteorological Department.
A group of NEA engineers has been investigating
traditional uses of windmills in several areas and is also
preparing detailed questionnaires. A research centre
(which will carry out testing of different types of
windmills) is under construction at Rang Sit, near the
Asian Institute of Technology.
5.
NEA has also proposed a five-year plan, starting
from the year 1977, on research and development of
alternative ener,y scurces, which includes wind energy.
Thii proposal is under consideration by the National
Economic Development Board. The goals of the wind
energy section are to:
(a) Carry out research and improve efficiency of
wind energy use for water pumping in salt farming, fish
culture, irrigation, and domestic use in villages;
(b) Develop wind energy units for mechanical
and electrical Power sources in the villages as a substitute for sources of energy based on Petroleum
products.
The programme of research and development for
the five-year plan includes:
(a) Gather all available literature concerning
wind energy;
(b) Purchase wind-measuring instruments, and
install at locations of interest;
(c)
Collect, compile, analyse and assess wind
data from the Meteorological Department and NEA
stations;
(d) Survey the present use of wind energy in
Thailand;
(e) Make improvements on traditional Thai
windmills;
(f) Design, construct and test a slow-speed,,-amti for multiple uses;
(g) Purchase and test a small-scalewind+]DC generator;
(h) Install several improved windmilk
demonstration units (water pumping and provision z
mechanical power) ;
(i) Survey the electricity demand in the rem*
areas where wind data have been collected;
(j) Design, construct and evaluate a large-de
windmrll pump at the NEA electrical pumpbe sta~ia3
on the Mekong River; followed by adaptation of ti
design, and construction of a 5-10 kW windt]eclk
generator;
(k)
Apply similar units where appropriate;
(1) Evaluate over-all progress in wind rese;iKb
and plan developments in the next five-year plan.
6. Private industry. The small-scale manufaau~
in Bangkok which has successfully designed and constructed multi-blade type windmills plans to dcv&p
less expensivewooden-blade type windmills for farmand has also developed a sail-type windmill (with
aluminium sheet sails) which can be used with eiiha
a ladder pump or a piston pump.
Australian multi-blade windmills are distrihutcd
in Thailand.
A manufacturer in Chachoengsao has designed
and constructed two-blade and four-blade windmills for
many years, and also produces all sizes of ladder
pumps.
C.
REQUIREMENT
ASSISTANCE
FOR COLLABORATlON
Wind energy utilization is a new field of techno)og)development in Thailand. Technical assistancein h
development of windmills for generation of elect*t>
in rural areas, and pumping from the Mekong fivt~
for large-scale irrigation, would be welcomd
Assistance will be needed iu the supply of medium-s&ok
wind-electric generators and related testing equiPmrat
for f&her development and tests.
IL
115
Information papers prepared by participants
THE UTILIZATION
OF WND ENERGY
(NR/ERD/EWGSW/CR.13)*
IN AUSTRALIA
by
The Department of Science, Australia
No major research or development programme is
being carried out in Australia in connexion with windmill pumps. Manufactured pumps have operational
lifetimes of more than 30 years, and pumping capacities
are matched to the requirements of the Australian
market. There is little incentive for manufacturers,
who also produce competing diesel and electric pumps,
to commit large sums to development work in this area.
There are, of course, occasional minor changes in
design, resulting in increased efficiency or reliability, or
reduced costs.
Introdllclion
The wind has been harnessed as a source of
power in Australia since early colonial times, when
windmills of traditional European design were used to
grind wheat. The manufacture of windmill pumps on
a large scale was stimulated by the discovery of
extensive artesian and sub-artesian basins, and designs
were evolved to meet the high standard of reliability
required for long periods of unattended operation, far
from maintenance facilities. Today, it is estimated
that more than 250,000 windmill pumps are in use,
supplying bore, well and surface water for irrigation,
stock watering and domestic use on farms and stations
throughout Australia.
B.
Until recently, wind-driven generators were also
widely used, but they have now been largely supplanted
by diesel generators and extended rural mains electricity
supplies, and only one Australian firm continues to
manufacture them. A large proportion of the
generators is exported, chiefly to the United States and
southeast Asia. The major user of wind-driven
generators in Australia today is the Australian Telecommunications Commission (ATC) , which employs
them to supply electricity to isolated telephone
exchangesand radio repeaters.
A.
WINDMILL
PUMPS
The products of the various Australian manufacturers of windmill pumps vary in the details of their
design, but in general follow a basic pattern. The
rotary motion of a multi-blade rotor is converted by
means of a crank mechanism to reciprocating motion
of a vertical pump rod connected to a piston pump at
the bottom of the supporting tower. Reduction gearing
is frequently employed in some models, while in other
windmills the rotor is directly coupled to the crankshaft. The windmill head can rotate freely about a
vertical axis defined by the pump rod and is aligned by
a tail vane according to wind direction.
Wind pressure on the rotor exerts a torque about
the vertical axis of rotation due to the offset disposition
of the rotor axle, and, at potentially destructive wind
speeds,the windmhl head turns so as to spill wind and
litnit the speed of rotation.
l
Abridged.
.
WIND-DRIVEN
GENERATORS
The “Dunlite” generator employs a three-phase
rotating field alternator with a rated maximum output
of 2 kW. Current for the rotating field is supplied by
a small exciter armature. The alternator is driven by
a three-blade variable-pitch propeller through 5: 1 ratio
gearing, and a vane maintains the correct position of
the propeller in relation to wind direction, the whole
machine being able to rotate in a horizontal plane
above a fixed base. The alternator output is rectified
before being transmitted to the base by a set of slip
Solid-state automatic voltage regulation and
rings.
control equipment holds the generator output voltage
steady, between ,12 and 110 volts depending on the
model, under all conditions of load and windmill speed,
and channels power to the load or to storage batteries
as required. The operation of a back-up diesel
generator can also be controlled automatically. The
generator starts to deliver power at a wind speed of
about 16 km/h and full output is obtained at a wind
speed of 40 km/h. The power output of a generator,
as modified by ATC, is plotted against wind speed in
figure 1.
At high wind speeds, the speed of rotation of the
propeller is governed by the centrifugal force on a set
of weights attached to the propeller assembly, acting
to feather the blades. A system of magnetic latching
may be fitted to prevent operation of the feathering
device, and the consequent loss of efficiency, in the
normal operating range of the generator. It is claimed
that, when fitted with the siandard 3.69-m diameter
propeller, the unit will withstand wind speeds of up to
Shorter blades are available if ‘higher
130 km/h.
wind speeds are likely to be encountered.
ATC has also monitored the performance of the
generators under operational conditions. About 30
2.6
2.4
2.2
2.0
:
z
g
1.6
1.4
l
z4
0.
.
s
0
1.2
s
0
ii
s
*
1.0
0.8
0.6
0.4
0.2
0
IO
20
30
Wind
.
50
40
speed
60
70
km/h
Figure 1. Characteristics of modified Dunlite generator
generators are used to meet part of the power requirements of repeater stations on a microwave route linking
Western Australia and South Australia.
The winddriven generators each operate in conjunction with a
4 kW diesel generator, and storage batteries of 1,000
Ah capacity, the normal load being a continuous
0.5 kW s?t24 V. With average wind speeds in the
region oi IS km/h, the wind generators were found to
be meeting about 66 per cent of the load, and, at
many stations, the total running time of the diesel
generator over five years was limited to 3,000 hours.
Simultaneous measurements of the output of a
standard Dunlite generator and wbd speed are currently being conducted at the Flinders University in
South Australia. The results, when available, will
serve as a data base for the manufacturer’s development
programme. A 5 kW generator is currently under
development, and a prototype is expected to be ready
for testing within a year. Future work will be con-
cerned with improving the efficiency of the propeM
so that better performance is obtained at low wind
speeds.
c.
OTHER RESEARCH
Research and development associatedwith the Pploitation of wind energy is almost exclusively coaducted by manufacturers of wind-driven machiiq.
There is no official wind energy research programra
in Australia, and no university or other rcs~lrrcfr
organization is formally engagedin research in this frfM.
However, a few university scientists have a pee
interest in the subject, and at least one has pubId
some general ideas on the large-scale utilization of w&J
energy (reference W 67). The topic is an ‘a!uJdone for private inventors, one of whom roccnflY fcceived a government grant for the construction of JJ
prototype of a modified version of the vcfii=s)-fizi
Savonius rotor.
IL
Information papers prepared by participants
A REVHZW OF RENEWABLE ENERGY IN NEW ZEALAND WITH EMPHASIS ON
WIND POWER UTILIZATION (N-R,/ERD/EWGSW/CR.lS)*
b
Mr. R. E. Chllcott (New Zealand)
i.
RENEWABLE ENERGY IN NEW ZEALAND
In New Zealand, oil, coal, natural gas and
electricity are consumed at a rate equivalent to about
3.5 kW of continuous power per person (reference
W 68).
Oil supplies about 60 per cent of the primary
ener,T requirements. In 1975, the generation of
electricity per head of population was about 6,000 kWh,
which is equivalent to a continuous electrical power of
nearly 700 W per person. Renewable hydroelectric and
geothermal sourcessupplied 78 ,per cent and 7 per cent
respectively, the remaining 15 per cent being supplied
from fossil-fired thermal-electric power stations. About
half of the electricity generated flows into the home:
the annual amount of electrical energy consumed by
an average family is about 8,000 kWh, half of which
flows down the dram in the form of hot water.
A.
SOLAR ENERGY
The intensity of solar radiation is about 1,400
W/m*; this figure is known as the “solar constant.”
As the surface area of a sphere is four times its
cross-sectional area, the global average intensity of
solar radiation perpendicular to the top of the
atmosphere is one quarter of the solar constant, or
Owing to reflection from cloud
about 350 W/m*.
tops, diffusion and absorption in the atmosphere, the
global average intensity of solar radiation incident on
a horizontal plane at the surface of the earth is about
half this value. The annual average value of solar
radiation in the region of the Tasman Sea and Pacific
Ocean near New Zealand is about 150 W/m*. More
precise figures for North Island and South Island
stations are shown in table 1 (see reference W 69).
The typical annual cycle of solar radiation and temperature, in which temperature lags behind radiation, is
shown for Wellington in figure 1.
B. HYDRO AND THERMAL ELECTRICITY
Hydroelectric energy is a familiar form, derived
from solar energy through the hydrologic cycle.
Hydroelectric works currently planned will increase the
total national installed hydroelectric capacity to about
4,500 MW by 1983. Ultimately, the capacity may be
stretched to about 6,000 MW, but the later projects
would become increasingly expensive and limited by
environmental considerations (see reference W 70).
By the end of the century, hydropower may only meet
about 5 per cent of the projected total energy demand
(see reference W 71).
. Abridged.
C.
<GROWING ENERGY
A’,a
Solar energy is captured by photosynthesis ar,q,.:
store:1 as wood fuel which is virtually sulphur-free.,,:!\
The ,tsh CM be returned to the land and the global herii (
balance will not‘ be disturbed. Typically, an annual :‘I
average solar radiation intensity of 170 W/m* i&
assurled to give an over-all photosynthetic conversio#’
et&it ncy of about 0.4 per cent. It has been suggeste&$’
that C.7 per cent could easily be achievedby appropriate I,
plant1ag and double cropping and that ultimately ant’
efficiency of 1 per cent -may be possible (see reference ’
W 72). The successof the solar forest or fuel plantation concept depends on many factors, including the
selection of trees that grow fast on poor soils.
Il:esearch on the production of fuel from New
2ealar.d crops is currently under way (see reference
w 71).
