REP-009 Thermie Final Report

REP-009 Thermie Final Report
European
Commission
Energy efficiency
i n Tr a n s m i s s i o n &
Distribution
The scope for
energy saving
in the EU
through the use of
energy-efficient electricity
distribution transformers
ENERGIE
ENERGIE
This ENERGIE publication is one of a series highlighting the potential for innovative non-nuclear energy
technologies to become widely applied and contribute superior services to the citizen. European Commission
strategies aim at influencing the scientific and engineering communities, policy makers and key market actors
to create, encourage, acquire and apply cleaner, more efficient and more sustainable energy solutions for
their own benefit and that of our wider society.
Funded under the European Union’s Fifth Framework Programme for Research, Technological Development
and Demonstration (RTD), ENERGIE’s range of supports cover research, development, demonstration,
dissemination, replication and market uptake - the full process of converting new ideas into practical solutions
to real needs. Its publications, in print and electronic form, disseminate the results of actions carried out under
this and previous Framework Programmes, including former JOULE-THERMIE actions. Jointly managed by
Directorates-General XII & XVII, ENERGIE has a total budget of €1042 million over the period 1999 to 2002.
Delivery is organised principally around two Key Actions, Cleaner Energy Systems, including Renewable
Energies, and Economic and Efficient Energy for a Competitive Europe, within the theme "Energy,
Environment and Sustainable Development", supplemented by coordination and cooperative activities of a
sectoral and cross-sectoral nature. With targets guided by the Kyoto Protocol and associated policies,
ENERGIE’s integrated activities are focussed on new solutions which yield direct economic and
environmental benefits to the energy user, and strengthen European competitive advantage by helping to
achieve a position of leadership in the energy technologies of tomorrow. The resulting balanced
improvements in energy, environmental and economic performance will help to ensure a sustainable future
for Europe’s citizens.
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Neither the European Commission, nor any person acting on behalf of the Commission,
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The views given in this publication do not necessarily represent the views of the European Commission.
© European Communities, 1999
Reproduction is authorised provided the source is acknowledged.
Printed in Belgium
The scope for energy saving in the EU
through the use of
energy-efficient electricity
distribution transformers
THERMIE B PROJECT Nº STR-1678-98-BE
First Published December 1999
CONTENTS
1.
EXECUTIVE SUMMARY
5
2.
CONCLUSIONS AND RECOMMENDATIONS
2.1
Conclusions
2.2
Recommendations
6
6
INTRODUCTION
3.1
Background
3.2
Project Components
3.3
Methodology
7
7
7
3.
4.
5.
6.
7.
8.
9.
9.4
9.5
9.6
9.7
9.8
9.9
9.10
9.11
9.12
10.
THE ROLE OF TRANSFORMERS
4.1
Electricity Supply System Concepts
4.2
Distribution Transformers
4.3
Transformer Losses
8
8
9
ELECTRICITY SUPPLY AND DEMAND IN THE EU
5.1
Supply System Design
5.2
Power Generation and Distribution Utilities
5.3
Non-utility Electricity Supply
5.4
Production Capacity
5.5
Demand and Growth Rate
5.6
Representation
5.7
Regulation
5.8
Environmental Impact
5.9
Energy Losses
5.10 Distribution System Losses
9
10
10
11
11
12
12
13
13
13
DISTRIBUTION TRANSFORMER INSTALLATIONS
6.1
Ownership
6.2
Population
6.3
Transformer Age Profile
6.4
Failures
6.5
Investment Programmes
15
15
15
15
16
THE EU DISTRIBUTION TRANSFORMER MARKET
7.1
Market Size
7.2
Growth Rates
7.3
Purchasing Policies and Procedures
7.4
Standards and Designs
16
16
17
17
TRANSFORMER MANUFACTURE IN THE EU
8.1
Industry Overview
8.2
Industry Structure
8.3
Manufacturing Investment
8.4
Product Ranges
8.5
Exports
8.6
Repair and Maintenance
8.7
Representation
18
19
19
19
19
20
20
DISTRIBUTION TRANSFORMER TECHNOLOGY
9.1
Design Concepts
9.2
Transformer Steels
9.3
Grain-oriented Steels
20
21
21
11.
12.
13.
Domain Refined Steels
Amorphous Iron
Future Developments
Conductor Developments
Other Materials
Core Fabrication and Assembly
Coil Winding and Assembly
Superconducting Transformers
Technology Sources
22
22
22
22
23
23
23
25
25
TECHNICAL AND ENGINEERING APPRAISAL
10.1 Distribution Transformer Standards
10.2 Rated loss levels of Standard
Distribution Transformers
10.3 Loss levels of Standard Distribution
Transformers when Loaded
10.4 Achievable Loss levels
10.5 Loss Levels in Practice
10.6 Loss Evaluation
10.7 Case Study 1: Replacement of Old
Transformers
10.8 Case Study 2: Evolution of Dutch
Transformers Specification
10.9 Case Study 3: Large AMDT in Europe
26
27
27
29
30
32
34
37
38
ECONOMIC AND MARKET ANALYSIS
11.1 Assessment of Energy-saving Potential
11.2 Contribution to Energy Efficiency and
Global Warming Goals
11.3 Characterisation of the Utility Market
11.4 Characterisation of the Non-Utility Market
11.5 National/International Policies and
Initiatives
11.6 Potential Mechanisms for Change
11.7 International Perspective
44
44
46
ANALYSIS,
RECOMMENDATIONS,
ACTION PLAN
12.1 Analysis
12.2 Recommendations
12.3 Strategy Development
12.4 Strategy Components
12.5 Action Plan
47
47
48
48
48
3
42
42
43
STRATEGY,
ACTIONS, PARTNERS
13.1 Examples of Proposals, Actions and Impact
13.2 Approach to the Non-utility Sector
13.3 Partners for Collaboration, Facilitators
13.4 Sources of Funding
APPENDICES:
A: Losses, EU Electricity Systems, 1980-2010
B: Members of COTREL
C: References
40
49
50
50
50
ers)
LIST OF FIGURES
Figure 1
Build-up of Three-phase Distribution transformer
Figure 2
Electricity Distribution System
Figure 3
Maximum Net Generating Capacity at end-year,
European Union (MW)
Figure 4
Electricity Consumption, European Union, 1980 2010 (TWh)
Figure 17
Figure 5
System Losses - European Utilities (%)
Figure 18
Figure 15 Dependency of Transformer Losses on Size (kVA)
for 12kV and 24kV transformers
Figure 16
Fictitious
Example
of
Different
Europ
Transformer Standards
Comparison of Technologies to Improve Energy
Efficiency
Cost
comparison
of
typical
Distribu
Transformers according to Figure 8
Figure 6 Distribution losses for LV and HV Customers, United
Kingdom Distribution Utilities (%)
Figure 19 Typical transformer replaced in the context of the
Groningen Project
Figure 7
European Distribution Transformer Production
Figure 8
Typical Distribution Transformer Parameters
Figure 9
Development Stages, Transformer Steels
Figure 20 21 Transformers 400 kVA evaluated for Groningen
Figure 10
Spiral Sheet Low-voltage Winding
Figure 11
Multilayer Coil High-voltage Winding
Figure 12
Disc Coil High-voltage Winding
Figure 13
Distribution Transformer Loss Standards
Figure 14
Total Losses of a 400 kVA Transformer as
Function of the Load (12kV and 24 kV transform-
4
Project 1983 - 1999
Figure 21
Transformers 400 kVA evaluated for Groningen
Project (NL) 1982 - 1999 at peak load / rated
load = 0.6
Figure 22
Figure 23
Distribution System Losses
Savings Potential through installing Energy-effi
cient Transformers, Europe
Figure 24 Energy Saving Potential and Payback - Energy-efficient transformers
1
E X E C U T I V E S U M M A RY
The ultimate scope for saving energy in the EU through the use of
energy-efficient distribution transformers, is approximately
22TWh/year, worth €1,171 million at 1999 prices. Despite the
efficiency of individual units, up to 2% of total power generated
is estimated to be lost in distribution transformers, nearly onethird of overall losses from the system. This is comparable in scope
with the energy savings potential estimated for electric motors and
domestic appliances. It is equivalent to the annual power consumption of over 5.1 million homes, or the electricity produced
by three of the largest coal-burning power stations in Europe.
We believe that distribution transformers represent an important
focus for energy efficiency initiatives within the EU and a worthwhile area for R&D, demonstration and promotional effort. We
therefore recommend the following:
l
l
the potential for reducing losses from distribution transformers
should be considered as one element of EU and national strategies on energy efficiency, global warming, and environmental
impact
an action plan should be developed to achieve these goals. The
strategy and action plan need to be carefully co-ordinated, technically sound, and carry partners from all levels in the supply
chain.
Because of the long life span of distribution transformers, ultimate
market penetration will only be achieved gradually. However, we
estimate that energy-efficient units could contribute 7.3TWh of
savings by 2010, representing over 1% of the European commitment to reducing carbon emissions.
Europe has an urgent need to develop a strategy on existing and
future global warming actions. As far as we have been able to
ascertain, no European country has yet developed targets for the
global warming savings potential which could result from distribution transformer programmes, nor has a formal estimate been
made for the EU or Europe as a whole.
Europe has considerable potential to offer world-wide in transformer technology and experience. However, national governments and utilities appear to lag behind the US in terms of programmes and initiatives to encourage energy efficiency. There are
no initiatives comparable to the US DOE/EPA programmes on
utility commitments, information and software dissemination.
This is despite the fact that most of the major European countries
have a very poor position on energy self-sufficiency.
There is already considerable R&D and promotional effort within Europe aimed at reducing losses in small transformers, e.g. for
domestic and office equipment, and some IEA/OECD work has
been undertaken. Initiatives have included campaigns to urge consumers to switch off appliances, and the use of more efficient core
materials. This could assist in focusing attention on the equally
significant target of distribution transformers.
It is apparent that both utilities and private sector purchasers are
difficult to influence. The transformer market is extremely competitive, and efforts to improve energy efficiency in the past have
had limited success. However, the sector involves a limited number of professional buyers, already reasonably aware of the arguments for energy efficiency, and with well-established techniques
for evaluating transformer performance. They are therefore likely
to be receptive to rational arguments, provided that benefits are
clearly demonstrated
5
2
CONCLUSIONS AND
R E C O M M E N D AT I O N S
2.1
Conclusions
The theoretical scope for energy savings through the use of energy-efficient distribution transformers in the EU is very substantial.
Despite the efficiency of individual units, up to 2% of total power
generated is estimated to be lost in distribution transformers,
equivalent to nearly one-third of overall losses from the power system.
The savings potential is approximately 22TWh/year, worth
€1,171 million at 1999 prices. This is comparable in scope with
the energy savings potential estimated for electric motors in the
EU (27TWh) and domestic appliances. It is equivalent to the
annual energy consumption of over 5.1 million homes, or the
electricity produced by three of the largest coal-burning power stations in Europe.
Because of the long life span of distribution transformers, ultimate
market penetration will only be achieved gradually. However energy-efficient units could contribute 7.3TWh of savings by 2010,
representing over 1% of the European commitment to reducing
carbon emissions.
As far as we have been able to ascertain, no European country has
developed targets for the global warming savings potential which
could result from distribution transformer programmes, nor has a
formal estimate yet been made for the EU or Europe as a whole.
European countries are currently developing strategies on existing
and future global warming actions. As this happens, the potential
for reducing losses from distribution transformers could be promoted, to ensure that they are incorporated as a component of the
plan.
Europe has considerable potential to offer world-wide in transformer technology and experience. However, national governments and utilities lag behind the US in terms of programmes and
initiatives to encourage energy efficiency.
There are no initiatives comparable to the US DOE/EPA programmes on voluntary utility agreements, or information and
software dissemination. This is despite the fact that most
European countries have a poor position on energy self-sufficiency. The US has also recently started a process to evaluate the role
of regulation in transformer efficiency.
There is already considerable R&D and promotional effort within Europe aimed at reducing losses in small transformers, e.g. for
domestic and office equipment, and some IEA/OECD work has
been undertaken. Initiatives have included campaigns to urge con-
6
sumers to switch off appliances when not in use, and the adoption
of more efficient core materials. These are directed at domestic
consumers, rather than utilities and professional buyers, but could
assist in focusing attention on the equally significant target of distribution transformers.
It is apparent that both utilities and non-utility purchasers are difficult to influence. The transformer market is extremely competitive, and efforts to improve energy efficiency in the past have had
limited success. However, the sector involves a limited number of
professional buyers, already reasonably aware of the arguments for
energy efficiency, and with well-established techniques for evaluating transformer performance. They are therefore likely to be
receptive to rational arguments, provided that benefits are clearly
demonstrated.
2.2
Recommendations
We consider that distribution transformers should be recognised
as an important focus for energy efficiency initiatives within the
EU, and that they represent a worthwhile area for R&D, demonstration and promotional effort. We therefore recommend the following:
l
l
l
as EU and national strategies on energy efficiency, global warming, and environmental impact are developed, the potential for
reducing losses from distribution transformers should be considered, to ensure that they are incorporated as a component
a strategy should be developed to set and achieve goals for reducing losses from distribution transformers, or possibly from all
power systems transformers in the EU. The strategy needs to be
carefully co-ordinated and be both technically and commercially sound
the main elements of an action plan to achieve the strategy
should be identified and developed.
3
INTRODUCTION
3.1
Background
This project was undertaken to provide a detailed assessment of
the scope for installing energy-efficient distribution transformers
in both utility-operated and private electricity supply systems in
the European Union.
An estimate has been made of the contribution which they could
make to energy savings in the EU. The study has also identified
the main technical, engineering and financial barriers to their
application, and develops a suggested strategy to encourage their
introduction.
The proposed strategy relates specifically to Europe, evaluating
R&D and technical advances against factors such as the installed
age and population of distribution transformers, replacement levels, utility ownership, distribution network design, operating voltages, purchasing criteria and financial constraints.
The study enables the European Commission, the governments of
Member States, and regulators, to understand the current and
future scope for energy saving which is associated with energy-efficient distribution transformers. It also allows to assess specific
actions taking place or planned within the Community, and its
priority compared with other sectors.
We believe that the study will also help electricity utilities and private electricity network operators to identify and specify energyefficient equipment, based on a clearer understanding of available
products and concepts, ways of evaluating financial pay-backs and
life-time costs, and the use of concepts such as demand side management (DSM).
3.2
Project Components
The study has collected data from all EU countries. It takes
account of national and regional priorities, installed electricity system networks, engineering practice. Some factors, for example the
recent change in distribution operating voltages, affects various
countries differently.
We have collected and analysed the limited amount of available
statistical and marketing data to derive estimates of distribution
transformer populations. We have also made estimates of
pole/ground-mounted ratio, total capacity in GVA, operating
voltages, unit size and rating profile, oil-filled/dry-type ratio, ownership, age profile, current and planned new installation rates.
The major technologies offering scope for energy efficiency in distribution transformers have been identified and appraised. These
include transformer sizing, core/coil loss ratios, materials and
components currently available and under development, such as
amorphous iron, special magnetic steels etc.
We have also collected some technical and cost data, and operating experience, from existing energy-efficient transformer installations. Their success and relevance for wider application has been
assessed, and a specific profile prepared for dissemination. An
appraisal has been made of world-wide R&D developments likely
to improve energy efficiency in distribution transformers, and the
technical and commercial barriers which they face.
We have made an estimate of the potential impact on Europe of
energy efficiency developments and initiatives in this sector, and
identified strategic plan components for Europe in this sector.
These are quantified as far as possible in terms of total energy savings, contribution to global warming goals, scope to delay or avoid
new capital investments, demand side management, etc.
3.3
Methodology
The study is based on desk and telephone interviews, combined
with a brief field programme in four key markets, France,
Germany, Italy and the UK.
Our contacts included electricity utilities, specifying authorities
such as consulting engineers, transformer manufacturers, the
European Commission, national governments and energy agencies, raw materials producers and semi-fabricators, as well as individuals concerned with national and European transformer standards.
We also held discussions with the trade associations responsible for
each point of the supply chain, including utilities, transformer
manufacturers, raw materials producers and semi-fabricators.
A workshop has been organised to discuss the findings of the project was held at Harwell, UK, on 23d September 1999. This
brought together delegates from all points of the supply chain,
including raw material producers and semi-fabricators, transformer manufacturers, utilities, consultants and energy agencies,
as well as a representative of the European Commission.
Participants were provided in advance with a copy of our draft
report. They confirmed the basic findings of the project, recognising the potential of energy-efficient transformers to contribute to
global warming goals, and contributed specific additional initiatives to overcome the barriers to change,
7
4
4.1
THE ROLE OF TRANSFORMERS
Electricity Supply System
Concepts
Modern electricity supply systems depend on a number of
advances in electrical theory and engineering which were made in
the late 19th century. These include the principle of AC generation, motors and transformers, the concept of creating interlinked high and low voltage networks, and the use of parallel
rather than series connections to supply end-users. Their application enabled reliable electricity supply services to be provided to
industry, commercial and domestic customers throughout Europe
and the industrialised world.
Further developments resulted in electricity being generated in
large efficient power stations, far from the point of use.
Generating stations were then linked to each other, and to urban
and industrial centres, through a country-wide network of overhead conductors and underground cables. This improved the balance between supply and demand, and further enhanced the quality of the service. Initially electricity in Europe was produced
mainly from coal and hydro-electric power stations, but the
national networks also proved ideal when nuclear power generation became feasible.
Losses in electricity supply systems depend on the voltage level.
They are minimised by transmitting electricity at as high a voltage
as possible, consistent with demand load levels, extent of urbanisation, etc. Transformers, which initially step up the generation
voltage, and then reduce it to the level required by users, are therefore an essential component in transporting electricity economically from the power station to the final customer.
4.2
D i s t r i b u t i o n Tr a n s f o r m e r s
In an electricity supply system, the high and low voltage power
networks terminate within a transformer in wound coils, of copper or aluminium. The coils generate a magnetic flux, which is
contained by an iron core. Energy is then transferred between the
networks through this shared magnetic circuit.