Indications in the United States are that
alcohl from grain may soon become cost-competitive
with ethyl-alcohol derived from oil. However, grain
crops nay be heavily subsidized by ferttiers dependent
on fossil fuels, in which case the net fuel energy cost
needs careful analysis (see references W 73, W 74,
W 75.1. Siiilarly, growing and harvesting algae or
giant !:elp for alcohol production is likely to have
signiticsnt energy costs for harvesting and processing.
Resear.:h into the energy costs of crop production. is
being 1ndertaken at Lincoln College. It appears that,
withou, careful planning, processing and management,
the net energy production may well be zero.
In Canterbury, energy-conversion efficiency of
wheat ;!t the farm gate is about 0.1 per cent. At this
efficiency, to produce the food energy consumed by the
average resident requires a land area of about 0.1 ha.
The po:,ulation density should therefore not exceed 10
persons per hectare of agricultural land (see reference
W 76). Among other things, this highlights potential
conflict: between energy, food and population
requirer,lents.
D. SOLAR HEAT
On: of the most effective uses of solar energy is
the direct heating of water for non-domestic and
domestic purposes (see referencesW 77, W 78, W 79).
An installation currently under test at the National
Dairy Lirboratory, Ruakura, consists of a 16, ms bank
of colle,tors inclined at 35’ to the horizontal and
mounted on a milking shed roof to face north-northwest
(see figure 2). A circulating pump and an 800~litre
118
Part Three. Documentation on
,Wind
wind
y>.ywz4*.Q
;:“,j;s*,:L&:*
-rdkw&y?&
energy
336
162
100
I
/sx x M
/ XfA
AS
0
/
I
IO
5
Monthly
Solar energy
on a horizontal
surface
12.4
I
1’5
mean temperature
1
i0
OC
Figure 1. Wellington monthly average solar and wind energy
storage tank are located under the roof. The heated
wa?er is used to 6ll two conventional 2004itre hot-water
he:;ters twice a day, and the electrical supply is used
on?y to boost the water temperature to 90°C or more.
Frcjm March to August 1975, the installation averaged
a solar input of about 200 W/m* of collector area
If required, collectors can be designed to produce
low-pressure steam for food processing, industrial processing and power production. A solar-t*electrical
energy conversion efficiency sometimes quoted is
10 per cent, which on 1 per cent of land
are:1 implies an over-all energy conversion efficiency,
on a total land area base, of 0.1
More conventional uses of solar heat iac
glasshouses, air heating for drying fruii grain :~~~~~~~~~
timber, and the production of solar salt, for cXam#u:“*“‘- *’
from Lake Grassmere. With collectors iu the fOrIll $,
large non-convecting ponds, it is possible to &riv$
power, particularly where sea water and laod m
available (see reference W 71). Marine sol
thermal energy can be tapped only where
temperature difference exists, usually more th
and is unlikely to find wide application in New
waters (see reference W 80).
II.
119
Information papers prepared by participants
Many small-scale solar water-heater installations,
which take advantage of the distributed nature of solar
energy and do not take up valuable land area, are
operating successfully in a variety of applications
ranging from iceprevention for stock-water troughs to
solar water-heating at the Kaikoura youth hostel. Solar
water-heaters will probably become widely accepted as
architectural features of new towns, factories, schools,
swimming pools and homes. Department of Scientific
and Industrial Research estimates indicate that about
half the total domestic hot water used in New Zealand
could be heated by solar energy; the fraction varies
with locality and is typically about 50 per cent for
Dumdin and 60 per cent for Blenheim. Ideally, a
solar system, in addition to being economically viable,
should generate more energy than is needed for its
manufacture, installation and maintenance (see
reference W 7 1) .
Figure 2. Solar collectors at National Dairy Laboratory
E.
WIND POWER
The long-term average value of the kinetic energy
of the atmosphere is fairly constant and is estimated at
about 3 x 10” k.I (see reference W 81).
The flight path of a balloon released from Christchurch gives a graphic indication of the circulation of
the atmosphere around the southern hemisphere at that
A rough estimate of the
latitude (see figure 3).
balloon’s average speed during three circuits of the
earth in 33 days, at a height of 12 km, is 130 km/h.
From observations of the isobar spacing on weather
maps, it is seen that gradient wind speeds of up to
100 m/s may occur occasionally. Near the surface
of the earth, in the lowest 500 m, the surface exerts a
frictional drag on the air and reduces the wind speed:
this effect is greater over forests and lesser over the sea.
Surface wind speed is usually measured by
anemometers at a height of 10 m. Zones of medium
wind speed, such as the Canterbury Plains, have an
annual average wind speed of 14 to 22 km/h, while
more exposed locations, such as the Wellington area,
;,,p:.L$T.~
Ii.;&,&j
,.s..‘.,
4..;
Figure 3. Plight path of a balloon launched from Christchurch (33 days)
Stewart Island and the Cbatham Islands, have higher
annual average wind speeds, in the range 22 to 33
km/h (see reference W 82).
An over-all annual
average wind speed at 10 m height for New Zealand
might be taken as 18 km/h. The annual average wind
power intensity at 10 m is about 150 W/m*; above
10 m it would be greater. There are of wurse
significant variations in wind speed, wind frequency
and wind energy between stations, for example
Wellington has about three times as much wind energy
available as at Christchurch (see table 1).
A wnservative estimate of the allowable installed windelectrical capacity of a zone of medium wind speed is
abgut 5 kW/ha, with a load factor of about one third.
This means that, in such a zone in New Zealand, the
available annual average wind-electric energy is about
0.1 per cent of the annual average solar energy incident
on a horizontal plane.
Small windmills have been in use in New Zealand
for at least a century. Typically, they were used to
lift water for steam locomotives and are still used extensively for watering stock. In remote areas, small
wind generators are used with storage batteries for
Table 1.
ANNUAL AVERAGE TEMPERATURE, SOLAR ENE&
WIND ENERGY AND WIND SPEED IN NEW 2!am
.
. -.
14.0
. . .
. . .
13.1
12.4
Christchurch .
.
.
,
10.9
lnvcrcargill .
.
.
.
9.5
Auckland.
.
Ohakca . .
wclrmgton .
Sources:
. .
171
108
1)”“&
y,;.j
i
173
162
165
147
178
336
114
214
l,;‘;.;$yf
, .<‘.+s>
22, ‘3;
14 ‘%J$
17 $$j
t,
New Zealand Mctmrological Scrvicc i
Publication No. 143 and rcfcrcnccs W69 and W&
‘Nominally at 10 m height.
, $J
electric fence energizing, communications and I
It has been suggestedthat 1
navigation lights.
generators could be integrated into existing elect
networks in order to supplement hydroelect6c
In order to detcin;
and conserve fossil fuel,
sufficient wind energy potential exists, a national w
energy resource survey is currently under way ,I,
reference W 82). Detailed wind surveys01 Gm=w
I:,,<
i ;q%>..
I:;>-“;
and Otago are being carried out.
.‘,,$&.?a.
IL
Information papers prepared by participants
II.
A.
121
NEW ZEALAND WIND ENERGY TASK
FORCE ACHQTIES,
1974-1976
arbitrary wind regimes. Confirmation is to be obtained
with au 8 kW machine, currently at an early stage of
construction.
PROJECTS SPONSORED BY THE NEW
ZEALAND RESEARCH AND
DEVELOPMENT COMMITTEE
2. Iuvestigation of the ruraI boundary Iayer
This project is also related to project A. 1. above,
with additional funds of $NZ 3,400, and has resulted
in the design and production of a 20-m guyed, welded
steel instrumentation mast.
1. Wmd energy resource survey of New Zealand
(references W82, W83)
A two-year project has been authorized, with funds
of $NZ 41,000, to be carried out by Lincoln College,
the University of Canterbury, Otago University and the
New Zealand Meteorological Service, and is intended
to:
C.
PROJECTS SPONSORED BY THE MINISTRY
OF WORKS AND DEVELOPMENT
1.
(a) Identify advanced farm, rural and remote
systems in which significant energy demands can be
met by the use of wind power;
(b) Detail the speciiic output and operating requirements of such systems;
2.
Wmd power for Stewart Island
Funds of $NZ 2,000 have been allocated to
Lincoln College for an investigation similar to project
C. 1. above.
2. ‘I’be utilization of wind energy
(references W84, W85)
3.
At Auckland University, with committed funds of
$NZ 25,000, an analysis ls being undertaken of the
technical and economic feasibiiv of the integration of
wind power into the New Zealand electricity supply
system.
Water pumping on Mana Island
Funds of $NZ 500 have been allocated to Lincoln
College for a prelimiiary assessmentof the use of wind
for pumping water on the island.
D. MISCELLANEOUS
PROJECTS
1. Vertical-ask3 windmill
B. PROJECTS SPONSORED BY THE
GRANTS COMMITTEE
A Canadian-made vertical-axis wind-electric
machine is currently under test at Auckland University.
1. Performance characteristics of wind turbme
systems for advanced farm, rural and remote use
.
This project is related to project A. 1. above, with
additional funds of $NZ 5,150, and has resulted in the
establishment of a generalized method to predict
energy output performance of typical wind turbines in
WINDPOWER
Island
Funds of $NZ 1,500 have enabled prelimiiary
investigation to be completed.
(c) Prepare specifications for wind-powered
systems to meet such requirements,
UNIVERSITY
Wind power for Chathi
2. windmiu
and pump
A commercially available windmill and pump are
to be installed at Lincoln College for test and
demonstration purposes.
STUDIES IN KOREA (NR/ERD/EWGSW/CR.l6)*
by
Mr. Chung-Oh Lee (R&public of Korea)
In recent years, the possible utilization of wiudpower has been receiving close attention in the Republic
of Korea, especially for the electrification of off-shore
islands. There are more than seven hundred islands
around the Korean peninsula, but only a small number
have electricity supply, generated by diesel-electric sets
b Abridged.
or similar conventional methods. The meteorological
data supplied by the Korean Weather Bureau indicate
that these areas have dependable wind sources, and, in
1974, the Ministry of Science and Technology awarded
a research grant to the Korea Advanced Institute of
Science for the preliminary study, design and testing
of a small experimental wiudpower system capable of
producing 2 kW maximum continuous output.
Part Three. &mmentation
On
wind energy
(b) Winter is considered to be the mm
favourable season;
(c) The number of consecutive calm days neva
eqeeds three in the southern islands. -
‘arerelative.
The conclusions drawn from the analysis of records
from 27 stations along the coastline were:
,-,
(a) The southern coastal area is extremely
favourable for windpower systems;
B. MAIN DESIGN FEATURES
The 4-m diameter rotor conbiStS of a three-bladed
propeller iu which each blade is twisted appropriately,
with a fully feathering hub controlled by [email protected]
weights. The special brushless generator produces
2 kW, three-phase, 400 V AC (reference W 87),
which in the experimental unit was fed through a
rectifier to 16 lead-acid 12 V batteries, arranged to give
a storage of 1.92 kWb at 96 V.
Other design and
aerodynamic features are:
Maximum propeller rev/min - 200
Maximum generator rev/mitt - 1,000
automatic constant voltage
Voltage regulation
.
regulation
Tower height - 12 m
I. Cheju
bland
2. Ulnung
Isl and
3 Chupungryung
600
400
200
I
“:’
: .‘P,’
cm,.
:‘z2”*
.:ib4:
.;
J-:,:f!
,C.$.‘
:,2..‘+
.3&F::
‘ra:t&n,
:
pg..:
p;y&
~::;~~~~.