The smallest transformers in an electricity supply system, which
provide electricity to commercial and domestic customers, are
described as distribution transformers. Figure 1 shows schematically the arrangement of the active components of a typical threephase distribution transformer as used in Europe. It can be seen
that the iron core of the transformer has three limbs, and that the
Build-up of Three-phase Distribution Transformer
Figure 1
8
HV and LV coils of each phase are wound on the same limb, separated by insulating material.
4.3
5
Tr a n s f o r m e r L o s s e s
5.1
The energy losses in electricity transformers fall into two categories:
l
l
E L E C T R I C I T Y S U P P LY A N D D E M A N D
IN THE EU
no-load losses or iron losses, which result from energising the
iron core. These are incurred whenever the transformer is coupled to the network, even if no power is being drawn
load losses which arise from the resistance of the windings,
when the transformer is in use, and from the eddy currents
which flow both in the windings and the transformer housing
due to stray flux. Sometimes referred to as copper losses, or
short circuit losses, as they are measured by shorting the windings.
Supply System Design
Electricity supply systems are similar throughout the world,
although the voltages used for transmission and supply to the final
customer may vary. In Europe electricity is typically generated at
10-20kV AC in a power station, and stepped up to transmission
voltages of 275-400kV, for transportation by overhead transmission line or supertension power cable to regional load centres.
Within a region, electricity is transformed to lower voltages for
supply at 110-150kV. This is often the stage at which power-generating companies sell electricity to local distribution utilities.
The transformers installed in electricity supply systems are
extremely efficient when compared with other machines. There
are no moving parts, and large modern power station and transmission transformers typically have an efficiency above 99.75%.
Distribution transformers are less efficient, but levels can still
exceed 99%.
Power at 110-150kV is also supplied directly to major industrial
customers, for example chemical works or steel producers, or carried into urban areas for further reduction at system
transformation points to 10-20kV. Smaller industrial consumers
as well as commercial offices, schools, hospitals and public sector
buildings are supplied at this voltage, reducing levels within their
own premises as necessary.
Despite the high efficiency of individual units, losses occur at each
of transformation steps in an electricity supply network. Even in a
modern network, the losses arising from power transmission and
distribution can amount to as much as 10% of the total electricity generated. Losses are relatively higher when transformers are
lightly or heavily loaded. This means that there is considerable
potential for energy saving with efficient transformers.
Finally the voltage is further reduced at distribution sub-stations,
close to the point of use, for supplying smaller commercial and
domestic customers at national consumer mains voltages, recently
standardised in Europe at 400/230V. Figure 2 is a simplified representation of an electricity distribution system, showing the supply to industrial, commercial, rural and domestic customers, by
either underground cable or overhead line.
The basic pattern of electricity network design, with four main
operating voltage levels, is now used throughout Europe, irrespective of the relative utilisation of overhead and underground networks. It has been proven to provide a good balance between supply and demand, and reduce losses to a practical minimum.
The existing systems in most European countries are however
rather more complex. They have been built up over a long period,
and there are a variety of intermediate transmission voltages, such
as 66kV, 50kV. These are slowly declining, but they represent a
considerable proportion of existing networks, and can still provide
the most economical option for system reinforcement and renovation.
A large number of different classes and sizes of transformers are
therefore required in a modern electricity supply network, reflecting the wide range of operating voltages and currents. In addition
to the four main operating voltages, and the intermediate voltages
which have been described above, transformers are also specified
in terms of their capacity. This is the quantity of electricity they
can handle, expressed in volts(amperes (VA). Because the flux and
9
Electricity Distribution System
Figure 2
Industrial
Agricultural
Domestic
System transformer
Commercial
Distribution
transformer
current-carrying capacities of the core and windings are limited,
heavier currents require larger transformers.
made on investments in capital plant such as distribution transformers.
5.2
5.3
Power Generation and
Distribution Utilities
Utilities produce and distribute over 90% of the total electricity
generated in the European Union. There are approximately 2000
electricity utilities in the EU. They range in size from small town
or rural area systems, controlled by municipal and local government, to very large state-owned bodies serving a whole country.
Considerable structural changes are now taking place in the sector,
with a transfer to private ownership, joint ventures across national boundaries and new investments in power generation as main
trends. Recent privatisation and decentralisation have left only
France and Italy among the major countries in Western Europe
following the traditional pattern of state ownership. Italy has
already started a far-reaching privatisation plan for its national
utility.
The Electricity Directive, which came into force in February
1999, is designed to create an open and competitive market for
electricity in Europe. Member States are required to open up
about 25% of their markets to free competition. These changes
have important implications for the way in which decisions are
10
Non-utility Electricity
Supply
Non-utility electricity supply systems include traction companies
operating electrified railways, metros and tramway systems, large
plants in the chemical, oil and gas and metals industry.
Organisations in this category either generate their own requirements, or purchase electricity at high voltage from utilities and
operate their own distribution networks. There is considerable
mining and mineral extraction in Europe, often involving the distribution of power underground.
Private generation represents less than 10% of total capacity in the
EU. However, generation of electricity on site for non-utility systems is growing rapidly, frequently using gas as a raw material.
Overall, it is estimated that private generation could reach 20% of
total capacity in the near future. Growth is being assisted by a
number of special factors, including the development of renewable
and combined heat and power technology, improved economics
for gas-based generation, the liberation of tariff controls, and
deregulation of electricity supply.
Figure 3
Maximum Net Generating Capacity at End Year, European Union (MW)
Ty p e o f o r i g i n
1980
1990
1995
1996
2000
2005
2010
40.106
40.106
114.837
114.837
119.581
119.581
120.710
120.710
122.427
122.427
121.062
121.062
119.232
119.232
Conventional thermal
l coal
l brown coal
l oil
l natural gas
l derived gas
101.847
17.743
76.309
33.529
3.500
117.090
18.535
59.507
43.302
2.314
115.132
30.226
53.339
63.850
2.695
114.638
27.442
51.970
73.991
2.756
110.928
28.647
36.023
105.230
5.178
103.032
28.993
33.870
116.890
4.455
107.552
30.332
27.785
134.574
4.378
Subtotal
232.928
240.747
265.242
270.797
286.006
287.240
304.620
Hydro
l gravity scheme
(of which run of river)
l pumped + mixed
Subtotal
Other renewables
Gas turbines, diesel, etc.
Not specified
67.846
15.470
20.284
88.130
1.830
12.922
6.186
76.902
16.945
32.303
109.205
4.602
17.297
7.865
80.064
17.648
34.586
114.649
6.734
21.208
6.579
80.387
17.746
34.597
114.983
6.815
21.632
9.335
82.985
18.075
34.909
117.893
13.958
20.824
12.330
84.225
18.261
36.109
120.334
20.561
21.306
18.547
86.755
18.666
37.290
124.045
25.747
24.067
22.054
Subtotal
20.938
29.764
34.521
27.782
47.112
60.414
71.868
TOTAL
382.102
494.553
533.993
544.272
573.438
589.050
619.765
Nuclear
Subtotal
While utilities generally rely on their own engineering staff to set
standards for performance, including energy efficiency, private
sector electricity supply systems are often designed with outside
assistance. The pattern in Europe varies widely. In some countries,
this work is undertaken mainly by firms of management contractors, or the design staff of a major electrical contractor. Elsewhere,
independent professional consulting engineers are responsible for
design and project management.
5.4
Production Capacity
The installed generating capacity for electricity in the European
Union is about 550GW (Figure 3). Germany and France are by
far the largest producers, accounting for approximately 35% of the
total.
It is estimated that about 60GW of new generating capacity will
be added in the period to 2010, during which time about 15GW
will be decommissioned. Two-thirds of new investment is planned
to be based upon gas, particularly in Italy, France and the
Netherlands. Much of this will be installed by independent generators for their own use and resale, or for the co-generation of heat
and power. The remainder of the predicted capacity increase is
mostly new nuclear power stations, in France and Finland.
5.5
Demand and Growth Rate
Electricity consumption in the European Union is nearly
2,500TWh per year. Four countries, Germany, France, the UK
and Italy, account for approximately two-thirds of the total (Figure
4). Population levels, size of economy, degree of industrialisation,
the volume of heavy industry, climate, prices and competition
from other fuels all contribute to the pattern of consumption in
individual countries.
The demand for electricity in Europe grew rapidly in the 1960s
and 1970s, in line with increasing industrialisation, rapid economic growth rates, the completion of national networks and the
development of nuclear power. The rate of increase in consumption has slowed dramatically in the 1990s. The current annual
growth rate is 1.7%, compared with 4.3% in the 1970s and 2.7%
in the 1980s.
The power industry has found it difficult in the past to forecast
demand, but the International Union of Producers and
Distributors of Electrical Energy (UNIPEDE), the international
utilities’ industry association, predicts that growth in the EUR-21
(those shown in Figure 4 together with the Czech Republic,
Hungary, Norway, Poland, Slovakia and Switzerland) will be 1.7%
per year over the next 15 years.
The fastest growing end-use sector is expected to be services, averaging 2.4% per year, and transport, growing at 1.6% per year.
11
Figure 4
Electricity Consumption, European Union, 1980-2010 (TWh)
Actual
Year
Austria
Belgium
Germany
Denmark
Spain
Finland
France
Greece
Ireland
Italy
Luxembourg
Netherlands
Portugal
Sweden
UK
EUR 15
Forecast
1980
1990
1995
1996
2000
2005
36,3
47,7
351,0
23,9
102,0
39,9
248,7
21,9
9,5
179,5
3,7
59,7
15,3
94,1
264,8
46,9
62,6
415,0
30,8
145,4
62,3
349,5
32,5
13,0
235,1
4,4
78,0
25,1
139,9
309,4
51,0
73,5
493,0
33,7
164,0
69,0
397,3
38,8
16,4
261,0
5,1
89,6
29,3
142,4
330,7
52,3
75,3
500,0
34,8
169,0
70,1
415,2
40,5
17,6
262,9
5,1
93,5
30,9
142,7
343,9
56,6
81,2
512,0
35,8
188,2
78,0
444,0
47,2
21,7
296,0
5,6
101,2
36,5
145,5
360,8
62,1
89,0
531,0
36,8
218,2
85,4
479,0
54,2
26,8
330,0
5,9
110,9
42,8
147,8
393,0
67,3
94,5
547,0
37,7
246,7
92,1
516,0
63,4
32,1
360,0
6,3
121,5
49,0
152,3
425,7
2,60
2,76
1,69
2,57
3,61
4,56
3,46
4,03
3,19
2,74
1,75
2,71
5,07
4,05
1,57
1,69
3,26
3,50
1,82
2,44
2,06
2,60
3,61
4,76
2,11
3,00
2,81
3,14
0,35
1,34
2,55
2,45
1,42
3,26
3,05
1,59
4,51
4,38
7,32
0,73
0,00
4,35
5,46
0,21
3,99
1,99
1,90
0,59
0,71
2,73
2,71
1,69
3,90
5,37
3,01
2,37
2,00
4,25
0,49
1,21
1,87
1,85
0,73
0,55
3,00
1,83
1,53
2,80
4,31
2,20
1,05
1,85
3,24
0,31
1,72
1,62
1,21
0,60
0,48
2,49
1,52
1,50
3,19
3,68
1,76
1,32
1,84
2,74
0,60
1,61
1,82
1,64
0,64
0,57
2,74
1,97
1,56
3,25
4,39
2,27
1,52
1,89
3,35
0,47
1,54
1.498,0
1.949,9
2.194,8
2.253,8
2.410,3
2.612,9
2.811,6
2,67
2,39
2,69
1,69
1,63
1,48
1,59
Major planned investments include a US$1.3 billion HVDC
power bridge to link Western and Eastern Europe.
A number of countries in Western Europe have published formal
plans for their electricity industry. Some utilities have also prepared detailed forward plans. Typically, these address issues such as
electricity consumption, maximum demand, regional trends and
growth rates, major planned generation and transmission investments.
Increasingly, national and utility plans also cover energy efficiency. As far as we have been able to ascertain, there have been no
statements by organisations in the EU of targets to reduce losses
through the use of energy-efficient distribution transformers. In
practice there are considerable problems in estimating the potential for savings, discussed in Sections 10.5 and 11.
5.6
Implied Average Annual Increase (%)
2010 1980- 1990- 1995- 1996- 2000- 2005- 19961990 1995 1996 2000 2005 2010 2010
Production and Transport of Electricity (UCPTE) helps co-ordinate power transmission in Continental Western and Central
Europe.
The organisations directly responsible for the technical specifications of distribution transformers are described in Section 7.4.
5.7
Regulation
The decentralisation and privatisation of utilities in EU countries
has resulted in the creation of independent regulatory bodies at
national level. These cover issues such as price control, investment
levels for new plant and equipment, safety, environmental impact.
These responsibilities can be undertaken by a government department, usually the ministry responsible for energy policy, or by the
creation of an independent agency.
Representation
The electricity utilities in most European countries are represented by one or more industry associations. These are co-ordinated at
European level by EURELECTRIC, which was created in 1989.
EURELECTRIC has recently formed a joint secretariat with
UNIPEDE.
Technical issues, and other developments associated with the operation of electricity supply systems, are handled by a number of
international representative bodies. These include the
International Conference of High Tension Networks (CIGRE)
and the International Conference of Distribution Networks
(CIRED). A further body, the Union for the Co-ordination of the
12
The regulatory bodies have varying degrees of control over energy
efficiency. Some allow utilities to levy their customers to help fund
for environmental spending. Others can reward utilities with
rebates or capital allowances for energy efficiency or environmental improvements and investments.
The Electricity Directive, described above, establishes rules for the
generation, transmission and distribution of electricity. The
implementation of the Directive is contributing to the growth of
the regulating process. A further item of European Community
legislation, the Utilities Directive, covers certain aspects of the
electric power industry operations. Energy efficiency is not included.
Figure 5
5.8
System Losses - European Utilities (%)
Environmental Impact
Power generation is the largest contributor to toxic emissions and
global warming in Europe. Carbon dioxide emissions are forecast
to increase rapidly in the period to 2010, particularly in Italy,
where they are expected to rise by one-third, with investment in
gas generation plant a major contributor. Releases of sulphur and
nitrogen oxides in Europe are forecast to fall.
Initiatives to reduce toxic emissions, and meet agreed climate
change and global warming targets, are often similar to those
aimed at improving energy efficiency. There has been considerable
discussion in EU countries about the use, by the either European
Commission or national governments, of economic instruments,
e.g. taxes or levies, to regulate emissions and global warming.
These include the imposition of a carbon tax to increase the cost
of burning fossil fuels.
losses, ranging between 4-11%. Obviously, distribution losses
could be expected to be higher in small lightly populated rural
countries than in major industrialised countries. There is some
doubt about whether losses are always measured on a consistent
and comparable basis.
Among major countries, Germany reports exceptionally low loss
levels, has made significant progress in the period since 1970, and
set ambitious targets for the next 15 years. In contrast the UK,
France and Italy are showing persistently high loss levels, and with
no foreseen or planned improvement.
In Central Europe, losses in the system are reported to be much
higher, up to twice the average for Western Europe. Some indication of this is provided by data from Germany, where losses in the
former DDR were reported at 10.0% in 1992, compared with
4.7% for West Germany, but had improved to 9.0% by 1995.
5.10
5.9
Energy Losses
Detailed figures of estimated and forecast energy losses for EU
countries in the period 1970-2010 are provided in Appendix A.
Total losses for the EU are running at about 150TWh, representing approximately 6.5% of total power generated, or the output of
15 large power stations. However, losses have fallen steadily, from
about 7.5% in 1970.
Some examples of the losses in the power systems of a number of
Western European countries are shown in Figure 5. There is a significant variation between countries in reported electricity system
Distribution System
Losses
It is estimated that over 40% of the total losses in an electricity distribution network are attributable to transformers (See Section
11.1). The remainder is mainly in the cable and overhead conductor system.
Modern electricity supply grid networks are extremely complex.
Transformers may operate at close to full load for most of the year,
or else be very lightly loaded, either to provide spare capacity or as a
result of lower than expected growth in demand. Distribution transformer losses are discussed in more detail in Sections 10.1-10.4.
13
Figure 6
Utility
Distribution Losses for LV and HV Customers, United Kingdom Ditribution Utilities (%)
1990/1991
1991/1992
1992/1993
1993/1994
1994/1995
1995/1996
1996/1997
1997/1998
Eastern
East Midlands
London
Manweb
Midlands
Northern
Norweb
Seeboard
Southern
Swalec
Sweb
Yorkshire
Scottish Power
Hydro-electric
7,0
6,6
7,8
9,8
6,2
7,5
7,1
7,9
7,1
8,9
8,6
6,3
8,5
9,5
7,0
6,5
7,2
9,1
5,9
7,6
7,1
7,7
7,2
8,4
8,5
6,3
7,2
8,9
6,8
6,7
7,0
8,7
5,7
6,8
6,3
7,6
7,1
8,1
8,5
6,2
7,7
9,0
6,5
6,8
7,0
8,7
5,5
7,2
6,3
7,5
7,0
7,0
8,3
6,2
8,1
9,1
6,7
6,0
7,1
8,1
5,5
6,1
6,4
7,5
7,0
7,0
7,3
6,5
8,0
9,1
6,9
6,1
6,7
8,8
5,5
6,8
4,8
7,1
7,2
6,7
7,2
6,5
6,7
9,0
7,1
6,1
7,1
8,8
5,6
6,9
5,0
7,6
7,2
8,0
7,9
6,5
7,2
9,0
7,0
6,1
6,8
9,0
5,5
6,7
5,7
7,7
7,2
6,9
7,3
6,5
7,2
9,1
Average
7,6
7,2
7,1
7,0
6,9
6,7
6,9
6,8
There is also a need to balance the loading of the network as far as
possible, and provide alternative routes to the major points of
demand. Transformers are sometimes moved between sites to meet
changed load demands. Some techniques now used in network
management, for example deliberately running transformers at
above their rated capacity, can be expensive in terms of losses.
The lack of reliable data also applies to individual utility losses, as
well as the national loss statistics described in Section 5.9. Some
utilities produce figures for distribution system losses (See Figure
6). Utilities may be rewarded by a regulator or national government for reducing losses, for example by environmental subsidies
or tax concessions.
Unfortunately, these loss figures are produced by various empirical calculations, and not directly by metering or data logging.
They cannot be reconciled with generation or engineering data, or
by comparing energy purchases with sales. For this reason, it is not
possible to demonstrate, for example, the incremental savings
which a utility would achieve by the installation of a single energy-efficient transformer.
14
6
DISTRIBUTION TRANSFORMER
I N S TA L L AT I O N S
6.1
Ownership
Electricity utilities are estimated to own and operate about 70% of
the total population of distribution transformers in the EU, and
represent a similar proportion of the market for new units. Major
utilities also control most of the larger items of installed generation and transmission plant in Europe, but the distribution transformers can be owned by the host of regional and municipal distribution utilities. Changes in utility ownership, for example as a
result of privatisation, usually result in changes in the ownership
of the transformers installed in the network.
Transformer ownership outside the utility sector is shared between
the non-utility electricity supply systems, described in Section 5.3,
and the medium-sized customers for electricity. These include the
proprietors of small factories, office blocks, supermarkets, schools,
hospitals, apartments, hotels etc. They typically purchase power
from a utility at 10-20kV, and own the distribution transformer
and associated switchgear which undertakes the final step in
reducing the voltage to 400/230V.
6.2
6.3
Tr a n s f o r m e r A g e P r o f i l e
The distribution transformers which have been installed in the EU
in the post-War period, have shown great reliability. They have no
moving parts, and are designed for a lifetime of 20-30 years, but
have successfully operated for much longer. A rough indication
from comparing the distribution transformer annual sales estimates in the EU, (approximately 150,000) with the transformer
population (approximately 4 million) suggests a lifetime for each
unit, in a market which is relatively static, of 30-40 years.
Life spans have also been extended by the fact that many transformers installed in the 1960s, when the growth of demand for
electricity was at a peak, were lightly loaded to allow for future
expansion, thus reducing the effects of heating, cooling stresses
and insulation ageing. Combined with lower investment levels to
meet new demand, the result is a skewed age profile for the population of distribution transformers currently installed in Europe.
Although modern transformers can be more efficient in terms of
energy losses, older transformers have a reasonable performance.
Their costs are completely written off, they are compatible in engineering terms with the associated circuit breakers and fuse-gear,
and provide little incentive for replacement. Cases of transformer
damage and failure, major network redesign schemes, and excessive transformer noise levels, represent the main opportunities for
reinvestment.
Population
6.4
The population of distribution transformers installed in European
electricity utility and private sector networks is estimated to be
about four million units. Statistical records are poor, particularly
for privately owned installations, but the data which is available
suggests that the total is broken down by size and type of construction approximately as follows:
Table A
Failures
Only limited information is available about the transformer failure pattern in Europe. Several studies have been undertaken, but
the results are rather inconclusive. A 1983 survey based on 47,000
transformer-years of service in 13 European countries estimated
the mean-lifetime-between-failures (MLBF) of installed transformers to be 50 years, and showed design defects, manufacturing
problems and material defects to be the main causes of failure.
Distribution transformer population, European Union
Category
Primary
Voltage (kV)
Liquid-cooled, <250kVA
20,10 etc
Liquid-cooled, 250kVA and above 20,10 etc
Dry-type, cast-resin
20,10 etc
No of
Total
Transformers Capacity
(GVA)
2,000,000
1,600,000
400,000
The same project identified windings and terminals to be the
components most likely to cause failure in service. Failures in coils
using jointed conductors, built in earlier years, have caused some
problems. A high proportion of failures in pole-mounted distribution transformers result from lightning strikes.
1,600
Source: Utility statistics, ECI estimates
Non-utility distribution transformers account for about 30% of
the total population, but a much higher proportion, possibly
around 50%, of the total installed capacity. Non-utility transformers tend on average to be larger than those operated by electricity utilities.
Unacceptable noise levels, and incompatibility with more modern
circuit breakers and fuse-gear, are often cited as being more important influences on renewal programmes than complete breakdown. One source reports the failure rate for installed distribution
transformers at approximately 0.2% per year.
15
6.5
Investment Programmes
There is evidence of considerable remaining spare capacity in the
existing population of distribution transformers in the EU. Load
diversity factors, load monitoring and overload characteristics are
now much more sophisticated than in the past. These factors tend
to depress further the installation rates for new transformers.
A number of new electronic control technologies for power supply systems are being introduced to optimise the use of existing
hardware, as an alternative to installing new plant, although these
mainly apply to the HV system rather than the distribution network. Condition monitoring of transformers, to provide warnings
of overload and failure, is contributing to transformer lifetimes.
Some utilities are introducing demand side management (DSM)
techniques, to reduce the load on the generation and distribution
system. These trends tend to work against investment in new
transformers.
However, the existing population of distribution transformers is
ageing, with many transformers over 40 years old. The age profile
of the power transformer population in Europe is widely regarded
as giving cause for concern.
Some EU Member States have made attempts to direct utility
funds to distribution network renovation, but these have not been
generally successful. Newly privatised utilities are reported to show
less interest in longer-term problems, and demand more rapid
paybacks, than the public sector network operators they have
replaced. However older transformer installations are being gradually renewed, and possibly 60-70% of current spending is associated with replacement.
7
7.1
THE EU DISTRIBUTION TRANSFORMER MARKET
Market Size
Figure 7 shows the estimated breakdown of 1997 sales of distribution and smaller systems transformers in the EU by number of
units, size and sales value. Smaller transformers, below 650kVA,
account for about 85% of sales and 55% of value.
There is a sharp contrast in size and sophistication between conventional distribution transformers and the larger units, between
1,600-10,000kVA, used in the primary distribution network and
for supplying larger consumers. Distribution transformers account
for about two-thirds of sales value, but represent 95% of total
numbers.
7.2
Growth Rates
The European market for distribution transformers has been
depressed since the early 1980s, and at present, the size of the market is reported to be approximately static. This reflects the age profile and investment levels discussed in Section 6.
The future impact of power industry development on distribution
transformer volumes is difficult to assess. The spare capacity in the
installed population of distribution transformers is considerable.
Electricity generation based upon natural gas or renewables,
including combined heat and power installations, at sites close to
the point of use, suggests a reducing need for transmission across
long distances, but will increase the volume of smaller transformers in the network.
The age of the installed population, and the replacement of units
contaminated with toxic coolants, represents a possible opportunity. Some specific programmes to replace distribution plant more
frequently have been mentioned.
On balance, we forecast that distribution transformer sales will
remain constant in Europe in the next 10 years. The increase in
private generation and the need for replacement of older units is
likely to be balanced by continuing overall low growth rates in
electricity demand, and the more sophisticated operating techniques for managing the low-voltage network.
16
Figure 7
7.3
European Distribution Transformer Production
Purchasing Policies and
Procedures
Distribution transformers are usually built against a specific customer order. The large number of operating voltages and capacities in grid networks means that it is quite common in Europe for
a single utility to be buying 50 or more different types and sizes of
power systems transformer.Electricity utilities may place contracts
for their transformer purchases for a year or more in advance. A
typical requirement would be several hundred units. In this case,
a contract is negotiated, based on tenders received from a short-list
of approved suppliers. Public sector utilities in the European
Community must advertise major contracts Europe-wide.
In the tender, utilities either specify maximum levels for load and
no-load losses, or use loss capitalisation, leaving it to the transformer manufacturer to design the optimum transformer in terms
of minimum total cost (purchase price + cost of losses). The former is common practice in France, Belgium and Germany. Loss
capitalisation, on the other hand, is commonly used in UK,
Scandinavia and Switzerland, among others. The use of loss capitalisation tends to lead to higher efficiency transformers (cf
Scandinavia, Switzerland) but not necessarily (cf UK). These practices are further explained in sections 10.5 and 10.6.
7.4
Standards and Designs
There are European specifications for power systems transformers,
which set standards for performance, including power losses.
These have consolidated earlier national standards, and are compatible with International Electrotechnical Commission (IEC)
world standards. They have been developed by the European
Committee for Electrotechnical Standardisation (CENELEC), in
consultation with UNIPEDE.
The distribution transformer standards applicable within the EU
are described in detail in Section 10.1. Non-utility outdoor distribution transformers are superficially very similar to utility transformers, but the specifications and sizes may be different. For
example, many European railways are supplied at 15kV, 162/3Hz,
single phase. Mining transformers are often flameproof.
Distribution transformers with conventional oil cooling and
installed on indoor sites, for example the basement of a large
commercial building, are considered to pose a possible fire risk.
They are required by the building regulations in many EU countries either to use non-flammable coolants, or to be dry-type,
without coolants. Polychlorinated biphenyls (PCBs), the principal
coolant used in the past, have been linked with the production of
highly toxic chlorine compounds, mainly dioxins, at high temperatures. Non-toxic coolants are now available, and cast resin clad
transformers offer an alternative to dry-type construction.
17
Reliability is reported to be the main factor influencing the way in
which distribution transformers are chosen by consulting engineers and non-utility sector customers. Their installations are relatively small in scale, and unlike utility networks may have only
limited back-up in the case of transformer failure.
8
T R A N S F O R M E R M A N U FA C T U R E I N
THE EU
8.1
Industry Overview
The EU electricity systems transformer industry is an important
component of the electrical engineering sector, with an output
valued at approximately €3 billion per year. The European transformer manufacturers are major exporters of transformers worldwide, and the leading producers have established a number of
overseas manufacturing operations. These factories mainly supply
local markets, and replace earlier export business, but in some
cases are capable of building transformers for sale world-wide,
complementing the resources of the parent company. EU manufacturers have moved rapidly to establish a position in Central
Europe, mainly by the acquisition of existing companies.
Following substantial growth in post-war years, the industry has
been forced to contract and rationalise in the period since 1980,
in the face of slowing growth rates in electricity demand, the completion of national electricity supply grid networks, and the long
installed life span of transformers in service.
Since 1990 transformer demand in Europe has stabilised and
remained reasonably steady, although at lower levels, and competition is still intense. This is reflected in selling prices, continuing
losses by some companies, further closures and mergers, and a
Figure 8
Typical Distribution Transformer Parameters
RATING
kVA
100
400
1600
HV
kV
20
10
20
LV
V
400
400
690
LOSS-LEVEL
HD428
A-A'
C-C' A-AMDT C-AMDT
A-A'
A-A'
C-C'
C-C' A-AMDT C-AMDT
NO-LOAD LOSSES
W
320
210
60
60
930
930
610
610
150
LOAD LOSSES
W
1.750
1.475
1.750
1.475
4.600
4.600
3.850
3.850
TOTAL MASS
kg
520
650
740
770
1.190
1.200
1.300
1.400
CORE MASS
kg
150
220
220
225
435
440
450
FLUX DENSITY
T
1,83
1,45
1,35
1,35
1,83
1,84
1,65
Cu/Al
Cu
Cu
Cu
Cu
Cu
Al
Cu
Al
Cu
Cu
Cu
Al
Cu
Al
Cu
Cu
kg
85
115
130
155
203
145
350
220
360
450
505
295
725
465
1.120
1.225
CONDUCTOR MATERIAL
WINDING MASS
CURRENT DENSITY
A-A'
A-A'
C-C'
C-C' A-AMDT C-AMDT
160
2.600
2.600
1.700
1.700
380
420
4.600
3.850
14.000
14.000
17.000
17.000
17.000
14.000
1.590
1.750
3.300
3.240
3.370
3.680
4.310
4.550
540
570
600
1.100
1.210
1.200
1.460
1.400
1.550
1,6
1,35
1,35
1,84
1,84
1,7
1,6
1,35
1,35
A/mm2
2,9
2,3
2,35
2
2,9
1,55
2,1
1,1
2,3
1,85
3,65
2
2,75
1,4
2,45
2,1
HEIGHT
mm
1.300
1.300
1.300
1.300
1.330
1.420
1.350
1.550
1.400
1.400
1.890
1.820
1.860
2.000
1.870
1.900
LENGTH
mm
890
830
1.050
1.100
1.320
1.100
1.010
1.130
1.340
1.240
1.820
2.000
1.710
1.850
1.770
1.770
WIDTH
mm
600
560
620
620
800
840
800
780
770
800
1.180
1.280
1.100
1.020
1.320
1.200
EFFICIENCY (*)
%
97,94
98,32
98,19
98,46
98,62
98,62
98,89
98,89
98,81
99,00
98,78
98,78
99,02
99,02
98,91
99,10
SOUND POWER
dB(A)
57
36
59
59
61
68
56
58
68
68
68
72
63
63
76
76
UNIT COST
BEF
102.400
112.900
139.400
143.900
176.900
172.900
196.900
189.800
257.100
274.200
391.000
373.200
415.800
408.200
607.100
626.500
UNIT COST
%
90,7
100
123,5
127,5
93,2
91,1
103,7
100
135,5
144,5
95,8
91,4
101,9
100
148,7
153,5
(*) at full load and cos phi = 1
18
determination on the part of companies to secure orders, even at
very low margins, in order to survive.
Competition from companies in Central, Eastern and Southern
Europe, where labour costs are lower and home markets are
depressed, is adding to the pressure, as is the business in secondhand and refurbished transformers. There are however some signs
that volumes may be beginning to improve.
8.2
Industry Structure
Distribution transformers, together with special transformers of
similar size used for applications such as power rectification, electric furnaces, electrolytic refineries etc, are produced by about 200
companies in the Europe. A considerable number of additional
companies work only on transformer repair and refurbishment,
although they have the skills to build new units.
We estimate that over 200 transformer factories have closed since
the mid-1960s. Increased productivity, combined with pressure
from imports and moderate forecasts for growth, mean that further rationalisation can be expected.
Following a major merger in 1999, creating a clear leader in the
sector, the European market is now dominated by 6 producers.
Two of these are part of major electrical engineering groups,
organisations manufacturing a comprehensive range of products
and systems for power supply and heavy electrical engineering,
including steam and gas turbines, generators, transformers and
motors, switchgear and transmission equipment.
Together the major producers account for over 50% of the total
EU output of distribution transformers. Additional three companies, all capable of building both distribution transformers and
larger units, are responsible for a further 10% of output.
8.3
Manufacturing Investment
Sophisticated mechanised or flow-line production is not usual in
distribution transformer factories, except for the smallest sizes of
pole-mounted units. There are, however, some examples in
Europe of high levels of investment and automation. Groundmounted distribution and larger transformers are mostly built in
bays or on stands, reflecting the very wide range of standards and
sizes involved.
Utility customers often let an annual contract for a number of distribution transformers, typically several hundred units. Labour
content and skill levels are high, with a great deal of specialised
knowledge and experience associated with design and testing.
sector, have been built up partially by acquisition and rationalisation, but they continue to operate a number of separate transformer factories. Each of these will have its own product range,
specialist skills and customer base. Typically an independent
power systems transformer producer, or a transformer factory
within a large group, has a volume of output in the range €20-100
million per year.
8.4
Product Ranges
An example of the product range of a typical major European
transformer manufacturer is as follows:
l
oil-filled distribution
3,150kVA/36kV
transformers
from
15kVA
l
cast resin transformers up to 10MVA/36kV
l
power transformers from 4MVA to 500MVA/500kV
l
autotransformers up to 400MVA/500kV
l
HVDC transformers up to 275MVA/500kV.
to
An overview of typical parameters for the distribution transformers used in European electricity supply networks is shown in
Figure 8. This provides a further indication of the wide range of
products manufactured, in terms of physical size, use of materials
and price.
A standard ground-mounted distribution transformer costs about
€10,000 and weighs four tonnes. A typical distribution transformer factory could build a few thousand of these units per year.
Distribution transformers factories are usually dedicated to manufacturing these products for electricity supply industry and nonutility customers. Manufacturers do not normally build other
equipment, such as large power systems transformers or small
transformers, on the same site. Some smaller companies produce
only pole-mounted transformers. Non-standard power transformers, such as flameproof units, electric locomotive transformers or
marine power supplies are often produced in specialist facilities.
8.5
Exports
Exports by European transformer manufacturers are running at
about €1000 million per year. Export volumes help to balance the
workload of transformer factories, and are particularly important
when domestic demand is depressed.
This pattern of manufacture and ordering is reflected in the structure of the industry. The larger companies, which dominate the
19
Trade within Europe is increasing as the power supply industry is
progressively deregulated. This new competition is often not welcomed by those manufacturers who have had to face the decline in
industry size, but were previously protected in their home markets
by utility purchasing policies and national specifications.
Exports to non-European destinations account for over one-quarter of the total output. The main overseas markets for power systems transformers manufactured in Europe are the United States,
India, Saudi Arabia, Indonesia and China. A proportion of this is
associated with turnkey projects undertaken by major electrical
engineering groups.
8.6
Repair and Maintenance
9
9.1
8.7
Representation
There are national trade associations representing the transformer
manufacturers in larger European countries, usually linked to the
national electrical engineering trade body. The trade association
for the European transformer industry is the Committee of
Associations of European Transformer Manufacturers
(COTREL), which links the national trade associations. The
members of COTREL are shown in Appendix B.
Non-members of COTREL could represent a further 20-30% of
total production volume. COTREL also takes responsibility for
transformer industry relationships with the European
Commission, through the national association in Belgium
(Fabrimetal).
COTREL meets three times per year, when an agenda of issues is
discussed by the executive and members. Statistics are also collected on transformer production. COTREL report that 2-3 years ago
a working group was set up to consider the problem of older transformers and possible replacement initiatives. It was however abandoned.
20
Design Concepts
Transformer design is extremely specialised, and requires a capable
and experienced design team. Transformers are manufactured
against specific customer invitations to tender, taking into account
the following basic parameters:
l
Repair and maintenance now represent a considerable proportion,
up to 20%, of the activities of some transformer manufacturers.
This ratio is increasing as the population ages. Rebuilding provides an opportunity to improve efficiency at a lower cost than
purchasing new machines.
Special skills are required to deal with the PCB contamination
which affects many older transformers installed in the EU, even
those using mineral oil as the coolant. It is not clear in some cases
how this contamination has occurred, but it may result from poor
housekeeping in past manufacturing or maintenance routines.