,&W+
t
-
-
-
IiWind velocity
in km/h
Figure 1. Wind velocity hourly duration curve
il i
I.:
>
77,syi
.‘.;‘>,
.:
600
2.Ulnung
island
250
I
2345678
9
IO
II
I2
Months of the year
Figure 2. Monthly distribution of hours of usable wind (above 16 km/h)
Starting wind speed- 16 km/h
Maximum output wind velocity - 43 km/h
C.
INSTALLATION
A series of laboratory tests was conducted to check
the performance of the generator and the feathering
hub. A test for the durability of the whole system
was then undertaken in non-uniform air currents produced by a 2.5-m diameter propeller attached to a
200 hp engine (see reference W 88)After the completion of the laboratory tests, a
wind-power system was installed in February 1975 on
an island in the Yellow Sea for actual testing and
evaluation. Figure 4 shows the output against wind
velocity as measured in the tield test.
D.
REINFORCEMENT
OF THE PROPELLER
After operation of the system for three months,
two blades broke and the hub was destroyed by the
resultant unbalanced torque. A thorough study of
possible causes of the accident, including investigation
of stress distn%ution in the blades, led to the design of
appropriate reinforcement (see reference W 89).
Blades constructed ,to the modi6ed design have been
operating satisfactorily since in$allation.
On the assumption that one of the contributory
causes of the initial fracture might have been the very
fast action of the feathering system, with a rapid change
of stress, further work is being carried out on a possible
modification in the design of the feathering system.
E.
FUTURE
WORK
Details of a follow-up project are now being pre
pared, the objective being to develop a reliable and
cost-competitive wind energy conversion system of
relatively small scale (2-5 kW) for lighting and communication purposes in off-shore islands.
LCheju
Island
2.lJlnUng Island
3.Chupungryun
0
3
s
=
Q:
g
6
5
4
3
II
33
22
Wind velocity
in km/h
Figure 3. Relative annual energy in winds
44
If.
Inforrnatton papers prepared by participants
125
2,300
II
22
33
Wind velocity
44
in km/h
55
Figure 4. Output against wind velocity
RESEARCH AND PROSPECXS OF UTILIZATION OF WIND ENERGY IN INDONESIA
(NTt/ERD/EWGSW/CR.U)*
.
by
Mr. H. Djojodihardjo (Indonesia)
The possible increase in wind energy utilization
in Indonesia is a challenging problem (reference W 90)
because:
(a) There is a scarcity of wind data, although
it has been believed that Indonesia is a low-velocity
windarea;
(b) There is no precedent or available expertise
in Indonesia;
(c) Wind energy could be economical in the
sense that foreign exchange could be saved;
(d) There has been a growing pu SC concern to
preserve the ecological balance of the environment.
l Abridgal.
A.
REVIEW OF WIND ENERGY CONVERSZON
SYSTEM CHARACTERISTICS
Table 1 indicates the theoretical dependence of
available energy on wind speed and rotor diameter
(references W 42 and W 51). The a&al power output
that can be delivered to the output system that utilizes
Table 1. THEORECTICALWIND ENERGY AVAILABLE
(in kW)
9
18
27
36
45
54
0.070
0559
1.887
4.474
8.738
15.100
0.157
1258
4146
10.070
19.660
33.970
0380
2.236
7.540
17.880
34.950
60390
0.437
1.748
3.493
13.970
11.790 47.180
27.960 111.900
54.610 218.500
94.360 377500
\
Part Three. Documentation on wind energy
126
-
the wind energy is further reduced by.a power coefficient
which can vary up to the order of 0.7 for the most
aerodynamically efficient windmills.
i8 required. Figure 1 shows a typical specrnun d
horizontal wind speed near the ground for an wnsh,e
frquency range, taken from reference W 92.
Furthermore, the output system usually has an
efficiency substantially less than unity (see reference
W 91). The maximum over-ah efficiency of the wind
conversion system would be of the order of 20 to 25
per cent. Table 2 indicates the actual power output
of a wind energy conversion system with over-all
efliciency of 20 per cent, for different wind velocities
and rotor diameters.
B.
AVAILABLE
(in kW)
Diwrln
Wild
.
speed im &m/h
72
.
.
.
9.0
10.8
12.6
14.4
18.0
21.6
28.8
36.0
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
2
o.I103
0.006
0.011
0.017
0.026
0.050
0.087
0.206
0.402
0.013
0.025
0.044
0.069
0.103
0201
0.347
0.823
1.610
of maw
im ma
6
II
10
20
0.029
0.056
0.098
0.155
0.231
0.452
0.781
1.850
3.620
0.051
0.101
0.172
0.276
0.412
0.804
1390
3290
6.430
0.080
0.157
0.272
0.431
0.643
1.260
2.170
5.150
10.000
0320
0.628
1.086
1.720
2.570
5.020
8.680
20.600
40200
4
. : .,,3
5
” ‘_
_I-.:ti.‘><
.,_
WIND DATA IN INDONESIA
In Indonesia, wind data, rainfall, solar e
and other climatic factors are compiled by the center
for Meteorology and Geophysics (PMG) from
measurementsmade by meteorological stations at meet
aerodromes, agricultural and maritime meteorologiclrl
stations and meteorological stations of other agenciesm
co-operation with PMG.
The Indonesian Na&naJ
Institute of Aeronautics and Space (LAPAN) &o
conducts meteorological studies, mostly for the upper
atmosphere, at its premises in Bandung and CitautEureun. A sample of wind records for various selected
places in Indonesia taken at an elevation about 10 m
above the ground is shown in table 3.
Table 2. TYPICALACTUALMAXIMUM OUTPUTPO-R
I
I
,
1
Van der Hoven (at IO0 metre
I
I
I
,
I
height)
!
- - - T - -
Speculative
1 Davenport
)
t
2
J.
-Micrometeorological
range
3
2
C ycles/hr
Hr
I
I1 yr sun-spot
-
10m4
10,000
I
Annual
10-3
1,000
Macrometeorological
( Weather-
map
IO-Z
lo-'0.2
IO 5
I
Semi-diurnal
100
I
4 day
range
fluctuations
Time
,:
,: i
.!.Y?
.‘:,
2
-,.“.,.
,/
::;,:
.:e.:-:
?i”.,
: :;
.:;,
Table 4 shows average values of wind velocitia ,.,,,I;‘:
and predominant wind direction for Jakarta during / “,$,$ ,.
the period 1961 - 1970. These data illustrate relative
,-;:i2
[email protected] intensity prevailing at most places in Indone&
’ ,%$!j
,,.L
i.e. of tbe order of 2 to 5 m/set (7 to 18 km/h),
i :::
although f is well understood that both the locations
of observation stations and the method used are not
very useful for the assessment of windpower pob
r&iities, and higher values of wind speed may oamr
at other locations. From table 3, some locations like
Y.
Banda Aceh, Semarang and Madiun seem to have a
?
mean wind speed of 5 m/set (18 km/h). Jt is also
‘: I.
It is noted that, for a typical wiudmih application
to provide 1 kW of power, at a site with a design wind
speed 18 km/b, a rotor diameter of the order of 10 m
8
y.&.:
. -ii’J+
‘i..;.q,*:l
‘..$
’ ‘i.~;:,‘>‘:“.:
.“:.”-J
,.r
,;”‘72.’
‘$
0.5 I
2
5 lo 20 50 loo
500 I,000
0.02
0.005
0.001
I 0.5 0.2 0.1
I
I
I
5 SIC
lmin
5 min
)
(Gusts)
scale
Figure 1. Spectrum of horizontal wind speed near the ground for an e&n&e
frequency range
-‘IL
hbmati;n
papers prepared by participants
Table 3.
127
SAMPLE OF ~~DVELOCITYDATAIN
INDONESIA,1974
(in km/h)
I
P
Y
A
iii
Nean
windveloaly
I
J
17
11
28
9
22
15
13
15
11
19
13
11
17
7
19
7
7
15
6
15
6
7
19
7
15
. .
. .
15
6
13
6
Is
17
15
6
13
9
13
13 .
13
6
17
9
13
15
11
6
13
7
9
11
Dmpasar . . .
Psirpmjang. . .
24
33
19
11
15
17
7
9
smioo
-
Muilwvrn
0&ui8y
A
S
7
7
7 ..6
24
28
7
7
15
13
7
7
24
7
15
9
9
9
9
7
28
7
15
7
24
7
13
7
24
7
11
7
15
9
11
40
58
53
41
41
11
4
9
7
9
I1
13
6
11
7
9
15
15
4
11
9
11
I5
19
4
9
7
11
17
15
4
11
9
9
11
NA
7
11
9
9
13
11
7
11
9
9
9
13
9
NA
6
9
9
50
41
33
60
58
41
17
24
19
31
15
26
17
22
19
22
17
19
9
15
9
11
58
83
0
N
D
Java:
Bandung . . .
Jakarta(H)...
Madiun . . . .
Jakarta(K)...
tl#smmg . . .
sumun:
Bar& AC& .
lkogkuln
.
b¶dan . .
Padaog....
Palcmbaug .
Pangkal~g
. .
. .
. .
NusaTa~ggara:
C.
Table 4.
WIND VELOCITYDATA IN JAKARTA,1961-1970
J==Y . . . . .
Fd=-w. . . . .
. . . .
biarch.
April . . . .
May . . . .
June . . . .
JOY . . . .
August . . .
. .
*-l=
CktolKr. . .
Novanbcr . .
. .
Yarlyavaage..
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
E
E
E
E
N
N
N
NW
5.8
6.1
5.4
5.4
5.8
5.8
6.5
6.1
6.5
6.5
5.4
5.4
.
E
5.8
E
47
43
36
41
41
41
36
36
43
50
49
50
1965
1966
1970
1965
1965
1965
1966
1966
1967
1969
1967
1970
50
1970
kuown that the surface wind is intensified in flowin;
over mountain ridges, which can be regarded a8 favourable places for windmill utilization in view of the
unavailability of transmitted ele&icity in many rural
mountain regions. In order to be able to predict the
possible amount of windpower, there is a need for
wind distriiution
Indorlesia.
curves at various
locations
in
RESEARCH AND DEVELOPMENT
-
In 1968, the Department -of Mechanical ‘Engineering of the Institute of Technology, Bandung, was
involved in the design and construction of a multi-vane
fan type windmill (see reference W 33).
The wind
energy conversion system was constructed for water
pumping, with rotor diameter 4.2 m, tower height 42 m,
- head 15 m and pump capacity 20 m3/day; and was
instahed at Pangarasan in central Java. The wind
velocity was measured as 12 km/h while wind gust
velocities could reach 40 km/h. The unit was constructed without research and developmental work, and
no provision was made for feedback of technical problems which occurred.
Motivated partly by the need for conducting a
more systematic effort for wind energy conversion
system design, construction and utilization, a smallscale research effort was started at the Aero anil
Hydrodynamic8 Laboratory of the Institute in 1973.
The work has been performed in conjunction with
student projects and has been restricted by scarcity of
fund8 and lack of supporting-literature. The work was
geared to small-scale wind [email protected] conversion systems
for rural areas, and the objectives were, briefly, to
initiate research and development effort in this field,
and to explore the development of local technology in
wind energy conversion systems. Good progress has
been made on an experimental study of vertical-axis
(Darrieus) type rotors (figure 2), followed by design
and construction of a prototype 2-blade rotor wind-
Part Three. Documentation on wind energy
128
mill (reference W 93), an experimental study *of a
propeller type windmill model and analysis and design
of a sail-type windmill (reference W 94).
The Darrieus-type windmill rotor blades were
made from locally available steel, and were machined
to shape at the army industrial workshop. The blades
have a symmetrical aerofoil cross section to United
States standard (NACA 0012), with maximum aerofoil
Figure 2.
thickness of 3 mm and a chord length of 2.5 cm
Torque measurementswere made with a simple ponytype brake with a piece of string to provide the friction
for lifting a weight.