DISTRIBUTION TRANSFORMER
TECHNOLOGY
l
l
flux density (or induction), a measure of the loading of the iron
core. Each magnetic steel has its typical inherent core loss, directly related to its flux density. Once above the saturation induction
of the steel, the flux will leave the core and no-load losses are no
longer under control. Maximum flux density should therefore be
limited to well below this saturation point. Energy-efficiency can
be improved by selecting better performing, lower core loss
steels, or by reducing flux density in a specific core by increasing
the core size
current density in the copper windings. Increasing conductor
cross-section reduces the current density. This will improve energy efficiency, but also result in higher cost. Because copper losses are dependent on the loading of the transformer, it is necessary to consider how the unit is to be installed and used in practice
iron/copper balance. The balance between the relative quantities of iron and copper in the core and windings. A “copper-rich”
unit has a high efficiency across a wide range of load currents. An
“iron-rich” unit has a lower initial cost price, and may be more
economical when transformers are expected to be lightly loaded.
These basic considerations must then be combined with a wide
range of other factors, to enable a competitive tender to be submitted to the customer. Copper and iron prices are continually
changing, and this can affect the balance between the two materials.
A variety of proprietary steels are available for building the core,
and the techniques to be used for the construction of the transformer core, windings, insulation and housing need to be decided. Alternative materials, such as aluminium coils or pre-formed
copper windings, could be considered.
The energy efficiency of a distribution transformer, in terms of
losses, is usually specified by the customer. These, and other factors directly associated with energy efficiency, are discussed in
Sections 10.1-10.4.
Figure 9
Development Stages, Transformer Steels
9.2
Tr a n s f o r m e r S t e e l s
The energy efficiency of distribution transformers is fundamentally dependent on the type of steel used for building the transformer
core. More specialised steels, particularly suitable for distribution
and larger transformers, have developed in a number of stages.
(Figure 9).
Thin hot-rolled steel sheet, with a silicon content of about 3%,
became the basic material for fabricating electromagnetic cores in
about 1900. Individual sheets were separated by insulating layers
to combine low hysteresis losses with high resistivity. Cold rolling
and more sophisticated insulation techniques were progressively
developed.
Grain-oriented silicon steels, in which the magnetic properties
of transformer steels are improved by rolling and annealing, to
align the orientation of the grains, became available in the mid1950s.
Various processing and coating techniques, combined with a
reduced silicon content, were incorporated into high permeability grain-oriented steels, about 10 years later. During the 1980s,
techniques were introduced for domain refinement, reducing
domain width by mechanical processes, principally laser-etching.
A recently developed core material, amorphous iron, represents a
significant new advance in transformer steels. Amorphous iron is
produced by rapidly cooling molten metal into a very thin ribbon
with a non-crystalline structure.
At the same time other technology advances have progressively
improved the performance of the steel used in distribution transformer manufacture. These include rolling and coating technology, reduced gauge (thickness), material purity, dimensional tolerances, internal and surface stresses and tension. The various materials, their properties, and the extent to which they are used, are
described in more detail in Sections 9.3-9.6.
9.3
Grain-oriented Steels
Conventional grain-orientated (CGO) steels are rolled from silicon-iron slabstock, and coated on both sides with a thin layer of
oxide insulating material to reduce eddy-currents. They are supplied in Europe in about 10 standard thickness. The European
standard, EN10107, reflects the international IEC 60404 standard, and describes a range of gauges from 0.23-0.50mm (previously M3-M7, a nomenclature which is recognised world-wide).
21
CGO steels remain the standard raw material for distribution
transformer manufacture in Europe. They are estimated to account
for over 70% of the total steel consumption in distribution transformer production, estimated at about 100,000 tonnes per year.
Demand is still very much skewed to the thicker gauges. Thinner
gauge CGO and other more sophisticated raw materials are considerably more expensive, reflecting higher capital investment and
technology levels, as well as additional processing steps. Core production costs are also higher.
High permeability steels are manufactured to the same European
Standard as CGO, and are available in about five gauges ranging
from 0.23-0.30mm. They account for about 20% of total consumption in transformer manufacture.
9.6
Future Developments
Research and development on magnetic steels is vigorously pursued world-wide. The licensing of new processes has been
extremely prevalent in this sector for many years.
Distribution transformers appear to represent a poor return on
recent development effort, with the possible exception of amorphous iron, because of the competitive nature of the market.
However new magnetic steel developments also benefit from other
applications, notably electric motors and small transformers.
Future emphasis on energy efficiency and environmental impact
could change this picture.
Among areas of interest are:
9.4
Domain Refined Steels
A further reduction of losses is achieved by domain limitation.
Domain refined steels are produced mainly by proprietary laser
etching processes. Together with grain-oriented steel, they offer
material with specific losses ranging from about 0.85-1.75W/kg at
1.7T/50Hz for distribution transformer manufacture.
l
l
l
Commercially available domain-refined steel is typically 0.23mm
thick. Together with amorphous iron, see below, it has a market
share in Europe for transformer manufacture of about 10%.
9.5
l
Amorphous Iron
Distribution transformers built with amorphous iron cores can
have more than 70% reduction in no-load losses compared to the
best conventional designs. There is only one known producer
world-wide of amorphous iron material suitable for distribution
transformer manufacture.
Amorphous iron became commercially available in the early
1980s. It is reported to have been used in the construction of several hundred thousand distribution transformers in the US, Japan,
India and China.
the adoption of the design of amorphous iron transformers to
European practice (i.e. use a three legged Evans-core design for
Dy-connected transformers, resulting in reduced length, cost
and noise)
mechanical or thermal processes other than laser etching for
domain limitation
the use of thinner steels. Magnetic steels with gauges as low as
0.05mm are being offered in narrow strip for small transformers
and coils. For larger transformers 0.18mm steel is available, but
both raw material and core fabrication costs rise very rapidly as
the gauge is reduced.
9.7
Conductor Developments
The conductor materials for winding the coils of distribution
transformers are supplied in the form of wire, narrow strip or
sheet. They have not experienced the same significant step changes
in recent years as core steels. The main developments have been:
l
European experience of manufacturing and installing amorphous
iron distribution transformers in the EU has been very limited
(See Section 10.5) This is partly due to network design characteristics which differ from US and Japanese practice. However a very
large (1,600kVA) amorphous iron three-phase distribution transformer has recently been built and installed in the EU.
l
22
the ending of certain patents on amorphous iron processes,
which could encourage other producers to enter the market
the availability of copper and aluminium wire-rod produced by
continuous casting and rolling (CCR) processes, combined with
mechanised handling techniques. This has enabled semi-fabricators to offer wire and strip in much longer lengths than was previously possible, increasing transformer reliability. The welded or
brazed joints in strip, which were inevitable in rod produced
from wire-bar, created weak points in the finished coils
both copper and aluminium are now available in wide sheet and
foil form with high dimensional tolerances. Sheet has extensively replaced strip for the LV windings of distribution transformers
l
continuous cold rolling processes are now being introduced for
conductor strip production. This potentially offers better availability, and more consistent quality, than is available from drawn
strip.
Potential developments include the shaping of conductors to
improve the mechanical strength of the completed coil, and more
compact fabrication of coils.
9.8
Other Materials
Developments have also taken place in the other components used
in distribution transformer manufacture. The most significant are
the development of flame-proof coolants to replace PCBs, and the
use of cast resin encapsulation as an alternative to dry construction
in non-liquid cooled transformers (See Section 7.4)
More sophisticated insulating papers and boards, including synthetic and self-bonding papers, are also available.
9.9
Core Fabrication and
Assembly
The way in which distribution transformer cores are designed, cut,
fabricated and assembled, plays an important part in energy efficiency. The cost of a completed core is also affected by these factors. Various levels of mechanisation and automation are available
for the cutting and stacking processes.
There is a specific problem of the capacity of European transformer manufacturers to handle and process magnetic steel at
gauges below 0.23mm, and to fabricate amorphous iron in-house.
It seems likely that the steel suppliers will attempt to extend their
capability to supply built cores and semi-fabricated components.
9.10
Coil Winding and
Assembly
The processes of winding the conductor coils and then fitting
them onto the assembled core are labour-intensive, and require
skilled workers. Again the performance and energy efficiency of a
distribution transformer greatly depends on these steps.
Mechanised winding, under operator control, is increasingly used
Figure 10
Spiral Sheet Low-voltage Winding
23
Figure 11
Multilayer Coil High-voltage Winding
Figure 12
Disc Coil High-voltage Winding
24
for producing coils based upon copper wire, wide strip and aluminium foil.
turers in Europe have significant fundamental R&D capabilities
dedicated to transformer research.
The main types of coil which are now used in distribution transformers are:
Much of the recent work on the steels used in distribution transformers has originated from Japan and the United States, although
European companies have a world reputation for the steels and
non-ferrous alloys used in smaller transformers. Some of the technology for adding value to conductors and coils, such as the continuous cold rolling of narrow strip, has also been imported.
l
l
l
spiral sheet windings, using wide copper strip or aluminium foil
(Figure 10). A relatively recent development, used in place of
helical coils for the LV windings of distribution transformers,
particularly where there are only a small number of turns
required in the coil
multilayer coils for HV windings (Figure 11). The complete
winding is a single unit, wound in wire, consisting of several layers and a number of turns per layer
However there are a number of centres of excellence in Europe,
with a capability for R&D and demonstration of distribution
transformers or component materials. Many European universities
have a capability in magnetic materials within their electrical engineering or materials departments.
disc coils, particularly for the HV windings of dry-type transformers (Figure 12). A number of radially wound discs produced
from a single length of conductor, separated from one another by
insulating spacers.
There is also an established coil-winding industry in the EU,
which mainly offers windings for smaller transformers, and specialist products such as current transformers. These companies frequently have encapsulation capabilities, and are able to supply
ready-built coils for dry-type transformers.
9.11
Superconducting
Tr a n s f o r m e r s
A number of superconducting distribution transformers have been
built. One company has developed a nitrogen-cooled 630kVA
high temperature superconductor (HTS) transformer, which was
installed in the Swiss electricity supply network in 1997. This is a
single-phase transformer, and considerable engineering problems
are reported in producing three-phase versions.
It is widely agreed that superconductivity will always remain much
more expensive for power distribution transformers than conventional technology. The most promising areas appear to be in specialist applications, particularly traction transformers, where
increasingly large transformers are required for train motors in
railway networks.
9.12
Te c h n o l o g y S o u r c e s
Power systems transformers are very specialised products, and
R&D activities outside the major transformer manufacturing
companies are limited. Even here most effort is centred on practical product development, together with the testing and evaluation
of new materials. Only a few distribution transformer manufac-
25
10
TECHNICAL AND ENGINEERING
APPRAISAL
10.1
D i s t r i b u t i o n Tr a n s f o r m e r
Standards
finalised by eliminating as many national differences as possible.
When a harmonisation document (HD) has been issued, conflicting national standards have to be withdrawn within a specified
period of time, or modified to be compatible with the HD.
Usually, the HD is the predecessor of an European standard (EN),
which must be adopted as a national standard in the EU member
countries. Thus, purchase orders which refer to national standards
are compatible with European standards (EN) and/or harmonisation documents (HD).
Most of the characteristics of distribution transformers are specified in national or international product standards. The application of standards can be legally require, or by specific reference in
the purchase contract.
Among the many international standards for distribution transformers, two main European Harmonisation Documents specify
energy efficiency levels:
l
Generally, the purpose of standards is to facilitate the exchange of
products in both home and overseas markets, and to improve
product quality, health, safety and the environment. International
standards are also of importance in reducing trade barriers.
l
For distribution transformers purchased in the European Union,
three levels of standards are applicable:
HD538: Three-phase dry-type distribution transformers 50Hz,
from 100 to 2,500kVA, with highest voltage for equipment not
exceeding 36 kV.
A separate HD is under consideration for pole-mounted transformers.
l
world-wide standards (ISO, IEC)
l
European standards and regulations (EN, HD)
l
national standards (e.g. BSI, NF, DIN, NEN, UNE, OTEL).
European Harmonisation Documents are initiated if there is a
need for a European standard. The draft HD is a compilation of
the different national standards on the subject. The HD is
Figure 13
HD428: Three-phase oil-immersed distribution transformers
50Hz, from 50 to 2,500kVA with highest voltage for equipment
not exceeding 36kV
In the next Section, the efficiency limits defined in these standards
are discussed. The standards however leave considerable freedom
for local deviations in energy efficiency, which implies that energy
loss levels may (and do) still vary across European countries. This
is also discussed in the next Section.
Distribution Transformer Loss Standards
Load Losses for Distribution Transformers
RATED
POWER
kVA
50
100
160
250
400
630 /4%1)
630 /6%
1000
1600
2500
Notes:
1.
2.
3.
OIL-FILLED (HD428) UP TO 24kV2)
No-Load Losses for Distribution Transformers
DRY TYPE
(HD538)
OIL-FILLED (HD428) UP TO 24kV2)
DRY TYPE
(HD538)
LIST A
LIST B
LIST C
12kV
PRIMARY 3)
LIST A’
LIST B’
LIST C’
12kV
PRIMARY 3)
W
W
W
W
W
W
W
W
1,100
1,750
2,350
3,250
4,600
6,500
6,750
10,500
17,000
26,500
1,350
2,150
3,100
4,200
6,000
8,400
8,700
13,000
20,000
32,000
875
1,475
2,000
2,750
3,850
5,400
5,600
9,500
14,000
22,000
N/A
2,000
2,700
3,500
4,900
7,300
7,600
10,000
14,000
21,000
190
320
460
650
930
1,300
1,200
1,700
2,600
3,800
145
260
375
530
750
1,030
940
1,400
2,200
3,200
125
210
300
425
610
860
800
1,100
1,700
2,500
N/A
440
610
820
1,150
1,500
1,370
2,000
2,800
4,300
The short-circuit impedance of the transformers is 4% or 6%, in most cases. This technical parameter is of importance to a utility for designing and dimensioning the low-voltage network fed by the transformer. Transformers with the same rated power but with different short-circuit impedance have a different construction and therefore slightly different losses. For HD428 / HD538 compliant distribution transformers, the preferred values for the short-circuit impedance are 4% for transformers up to and including 630kVA,
and 6% for transformers of 630kVA and above.
For 36kV transformers, different values apply.
For 24 and 36kV transformers, different values apply.
26
10.2
Rated loss levels of
Standard Distribution
Tr a n s f o r m e r s
Distribution transformers built to HD428 and HD538 have a
limited number of preferred values for rated power (50, 100, 160,
250, 400, 630, 1,000, 1,600 and 2,500kVA). Intermediate values
are also allowed. The two key figures for energy efficiency, the load
losses and the no-load losses, are specified for each rated power.
Figure10 gives the limits for load losses (often called “copper losses”) for some important types of oil-filled and dry-type distribution transformers according to HD428.1 and HD538.1 for the
preferred rated power range of the transformers. For oil-filled distribution transformers, the HD allows a choice of energy efficiency levels, A, B and C.
Loss values for transformers are usually, declared as maximum values with a specified tolerance. If higher losses are found at the factory acceptance test, the transformer may be rejected or a financial
compensation for exceeding the loss limit may be agreed between
client and manufacturer. In the same way, a bonus may be awarded to the manufacturer, mainly for large transformers, for a transformer with losses lower than the limits agreed.
The no-load losses (iron losses) for the same range of transformers
are given below. For oil-filled distribution transformers, the HD
offers a choice between three efficiency levels, A’, B’ and C’ (Figure
13).
HD428 therefore allows customers to choose between three levels
of no-load losses and three levels of load losses. In principle, there
are 9 possible combinations, ranging from the lowest efficiency,
(B-A’) to the highest, (C-C’), which may be regarded as providing
a high practical standard of energy efficiency for a distribution
transformer.
HD428 defines five preferred combinations of these losses. These
combinations are shown below in Table B, where the combination
A-A’ is chosen as the base case (shown as a bold line - the percentages refer to this combination).
Table B
There is a significant difference in total no-load and load losses
between A-A’ and C-C’ distribution transformers, approximately
1.5kW for a 630kVA unit.
The freedom for choosing different levels of energy efficiency is
increased by the fact that transformer buyers can comply with
HD428/538 through the use of a capitalisation formula, rather
than the tabulated losses shown in the standard. In this, they are
free to insert their own capitalisation values, to which no restrictions are imposed. This process of loss capitalisation is described
in Section 10.6.
If high capitalisation values for losses are chosen, transformers
with low losses but with higher investment cost tend to be
favoured. If however capitalisation values are set to zero, a purchaser effectively eliminates energy loss evaluation from the purchase decision, which favours the cheapest transformer.
HD428.1 (part 1: general requirements and requirements for
transformers with highest voltage for equipment not exceeding 24
kV) as well as other HD sections also contain phrases such as “(...)
in the case of established practice in the market (...) the transformers can be requested and, by consequence, offered, with losses differing from the tabled losses”, which indicates some freedom
to national or local deviations.
As stated before, HD428 and HD538 represent a compilation
and/or compromise on the various old standards which were used
in European countries. It appears to be rather unambitious in
terms of the standards set, and by allowing capitalisation formulas
to be used.
10.3
Loss levels of Standard
D i s t r i b u t i o n Tr a n s f o r m e r s
when Loaded
The losses of a transformer show considerable dependence on the
actual load. At no-load, the no-load losses are still present. At full
load, the load losses are added to the no-load losses. For less than
full load, the load losses decrease proportional to the square of the
load.
For example, the total losses of a 400kVA oil-insulated transformer are shown opposite as a function of the transformer load,
for the different loss combinations mentioned above.
The transformer efficiency can be calculated by dividing the losses by the power transferred. Here, the effects of reactive power
should be accounted for, as reactive power causes current to flow,
with its associated losses. This causes the efficiency of the transformer to decrease. By multiplying the transformer load (in kVA)
by the so-called power factor (usually designated cos (), this effect
is accounted for, showing the net power transformed.
Figure 14 shows the relative transformer loss as a function of the
load. The relative transformer loss is equal to 100% minus transformer efficiency. Clearly, the relative losses follow a U-shaped
curve, and transformers are typically at maximum efficiency when
27
Figure 14
Total Losses of a 400 kVA Transformer as a Function of the Load (12kV and 24 kV Transformers
50% loaded. The figure also shows that B-B’ transformers have
less loss than A-A’ transformers in the lower load region, while the
A-A’ transformers show lower loss in the region above 40% load.