1
Test results on the prototype gave an OUQ~
coefficient curve similar in shape to that from tests
made on a large unit at the National Research Counc&
Canada, but the peak value was lower by about 30 per
cent.
3-blade Darrieus rotor model in wind tunnel
IL
Information
papers prepared by participants
The blades for the propeller-type windmill were
made of lamina ted wood, with a diameter of 0.7 m, a
constant chord length of 0.07 m and hub diameter of
0,07 m. The pitch angle setting of the propeller blade
is shown in table 5.
’
Table 5. BLADE THICKNESS
AND ANGLE SETTING OF THE TEST PROPELLER
Radins
Etmeluwillgpoiac
-
tdorimnmthic~mcsc
(4
f-1
3.5
7
10.5
14
17.5
21
24.5
28
31.5
35
1.12
1.12
098
098
0.70
056
0.42
0.42
0.42
0.42
P”‘:&~k$ti~~
28.4
18.6
15.0
92
7.0
7.0
5.0
5.0
4.9
4.5
The following conclusions have been drawn from
the work to date:
(a) Multi-vane,
propeller, sail, and Darrieus
types of windmills, and Savonius rotors, could be
manufactured locally due to their simplicity of construction, and yet could provide suitable power output
at rated wind speeds of 14 to 18 km/h.
(b)
Propeller and Darrieus type windmills have
excellent aerodynamic efficiency at relatively vgh tip
129
velocities and would be attractive for wider application
in Indonesia. Further development would be necessary in order to reduce the cost.
(c) Sail-type windmills and Savonius rotors are
also attractive for wider application in rural areas.
D.
POTENTIAL
APPLICATIONS
IN ZNDONESZA
The current cost of transmitted electric power in
Indonesia is about 3 -4 US cents/kWh, while a
locally-manufactured propeller-type windmill may
produce electricity at about 15 US cents/kWh, but this
cost could probably be reduced by large-scale production. At present, windmills would not be economic if
transmitted electric supply were available.
E.
CONCLUSIONS AND RECOMMENDATIONS
Wind energy conversion systems are attractive
because of their non-polluting nature, utilization of
renewable energy resources, low maintenance and
simplicity of operation, and could have potential
applications in Indonesia, particularly for rural areas
and islands.
Hardware development work should be initiated
and encouraged in order that technological capabilities
can be developed for local manufacture of economical,
simple and efficient windmills.
III.
CONSOLIDATED
LIST OF REFERENCES
ON WIND
ENERGY
W 1. E. W. Golding, The Generation of Electricity by
Wind Power, (London, E and EN. Spon Ltd.,
1955), pp. 22.
(Agricultural
Ma&[email protected],
W 16. Nognye Jixie
Northeastern Machinery Institute of China,
Nos. 11 and 12, 1958.
W 2.
W 17. Chen Li, “Why has the windmii not been more
widely used in North China? A report on the
construction of the windmill (of the Salterns)
used on the coast of the Gulf of ChiUi (near
Tientsin)“, Kho Hsueh Thung Paro (Sch~e
Correspondent), 195 1, vol. 2, No. 3, p. 266.
Arthasastra of Kautilya, quoted from Studies in
Ancient Hindu Polity by Narenda Nath.
W 3. A. Makhijani and A. Poole, Energy and
Agriculture in the Third World, (Cambridge,
Massachusetts, USA, Bahinger, 1975).
W 4.
w 5.
E. W. Golding, ‘Windmills for water lifting
and the generation of electricity on the farm”,
FAO Internal Working Bulletin Nb. 17.
.
“Energy from the wind-assessment of suitable winds and sites”, WMO Technical Note
No. 4, Geneva, 1954.
.
W 6.
Communication from J. Park, (Helion), USA.
W 7.
Calvert, ‘Wind power in eastern Crete”,
Trqnsactions
of the Newcomen Society, UK,
1972, vol. XLIV, pp. 137-144.
W 8. M. M. Sherman, “6,000 handcrafted sail wing
windmills of the Lassithiou, Greece, and their
relevance to windmill development in rural
India”, Proceedings, Wind and Solar Energy
for Water Supply, German Foundation for
International Development, Berlin, 1975.
w 9.
“Plans for 25 foot diameter sail windmill”,
Windworks, USA.
W 10. “Performance data for 25 foot diameter sail
windmii’, Brace Research Institute, Canada.
W 11. “Construction plans for 10 m diameter sail
windmill”, TOOL Foundation, Netherlands.
W 12. ‘Note on 6 m diameter sail windmill”,
Sarvodaya Educational Development Institute,
Sri Lanka.
W 13. P. Fraenkel, “Food from windmills”, Intermediate Technology Development Group, UK.
W lg. Water Conservancy in New China, Ministry of
Water Conservancy, (Shanghai, People’s Art
Publishing House, 1956).
W 19. Nogyne Jishu (Agricultural Techniques) china,
No. 9, 1958, pp. 15-16).
W 20. W. E. Heronemus, ‘A survey of the possible *
use of wind power in Thailand and the
Philippines”, USAID, Contract No. TA-C
1143, 1974.
l
W 21. F. Stokhuyzen, The Dutch Windmill, (New
York, Universe Books, Inc., 1963), pp. 21-46.
W 22. R. Garcia, “Low-cost windmill”, Volunteer
Technical Assistance, USA.
W 23. Report by the commission on the Church’s participation in development, World Council of
Churches, Switzerland.
W 24. A. Bodek, ‘How to construct a cheap wind
machine for pumping water”, Brace Research
Institute, Publication No. 5, Canada.
W 25. Koslowski, “Investigation of whether a Savonius
rotor is a suitable prime mover”, Intermediate
Technology Development Group, UK.
W 26. U. Hutter, “Planning and balancing of energy
of small output wind plant”, Proceedings of the
Symposium
on
Wind
and Solar
Enetgy.
(UNESCO, October 1954), p. 85.
W 27. Energy Primer, (USA, Portola Institute, 1974).
pp. 74-105.
W 14. F. H. King, Farmers of Forty Centuries,
(Wisconsin, USA, Madison, 1911) .
W 28. P. Johnston, “Notes on rural electrification by
windpower”, report to the Ministry of Finam%
Fiji Government, 1975.
W 15. J. Needam, Science and Civilization in China,
(Cambridge University Press, UK, 1955), vol.
4:2, pp. 555-567.
W 29. Proceeding of the Second Workshop on Wind
Energy Conversion Systems, Energy Resd
and Development Administration, USA.
III.
Consolidated list of references on wind energy
W 30. Nognye Ji9t.u (Agricultural
No. 19, p. 11.
techniques), China,
W 3 1. M. M. Sherman, ‘The design and construction
of an appropriate water pumping windmill for
agriculture in India”, Transactions, Wind and
Solar Energy
for
Water Supply,
Foundation for International
Berlin, 1975.
German
Development,
W 32. D. K. Biswas, report to the Indian Agricultural
Research Institute, India.
W 33. F. Harahap, “Design and construction of a
windmill: an experience of the Mechanical Engineering Department of ITB”, workshop
paper, Bandung Institute of Technology,
Indonesia, 1972.
W 34. “Wind pump for lifting water”, Infrormation
Kit Section II-Part B, vol. II, No. 5, USAID
Technical Digest Service, Washington, USA,
1962.
W 35. Detailed plans of Princeton sail wing rotor
windmill design, (New York, Flanagan Plans).
W 36. M. M. Sherman, “‘A water pumping windmill
that works”, Journal II of iiFe%w Alchz&s,
USA, 1973.
W 37. H. Stam, “Adaptation oi! windmill esigns,
with special regard to thr: needs of 4he less
industrialized areas”, Praceedings of United
Nations Conference on New Sources of
Energy, Rome, 1961, vol. ‘7, paper No. W/40,
pp. 347-357.
W 38. J. Park, “Simplified wimi power systems for
experimenters” and “1%;16: complete plans
and instructions”, Helion, USA.
W 39. H. Meyer, “12 footer plans”, Wmdworks,
USA.
W 40. R. E. Chilcott, “The deign, development and
testing of a low cost 19 hp windmill prime
mover”, Brace Research,Institute, Publication
No. 7, Canada, 1970.
W 41. R. Wailes, “Horizontal o ‘andmills”,Transactions
. of the Newcomen &c&y, London, 1967/8,
vol. XL, pp. 125-145.
W 42. P. South and R. S. R$mgi, “An experimental
investigation of a 12 f l. diameter high speed
vertical axis wind turbine”, National Research
Couucii Report LTR-L 14-166, Canada, 1975.
W 43. J. R. Godfrey, DAF Company report, Canada.
131
W 44. P . V. Brulle, H. C. Lavsen, “Gyrorr ,’
(cydogyro windmill) investigation for gent.’, .
non of electrical power”, Proceedings of z
S,?cond Workshop on Wind Energy Conv:
;c,n
S vstems,Mitre Corporation, Washington. SA 1375, pp. 452-457.
W 45. P. Bade, “Flapping vane wind mar me and
rod-piston pump” and “Flappinl, * t $y,‘:
??
machine”, Transactions, Wind and : p ?‘
fbr Water Supply, German Fo,
.ru &r
Ir temational Development, Berlin, 1975.
W 46. Communication from E. Barnhart,
Alchemy Institute-East, USA.
;I’ )
3
,!‘,
Nay
1,;
4.
i:
W 47. “Water lifting for agriculture using non- 1
cc nventional power equipment”, Ministry of
Agriculture and Co-operative, Government of
Tl ailand, 1974.
J!
#’
:
i
,
‘1
J,
W 48. S. Wilson, “Note on low lift irrigation
punping”, Department of Engineering Science,
Gxford University, UK.
Q
;,
i’.i
‘,i
W 49. R L. Pendleton, Thailand, Aspects of Land-
4;’ 1
, ‘8,I,
11 !
‘i
‘\I
1
) j’
Ii
scape and LifeAn Ammicm ~~g:qz.‘.,I.
S;&iy
Handbook, (New York, Duell, Slo;ln
and Pearce, 1963).
W 50. I. A. Rubinski and A. I. Rubinsky, “A btw
specific speed pump for small discharge:;“,
Civil Engineering and Public Works Review,
vol. 50, No. 591, September1955, pp. 987-990.
W 51. M. F. Merriam, Wind Energy jar Humm
Needs, (UC
1 D - 3724),
(Berkelv,
California, USA, Lawrence
Berkely
Laborator,
I,
..
1974).
--.
W 52. “Review of progress on utilization of wind
power”, National Aeronautical Laboratory,
India, Report No. SR-WP-l-60, 1960.
.
+!
,,
.’
i
W 53. S. P. Venkiteshwaran, “Operation of AUglier
type wind y’electric generator at Porbanday”,
National Aeronautical Laboratory, Indrl, i
Report No. TN-WP-2-61, 1961.
I
W 54. R. Ramanathan and S. Viswanath, “Estimated i
annual energy output of two types of wind 4
electric generators at selectedstations in India”, I
National Aeronautical Laboratory, India “’
‘.“:>
Report No. TN-WP462, 1962.
?I,
W 55. S. P. Venkiteshwaran, K. R. Silvaraman and-,8
C. G. Gupte, “A note on the feasibility of win$,
generation of electric power for communicationsc
links in India”, National Aeronautical,:’
Laboratory, India, Report No. TN-WP-3665;,
1965.
i!”
13:.
’ W 56. S. K. Tewari aud L. S. Srinath, “A systems
approach towards utilization of wind energy (a
preliminary study)“, National Aeronautical
Laboratory, India, 1975.
Part Three. Documentation on wind energy
W 69. R F. Benseman and F. W. Cook, “Solar
radiation in New Zealand-the standard yea
and radiation on inclined slopes”, New ZeuZ&
Journal of Science, No. 12, December 1969,
pp. 696-708.
W 57. S. Janardhan, “Some prelimmary considerations
in the choice of rated speeds for wind
machines”, National Aeronautical Laboratory,
India, Report No. TN-WP-20-63, 1963.
W 70. H. I. Odum, Environment, Power und Society,
(New York, Wiley Interscience, 1971).
W 58. E. W. Golding, Electrical Research Association,
UK, Report No. C/I’ 118, 1956.
W 71. Proceedings of the Second New Zealand Energy
Conference, University of Canterbury, New
Zealand, May 1975.
W 59. P. Nilakantan, K. P. Ramakrishnan and S. P.
Venkiteshwaran, “Windmill types considered
for large scale use in India”, National
Aeronautical Laboratory, India, Report No,
TN-WP3-61, 1961.
W 72. G. C. Szego and C. C. Kemp, “Energy Forests
and Fuel Plantations”, Chemical Technology,
May 1973, pp. 275-284.
% 60. K. R. Silvaraman and S. P. Venkiteshwaran,
“Utilization of wind power for irrigation of
crops in India with special reference to the
distribution of wind and rainfall”, National
Aeronautical Laboratory, India, Report No.
TN-W-P-30-63, 1963.
W 61. S. P. Venkiteshwaran and K. R. Silvaraman,
“Utilization of wind power in arid and semiarid areas in India”, National Aeronautical
Laboratory, India, Report No. TN-WP-35-64,
1964.
W 62. S. K. Tewari, “How feasible is the substantial
utilization of wind power in India?“, National
Aeronautical Laboratory, India, 1975.
W 63. S. K. Tewari, “‘It’s time to talk about wind
power”, Science Today, November 1975.
W 64. P. N. Shankar, “The design, fabrication and
preliminary testing of NAL’S 1 kW vertical
axis wind turbine”, National Aeronautical
Laboratory, India, Report No. AE-TM-22-75,
1975.
W 65. P. N. Shankar, “On the aerodynamic performance of a class of vertical axis windmills”,
National Aeronautical Laboratory, India,
Report No. AE-TM-13-75, 1975.
W 66. BHEL Research and Development News,
Second Annual Day Issue, January, 1976.
W 67. J. O’M. Bockris, “The case for sea-borne windbased power”, Search, July 1975.
W 68. “The role of research and development in New
Zealand’s energy economy”, Department of
Scientific and Industrial Research, New
Zealand, March 1974.
W 73. E. Flatteau and J. Stansbury, “It takes energy
to produce energy: the net’s the thing”,
Washington Monthly, March 1974, pp. 20-26,
. and “Net Energy”, April 1974, p. 6.
W 74. N. Geogescu--Roegen, “Energy and economic
myths”, Southern Economic Journal, VG!. 41,
@mry
1975, pp. 347-381.
W 75. J. G. R. Stevens, “Energy and agriculture”,
Spun (Shell Oil Company), vol. 18, No. 1,
1975.
W 76. M. Slesser, “How many can we feed?“,
Ecologist, 3, 1973, pp. 216-220.
W 77. “Solar water heaters”, Consumer, New Zealand,
No. 114: January-February 1975, pp. 16-19.
W 78. D. A. Hilis and G. L. Allen, “Solar water
heating”, Department of Scientific and Industrial Research, New Zealand (Christchurch),
Technical Bulletin No. 1 (revised edition),
June 1975.
W 79. “The status of solar energy utilization in
Australia for industrial, commercial and
domestic purposes”, Commonwealth Scientific
and Industrial Research Organization, Australia,
Solar Studies Report No. 74/l, 1974.
W 80. Proceedings of the New Zealand Energy Conference, University of Auckland, New Zealand,
May 1974.
W 81. J. van Me&hem, Atmospheric
Oxford, 1973.
Energetic&
W 82. N. J. Cherry, “Prehmiiary analysis of meteorological data”, L- xoln College, Canterbury,
New Zealand, Report No. WER-1, 1975.
III.
Consolidated list of references on wind energy
W 83. N. J. Cherry, D. J. Edwards and A. 1.
Roxburgh, “Low-cost instrumentation for a
wind energy survey”, paper to be presented at
Instrumentation
the 22nd International
Symposium, San Diego, California, USA, May
1976.
133
Other useful references
R. van Steyn, Wind Energy, A Bibliography
with
Abstracts and Keywords, Parts I and II, De-
partment of Physics, Eindhoven University,
Netherlands.
W 84. J. R. Wood, “Wind energy utilization in New
Zealand”, University of Auckland, New
Zealand, 1975.
Wind Energy Utilization, a Bibliography with Abstracts,
W 85. D. Lindley, “New Zealand’s place in the energy
economics of the Pacific basin countries”, Conference on Energy in the Pa&c Basin,Pepperdine University, California, USA,
December 1975.
Wind Energy Bibliography (USA, Wiudworks).
W 86. C. 0. Lee, “Study on windpower utilization as
a source of energy’*, Ministry of Science and
Technology, Republic of Korea, Report No.
STF-74-2, 1974.
W 87. K. Z. Cho, “Performance analysis of a selfexcited brushless generator”, Korea Advanced
Institute of Science, M. S. thesis, 1976.
W 88. H. V. 0, ‘%rame analysis of structural design
system”, Korea Advanced Institute of Science,
M. S. thesis, 1976.
W 89. T. S. Ahn, “Stress analysis of a windmill propeller”, Korea Advanced Institute of Sgence,
M. S. thesis, 1976.
W 90. A. Arismunandar, “The Indonesian energy
demand in the year 2000: views and comments”, Symposium on Energy and the
Environment, Jakarta, Indonesia, February
1975.
W 91. D. J. Grace and others, Report of the Task
Force on wind energy, Alternate Energy
Sources for Hawaii, 1975, Hawaii Natural
Energy Institute, February 1975.
W 92. D. E. Walshe, Wind Excited Oscillations of
Structures, London, H. M. S. O., 1972.
W 93. Asyaman, Final project, Department of Engineering Physics, Bandung Institute of
Technology, Indonesia, 1976.
W 94. R Rosad, Final project, Depnitment of
Mechanical Engineering, Bandung Iu&ute of
Techuology, Indonesia, 1976.
National Aeronautical and Space Administration, USA, 1974.
Wind Power, (J. G. Symons, Mankato, Minnesota,
USA).
Wind Powered Machines, (USA, National Technical
Information Service).
T. Savino, Wind Energy Conversion Systems, Workshop Proceedings, Washington, DC., June
1973, (USA, National Technical Information
Service).
T. Savino, Status of Wind Energy Conversion, (USA,
National Technical Information Service).
Soedergard, Analysis of Possible Use of Wind Power
in Sweden, part I, Resources, Theory, Model 1
and 10 MW, (USA, National Technical Information Service).
Christaller, “Exploitation of wind energy”, parts I and
II, National Technical Information Service,
USA.
U. Hutter, ‘The development of wind pozer installations for electrical power generation in
Germany”, National Technical Information
Service, USA.
Bettlgnies, “Wind energy-its
utilization in isolated
areas of the Americas, ?4 - 100 kw”,
Engineering
Centre,
Ecole
Northern
Polytechnique, Montreal, Canada.
M. F. Merriam, “Is there a place for the windmill in less
developed countries”, Working Paper Series
No. 20, East West Centre, Honolulu, Hawaii,
USA.
G. Smith, “List of manufacturers of water pumping and
electric generating windmills”, School of
Architecture, Technical Research Division,
Cambridge, UK.
T
3
134
IV.
ORGANIZATIONS
CONCERNED
WJTH WIND
ENERGY
(Preliminary List)
Oficer
Organization
A.
concerned
Fields of work
Research Cen:rcs in the ESCAP Region
1.
Arui&a
Wind generators
PBndcrs University, Bedford Park, Soutb Australia 5042
2.
Fiji
P. Johnston
Wind generators, integrated systems
B. Behari
Promotion
National Council of Scicncc and Technology, Technology Bharan,
New Mchravlcy Road, New Delhi
C. S. Chattajec
Researchco-ordiiation
National Aeronautical Laboratory, Post Bag 1779, Bangalore,
Kornataka, 560017
S. K. Tcwari
Wind generato. wind pumps,
Danicus rotor
Indian Institute of Science,Cell for the Application of Science and
Technology to Rural Areas, Bangalore, Kornataka, 560012
A. K.%. Rcddy
Vertical-axis rotors, integrated
systans
Indian Agricultural Research Institute, Agricultural Engineering
Division, Dairy Road, New Delhi 110012
D. K. Biswas
Greek sail rotor, Savonius rotor
Cur& Arid Zone Rcscarcb Institute, Wind and Solar Division,
Jodhpur
A. Krishnao
Data analysis
Aurovillc Ccntrc for Environmental Studies,
Pondichcrry-2, 605001
C. L. Gupta
Low-cost windmills, integrated
systems
Organixation of the Rural Poor, Kosumihkalan,
P.O. Madnahi Urf Pahonchi, Ghazipur District, Uttar Pradesh
H. Prasad
Rcncwablc energy systems
Social Work and Rcsarcb Ccntrc, Tilonia, Admu District,
Rajastban
S. Roy
Multi-use sail rotor
H. Djojodibardjo
Darrieus rotor, sail rotor water pump
Central Planning Office, Energy Unit, Government Buildiigs,
P.O. Box 2351. Suva
3.
4.
India
.
hlinistry of Industry and Civil Supplies
Appropriate Technology Cell, 268 Udyog Bharan, New Delhi-l
Indonesia
Bandung h?iNtc
of Technology, Acre and Hydrodynamic
Laboratory, Bandung
5.
MaIaysia
Malaysian AgriculNraJ Research and Development btstitute,
P.O. Box 208, Sungai Bcsi, Scrdang, Sclangor
6.
7.
Sail rotor, peristaltic pump
New Zealand
Lincoln College, Department of Mechanical Engineering,
Canterbury
R. E. Chilcott
Wind generators, low-cost
ancmograph
AuA$~~d$rivcrsity,
J. R. Wood
Large-scale wind generators
A. Khan
Savonius rotor
Cbung-Oh Lee
Wind gcnnator
Department of Mechanical Engineering,
Philippines
International Rice Research hstiNtc,
Agricultural
Department, P.O. Box 933, Los Banos, Manila
8.
-
Engineering
Republic of Korea
Korea Advanced hstitutc of Science, Dcparrmcnt of Mechanical
kbzring,
P.O. Box 150, Cbcoug-Ryang-Ri, Seoul
.lV. Organkations concerned with wind energy
135
Organization
O&r
Fields
of work
A. D. N. Fernando
Development programme
-4. J. Ariyaratnc
Low-cost wind pumps and
demonstration
National Energy Administration, Design and Energy Research
Section, Pibultharn Via, Kasatsuke Bridge, Bangkok
S. Chantavorapop
Dcvdopmcnt programme,
wind generator
Ministry of Agriculture and Co-operative, Agricultural
Engineering Division, Kxctsart University Grounds, Bangkhcn,
Bangkok 9
C Suksri
Low-cost wind pumps development
and demonstration
Brace ResearchInstitute, MacDonald College of M&ii University.