Which transformer is best with regard to energy efficiency thus
depends on the application. C-C’ transformers have 20-30%
lower loss than the A-A’ and the B-B’ types.
Figure 15 shows how efficiency at full load varies with the size of
the transformer, and includes dry-type transformers. The graph
shows efficiency of the transformers of various sizes at full load.
Clearly, economies of scale apply to the oil-filled distribution
transformer and, to a stronger extent, to the dry-type transformer.
Because energy efficiency varies with load, the calculation of the net
efficiency of a transformer over a year or over its lifetime is rather
complex. Due to the square relationship between losses and load,
the average load of a transformer is not an adequate parameter to
calculate the annual energy losses or the average efficiency directly.
There are, however, some empirical formulae available to estimate
the annual transformer losses from the average annual load.
Figure 15
Dependendy of Transformer Losses on Size (kVA) for 12kV and 24kV transformers
28
10.4
Achievable Loss Levels
The HD428 C-C’ loss level for oil-filled distribution transformers
may, as mentioned before, be regarded as providing a high practical standard of energy efficiency for a distribution transformer.
There is no internationally agreed definition of an “energy-efficient” transformer. It is proposed to use the term “energy-efficient” transformer for the following transformers:
l
l
l
oil-filled transformers: range C-C’ (HD428.1) and D-E’
(HD428.3)
dry-type transformers up to and including 24kV: 20% lower
than specified in HD538.1. HD538 mentions one list of preferred values, but explicitly allows the possibility for national
standards to specify a second series with load and/or no-load
losses at least 15% lower. Some transformer manufacturers offer
dry-type transformers in normal and low-loss versions
dry-type transformers 36kV: 20% better than specified in
HD538.2, analogous to the previous category.
An important reason for choosing the values suggested above is
the fact that these levels are entirely feasible within the current
“state of the art” of nearly all transformer manufacturers. In the
remainder of this report, the class of energy-efficient transformers
is often referred to as C-C’, as the oil-filled transformers form the
majority of the transformers, and, among these, units up to 24kV
are the most numerous.
An alternative way of defining “energy-efficient transformers”
would be to by considering the energy-efficiency levels of the
transformers sold on the market. This is be analogous to the con-
cept of the US “energy star” transformer program (see Section 11).
Here transformers with energy efficiency equal to or above that of
the most efficient 35% being currently sold meet the requirement
for Energy Star rating.
Figure 16 gives an impression of the way in which the distribution
transformer population varies in Europe. It can be seen that reference to the population per country or for the European Union as
a whole will produce different results. However, it seems preferable to address losses more absolutely.
Another way to define “energy-efficient transformers” would be
the application of special windings, advanced steels or amorphous
iron. An argument against this definition is that there are a number of practical considerations involved in deciding on the optimum choice of transformer for installation into a network.
Moreover, the energy loss level is the key performance indicator of
each transformer design with respect to energy efficiency and
would consequently the fairest benchmark.
As expected, the loss level of “energy-efficient transformers” as
defined above does not represent the maximum efficiency which
is technically possible. Both load and no-load losses may be
reduced significantly.
Load losses may be reduced beyond the levels mentioned above by
following technical design measures:
l
increasing the conductor section of the transformer windings,
which reduces conductor resistance and thus load losses. To a
lesser extent, the application of ribbon or sheet conductors also
contributes to reducing load losses. The disadvantage of increasing the conductor section is the higher investment cost. Another
disadvantage is the larger size of the transformer, which may
exceed the maximum sizes specified by the purchaser. This is
Figure 16
Fictitious Example of Different European Transformer Standards
29
partially offset by the reduction of heat production in the transformer, which lowers the need for cooling
l
application of superconductor material for the windings, eliminating load losses. This technology is not yet mature and still
very expensive. The main application will lie in larger transformers. Another drawback of superconducting transformers is
the inability to withstand short-circuit currents of the level that
are common in medium-voltage networks. These problems need
to be solved before the superconducting transformer will become
a viable option.
There are, however, some other important technical aspects that
are essential to the adoption of energy-efficient distribution transformers and critical to some technologies:
l
l
No-load losses may be reduced beyond the levels mentioned above
by following technical design measures:
l
l
l
l
l
increasing the core section, which reduces the magnetic field in
the transformer core and thus the no-load losses. However, this
results in higher investment cost. Another disadvantage is the
larger size of the transformer, which may exceed the maximum
sizes specified by the purchaser
application of high-grade modern transformer core steel, see
Section 9. It should be noted that the C-C’ level can be reached
without applying laser-etched transformer steel, the latter being
regularly used in large transformers
reduction of the thickness of the core laminations, see Section 9
application of amorphous core material, see Section 9. The saving potential with respect to no-load losses is high, as shown in
the table below, where the amorphous transformer is compared
to the conventional types according to HD428.
dimensions. Distribution transformers need to be aligned to
switchgear, fit into enclosures or go through doorways. For larger transformers, the mass may also be a critical parameter. Many
dimensional features are still defined at national level or even
utility level
noise level. Distribution transformers are often sited in buildings
or residential areas, where strict limits on acoustic noise emission
apply
absence of technological risk. The distribution transformers currently in use are extremely reliable. Furthermore, the consequences of failure are severe, as most distribution networks are
operated in radial configurations. Many networks have no backup for a distribution transformer failure, with the consequence
that a transformer outage will affect customers until the transformer has been replaced. For this reason, utilities tend to be very
careful when adopting new technologies (see Section 11) unless
a new design has unequivocally proven its reliability (preferably
at another utility).
The options are compared qualitatively in Figure 17 (+ indicates a
favourable score).
10.5
Loss Levels in Practice
(source: EDON)
In practical installations, the loss levels of transformers are determined by three factors, the efficiency class specified, the load profile of the transformer and deviations from the standard loss values. The three factors will each be discussed below.
Table C
The efficiency class specified
The conclusion is that transformer efficiency may be raised well
beyond the current level of energy-efficient transformers by using
existing technology.
Figure 17
There appears to be a “league table” of standards for distribution
transformer losses specified by the electricity utilities of the various European countries. Switzerland, Scandinavian countries are
said to set the highest standards, with France and Italy amongst
the lowest (A-A’) with France particularly keen to reduce no-load
Comparison of Technologies to Improve Energy Efficiency
Absence of
technological risk
Increased conductor section ++
Superconducting windings -Increased core section
++
Modern core material,
Thin laminations
++
Amorphous metal core
+
30
Dimensions
Noise
Cost compared
to C-C’
Energy saving
@ light load
Energy saving
@ heavy load
0/variable
0/-
0
0
0
---
0
+
+
+
0/+
0
-
+
-
--
++
+++
0/+
0/+
losses rather than load losses. Others are somewhere in the middle.
Among values reported in the project were (oil-filled transformers):
Table D
Utility Distribution Transformer Loss Levels in Europe
Country
Utility Distribution Transformer Loss Levels
Belgium
France
Germany
Netherlands
Spain
UK
C-C’
A-A’ and B-B’ and B-C’
A-C’ and B-A’ and C-C’
C-C’
50% meet C-C’
Uses capitalisation values
The load profile of the transformer
Although transformer efficiencies can be measured accurately in
the test house, the load profile and hence the efficiency differs for
every transformer in the field. The dependency of the efficiency of
the transformer on the load profile was mentioned in Section
10.4.
The table below gives an idea of the load profiles involved:
Table F
Typical Load profiles, Distribution Transformers, Europe
Transformer
As indicated above, the UK does not apply the HD428/538 losses table. Each utility uses its own values to capitalise losses, in
accordance with the alternative approach permitted by HD428.
The capital value of losses is normally assessed annually.
100kVA (small, rural)
lightly loaded
average loaded
● heavily loaded
●
●
There is quite a lot of movement at present in the loss standards
which are currently being applied. Newly decentralised and privatised utilities are changing earlier procurement standards for distribution transformers, and placing first cost above energy efficiency, either as a conscious action or as the result of reducing payback periods. German utilities are said to be reducing previous
higher standards. However Belgium has recently raised its national procurement standard to C-C’.
lightly loaded
average loaded
● heavily loaded
●
●
lightly loaded
average loaded
● heavily loaded
●
Total kVA
Belgium
Germany
Ireland
Netherlands
Slovakia
Spain
Switzerland
UK
10
1
101
3
2
14
5
25
4,000
500
3,100
1,200
800
8,330
1,540
2,390
Total
161
21,860
Loss
time
Power
factor
(cos j)
1,500 h
750 h
0.95
1,500 h
0.95
2,500 h
0.8
1.6%
6.5%
20%
20%
55%
110%
5.5%
15%
30%
3,500 h
30%
50%
110%
9.5%
16%
32%
The terms in the table are defined as follows:
l
l
Amorphous Iron Distribution Transformers, Europe
Number
Running
time, average
load
2,500 h
1,600kVA (industrial)
Table E
Location
10%
40%
120%
400kVA (average)
●
Energy-efficient transformers are generally regarded by European
customers as technically sound but uneconomic (but see Section
10.7 and Section 11). The number of extremely energy-efficient
transformers (beyond the C-C’ level) operating in Europe is quite
low, compared with a.o. the United States. We estimate that about
200 amorphous distribution iron transformers have so far been
installed, many of which are very small, and probably a slightly
larger number using laser-etched domain-refined steel. The amorphous iron installations we have identified are as follows:
Yearly
peak
load
l
yearly peak load: the highest load of the transformer as a percentage of its rated power. This load is only present for a small
part of the year
running time: the ratio of energy transmitted during a year
[kWh] and the yearly peak load [kW] - physically, this figure
indicates how much time it would take to transmit the yearly
energy at a power equal to the yearly peak load. A low value indicates strong fluctuations of the load, a high value a relatively constant load. The average transformer load is the yearly peak load,
multiplied by the running time over 8760 hours
loss time: the ratio of the yearly energy loss [kWh] and the maximum losses occurring in a year [kW] - this figure indicates how
much time it would take for the transformer to lose the yearly
energy loss when loaded at the maximum load occurring in the
year.
The data above result into the following data for an A-A’ and a CC’ transformer with an “average” load profile as indicated above:
31
Table G
Average load profiles - Distribution Transformer
Transformer rating (kVA)
100
400
1,600
Yearly energy transmitted (MWh)
57
523
2,240
A-A’ transformer
Energy loss (kWh)
Efficiency (%)
3,013
94.71
10,234 33,401
98.04 98.51
C-C’ transformer
Energy loss (kWh)
Efficiency (%)
2,017
96.46
7,091
98.64
23,642
98.94
A-AMDT transformer
Energy loss (kWh)
Efficiency (%)
736
98.71
3,401
99.35
13,954
99.38
C-AMDT transformer
Energy loss (kWh)
Efficiency (%)
703
98.77
3,149
99.40
12,429
99.45
The no-load (iron) losses account for 95% of the yearly losses in
the case of a 100kVA transformer, and 66% of the no-load losses
in a 1,600kVA transformer.
For very lightly loaded transformers, the efficiency falls rapidly.
There are several reasons why some transformers are so lightly
loaded. Often a limited number of transformer types used by a
utility (advantages of lower stock) is the cause, or allowing for a
load increase. Usually, the distribution network is dimensioned
with certain expectations of load growth, in order to postpone
upgrading of the infrastructure as long as possible. A final factor is
the usual technical practice to apply safety margins to electrical
equipment. This is good for the load losses, but increases the noload losses.
The extremely low loads encountered at some transformers seem
to suggest the need for smaller distribution transformer sizes, or
cores with extremely low losses.
Although the figures used are based on empirical rules validated by
measurements, there is a wide spread in the average transformer
loading and the running time. Although some utilities keep track
of the maximum loads of transformers, there are no representative
transformer load data available for the European Union. The figures given above should therefore be considered an example.
Deviations from the standard loss values
Apart from the efficiency class and the load profile, many other
factors may influence transformer losses:
l
medium-voltage (MV) network voltage - the core (iron) losses
are dependent on the network voltage. A higher network voltage
leads to higher core (iron) losses. For instance, 5% increase of the
network voltage may cause 10-20% higher core losses, depending on the type of core material and the design of the transformer.
The loss levels of individual transformers are, therefore, always
specified for a defined network voltage. For an individual trans-
32
former, the effect can easily be measured. In an electrical network,
the voltage at each substation varies according to the electrical distance to the feeding point and the load situation. A special case is
the gradual change (between 1989 and 2004) of the network voltage within Europe from 220V or 240V to 230V as defined in
IEC60038. In some cases, the increase from 220V to 230V is
realised by increasing the voltage level in the medium-voltage network, which leads to increased losses in the distribution transformers. On the other hand, the decrease from 240V to 230V may
be achieved by decreasing the voltage level in the medium-voltage
network, which leads to lower losses in the distribution transformers
l
l
l
l
operating temperature of the transformer. Conductor losses
slightly increase with the operating temperature of the transformer. The loss levels of individual transformers are, therefore,
always specified for a defined operating temperature
production deviations of the transformer. This is a quality assurance aspect, which will normally not yield large deviations from
the contracted loss values
ageing of the transformer. Older transformers may deteriorate in
several modes, one of which is a loss increase. Normally, this
effect is neglected. There are, however, some concerns about ageing of amorphous cores
poor power quality. The presence of non-linear loads in the network will lead to harmonic current components in the transformer. These harmonic currents tend to heat the transformer,
but normally the transformer design allows for some harmonic
contents of the load current. Normally, this effect is not taken
into account, except in industrial or comparable installations
with many distorting loads.
Accounting for these factors for a network would require a
detailed knowledge of operating conditions, Usually, efficiency
class and transformer loading are the two dominant factors, the
other factors are not taken into account when assessing transformer losses.
10.6
Loss Evaluation
A transformer purchaser aims to buy the cheapest transformer, i.e.
with the lowest total owning cost, which complies with the
requirements for a given application. The total owning cost of a
transformer consists of several components, including purchase
price, the value of energy losses, maintenance and repair costs over
the lifetime, and decommissioning cost. The purchase price and
the energy losses are the two key factors for comparison of the different transformers. Installation, maintenance, repair and decommission costs are seldom taken into account for choosing between
transformers as they are relatively insensitive to transformer
design.
In cases where transformers of different technologies are compared, e.g. dry-type and oil-immersed, installation costs (a.o. fire
protection, oil containment provisions) will be considerably different and do need to be taken into account.
where A represents the assigned cost of no-load losses per watt, Po
the value of the no-load losses per watt, B the assigned cost of load
losses per watt and Pk the value of the load losses per watt. This
formula can also be found in the HD428 and HD538.
When comparing two transformers with different purchase prices
and/or different losses, one must take into account that the purchase price is paid at the moment of purchase, while the cost of
losses come into effect during the lifetime of the transformer.
Usually the costs are converted to the moment of purchase by
assigning capital values. When transformers are compared with
respect to energy losses, the process is called loss evaluation.
An example of application of the formula to the transformers of
Figure 8 gives the capitalised cost values in Figure 18. In this
example, A and B have been chosen as 4 and 1.2 Euro/W respectively. It is obvious that there is a significant discrepancy between
the cheapest transformer at purchase and the cheapest transformer
in the long term. Even the expensive amorphous transformer may
be cheapest option.
In the basic process of loss evaluation, three transformer figures are
needed:
The formula is simple, but the choice of the factors A and B is very
complicated (see Section 10.5 for difficulties in determining load
patterns). Medium-size and large utilities use standard values for
loss evaluation, based on average values for energy cost and loads.
l
purchase price
l
load loss
l
no-load loss.
For the specified load loss of a transformer, the purchaser can
assign a cost figure per kW of loss representing the capitalised
value (net present value) of the load losses over the lifetime of the
transformer or a shorter time scale e.g. 5 or 10 years. This cost figure is based on the expected transformer load over time, the average cost per kWh and the interest rate chosen by the purchaser.
Similarly, for the no-load loss of a transformer, the purchaser can
assign a cost figure per kW of no-load loss representing the capitalised value of the no-load losses. This cost figure is also based on
the average cost per kWh and the interest rate chosen by the purchaser. As nearly all transformers are connected to the grid for
100% of the time, and the no-load losses are independent on the
load, the load curve is not relevant. The average cost per kWh will
tend to be lower than for the load losses, as the latter will tend to
coincide with peak loads, at which time energy is very expensive.
Thus, the capitalised cost (CC) of a transformer can be expressed
as the sum of the purchase price (Ct), the cost of no-load losses
and the cost of the load losses, or as a formula:
CC = Ct + A x Po + B x Pk
Figure 18
Usually, the loss evaluation figures A and B are submitted to the
transformer manufacturers in the request for quotation. They can
in turn start the complicated process of transformer design, to
obtain a transformer design which performs best using the same
formula. The result of this open process should be the cheapest
transformer, i.e. with the lowest total owning cost, optimised for a
given application.
Drawbacks of this process are its extreme complexity and the
uncertainty of the purchaser with the exact load profiles of the
transformers and energy prices in the future. Tariff structures are
very complex.
For large transformers, above a few MVA, the cost of losses are so
high, that transformers are custom-built, tailored to the loss evaluation figures specified in the request for quotation for a specific
project.
For distribution transformers, often bought by large batches, the
process is undertaken infrequently, e.g. once every 5 years. This
yields an optimum transformer design, which is then kept for several years until energy prices or load profiles have changed dramatically. In fact, the loss levels established in HD428, HD538
and national standards reflect established practice of preferred
designs with respect to loss evaluation values. It is then usual to
select one category e.g. C-C’ as the most appropriate, and omit the
Cost comparison of typical Distribution Transformers according to figure 8
33
tedious evaluation process by purchasing the cheapest C-C’ compliant transformer.
It can be concluded that the efficiency of transformers purchased
is, directly or indirectly, controlled by the choice of loss evaluation
figures:
10.7
Case Study 1:
Replacement of Old
Tr a n s f o r m e r s
Groningen saves 1.2 million kWh per year - Overview
l
l
l
if high loss evaluation figures A and B are used, energy-efficient
transformers tend to be favoured. A and/or B will be higher if a
value is assigned to energy saving, an allowance is made for taxes
on usage of natural resources. A low interest rate will yield high
A and B values, by valuing future energy savings to a greater
extent
low loss evaluation figures A and B, the result of a high rate of
return required, lead to cheap but relatively inefficient transformers
merely evaluating the purchase price will lead to the cheapest
transformers being chosen, which may be very inefficient. This
policy corresponds to A and B equal to zero, and is regularly
found with turn-key contracting firms or the project departments of utilities that are concerned only with direct project
costs.