P.O.B. 900, St. Anne de Bdlevue 800, Quebec H9x 3Ml
T. Lawand
Consultaacy services, research for
developing countries
National Rcxarch Council, Low Spud Aerodynamics Laboratory,
Montreal Road, Ottawa KIH 6R6
R. J. Tcmplin
Darricus rotor
Folkctcknik, Christiansmindcus 11, Copenhagen 2100
E. Hauncrik
Low-cost windmills
E. Rcsslcr
Low-cost windmills
Scicutific Research Institute for Wind Energy Tcdmique,
Institute of Applied Scicncc, University of Stuttgart, E.U.,
mcuwaldring
31. D-7000 Stuttgart 80
U; Huttcr
Rcscarchon windmills
Tahnial University of Berlin, Institut fur Wasscrbau und
Wassawhchaft, Strabc dcs 17 Juni 135. D-1000, Berlin 12
P. Bade
Flapping-vane wind pump
Eindhoven Technical Uuivcrsity. Steering Group, Wiid Euugy
for Dcvdoping Countries (Physics Department), Postbox 513,
Eindhovcn 1076326
P. T. Smuldcrs
Comprehensive dcvdopment
programme
TOOI,, Foundation, Postbox 525, Eindhovcn
T. de Wilde
Wind pumps, advisory service
T.N.O. Project Group Turbiie Machines, P.O. Box 496, Ddft
P. van Stavcrcn
Co-ordination, optimization
R. Wijewardcnc
Integrated systems
SWirzeriad
World Council of Churches, &nmission of the Church’s
Participation in Development, 150 Route de fcrncy, P.O. Box 66,
1211 Geneva 20
P. de Pury
Low-cost windmills
Syrrir
General Administration for the Development of the Euphrates Basin,
Duia, MEa
W. Khalayhi
Wind pumps
R stamlcy
Cambered flat plate rotor, UNICEF
demonstration
h4iaknkm~ ygation,
Power and Highways, Soxctariat Building,
Sarvodaya Educational Development Institute, Appropriate
Technology Project, 77 De Soysa Road, Moratuwa
10.
concerned
ThaiLmd
B. 0th~ Organizions
1.
Canada
2.
3.
Ethiopia
Christian Relief and Development Ass&ation, P.O. Box 5674,
Addis Ababa
4.
5.
6.
Federal Republic
of Germany
Neiherbnds
Niger
International hstitute
Ibadau
7.
a.
9.
e
of Tropical AgricdNre.
P.M.B. 5320,
Tanzati
Ministry of Lands, Settlement Fd. Watt! ,I+vdopmcnt,
z’ahDevdopmcnt
and lrrrgaclon DwIsIon, P.O. Box 3030,
Part Three. Documentation on wind energy
136
organixaf.ion
10.
Ofrca
Electrical Rcsrch Association, Power Engineering Division,
Clccvc Road, Leatherhad, Sutrcy KT 227 S.4
M. E. Hadlow
Co-ordiiation for United Kiugdo~
tcchnicd publications
Intcrmaliatc Technology Dcvdopmcnt Group Ltd., Parndl House,
25 W&on Road, London SW1 1JS
P. Fracnkd
Wind pumps, advisory scrvie
oxford university, DcpartmctIt of Engineering Scicncx,
Parks Road, Gxford, OXI 3PJ
s. s. Wdsml
Sail windmill, low-cost wind pumps
Univ~ty of Livupwl.
Livclpod 3
N. G. Calvcrt
Aerodynamic studies
D. Taylor
Low-cost windmill design and
demonstration
A. Paccy
Advisory scrviccs
Depattmcllt of Mcchanicd Engineering,
school of Industrial Design, Kensington,
Oxford Committee for Famine Rdicf, 274 Banbury Road,
OXfOIdOX27(X
Vnied Stam
of America
L. v. Divone
TcchnicaJ Assistance Information Qcaring House, 200 Park
Avcnuc South, New York, N.Y. 10003
J. M. Me&ill
Technical information
Dcpartmcnt of Stag Agency for International Development,
G&c of Scicuceand Technology, Washington, D.C. 20523
H. A. Arnold
Tcch&d
Altemativc
Sources of Energy, Route 2, Box 90-A, Milaca,
-a
N~~uuy~~o;;;3+Eas~
USC
Box 432, Woods Hole,
Co-ordination for USA
assistance
High-speed rotor aerodynamics,
system optimization
D. Maricr
Intcrmcdiitc technology, advisory
scrvicc
J. Todd
Low-cost windmills, integrated
hiillcsota 56353
SptUllS
Rinccton University, Flight Concepts Laboratory, Princeton,
New Jersey 08540
T. E. Swecncy
Rotor rcscarch
univusi~ of MawachU~
Dcpartmcnt of Civil Engineering,
Amllcm, Massarhuscns01002
W. E. Heronemus
Liugc-scale wind generators
okhhoma state univusity, School of Elcctricd EngJnccring*
south stiuwatcr, oklahoma 74074
W. L. Hughes
wind-datric
Volunteers in TahnicaJ Assistance, 3706 Rhode Island Avcrmc,
Mt. Rainicr,~Maryland 20822
R. Garcia
Tccbnicd consultation scrvicc
VoJuntccrs in Asia Inc., Appropriate Technology Project,
Box 4543, Stanford, California 94305
K. Darrow
Technical assi.9tancc
Upper
Vnhd
systems
Volra
L!f?colc Inter-Stats d’Ing&iarrs
B.P. 7023, Ouagadougou
13.
.
Energy Rucarcb and Dwdopmcm Administration, Wind Energy
Conversion Brat&, 1800 6th Sum, Washington, DC. 20545
Wind Energy Society of Amaica, 1700 East WaJnut, Pasadena,
Cdiirxnia 91106
12.
of work
Fields
United kihgdm
Ro&yiqsff,^f:
11.
cOncerned
Low-cost windmill demonstration
de J’i?quipcmcnt Rural.
Notions
Advisory scrvia
CCIIUCfor Naturd Resources,Energy and Transport,
Dcpartmcut of Economic and Social Affairs, New York, N-Y.,
USA
Regional co-ordination (upcrt
working group, 1976; roving
seminar, 1977)
Economic and Sodal Commission for Asia and the PacifiG
Natural Re.wurccsDivision, United Nations Building, Bangkok,
Tllauand
N
Economic Commission for Africa, Nairobi, Kenya
A. I. McCutchan
Food and Agriculture Organization of the United Nations,
Agricultmal Savico Division, Vi ddle tame di Cavacalla,
00100, Rome, Italy
W. J. Van Gilst
Publications
Unitcd Nations Environment Programmq P.O. Box 20,
Grand CcntraJ Station, New York, N.Y. 10017, USA
J. H. Usmani
Dcmonsuation ccntrcs
i-m;d
African mcctbrg
06
CnCWYg
N.
Orgmizations concerned with wind energy
Organa~ation
!
I
f
.
137
Ofua
concerned
Fields
of work
United Nations Industrial Devdopmcnt Organization,
Saliigcrgassc 40. A-1190, Vienna, Austria
M. Ddlos
Prngrarnmcs rdatcd to energy
Unital Nations International Childrcns Emergency Fund. Food
Engiuccring aod TccImology Section, 866 United Nations Plaza,
New York, N.Y. 10017, USA
A. Robinson
Demonstration unit (Nairobi, June
1976)
Uniti Nations Educational, !Schific and Cultural Organization,
New York, N.Y., USA
-
Supports non-conventional energy
activities
Uuitai Nations tXicc for Science and Technology, United Nations
Plaza, New York, N.Y. 10017, USA
B. Chatd
Co-ordination
United Nations Dcvdopmcut Programme, United Nations Plaza,
New York, N.Y. 10017, USA
J, Sdlew
Planning and funding
United Nations Devdopmcnt Programme, 200 Park Avcuuc,
Suite 303, East New York, N.Y. 10017, USA
B. P. Kdly
Wind-dectric. Paraguay
Part Four
DOCUMENTATION
ON INTEGRATED
SYSTEMS
139
I.
WORKING
AN INTRODUCTION
PAPER PRESENTED
TO INTEGRATED
SOLAR-WIND
lNTRODUCTION
Many rural villages in Asia cannot be integrated
effectively within the larger regional or national systems
because of the economic limitations on energy distribution. In order to increase the net productivity of these
villages, it is desirable to increase the net energy
available by increased and more effective use of all
local energy resources,including solar energy and wind
energy.
I
D
,
Diversity of energy sources is desirable because
each source his available in a form that is compatible
with certain tasks only, and some energy sources are
available only for limited periods and/or on an intermittent basis. An integrated energy system may use
a combination of different local sources at differenttimes for different uses, in order to satisfy the total
energy requirements of the village.
The careful addition of appropriate solar energy
and wind energy conversion devices to an integrated
energy system can increase the net productivity of a
village in three ways: (a) the total amount of productive energy available may be increased without
necessarily causing an increase in the flow of capital
and operating funds out of the system; (b) traditional
sources may be freed from some unsuitable tasks; and
(c) new uses of energy may become practicable.
Table 1, taken from reference T 1, indicates the
applicability of renewable resources of energy in rural
communities.
A.
BY THE SECRETARIAT
SOLAR AND WIND ENERGYCOMBINED USES
Several production processes may use a combination of solar energy and wind energy.
1. Salt production
Salt production by solar evaporation of sea water
is an ancient process. Thirty-six m3 of sea water are
required for every metric ton of common salt produced,
and a considerable amount of low-lift pumping is required at each of the three stages of the process.
Wind-powered pumping performs this job admirably in
many countries, as.in exposed coastal areas, where salt
fangs are located, wind velocity is invariably high.
l pmparcd by Mr. R. L. Datta and Mr. M. M. Sherman, consultants on
mh “crgy and wind energy rcspativdy, at the rcqucst of the ESCAP
-ctariaC
The views aprcsscd in this paper arc the authors’ own and
do not nacssahly rdlcct those of the secretariat or the United Nations.
SYSTEMS (NR/ERD/EWGSW/4)*
In many instances, salt crystals/lumps must be
crushed, reduced in size and washed, and a windpowered mill may be used for this purpose. In some
salt farm areas in different countries, solar distillation
is used to produce fresh drinking water from sea water,
and wind pumping may be used for distribution.
2. solar drying chambers
In solar drying chambers, utilization of [email protected]
has been considered for creating the necessary draught
as an alternative to solar chimneys or electric blowers.
Processes for seasoning of wood and solar drying of
food are being developed in the United States of
America, Australia and India, and mechanical power
from windmills is being used for air circulation.
Although windmills are effective in areas with a
wind velocity of 10 km/h or more, wind funnels
operate with a wind velocity of 6.5 km/h, and there
may be applications in which the wind funnel’s
potentiality to increase the velocity of air flow with
reduction in duct size could be useful.
3. Rural electricity supply
A combination of wind and solar energy has some
potential for rural electric supply. A 500 kW power
system for electricity supply to small communities in
the Philippines is suggestedin reference T 2, consisting
of three elements: (a) two three-blade high-speed
rotors to drive a 500 kW three-phaseconstant frequency
AC generator; (b) a boiler, designed to bum municipal
garbage, supplying steam to an auxiliary 375 kW
turbine generator during the night or when the wind
generator is operating below rated capacity; (c) solar
concentrators to focus the sun’s rays on a 200 kW solar
boiler, coordinated with the garbage-fueled boiler for
economic parallel supply of steam to the auxiliary
turbine generator. It was estimated that this trienergy system might produce electric energy at about
half the cost of an equivalent isolated diesel-fuelled
generator.
4. Solar houskg design
In several industrialized countries, complex solar
housing systems are being developed, which use solar
energy for water heating, cooking, space heating and
Integration of wind energy devices could
cooling.
make the over-all system more versatile by providing
power for water pumping, refrigeration, lighting, and
small appliances.