The chosen values for A and B are also the key factor in the application of new technologies.
In 1983 the municipal electricity utility of Groningen, a town of
165,000 inhabitants in the north of the Netherlands, decided to
replace 146 of the oldest of its stock of 613 10/0.4kV distribution
transformers by 75 new modern units. The total network load was
about 100MW, and annual consumption 450 million kWh. The
transformers to be replaced ranged in size from 100-400kVA.
They were all installed before 1955 and characterised by large
dimensions, heavy weights, and relatively poor annual efficiencies
of 97.5-98%. A typical transformer replaced under the Groningen
project is shown in Figure 19.
The 75 replacements, ranging between 250-400kVA, have an efficiency of 99%. By optimising the load and no-load losses of the
400kVA units, a balance was made between the highest practical
level of efficiency and acceptable cost. It was estimated that the
project could achieve energy saving of 0.5 cubic metres of natural
gas per Dutch guilder of investment. (1kWh=0.34m3 gas). A
Government grant was awarded to the project, under a scheme to
promote industrial investment.
Figure 19
Distribution transformer, replaced under the Groningen project
34
To achieve the planned goal, it was necessary to increase the rated
load from 0.65 to 0.80 without overloading. The work was carried
out by means of a carefully prepared schedule for exchanging the
transformer units. The project, which was completed in 1984, has
resulted in an annual saving of 1.2 million kWh. The total energy
losses in the HV and LV networks have been reduced by 0.25% to
3.8%.
Definition of Old transformers
The introduction of cold-rolled steel in about 1956 marked a revolution in transformer design. In Groningen, as elsewhere, only
lower loss transformers with cold-rolled iron cores have since been
purchased. From 1956 to 1968, transformer losses were further
improved. Since1968, losses have been standardised, using the
capital value method.
All the old distribution transformers replaced in the Groningen
project were built before 1955. With respect to losses they fell into
three clear categories:
- constructed before 1940
- constructed between 1948 and 1951
- constructed between 1951 and 1955.
In the period 1920 to 1940, transformer losses were gradually
reduced. After the war high quality raw materials were not available, and loss levels rose. Between 1951 and 1955 the quality of
transformers was slightly better than those manufactured in the
late thirties. It was found that transformers installed in 1953-1955
represented the critical point in deciding where replacements were
necessary.
Transformers manufactured before 1950 were difficult to
exchange, and adapt for new loads, because the high risk of damage during transportation. They were constructed for lifting and
had no transport rolls. Spare parts such as isolators and oil packing were not obtainable from the manufacturer. The cost of repair
was expensive. These transformers were therefore taken out of
service and discarded.
Table H
Groningen transformer replacement schedule
OLD
(replaced and converted into scrap)
3-phase 10,000/380V
NEW
(purchased)
3-phase 10,500/400V
Number
Power (kVA)
No-Load (W)*
1
6
2
2
3
20
75
100
125
150
150
150
634
684
798
513
656
798
5
12
13
14
15
200
200
200
200
200
684
969
741
1,208
741
4
7
16
19
1
6
300
300
300
300
400
400
1,368
1,630
1,089
1,094
1,539
1,300
Load losses (W)** Number
1
1,451
2,000
3
2,500
2,314
2,960
2,800
1
2,850
3,900
3,917
3,596
3,922
34
4,700
4,590
5,215
5,200
5,600
35
6,520
(kVA)
33,075
(kW)
142
(kW)
587
Name
N76
Power (kVA)
50
No- Load (W)
150
Load losses (W)
900
N76
100
210
1,415
N76
160
310
2,050
N76
250
450
2,815
C
400
540
3,300
(kVA)
23,010
(kW)
35
(kW)
218
Total
146
l calculated at 400V
74
** calculated at 75 oC
35
Low voltage grid network
Table I
In Groningen the low voltage system is entirely constructed as a
grid network. Depending on the locality, between 4 and 12 transformers feed a completely meshed cable grid. The cable forms
closed loops between the transformer sites and the low voltage
interconnection and switch cabinets along the streets. In this way,
the cables are double fed, and the transformers and cables are in
parallel operation. This has been found to be attractive both in
respect of investment levels and network losses.
Until 1965, transformer housings were constructed for two transformers, for reasons of reliability and maintenance. After a period
of fast growth in prosperity and electricity consumption, it
became less expensive to design and construct these housings for a
single transformer. The average standard unit size was increased
from 200kVA to 400kVA to optimise costs and energy efficiency.
The mean peak loading before conversion was 0.65. Most transformers were running at between 0.4 and 1.1 peak load in respect
of the rated load. The project was undertaken by exchanging
transformers and adapting then to their loads. Overloading was
not practicable, because of risk and a lack of experience in this
area. A summary of the replacement schedule is shown in Table H:
Energy Cost Figures A and B in Dutch Guilders NLG / Watt
Year
Project
Legend (TOC)
No-Load Load losses (B)
(A)
Peak / rated load
1982
1982
1982
1999
Groningen
Groningen
The Netherlands
The Netherlands
1982-Normal
1982-High
1982-Top (N84)
1999 (N95)
13.80
16.40
21.00
10.00
0.60
0.80
1.60
2.05
4.70
1.50
2.80
3.65
4.70
2.65
The transformer types were evaluated at 1982 prices of
NLG13.80/2.80, at peak load of 0.80. Subsequently transformers
F,E,D,B,C and A were offered. Transformer F was the Dutch standard (N76) at that time. Type C was chosen because the better
energy saving performance. Energy saving was of great interest
throughout the Netherlands at this time, as oil prices were growing rapidly. Transformer efficiencies were calculated under the following operational conditions. Efficiency is output kWh divided
by (output+losses) kWh:
Table J
All the three-phase distribution transformers installed Groningen
before 1961 are of rated voltage 380V. To make a comparison with
the new units, the no-load losses from the old data-sheets are multiplied by 1.14 to obtain the losses under 400V operating conditions. The load losses of the old sheets were recalculated at 75oC,
because previously load losses were stated at room temperature.
These recalculations enabled the criteria for government support
to be met.
However, the main gain in cost efficiency was achieved by improving the peak load of the new transformers. This resulted in savings
in both investment and energy. A further gain was obtained by
improving the balance between the transformer power rating and
the network loads. In practice, this meant that for Groningen it
was better to have a lower number of 400kVA units in place of a
greater number of lower powered units.
Process for choosing the Groningen 400kVA transformer
In 1982 Groningen were offered the normal type N76 (type F in
the figures), with losses of 640/4,000W, and a number of special
designs (K,L,I,J,G and H). The utility undertook financial and
economic evaluations, using the well-known method of capitalising the future loss cost over a period of 30 years. Energy cost figures are shown in Table I:
36
Operational Conditions for year based energy efficiency
calculation
Capacity factor (= peak load / rated load)
Mean power factor
Load time
Loss time
No-Load time
0.60 (for project Groningen 0.80)
0.90
3,500 hours / year
2,000 hours / year
8,760 hours / year
A summary of the decision-making process is shown in table K:
Table K
Groningen 1982-1983 Optimising Process Special
Transformer 400kVA
Transformer
Name
Price (1982)
Dutch
Guilder
No-Load
Load Losses Remark
Losses (W) (W)
Euro
(rate 2.20)
First round 1982
K
L
I
J
G
H
10,300
10,300
12,300
12,300
14,600
14,600
4,682
4,682
5,591
5,591
6,636
6,636
720
510
650
490
550
682
4,600
5,800
3,300
4,100
3,000
2,700
13,720
13,100
13,300
13,000
11,850
10,912
6,236
5,955
6,045
5,909
5,386
4,960
545
530
540
665
663
640
3,160
3,560
3,300
3,000
3,250
4,000
5,386
6,045
663
540
3,250
3,300
Dutch
Spec.1976
Final Decision 1983
E
C
11,850
13,300
Case Study 2: Evolution
o f D u t c h Tr a n s f o r m e r
Specification
The 400kVA transformer type described above is an example of
the level of the normalised range 50-100-160-250-400-6301,000-1,600kVA transformers in the Netherlands. In 1984, the
Dutch utilities decided to limit the price of the new transformer
(N84) at 110% of the price of the existing N76 transformer (type
F in the diagrams). The N84 was therefore not adopted. In 1991
a new type (N91) was developed. The low voltage was changed
from 400-420V. The efficiency was improved. Minimum load
losses were set at 3,100W.
The loss evaluation of types N84, N91, and the newly developed
N95, were extensively discussed by the Dutch utilities in 19931994, because the popularity of the N84 type. One factor was the
N91 transformer was not optimised for the universally applied
capacity factor of 0.60. Almost none of the Dutch utilities permit
transformers to be in overload condition. An exceptional loading
of between 100-120% is allowed in some years. An additional
argument is not to load a transformer too highly on environmental grounds.
Second round 1983
A
B
C
D
E
F=N76
10.8
Option
The new standard type N95 is more efficient than the C-C’ losses specified in CENELEC HD428. Figure 20 illustrates the noload and load losses of 21 types of 400kVA distribution transformer evaluated at Groningen in the period 1982-1999.
There is at present a good balance between energy saving and total
owing cost, because the pay-back time of the higher purchase price
Figure 20
21 Transformers 400 kVA Evaluated Project Groningen
1983 - 1999
AMDT
37
is within the calculated period of 30 years. A summary of the way
in which the Dutch specification has evolved is shown in Table L:
10.9
Case Study 3: Large
AMDT in Europe
Table L
Dutch Loss Specification Transformer 400 kVA (10/0.4 kV)
Year
Name
No-Load Losses (W) Load Losses (W)
Voltage (V)
1968
1972
1976
1984
1991
1995
N68
N72
N76
N84
N91
N95
680
680
640
600
680
515
400
400
400
400
420
420
4,000
4,000
4,000
4,000
3,100
3,750
History
In Section 9, amorphous steel was introduced as a low-loss core
material. Since the introduction of amorphous core material in the
early eighties, hundreds of thousands of amorphous metal distribution transformers (AMDTs) have been installed in the US,
Japan, India and China. Application of these units in Europe has,
so far, been very limited.
Figure 21
Transformers 400 kVA Evaluated Project Groningen (NL) 1982-1999
The purchase prices of the transformers shown in Figure 21 give
an overview of the relationship between price and performance of
the 21 400kVA distribution transformers evaluated at Groningen
in the period 1982-1999. These prices are not the actual market
prices. It provides a comparison between groups of lower priced
transformers, with normal no-load losses, and a higher priced
group with reduced no-load losses. The types between these
groups could be also of interest. See for example options C-E and
N84-N91-N95. From a practical point of view, the most economical option has to be decided in co-operation with transformer manufacturers.
38
However, a very large amorphous iron three-phase distribution
transformer has recently been built and installed in the EU at an
engine plant at Waterford in Ireland in 1998. The 1.6MVA transformer is the first to be designed specifically for the European
industrial market. The load losses are 18.2kW, the no-load losses
are as low as 384W, compared to 1,700W for a HD 428 C-C’
transformer.
With no-load losses up to 80% lower than a conventional siliconcore transformer, it should recoup its extra cost in about three
years, says Allied-Signal, which owns the Irish factory. ‘By going
with the amorphous core transformer, we managed to resolve several major issues in one action,’ reports the electrical engineer at
the Waterford plant. ‘The transformer has increased the site’s
power capacity by 40%, while providing dramatically lower losses
than a conventional transformer.’
At an average loading of 70%, the AMDT will use 13.3GWh less
energy a year than a conventional transformer.
With a price premium of £2,500 over a standard transformer, the
AMDT should pay for itself in about three years at current Irish
power prices - and continue to make savings over its 20-30-year
life. The transformer manufacturer reports that although the
1.6MVA AMDT has been bought by part of the AlliedSignal
group (an amorphous iron producer), the deal was done on a commercial basis.
The 20kV/400V transformer, completed by Pauwels
International, is the first AMDT to target European industrial
customers. Previously, Pauwels has focused on utility users with
AMDTs rated at up to 630kVA. The Irish transformer required
new construction techniques, which could now be applied to
build AMDTs up to 2.5MVA.
l
l
energy prices tend to be lowering, yielding lower loss evaluation
values (see Section 10.6)
the presently high $/€ exchange rate is unfavourable for amorphous core material in comparison to conventional core steels, as
it is produced in the US. At present (1999), the cost benefits
acquired by advances in transformer production technology
seem to be more than offset by the cost rise of the amorphous
material.
The future for the amorphous transformer in Europe does not
seem very bright. However, the above factors may in time be
reversed. The first will be addressed in Section 12, the latter two
fall outside the scope of influence of the EU.
Discussion
Some material properties of the amorphous metal have proven to
be a major obstacle for development of European amorphouscored transformers. Amongst others, the transformer core can not
be stacked from sheets but must be wound. In addition, the material properties require a more complicated transformer design. In
the US, with a large number of single-phase wound-core transformers, this did not cause problems. In Europe, however, all conventional three-phase distribution transformers are built with
stacked cores. Production of amorphous cores therefore requires
major changes in the transformer production process. Some
European transformer manufacturers have taken the plunge to
develop a new transformer production process. Three-phase distribution transformers may now be considered proven technology.
However, the success of the amorphous transformer in the US and
Japan has not yet been replicated in Europe. The main drawback
has been, and continues to be, the AMDT’s higher initial cost.
The premium over a conventional transformer was previously
around 40% or more, but this has now fallen to 30-35%, cutting
the time it takes to recover the extra cost.
At present (1999), there seem to be three important issues preventing large-scale adoption of amorphous distribution transformers in Europe:
l
reluctance of transformer users to make the higher initial investment (e.g. 35%) of an energy efficient transformer, even in cases
where, on basis of the chosen values of A and B, the total costs
(purchase price plus cost of energy losses) are significantly lower
(Figure 18). This is caused by the fact that the purchase cost of a
transformer takes only a small share, say one-quarter or onethird, of the total owning cost. The loss costs may, however,
hardly be visible or traceable within a utility, whereas the investment costs are clearly visible at the moment of investment, this
very important aspect is discussed in Section 10.6 and Section
12
39
Total Losses on the European Distribution System
11
11.1
ECONOMIC AND MARKET
A N A LY S I S
Assessment of EnergySaving Potential
Earlier Sections of this report provide some background information on the role of transformers in the transmission and distribution of electricity through the European Union. The European
Community (EUR 15) consumption of electricity for 1996 is
2,253TWh with forecast growth to 2010 to 2,811TWh (1.6%) by
2010.
There is significant energy loss on the total ‘system’, estimated to
be 146TWh (1996) or 6.5%. This is slightly more than the
demand for electrical power in Sweden in 1999.
An assessment has been made to establish the contribution that
distribution transformers make to the current level of energy loss
on the European electrical transmission and distribution system. It
is important to get a good understanding of the major contributors to this system loss.
To develop a simple European model, ETSU has used data available from an UK model developed under another project. The
data that has been introduced in to the model is summarised
below.
Distribution System Losses
Losses (%)
Company Company Company Average
A
B
C
132kV line losses
132kV – 33kV transformer losses
33kV line losses
33kV – 11kV transformer losses
11kV line losses
11kV – 414V transformer losses
LV line loss
Services
Meters
5
9
14
12
13
25
19
1
2
12
10
6
11
15
24
20
3
7
10
6
9
15
20
33
-
Total
100
100
100
Total line losses
Total transformer losses
51
46
53
45
61
39
Source: ETSU
40
Total Losses from Distribution Transformers
Transformers make up a large proportion of the loss. Again taking
the UK as an example Figure 22 provides information on what
level of distribution loss can be attributed to transformers. It
should be noted however, that there may be some loss due to theft
that is not declared. In addition, loss data is produced by various
empirical calculations, and not by metering, making the data
questionable.
By using the average transformer system loss of 43% and applying
it to the European model, it is estimated that transformers make
up 2.8% of total consumption.
Consideration of Figure 22 and the average load tables shown in
Table G (Section 10.5) suggests that distribution transformers are
responsible for losing approximately 2% of total electricity generated in Europe.
Other Factors Which Contribute to the Calculation of Energy
Loss
Using estimated production data for distribution transformers,
Table A, replacement is approximately 150,000 units a year within a total population of 4 million. This gives a replacement rate of
3.75% per year.
Figure 22
Type of Loss
By assuming that the ratio of transmission losses to distribution
losses in Europe is broadly similar to that in the UK model, distribution loss for EUR15 will be 4.8%, equivalent to 116TWh.
(This is based on the total loss in the UK of 24.6TWh. From published national statistics in 1994, this loss is made up of 6.8TWh
from the national transmission system and 17.8TWh from the
local distribution. This data is also identified in Appendix A.)
To establish the ‘base case’ for estimated savings it is unclear what
efficiency can be applied to those transformers currently installed
within the system. Transformer life can be as long as 40 years and
standards have improved over the years. However it is clear that
any future installation is likely to be to a minimum A-A’ standard
in line with European Harmonisation Documents. Therefore, to
assess energy saving potential, A-A’ is used in the model as the
‘base case’. Savings can then be identified from the more ‘energyefficient’ units.
Table M
Improvements From Energy-efficient Transformers
57
43
Base Case % Efficiency Improvement % Over Base Case
Transformer Rating
A-A’
C-C’
A-AMDT
C-AMDT
100kVA
400kVA
1,600kVA
94.71
98.04
98.51
33.0
30.7
29.2
75.6
66.8
58.2
76.7
69.2
62.8
In Table G, Section 10.5, the reduction in losses from using energy-efficient transformers are identified. Table M identifies the
energy savings possible for a single unit over and above the ‘base
case’. This data has been applied to the European model.
The population of transformers at different kVA rating has been
estimated from sales data. The contribution that each makes
toward the total loss within the European model, due only to
transformers, has been estimated in Table N.
Table N
Contribution Towards Total Loss On European Distribution
System
Transformer Rating
Contribution Towards Energy Loss %
100kVA
400kVA
1,600kVA
45
45
10
Total
100
Figure 23 has been produced by installing the above data into a
simple spreadsheet model. It can be seen that the introduction of
energy-efficient transformers on to the distribution system has the
potential of saving up to 22.3TWh/year, worth €1,171 million
(1999 prices).