Part Four. Documentation on integrated systems
140
Table 1. ENERGYDEMANDSOF RURAL COMMUNITIES AND
=lRPOTBNlUL
SUPPLYPROMRZNRWARLEENERGY SOURCES
rime roqmirmrur
E-SY
Solar-m’odmdoee
$0tmid
rruditlocd
Water hating.
cuoking . .
Lighting . .
.
I
.
.
.
.
.
.
.
.
.
.
Daily
Precisedaily
Predse nightly
Wood, cowdung
Wood, cowdung
-
Water supply .
.
.
.
.
constant
HlUIMIt
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
Prccix scamnal
Precise scamnal
Praise sca.snnal
Prccisc seasonal
Precise scasom-il
Prccisc seasonal
Pxcisc seasonal
Random daily
.
.
.
.
.
Prccsc seasonal
Water pumping
.
.
.
.
Preciseseasonal
Aquaculture
.
.
.
.
Constant
Human,animal
Human
Human,anti
HIUllatl
Human, animal
Human
Solar
Human, animal,
wind, water
Human, animal,
wind
Human, animal,
wind, water
Human
APlougbing .
sowing
.
cultivathu.l
Harvesting
Threshing..
winnowing
Drying.
.
Grindiig .
crushing
.
.
*
.
.
.
applg
Solar
Solar, methane
Wind-&&c,
methane
witld, solat
Insulated tank
Gas bolda
Battery, gas bolder
rank
Wind
Wind
wind
*
Solar, wind
Wind
-
Wind
-
wind, solar
Reservoir
Wind, solat
Rcsavoir
Community deuelopment
-
G~mmunicadon and education
Precisedaily
Transport .
Housing .
Rcfrigcration
Precise daily
seasonal
constant
Human, animal
Human
-
Raodom
Solar, wind
Precise ddy
Human
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
salt production . . . .
Entertainment (radio, tdcvision. cinema) . . . .
wind, solar
(datric)
Solar deign
solar, winddcctric
Solar, wind
Wind. ralar
Battuy
Solar wall
Banuy
Reservoir
BattCIY
(d&c)
B.
INTEGRATED BIO-ENERGETIC
ECOSYSTEMS
Several experimental projects aimed at the
development of integrated food-producing ecosystems
incorporating intensive agriculture and aquaculture
tecbhiques with solar energy and wind energy supplies
have recently been undertaken. The continuing increase of activity in this field indicates a signiticaut
future for bio-energetic ecosystems in economical food
production.
1. Asian pdyculture
Unlike modern Western agriculture, Asian agricultural production is typified by polyculture, diverse kinds
of useful plants and animals liviug together with men
in ecologically balanced and stable communities (see
references T 3, T 4 and figure 1).
Rubber/coconuts
Orchards/tobacco
pond
Figure 1.
Integrated agriculture-aquaculture system in Siigapore
The stabii and productivity of these classic
agricultural-aquacultural systems can be increased by
providing more energy input from solar energy and
wind energy. This b&energetic farming concept has
been practically demonstrated at the University of the
Philippines (reference T 5) where au experiment incorporated several biological and energy subsystems
integrated on. a total area of 164 m2 (see figure 2).
L
Working paper presented by the secretariat
W
-)i
+n
-d
ji?L
1
1
Solar collsctor
-
-----
Food
Food
Wdtsr
Figure 2.
University of the Philippines integrated farming system
Figure 3.
(a) Ten pigs to produce meat for human
consumption were each confined in a 4.5m2 pen.
Dried and ground hog manure was obtained as the basic
nutrient supply for Chlorella algae culture, and hog
manure was supplied to digesters;
(b) A Chlorella algae culture pond of 20 m2
was constructed on top of the pig pens to supply a
food supplement to the pigs, food for tilapia fish and
garden fertilizer;
(c) A methane gas generator, incorporating
two digesters and a 2.5m3 gas holder, was located near
the pig pens. The effluent of the digesters was available as garden fertilizer;
(d) A tilapia fish culture pond of 12 m2 was
added to provide storage of water required for the algae
culture. Water from the fish pond. was found to have
high value as garden fertilizer;
(e) A vegetable garden of 54 m2 was planted
with lettuce, tomatoes and pechay and used for a controlled study of different fertilizers;
(f) A Savonius rotor wind pump was used to
provide intermittent stirring of the algae culture and to
pump water from the fish culture pond to the algae
culture pond.
It was concluded that, by using such a scheme of
integrated farming, food and fuel can be produced
efficiently at a low operating cost.
New Alchemy Institute integrated backyard fish farm
2.
New Alchemy Institute
The New Alchemy Institute, in the United States
of America, has a programme of experiments to
different integrated food-producing systems geared to
the needs of families and small communities. The
systems are modelled after Asian polyculture farms,
but are adapted to northern temperature climates.
One system, a backyard fish farm (see figure 3), is
primarily an intensive fish-culture system incorporating:
(a) 22,000~litre tilapia fish culture pool (first stage)
supplied with Daphnia grown in a second stage and
with vegetable wastes from the adjacent garden, while
a biological filter (third stage) removes harmful fish
wastes; (b) insulated translucent covers over all three
stagesretain solar heat, and the pond water is circulated
through a large flat-plate solar collector to provide
additional heating; (c )a windmill constructed of locally
available materials circulates water through the solar
heater and three pools; ‘and (d) enclosed within the
translucent greenhouse, adjacent to the primary culture
pool, is an area for year-round cultivation of salad
vegetables.
The research group has also recently developed a
solar pond concept that integrates solar energy collection and storage, algae culture and fish culture in
individual cylindrical translucent fibre-glass pools,
1.5 m high and 1.5 m diameter. Planktonic algae
collect solar energy for their own growth, and at the
same time heat the water. The algae are eaten by
Part Four. Documentation on integrated systems
142
tihpia fish. An air compressor powered by a Savonius
rotor provides intermittent circulation of the water
through biologically active sub-sand filters to metabolize
i&h wastes into nutrients for algae growth. Algae pro
duction in these solar ponds is ten times greater than in
the backyard fish farm system. Forty of these ponds
will be used in the Canadian Ark, which is under construction at Prince Edward Island, Canada, as a project
of the United Nations Human Settlements Year.
The Ark has been designed as a completely
autonomous and self-controlled system for living,
This system will inresearch and food production.
corporate: (a) an aquaculture component (the 40
solar ponds) for protein production; (b) a greenhouse
section for year-round vegetable production; (c) large
solar collectors for heating all components of the
system; and (d) a 25 kW wind-electric generating
system for supply to lights, small appliances, system
control devices and scientific recording instruments, and
to provide supplemental heat during the windy winter
season.
greenhouse incorporates solar water heati- in its wa&
A wind-electric generator supplies power for water
pumping. Aquaculture tanks inside the structure
house gaint Malaysian freshwater prawns (macrobrachiom Rosenbergi), common carp, freshwater clams
and Daphnia in proper proportions so that there is a
balanced food chain established with a minimum of
wastes in the system. Vegetables growing in
hydroponic tanks utilize the animals’ metabolic wastes
as their growth nutrients (see figure 4).
4., Centre for Mhum
The Centre for Maximum Potential Building
Systemsat Texas University, United States of America,
has constructed several integrated living systemsincorporating wind pumping, wind-electric generation, solar
water-heaters, solar heating walls, methane gas generation, algae culture and intensive agriculture. The
Centre conducts research into the design potentials of
economical integrated housing systems (see figure 5).
5.
3.
Solar aquafarms
A private company (Solar Aquafarms) in the
United States of America has developed a greenhouse
aquaculture system intended to supply the animal
protein needs of a large number of people (see reference
T 6). The semi-cylindrical 30-m x 9-m insulated plastic
L
Potential Building Systems
Integrated Living Systems
Integrated Living Systems,in Tijeras, New Mexico,
United States of America, is a research laboratory that
has successfully integrated solar collectors and windelectric generators into autonomous living units. The
systems are designed for autonomous communities independent of outside energy supplies (see figure 6).
I. Working paper presented by the secretariat
143
Sobr water
heaters
Hydroponic
/
.- _-.
lrnwn
Prawns -
earing
Screen
sepamfor,\i
=L
Common
carp
16lls
w
Figure 4. A 30-m x 9-m “Aquasolarium” solar/wind-powered aquatic food production unit
.
I
Solar collector
Solar collector
\ 9
Wind generator
Pump
Batteries
t
gsnorator
Fiie
5. Maximum potential building systems
Electricity
1
Figure 6. Integrated living systems
144
II.
PLANNING
INFORMATION
PAPER
FOR SMALI&XLE
PREPARED
USE OF RENEWABLE
(NR/ERD/EWGSW/CR.20)*
BY PARTICIPANT
ENERGY SOURCES IN FIJI
by
Mr. P. Johnston (Fiji)
IWOdUCtiOD
(a) To assist communities and individuals, particularly in the rural areas, to exploit the sun, wind,
water, and wastes as energy sources;
_ The South Pacific islands generally have limited
conventional energy resources. Practically all
electricity production is by diesel sets, and all the oil
is imported. Petroleum prospecting is under way in
several island groups but there have been no commercial finds. Oil will be the predominant energy
source for electricity production for some time, although
there are medium- to long-term alternatives. Wind
energy and solar energy- should have considerable
potential for the small isolated communities.
(b) To encourage research into small-scale
energy conversion equipment, such as windmills and
solar water-heaters, in order to develop cheaper and
simpler designs which can be made and maintained
IOCdlJL
Water pumping, lighting, and communications
energy needs are met in a few island locations by wind
systems. Two Australian Dunlite 2 kW aero-generators
were recently installed on Pitcaim Island, several are
planned for village lighting in Fiji, and other territories
(Tahiti, Cook Islands) have used similar equipment.
A hypothetical solar/wind/bio-gas/hydra rural
energy centre has been postulated, in a community too
small for a diesel generator to be viable, too isolated
for connexion to an electricity grid, in an area with
reasonably good winds and solar radiation, and
accessible enough for monitoring.
In Fiji, solar energy is used for copra drying, salt
production, timber drying, and solar water-heating.
Water heating has become a thriving industry; 400
locally-assembled units have been installed since 1974
and an additional 50 exported to other islands. There
are probably 4,000 solar water-heaters, predominantly
of Australian manufacture, in the South Pacific islands.
I.
ENERGY
AND DEVELOPMENT
INFIJI
PLANNING
There was iittle serious concern with energy
policy in Fiji until the energy crisis of 1973/74. A
committce established in May 1974 reported to the
Cabinet in mid-1975 on energy policies and technologies
likely to reduce petroleum imports and conserve foreign
exchange, and this led to the formation of an Energy
Unit within the Central Planning Oflice.
Even allowing for a greatly expanded programme
for rural electrification, approximately 40 per cent of
rural areas could not be supplied with transmitted
electricity, and it is considered that renewable unconventional energy sources may be viable. The Energy
Unit has been allocated $F 350,000 ($US 400,000)
over the 19761980 development plan period to
investigate, evaluate and develop possible alternative
energy sources. Two specific objectives are:
l
Abridged.
II.
HYPOTHETICAL
SOLAR/WIND/BIO-GAS/
HYDRO ENERGY CENTRE
The assumptions include: a community of 90
people in 15 family dwellings, a mean wind speed of
19 km/h, and mean insolation of 450 cal/cm2/day
(typically, about 30 per cent more useful wind energy
occurs in June/July than in December/January, while
insolation values in December/January will be about
60 per cent higher than in June/July), a stream with
a useful flow of 2.27 ms/min and head of 3 m and the
wastes of 60 pigs and 5 kg/day of dry vegetable waste
(equivalent to 16 kg of fresh vegetation) available for
fuel gas production.