This is equivalent to a 35% reduction in transformer losses and
represents an 12% saving of all losses on the European electrical
distribution system. The technology to provide these savings is
already available today and therefore does not represent a large
R&D investment. However, there are many barriers toward the
integration of energy-efficient transformers and these are discussed
in the following Sections.
Payback on Investment
Figure 24 provides an indication of the savings possible per unit
and the payback period from fitting energy-efficient transformers,
compared with the ‘base case’ A-A’ standard.
It is clear from Figure 24 that the payback periods for C-C’ type
transformers are very short. With the help of some of the promotional measures identified in Section 13, C-C’ type units could
start to make a valuable contribution to energy saving. The economics for the purchase of this standard of transformer make it
very attractive and an effective awareness campaign would help to
stimulate increased sales.
Figure 24 gives also the internal rate of return for investment in
efficient transformers, which is consistently above 10%, and
sometimes as high as 70% per year. Considering the low risk of
the investment, and market capital rate of returns, this should
make efficient transformers attractive to distribution utilities.
The total possible contribution that C-C’ transformers can make
to saving can be seen from Figure 23 to be 9.7TWh. Savings could
be increased through the adoption of amorphous core transformers.
Figure 23
Savings Potential Through Installing Energy Efficient Transformers. Europe
41
Figure 24
Transformer
Rating
A-A’
C-C’
A-AMDT
C-AMDT
Energy Saving Potential and Payback-Energy-efficient Transformers
100kVA
Efficiency
Savings
400kVA
Unit Cost Payback Efficiency
Savings
1,600kVA
Unit Cost Payback Efficiency
Savings
Unit Cost Payback
(%)
(kWh)
(E)
(E)
(Years)
(%)
(kWh)
(E)
(E)
(Years)
(%)
(kWh)
(E)
(E)
(Years)
94,71
96,46
98,71
98,77
996
2.277
2.310
52
118
120
2.538
2.799
3.456
3.567
5,0
7,7
8,6
98,04
98,64
99,35
99,40
3.143
6.833
7.085
163
355
368
4.307
4.762
6.332
6.753
2,8
5,7
6,6
98,51
98,99
99,38
99,45
9.759
19.447
20.972
507
1.011
1.091
9.434
10.147
14.953
15.469
1,4
5,5
5,5
Premium
IRR
Note 1. Savings in kWh compared to ‘base case’ – losses for type A-A’
Transformer
Rating
100kVA
Efficiency
Savings
(%)
(kWh)
(E)
A-A
C-C’
96,46
A-AMDT 98,71
C-AMDT 98,77
’
996
2.277
2.310
Baseline
52
118
120
400kVA
Premium
IRR
Efficiency
(E)
(25 Years)
(%)
260
917
1.029
20%
12%
11%
98,64
99,35
99,40
Savings
(kWh)
(E)
3.143
6.833
7.085
Baseline
163
355
368
1,600kVA
Premium
IRR
Efficiency
(E)
(25 Years)
(%)
455
2.025
2.446
36%
17%
15%
98,99
99,38
99,45
Savings
(kWh)
(E)
(E)
(25 Years)
9.759
19.447
20.972
Baseline
507
1.011
1.091
713
5.519
6.035
71
18
18
Source: ETSU-ECI
However the long payback period makes this standard of transformer difficult to justify at the current first cost. Clearly manufacturing costs need to be reduced to make these very high efficiency transformers attractive to the market place. If reduced to
provide a reasonable payback period then the potential savings
could increase by a further 12.6TWh.
11.2
Contribution to Energy
Efficiency and Global
Wa r m i n g G o a l s
Emissions data suggested by the International Institute for Energy
Conservation (IIEC) for Europe is 0.4kg CO2/kWh. Electrical
energy savings of 22.3TWh will provide emissions savings of 8.9
million tonnes of CO2. The European Union is committed to a
reduction of 8 per cent on 1990 levels (266 million tonnes) by
2008-2012.
From Figure 23, potential savings from energy-efficient distribution transformers could reach 7.3TWh by 2010. This is equivalent
to 2.9 million tonnes of CO2, or approximately 1% of the total
European commitment.
To put the overall potential saving of 22.3TWh into perspective,
this is equivalent to the annual energy use of over 5.1 million
homes or the electricity produced by three of the largest coal burning power stations in Europe.
Distribution transformers have not yet been the focus of energy
saving measures and could, if developed, contribute significantly
to European targets for reduction.
42
11.3
Characterisation of the
Utility Market
Utility markets account for approximately half the installed transformer capacity in Europe. Throughout Europe, the purchasing of
transformers seems to be reasonably standardised, with the utilities
having open tender practices in line with European Purchasing
Directives. In almost all cases, losses (iron and copper) are factored
into the specification, with minimum standards in line with internationally accepted standards. However, the specifications in each
country differ in relation to the load characteristics (rural/urban),
the network being served or the requirements for low noise emission (e.g. in German urban areas).
Selection of the supplier is usually made on the “first cost” principle, i.e. the supplier providing the lowest cost offer that meets the
specification wins the business. Few exceptions are made where a
supplier offers a more efficient transformer (i.e. lower life-time
cost), but at a slightly higher price. The one exception to this is the
Nordic countries, where the efficiency of the transformer in specific applications is given a high priority, with the specification
giving the efficiency of the transformer a very high rating.
In almost all EU countries, first cost is the driving principle.
Where the utility is state owned, limitations on capital expenditure are paramount to assist in meeting the ever tightening budgets brought about by the strict monetary requirements associated
with the €. Where the utility is in private ownership, the availability of capital for efficient transformer purchases always competes against more attractive (i.e. quicker payback) investments
that can be made by the utility in other areas.
In both cases, the lack of interest in efficient transformers is compounded by the electricity suppliers’ inability to pass the cost of
any losses on to the consumer, hence removing any incentive to
overall system, and consequentially transformer, performance.
Example: A utility buys transformers under ‘framework’ contracts that
are competitively tendered approximately every two years. They specify the number and type of transformers that are likely to be required
by the utility over the following two year period along with the technical specification. This technical specification includes copper and
iron losses that are expressed using a capitalisation formula (i.e. a
comparison between efficiency gains and the depreciation of capital).
Contracts are always awarded to the lowest tender that meets the specification. Although partnerships are being established between utilities
and transformer manufacturers, these are developed within these
‘framework’ contracts subsequent to the initial tendering exercise.
These partnerships facilitate increased dialogue between the two parties and allow refinement of the original specification, a process that
sometimes leads to increased energy efficiency.
However, a counter to this has been the move towards the installation
of a limited range of transformers to minimise the stock of spare parts
and rationalise service requirements. This means that there are few
transformer sizes to select from and consequential matching to load
characteristics is likely to decrease.
The cost of distribution losses is passed from the utility to their customers. In the UK the acceptable distribution losses are calculated
according a Distribution Price Control Formula, issued by the electricity regulator. The Distribution Price Control Formula includes
factors that relate to energy efficiency. At present, there is no financial
incentive for utilities to improve their efficiency beyond that specified
by this formula.
Since privatisation, it appears that utilities are under greater pressure
to reduce capital expenditure. This tends to reinforce the ‘lowest first
cost’ policy that is prevalent. Even when the marginal capital is available to meet the higher cost of a more efficient transformer, there must
also be a straight payback of under five years.
The environmental policies of some utilities are driving them towards
increased energy efficiency. East Midlands Electricity, UK, has an initiative in this area, although this is the exception rather than the normal situation.
11.4
Characterisation of the
Non-Utility Market
l
large energy users (e.g. supermarkets, hospitals)
l
smaller energy users.
The major energy users are aware of the issues and tend to make
rational purchasing decisions. These companies retain sufficient
expertise to be able to derive their own transformer specifications.
Although energy efficiency and life-time cost of ownership will
form an important part of these specification, other factors are also
considered, e.g. the competitive cost of capital, life-time maintenance costs, potential growth capacity, etc. The overall result will
be the purchase of the most cost-effective transformer to the business. This will not always be the most efficient transformer.
This group will only be influenced to buy transformers that are
more efficient by external factors that change the business case.
For example, rebate schemes.
Increasingly, large energy users are becoming more aware of the
concept of transformer life time cost and its influence on operating profits. In particular, supermarkets have a high 24-hour base
load, which encourages the selection of more efficient units.
However, these customers rarely have the required in-house skill to
specify suitable transformers effectively, often relying on a turnkey package from a contractor to an agreed overall specification.
This group would therefore benefit from increased information
that would allow them to make better initial specifications to the
contractors. For example, labelling schemes or specification tool
kits.
Smaller energy users tend to use contractors on a turn-key basis
to provide premises that meet the requirements of their particular
business. Specification will concentrate on meeting the business
requirements, e.g. floor space available for the installation, adequate provision of utilities, infrastructure etc. The overall price of
the package, perceived competence of the contractor and service
levels are the key issues with the type of transformer installed
being of little consequence. These customers do not have sufficient knowledge to be able to specify transformers in detail, and
will be unaware of the business benefits of reduced life time costs.
As a corollary to this, contractors (including utility company contracting departments) will specify whatever the customer asks for.
However, in most cases, no detailed specification will be received,
because of lack of knowledge, and the contractor will simply specify the cheapest transformer available. Consequently, the provision
of information on the advantages of specifying more efficient
transformers and specification tool kits will allow these customers
to make more informed choices.
The non-utility market consists of three distinct groupings, each
with different characteristics and priorities:
l
major energy users (e.g. large industrial plants (chemicals, oil, gas
and steel), traction companies etc)
43
11.5
National/International
Policies and Initiatives
Across Europe, transformers are manufactured to individual
national standards. These are broadly compatible with the
European specification, Harmonisation Document 428. This in
turn is based on the International Electro-technical Commission
World Standard IEC60076. Through this harmonisation of standards, a mechanism is in place for communicating and enforcing
more rigorous requirements for energy efficiency. However at
present, compliance with HD428 is purely voluntary. For this
mechanism to be effective in increasing the overall level of transformer efficiency across Europe, the specification would have to be
formally adopted by CENELEC as a standard and compliance (via
the provisions of any national standard) would have to be compulsory.
Despite this apparent standardisation, national standards can vary
significantly. Each country has its own specific issues related to
distribution system strength, capacity considerations, etc. Other
differences result from variations in particular circumstances within countries. In France, the majority of generation is by nuclear
power station. The marginal cost of generation is therefore very
low and the environmental impact is negligible because emissions
are minimal. French utilities are therefore under no pressure to
purchase energy-efficient transformers and lowest first cost transformers are specified as standard. In Germany, where many transformers are based in the centre of residential areas, there are very
stringent noise regulations. There are also often size restrictions.
Harmonising the East/West supply systems and standardising the
equipment are also causing problems.
£1,110 per kW. The cost benefits for the use of amorphous core transformers compared to low loss transformers are as follows:
The example chosen was for a 630kVA, ground mounted transformer
which was said to have a loss load factor of 0.21. For a new transformer the utilisation for the transformer was suggested to be 70%
(company average 57%) therefore the copper loss factor of 0.72 =0.49.
Table O
Example of Utility Assessment of Amorphous Core
Transformers
No-load loss
Low -loss (C-C’) 824
Amorphous
230
Loss difference
44
5,320
8,150
824 + (0.21 x 0.49 x 5,320) = 1,371
230 + (0.21 x 0.49 x 8,150) = 1,069
302 watts
The following comments therefore can be made:
l
l
l
l
Example: Discussions with a utility company in the UK suggest that
the level of investment in these very low loss transformers cannot be
supported because of the low incentives provided by the UK
Government electricity supply regulator (OFFER). The company
explained that under the current distribution supply formula (which
is said by OFFER to provide incentive to reduce system loss) the lifetime value of continuous losses to the company is approximately
Total Watts Continuous equivalent
Using 302 watts the lifetime value of the savings from using amorphous core transformers compared to C-C’ standard transformers is
therefore 0.302 x £1,110 = £335 (€532).
The situation is further confused with the regulators in each country setting varying goals for the utility companies. In almost all
cases, continuity of supply is the key factor. However, variations
on other priorities are profuse and cover cost of electricity to the
customer, voltage tolerances, safety, noise, overall environmental
impact of the system, etc.
There appears to be little overall attempt to encourage the uptake
of energy-efficient transformers by any national government or
regulator. In the UK, the regulator includes an efficiency incentive
in the pricing formula for supply, but this is marginal compared
with other considerations. The following example describes how
one electricity supply company assessed the value of fitting amorphous core transformers into its network.
Load loss
the company has assessed the benefits of amorphous core transformers
the company has no incentive to use amorphous core transformers from the formula used by UK government electricity regulator
these savings have to be weighed against the price premium of
the amorphous core transformer. Increasing the load loss by 50%
reduced the cost of the amorphous unit, with negative effect on
the loss-savings. Since generally high capitalisation of no-load
losses will go together with considerable evaluation of load losses, amorphous transformers will tend to have also reduced load
losses (C, not B). This example should therefore not be generalised.
the evaluation factor used for no-load loss of £1,110/kW is very
low, which means a high discount factor is being used for future
energy savings. Factors being reported in Germany and
Switzerland prove to be at least 5 times higher, making a much
stronger case for the investment in amorphous iron transformers.
11.6
Potential Mechanisms for
Change
There appears to be several potential mechanisms that could
change the buying behaviour of transformer purchasers. Each
potential mechanism is briefly examined below.
No Change Scenario
It is possible that no action at the EU level will be required, as
national governments begin to realise the implications of international commitments on CO2 and act at national level to improve
the efficiency of transformers purchased. However, realistically
this is unlikely to occur, due to the long term nature of savings
from transformers and the complex nature of specification and the
purchasing cycle. National governments are much more likely to
concentrate on simpler targets, e.g. improvements in the performance of domestic appliances, etc.
Enforceable Minimum Standards
Discussions have already taken place between EC DGXVII,
COTREL and EURELECTRIC to discuss the possibility of voluntary agreements or a European Directive to initiate reduced
losses from distribution transformers through a minimum standard.
A minimum standard of sorts already exists in the Harmonisation
Document 428. This standard could be made more prescriptive
and specify improved minimum losses for all types of transformer.
Such a standard could then be made mandatory through an EU
Directive.
Unfortunately, such an approach is likely to be strongly resisted at
national level, due to the specific needs of each national distribution system and local political considerations. Further, the imposition of overall standards for efficiency higher than those already
in force would cause problems, due to the variations in demand
profiles from the various end use applications, e.g. rural/urban
uses.
An alternative approach would be for the EU to place obligatory
requirements on national regulators to include efficiency as one of
their key elements when forming regulatory policy. It is unlikely
that such an approach would work as, without specific guidelines,
regulators are likely to simply pay lip-service to the issue. Further,
the preparation of specific guidelines may impose on the principles of subsidiarity and would be difficult to draft in any case.
Financial Incentives
The major cause of purchases of “less efficient” transformers is the
requirement of many purchasers for the lowest first cost. If some
financial mechanism could be introduced, that would make the
purchase of efficient transformers more attractive, it is likely to
have a major impact on the marketplace. Such financial incentives
appear to fall into three categories:
l
rebates
l
tax incentives
l
increasing responsibility for cost of losses.
If a mechanism was in place to define efficient transformers (e.g.
transformer labels described below), it would be possible to offer
rebates on purchases of higher efficiency units, hence lowering the
purchase cost differential between the more and less efficient units.
Unfortunately, the rebate would be extremely expensive, given the
number of transformers purchased across the EU annually. Further,
such a scheme could only be sustained for a short period and following withdrawal, the marketplace would almost certainly revert to
the original situation with no lasting market transformation.
Changing national taxation systems to make the capitalisation of
transformers more attractive, e.g. shortening the allowable assets
write- off period, is likely to have a major impact on the purchases made by utility buyers (other buyers are unlikely to purchase
enough transformers for this to have any significant impact relative to other considerations). However, this would have to be
made a national issue, as the EU is specifically excluded from
direct interference with national taxation issues. As such, it is
unlikely that individual member states would adopt such a policy,
due to the complex requirements in drafting the required legislation and policing claims under the system.
Increasing responsibility for cost of losses. Obviously, financial
costs associated with losses from transformers owned by end users
are already borne by the end user. However, losses accruing from
transformers owned by utilities are currently almost universally
transferred to the end user as part of the cost of electricity.
This situation is difficult to change where the utility is state
owned. However, where the utility is privatised, there is an opportunity to use this “cost of losses” as an incentive to improve the
system. At present, if the utility improves the efficiency of the system, then the amount of “cost of losses” is adjusted accordingly,
hence the utility makes little improvement in profit.
A realignment of the pricing structure , to allow a fixed amount of
“cost for losses” to be passed to the consumer, with the savings
from any reduction in losses split between the consumer and the
utility (say on a 50:50 basis), would improve the business case for
examining lifetime costing. Such a system would allow investments in efficient transformers to be more competitive against
other demands on the capital budgets of the utilities. However,
this is again a national issue, with the individual pricing regimes
coming under the control of the national regulators.
Labelling system
Lack of knowledge is a significant barrier to the purchase of energy-efficient transformers. This is particularly true of large energy
users, where there is a desire to use efficient transformers, but not
the technical ability to specify them effectively.
A labelling system that indicated the efficiency of transformers
under specific load profiles would assist this group considerably,
and is likely to cause a significant movement in the market. While
there are obvious difficulties in creating a labelling system for
transformers, given the variability of losses depending upon
45
application, it is possible to develop a labelling system that provides the user with appropriate guidance in most instances. Such
a system is currently under development for electric motors, a
product with similar difficulties in efficiency definition.
The introduction of a labelling system also provides a framework
from which future minimum standards may be derived (if deemed
appropriate). The framework could also be used for financial
incentives, should they be required at a national level.
Buyer Clubs
If a number of purchasers combine, they will receive direct benefits in bulk purchasing, hence receiving lower prices from manufacturers. This in itself would not necessarily induce the purchase
of more efficient transformers, but it would increase the combined
knowledge of the purchasing group, and is likely to result in the
more effective specification. Such groups are however unlikely to
form, as buyers remain unaware of the potential.