The expected availability of energy would be:
Wind -_ 2,660 kWb/year electrical, or
Solar
-
4,380 kWh/year mechanical;
970 kWb/year/m2 low-grade heat;
Hydro
-
4,380 kWh/year electrical;
Bio-gas -
12,000 kWh/year high-grade heat.
The extent to which any of the sources would be
harnessed, and in what combinations, would depend
upon numerous factors, including initial cos’t, import
content, reliability, maintenance costs, and likely disruption of village social patterns, and only a crude
comparison can be made of the energy potentially
available and the energy needs of the community.
Il.
Information paper prcpzed by participant
”
A.
LIGHTING
FUR FOUR HOURS DAILY
Because fluorescent tubs are not generally available in Fiji, assume the use of incandescent bulbs.
Two lights/house x 15 houses x 60 watts/light would
require 2,628 kWh/year, :-e. nearly all the useful
output of the wind generator, or 60 per cent of the
output of the water turbine. If a wind unit is installed,
recall that output in winter :June/July) is 15 per cent
above average, while that in summer @~/Jan) is
about 15 per cent less than average. This means
typically 4% hours/day ot light in wjnter and 3%
hours/day in summer; avaihbility of energy is consistent
with demand.
Alternatively, two bio-gas mantles would require
about 13,500 kWh/year, ra :her more than the expected
output.
B.
Solar cookers are a possible alternative at midday,
but the sun is intermittent and social acceptability is
likely to be low. Elecuic cooking would require
2 kWh/day/family, which is approximately 2.5 times
the water turbine output.
If wood were burn d directly for cooking, the
village would require aboit 140 kg of wood daily. If
wood gas generators cot .id be used, about 70 kg of
wood would be needed.
Assuming a village wood gas generator and a
bio-gas digester feeding ‘he same reticulation system,
fuel gas needs could be ITet by a combination of wood,
faeces, and vegetation wa ,te. In Fiji, there are a great
many coconut trees beyo Id ,economic bearing age, and
these could be a good fu;l source. Younger trees are
also of use, as one ton oi mature coconuts (750-1,000
nuts) yields 450 kg of Eusk and 160 kg of shell.
WATER PUMPING
Generally, water pcmping is not necessary in Fiji.
However, assume the vliiage must be supplied from a
source 9 m deep. A re+irement of 45 litres/person/
day plus extra water for the digester would need
approximately 78 kW t/year, which would be no
problem electrically or mechanically.
D.
llI.
FOOD REFRIGE ,%4TION
A communal unit of 10 cubic feet capacity, run
ou No-gas, would take: less than half of the bio-gas
output, or an electric unit would need about 800
APPROACH TO PRACTICA$
ENERGY
COOKING FOR TW3 HOURS DAILY
For efficiency, cleanliness and ease of use, bio-gas
would be ideal, but requirements would be well beyond
expected output.
C.
iii! 145
!<
:;;I( kWh/year. An alternative would be ice bled,.“;; production by using mechanical power to drive aJ‘,i ,=czer
compressor, or solar radiation to run an abs t 3 ption
.:d
unit.
i;
1,’
E. SUMMARY OF REQUIREMENTS
I<;;;’
,I
Assuming lighting and water
supplied by electricity, either solar
could be used for food cooling, and some bi !, ,,:!scould
7
I :quked.
be used for cooking, supplemented by wood a,;,
On the basis that needs do not greatly outstr?
- ,i!1: I ptential
sonomic
SUPPlY
9 a more rigorous technical-socc,,,:
.?I
analysis is seen to be worth-while.
,.,;!‘r
<il’!
CENTRE
,~URAL
,‘I,
In line with exploratory investi f’y ,lons by the
? ;, .uug Office of
Ministry of Finance and the Central PI!,.,!‘,
the Government of Fiji, a detailed m#, ,,orandum was
prepared to assist itt the selection of/$,.’ iuitable mge
as a test site.
,; ’
P
The memorandum sets out rF,o I,nements in line
with those suggestedfor the hypoth<: i ;al energy centre,
and gives information on the possi , I’ ,;: use of renewable
F ,raabfiv
energy reSOUrCCS,iUClUdiIlg SOUl&~J;~
data and
standard methods of calculatingJ!
r’
;
Jbable
energy
out‘/)
puts, and some typical costs.
;f’,
IV.
A.
AVAILABLE
DA+
0~ m
SOLAR+SOLA’!!
j )N m FIJI
<,;;
4j
WIND
.
ANg)
;f
Annual meteorologicp,9
ummaries’ from 1947 to
1970 are available for tw$ j iations on #the main island
of Viti Levu, at
+rt
and Laucala Bay
respectively. The
‘lava been analysed in terms
of annual and monthly ;‘, 4arage wind speed, and yariation of wind during thj.‘, ::,ay (at Nadi airport the ratio
between wind speed .! ,.I the afternoon and during the
night may be 3:l). [;
i ords for about 10 years are availns on smaller islands, indicating
.m wind speeds of the order of
result ma; be typ%al for many areas
fI
Some oti;.:’
If ,,:I,.records have been L&C.::: ’ :Ca.r!ous
locations fr$
dme to time, but the reliabb L.-, *Ii
figures is c$$: idered to be somewhat doubtful.
,;!i
4”:
146
B. SOLAR INSOLATION
There is very little information on solar insolation
in Fiji, with the exception of Nadi airport on the dry
side of Viti Levu, where Eppley pyronometers and
Brown recorders have been in operation since 1957.
There are about ten years of solarimeter data for the
sugarmill at Lautoka and limited amounts for two
stations in the wet zone: Koronivia Research Station near
Part Four. Documentation on integrated systems
Suva and the University of the South Pa&Tic, Laucala
Bay, Suva. Mean daily sunshinehours during the period
up to 1970 were: Suva, 5.2 hours; Sigatoka, 5.2 hours;
Labasa, 5.9 hours, Nadi, 6.9 hours; and Lautoka, 6.9
hours. For Lautoka, the mean insolation from 1959
to 1969 exceeded 570 cal/cm2/day. For Nadi, from
1957 to 1973, the mean was about 440 cal/cm2/day.
However, insolation, as calculated from bright sunshine
hours, is about 12 per cent higher at 490 cal/cm*/day.
147
III..
CONSOLIDATED
LIST. OF REFERENCES
ON INTEGRATED
SYSTEMS
T 1. E. W. Gohiing, “The combination of local sources
of energy for isloated communities”, Solar Energy
Journal, II (l), 1958.
T 4. R Ho, “Mixed farming and multipIe cropping in
Malaya”, Proceedings of the Symposium on Land
T 2. M. I. Felizardo, ‘A new t&energy electric power
system for smaii Philippine communities”,
(ed.), Hong Kong University Press, 1961.
Mechanical Elect&al
Engineering (Philippines),
second quarter, 1974.
T 3. J. E. Bardach, J. II. Ryther and W. 0. Mclarney,
“Aquaculture: the farming and husbandry of
fresh water and marine organisms”, Wiley
Interscience, 1972.
Use and Mineral Deposits in Hong Kong,
Southern China and Southeast Asia, S. G. Davis
T 5. J. A. Eusebio, “Chloreila - Manure and gas-fish
pond recycling system in integrated farming”,
University of the Philippines, Los Banos College,
Philippines, 1975.
T 6. Energy Primer, (USA, Portola Institute, 1975),
p. 181.
I;
“/
I.?’
‘.
‘.
ENERGY RESOURCES DEVELOPMENT
I
SERIES
‘__
,?A...
1,
RURAL ELECTRIFICATION.
United Nations publication, Sales No. 54.11.F.I.
a equivalent in other currencies. Available in English.
Price $US 0.80
PROCEEDINGS OF THE REGIONAL S-AR
ON ENERGY RESOURCES AND ELECTRIC
United Nations publication, Sales No. 62.II.F.8.
POWER DEVELOPMENT.
Price $US 5.00 or
qGv&nt
in other currencies. Available in English.
RURAL ELECTRIFICATION IN ASIA AND THE FAR EAST.
a/TAO/SERC/63.
Available in English.
fi
United Nations publication No.
4.
PUBLIC ELECTRICITY SUPPLY-A
MANUAL ON MANAGEMENT.
United Nations publication, Sales No. 66.11.F.3. Price $US 2.00 or equivalent in other currencies. Available in English.
5.
THE ROLE AND APPLICATION OF ELECTRIC POWER IN THE INDUSTRIALIZATION
OF ASIA AND THE FAR EAST.
United Nations publication, SalesNo. 66.11.F.4. Price $US 1.50
or equivalent in other currencies. Available in English.
6.
COMPREHENSIVE ENERGY SURVEYS -AN
OUTLINE OF PROCEDURE.
United Nations
publication, Sales No. 67.11.F.14. Price $US 1.00 or equivalent in other currencies, Available in
English.
7.
PUBLIC ELECTRICITY SUPPLY-A
MANUAL ON UNIFORM SYSTEM OF ACCOUNTIIG.
United Nations publication, Saks No. 67.1LF.16. Price $US 2.00 or equivalent in other currencies.
Available in English.
8.
THERMAL POWER STATIONS-A
TECHNO-ECONOMIC STUDY. United Nations publication, Saks No. E.70.II.F.2. Price $US 1.50 or equivalent iu other currencies. Available in English.
9.
REPORT OF THE SEMINAR-CUM-STUDY
TOUR ON LOAD DESPATCH TECI-lNIQmS
AND -APPLICATION OF COMPUTER TECHNOLOGY TO POWER SYSTEM ENGINEERING
?ROBLEMS.
United Nations publication, Sales No. E.71 JL.F.14. Price $US 4.00 or equivalent in
other currencies. Available in English.
k
‘
10. BOILER CODES IN THE ECAFE REGION: SUGGESTED GUIDELINES FOR THE OPERATION, CARE AND INSPECTION OF BOILERS. United Nations publication, SalesNo. E.72.11.F.21.
Price $US 1.50 or equivalent in other currencies. Available in English.
11. PROCEEDINGS OF THE TWELFTH SESSION OF THE SUB-COMMITTEE ON ENERGY
RESOURCES AND ELECTRIC POWER. United Nations publication, Sales No. E.74.11.F.14.
Price $US 12.00 or equivalent iu other currencies. Available in English.
ELECTRIFICATION-PLANNIN
G. United Nations publication, Sales No. E.75.11.F.6.
12. URBAN
Price $US 6.00 or equivalent in other currencies. Available in English.
MEETING ON THE IMPACT OF THE CUR13. PROCEEDINGS OF THE INTERGOVERNMENTAL
RENT ENERGY CRISIS ON THE ECONOMY OF THE ESCAP REGION. United Nations
publication, Sales No. E.75.11.F.7. Price $US 10.00 or equivalent in other currencies. Available
in English.
SYSTEMS IN THE =P
14. NATIONAL POWER GRIDS AND EXTRA-HIGH-VOLTAGE
REGION. United Nations publication, Sales No. E.75.l.I.F.13. Price $US 4.00 or equivalent in other
currencies. Available in Eugikh.
15. PROCEEDINGS OF THE SECOND SESSION OF THE CO MMITTEE ON NATURAL REPrice $US 8.00 or quivaknt ia
SOURCES. United Nations publication, Sales No. E-76.H.F.l lother currencies. *‘Available iu English.
Note:
Publications Mos. I-10 wcrc issued without an Energy RCSOII~CM
Dcvdopmcnt h-bs number.
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