A possible method of inducing the formation of such groups
would be the funding of some demonstration activity by the EU,
e.g. the funding of the establishment and promotion of a buying
group by the SAVE programme.
Specification tool kit
Smaller users are large in number, but individually buy small
numbers of transformers. However, collectively they account for a
significant part of the market. Education of these users, through
promotional campaigns to purchase efficient transformers, would
not be cost effective. However, it would be possible to develop a
simple Specification Tool Kit (or buyer’s guide) that would assist
them in asking the right questions of the turnkey contractors.
Such a guide could include information on ensuring that the
transformer is correctly sized and has been specified to likely load
characteristics. Further, if combined with a labelling scheme, recommendations could be made on the type of transformer to be
specified to the contractor. If manufactures/contractors could be
persuaded to distribute this guide to potential buyers, costs would
remain at a manageable level, and the user would have at least the
basic knowledge to make a rational purchasing decision.
11.7
International Perspective
US and Canada
The US DOE is in the process of implementing a test standard for
distribution transformers, following a report from Oak Ridge that
supports a DOE determination that minimum performance
requirements for distribution transformers can be justified.
Following on from the test standard, formal analysis and legisla-
46
tion will be implemented. The standard is not expected to be
issued until after 2000.
The transformer industry opposes the prospect of a mandatory
minimum and would prefer a voluntary standard (NEMA TP1).
The Oak Ridge study concluded that the TP1 levels of energy efficiency do not meet the DOE criteria. A US ‘Energy Star’ programme which provides energy efficiency labelling, currently promotes the TP1 levels of energy efficiency.
Canada is in the midst of consultation to implement mandatory
levels equivalent to TP1, with a view to revising them once the US
legislation has been implemented.
China
Shanghai Zhixin Electrical Industry Co Ltd. have been developing
a relationship with GE under a licence agreement to produce
amorphous core transformers since June 1997. The contract was
signed in February 1998. Currently they are importing most of
the components and assembling them in Shanghai. A core winding machine has been purchased, to be installed in mid-July 1999.
Average transformer size is 400kVA. Shanghai Urban Power
Distribution Bureau have installed 116 sets of amorphous core
transformers, saved 770,000kWh power per year, worth about
27,900,000 RMB (€3.2 million).
Information from the company identifies the no load losses as
20% of those in a conventional transformer. The incremental cost
is 30% over that of a conventional transformer. They have a target
to reduce this to 20% when more components are manufactured
in China. Currently the estimated payback is 2.5 years.
Transformer sales in China are estimated to be 350,000 per year.
The company has a production target of 2,000/year, which will
rise to 3,000/year, and can see no technical barriers to more transformers being manufactured in China if the market can be stimulated. The main barrier to uptake is the increased cost over the
conventional product.
12
12.1
A N A LY S I S , R E C O M M E N D AT I O N S ,
S T R AT E G Y, A C T I O N P L A N
Analysis
Europe has considerable potential to offer world-wide in transformer technology and experience. However, national governments and utilities lag behind the US in terms of programmes and
initiatives to encourage energy efficiency.
No European country has yet developed targets for the global
warming savings potential which could result from distribution
transformer programmes, nor has a formal estimate been made for
the EC or Europe as a whole.
There are no initiatives in Europe comparable to the US
DOE/EPA programmes on utility commitments, information and
software dissemination. This is despite the fact that most of the
major European countries have a very poor position on energy
self-sufficiency.
Europe has an urgent need to develop a strategy on existing and
future global warming actions. As this happens, the potential for
reducing losses from distribution transformers could be promoted, to ensure that they are incorporated as a component of the
plan.
There is already considerable R&D and promotional effort within Europe aimed at reducing losses in small transformers, e.g. for
domestic and office equipment, and some IEA/OECD work has
been undertaken. To date this has mostly focused on the use of
more efficient core materials and campaigns to urge consumers to
switch off appliances when not in use.
It is of course relatively easy to obtain industry compacts on small
components and to exhort domestic consumers, compared with
influencing or coercing utilities and professional buyers in connection with major items of capital plant. The work on small
transformers could nevertheless assist in focusing attention on the
very significant target of distribution transformers.
It is apparent that both the utilities and private sector purchasers
are difficult to influence. The transformer market is extremely
competitive, and efforts to improve energy efficiency in the past
have had limited success.
The utility sector involves a limited number of professional buyers, already reasonably aware of the arguments for energy efficiency, and with well-established techniques for evaluating transformer performance. They are therefore likely to be receptive to
rational arguments, provided that benefits are clearly demonstrated. We believe however that rapid change is unlikely without support, the use of economic instruments, or legislation.
Devising an effective approach to the private sector, which is
growing steadily in terms of new investment, is very challenging.
There are a limited number of larger distribution transformer buyers to target directly, but even these are quite dispersed. There are
also consulting engineering and energy efficiency professional and
trade associations to address, as well as energy clubs at European
and national level. Other than the setting of minimum product
standards, any approach to the bulk of the market, would require
a ‘macro’ approach, involving the use of media, labelling, buying
clubs etc.
The impact of the current European transformer standard,
HD428, is very complex. Obviously product standards, in the
electrical engineering sector as elsewhere, are directed at reducing
barriers to trade by standardising minimum operating performance, dimensions, capacity and engineering practice, as well as setting high levels for health, safety, and reliability. Other CENELEC
product standards, for example TC 20(SEC)456e, covering building wires, provide data on energy efficiency. As far as we have been
able to ascertain, however, there is no treatment of energy efficiency similar to that of HD428 in other product standards.
Although HD428 sets a choice of specific energy efficiency levels,
ranging from B-A’ to C-C’ levels, the option to use a capitalisation
formula means that no effective minimum exists at present.
12.2
Recommendations
We consider that distribution transformers represent a worthwhile
area for R&D, demonstration and promotional effort within the
EU, with distribution transformers recognised as an important
focus for energy efficiency initiatives. To optimise energy saving,
an ideal way forward would be to raise standards EU-wide to the
best current practice in Europe, from A-A’ to C-C’ using conventional materials and technology. Subsequently this standard could
be raised to the cost-benefit balancing point, preferably with a formula that recognises the total cost of ownership.
Our recommendations are as follows:
l
l
l
as EU and national strategies on energy efficiency, global warming, and environmental impact are developed, the potential for
reducing losses from distribution transformers should be considered as a component
a strategy should be developed to set and achieve goals for reducing losses from distribution transformers, or possibly from all
power systems transformers in the EU. The strategy needs to be
carefully co-ordinated and be both technically and commercially sound
the main elements of an action plan to achieve the strategy
should be identified and developed.
47
12.3
Strategy Development
The steps in preparing a strategy to set and achieve goals for reducing losses from distribution transformers in the EU will have the
following elements:
l
l
identify and convene a steering group, ideally representative of
all levels in the supply chain, to manage the initiative
agree or revise the estimates for energy saving and global warming which have been made in this project. Reliable data is difficult to obtain, and there is a need to recognise that electricity distribution networks are extremely complex. It is therefore possible to oversimplify the potential for operational efficiencies and
cost savings, for example by simply considering the no-load and
load losses in single transformers
l
l
l
l
l
undertake any further work necessary to confirm the scope for
energy savings. In particular there is a need for more detailed
information on distribution transformer populations, ages, loading and efficiency
seek the agreements necessary to prepare a formal strategy. The
aim would be to carry all representative parties, including EU
and national governments, utilities, transformer manufacturers,
raw material suppliers
agree set targets for the strategy, including quantified savings levels, time-scales, monitoring
l
l
l
l
l
Strategy Components
l
The main components of an appropriate strategy are likely to be:
l
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l
goal-setting. In particular the current position and future position of the European transformer standard, HD428, should be
examined in detail. However there is little point in setting low
standards for energy efficiency
legislation, probably only appropriate if it is agreed that distribution transformers should form a component of EU global
warming strategies. It should be subject to a formal Compliance
Cost Assessment (CCA)
incentives, investment grants. If high standards are set, the initial
costs to the utility sector will be very substantial. There could be
adverse reactions, for example the postponement of distribution
transformer investment programmes
48
Action Plan
The mechanisms and activities which could be included as components of the action plan to achieve the agreed strategy, are:
identify and agree the action plan components necessary to
achieve the strategy.
12.4
the impact of regulation e.g. how a Framework Directive is
enforced at national level, whether regulation is appropriate.
12.5
l
l
monitoring of the implementation of standards and the benefits
in terms of energy saving. Whether a new standard is recognised
in the non-utility sector through national building codes etc
l
l
utility compacts on transformer standards, replacement programmes etc
regulation, for example the introduction of mandatory minimum distribution transformer efficiency standards
initiatives to involve all representative parties, such as conferences, seminars, workshops
demonstration, software, pay-back and lifetime cost assessments.
A specific example would be to undertake more pilot installation
programmes (such as the Groningen project described in Section
10.7) to generate realistic operational and cost data for energyefficient distribution transformers
benchmarking to understand the differences between the loss
evaluation factors used in various countries and categories of
non-utility customer
labelling, publicity, promotion, dissemination, investment grants
etc
support for new technical developments, for example new steel
core materials, both at the R&D stage and as they reach commercialisation
examination of the cost of new materials and manufacturing
technology, to identify mechanisms by which it could be reduced
and establish the longer-term pattern, advantages of scale etc
replacement of older transformers in Europe through planned
investment programmes, in which the best technology is used
investigation of whether there is scope to use PCB elimination
plans to promote energy-efficient practices
l
development of an effective approach to the non-utility sector
l
collaboration with partners and facilitators world-wide
l
encouraging utilities and private sector customers to employ
demand side management (DSM) and other network management tools to their installations. Highlighting the contribution
which energy-efficient distribution transformers can make to
optimising utility operations or reducing maximum demand tariffs.
13
13.1
A C T I O N S , PA R T N E R S
Examples of Proposals,
Actions and Impact
Given the possible alternative market transformation measures
available, and the costs/barriers associated with each, it is recommended that the EU consider the following specific actions:
Create a Mandatory Labelling System for Transformers:
Such a system would ensure that end users with minimal knowledge of transformers can make rational purchasing decisions.
Further, it produces a framework for the future introduction of
financial incentives for the purchase of more efficient transformers and/or the introduction of minimum standards should these
be deemed appropriate.
It is estimated that such a labelling scheme would cost approximately
€2-300,000 in development costs. It has the potential to save
850GWh/year, valued at €45 million (340,000 tonnes of CO2) per
annum within 20 years.
Production of a Specification Tool Kit for Buyers:
This tool kit would provide basic guidance on the issues relating
to the purchase of transformers, and would allow the purchaser to
better specify their transformer needs to the manufacturer/contractor. Such a tool kit should be developed in conjunction with
the manufacturer and contractor trade bodies, to ensure their
commitment to the project and increase the likelihood of dissemination to the end user at the point of specification. Further, the
act of seeking co-operation from both the manufacturer and contractor trade bodies will aid in understanding between both bodies and may lead to concerted actions by the two groups in the
future.
It is estimated that the development of a Specification Tool Kit tailored
to national situations would cost approximately €60-80,000 to develop, and €60,000 to print and distribute. The potential savings are of
8.5GWh, worth €1.8 million (3,400 tonnes of CO2) per annum
within 20 years. The Specification Tool kit has the added benefit that
the package could be developed and distribution begun very quickly.
Funding of a Demonstration Buyer Group:
While the principles of buyer groups are well understood throughout Europe, group purchasing of transformers has not yet
occurred. The establishment and consequential promotion of such
a buyer group would demonstrate the practicality of groups in this
area, particularly to large users.
49
It is estimated that the cost of establishing such a group would be
€40,000, and the promotion across Europe to targeted large users
would be a further €40,000. This should result in savings of
340GWh/year worth €18 million (136,000 tonnes of CO2) per
annum within 20 years.
gy-efficient small transformers. It may be possible to persuade
IEA to extend initiatives to distribution transformers
l
The Active Promotion by the EU of Financial Incentives at the
National Level:
l
While it is recognised that the EU cannot have direct control over
financial incentives at the national level, every effort should be
made to encourage national governments to offer financial incentives for the purchase of efficient transformers. This is particularly true of countries with privatised utilities, where the sharing of
any improvement in the “cost of losses” could be used as an incentive the utilities to reduce losses, while simultaneously reducing
the cost to the consumer.
l
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l
13.2
Approach to the Non-utility Sector
l
The main problems with the non-utility sector are the fragmentation of the market and the difficulty of identifying decision-makers.
l
There is a need to target larger distribution transformer buyers
such as railways, metros and rapid transit, chemicals and steelworks. The industry energy efficiency trade associations and energy clubs at European and national level can be addressed.
l
Smaller non-utility customers should be regarded mainly as an
opportunity to demonstrate good practice, because of their small
individual size and the effort required to convert them.
13.3
Partners for
Collaboration, Facilitators
Potential partners we have identified for collaboration in R&D,
demonstration and promotional initiatives on energy-efficient
power systems transformers in Europe include the following:
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l
national European government energy departments and energy
agencies, where the main goals would be demonstrating the
energy saving potential for distribution transformers, and
encouraging the implementation of national targets and initiatives
the International Energy Agency (IEA), an OECD agency which
operates mainly through a series of inter-country agreements
(chapters) supporting the development of specific energy technologies. The IEA appears to be showing some interest in ener-
50
l
the European Organisations for the Promotion of Energy
Technology (OPET) network, funded by the EC. The OPET
network has recently been relaunched, and is particularly useful
for collaborative efforts in Central Europe
utility trade associations at European (Eurelectric) and national
level, with the objective of securing a Europe-wide utility platform for energy efficiency issues
industry energy efficiency trade associations and energy clubs at
European and national level
European and national transformer trade associations, to promote energy efficiency and good practice
distribution transformer manufacturers. At this stage there is the
need to identify and start to work with champions for energy
efficiency in transformer manufacturers and utilities
private sector buyers of distribution transformers with an interest in energy efficiency
international collaboration, with countries able to both share
experience and to learn. The European transformer manufacturers are manufacturing world-wide, and are also major exporters,
particularly interested in business development in China, South
East Asia, India and the Middle East
transfer of US experience and concepts. The US Environment
Protection Agency (EPA) has developed a software programme
on transformer sizing for energy efficiency, which has been
adapted for European practice in one country, and is reported to
have received considerable interest
other countries working on similar issues. These include Canada,
India and China.
13.4
Sources of Funding
There has been very little funded work undertaken in Europe on
energy efficiency in distribution transformers, or related areas,
undertaken in Europe. Sources of financial support for R&D,
promotion and dissemination, in addition to the partners
described in Section 13.3, include:
l
the 5th Framework ENERGIE Programme, the successor of
Joule/Thermie within the EC Science, Research and
Development Directorate, which undertakes research and development projects in the energy sector
l l
l
l
l
the EC PHARE and TACIS programmes, working together
with the European Bank for Reconstruction and Development
(EBRD), to assist in the restructuring of the economies of
Central and Eastern Europe
technology transfer of US experience and software. Creation of
software and financial models applicable to the European market
trade associations, particularly the transformer trade associations
at national and European level (COTREL). The secretary of the
German trade association has agreed to inform his members
about EC interest in energy efficiency initiatives in power systems transformers
the utilities’ trade associations, including UNIPEDE and
CIRED, the technical association for electricity distribution.
51
Appendix A
Power Systems Losses - European Union, 1980-2010 (TWh)
Country
Actual
Year
Austria
Belgium
Germany
Denmark
Spain
Finland
France
Greece
Ireland
Italy
Luxembourg
Netherlands
Portugal
Sweden
UK
EUR 15
Demand
Losses
% of Demand
Demand
Losses
% of Demand
Demand
Losses
% of Demand
Demand
Losses
% of Demand
Demand
Losses
% of Demand
Demand
Losses
% of Demand
Demand
Losses
% of Demand
Demand
Losses
% of Demand
Demand
Losses
% of Demand
Demand
Losses
% of Demand
Demand
Losses
% of Demand
Demand
Losses
% of Demand
Demand
Losses
% of Demand
Demand
Losses
% of Demand
Demand
Losses
% of Demand
Demand
Losses
% of Demand
Forecast
Implied Average Annual Increase (%)
1980
1990
1995
1996
2000
2005
2010
19801990
19901995
19951996
19962000
20002005
20052010
19942010
36,30
2,60
7,16
47,70
2,70
5,66
351,00
14,00
3,99
23,90
2,10
8,79
102,00
9,90
9,71
39,90
2,30
5,76
248,70
17,20
6,92
21,90
1,60
7,31
9,50
1,10
11,58
179,50
15,90
8,86
3,70
0,10
2,70
59,70
2,50
4,19
15,30
1,80
11,76
94,10
8,20
8,71
264,80
21,60
8,16
1.498,00
103,60
6,92
46,90
3,00
6,40
62,60
3,40
5,43
415,00
17,00
4,10
30,80
2,20
7,14
145,40
13,70
9,42
62,30
2,90
4,65
349,50
26,60
7,61
32,50
2,90
8,92
13,00
1,20
9,23
235,10
16,40
6,98
4,40
0,10
2,27
78,00
3,10
3,97
25,10
3,20
12,75
139,90
9,30
6,65
309,40
24,90
8,05
1.949,90
129,90
6,66
51,00
3,30
6,47
73,50
3,70
5,03
493,00
21,00
4,26
33,70
2,20
6,53
164,00
13,80
8,41
69,00
3,00
4,35
397,30
29,40
7,40
38,80
3,20
8,25
16,40
1,50
9,15
261,00
17,60
6,74
5,10
0,10
1,96
89,60
3,50
3,91
29,30
3,30
11,26
142,40
10,10
7,09
330,70
28,50
8,62
2.194,80
144,20
6,57
52,30
3,30
6,31
75,30
3,80
5,05
500,00
20,00
4,00
34,80
2,40
6,90
169,00
14,10
8,34
70,10
3,00
4,28
415,20
31,00
7,47
40,50
3,30
8,15
17,60
1,70
9,66
262,90
16,90
6,43
5,10
0,10
1,96
93,50
3,60
3,85
30,90
3,50
11,33
142,70
10,10
7,08
343,90
29,60
8,61
2.253,80
146,40
6,50
56,60
3,40
6,01
81,20
4,10
5,05
512,00
21,00
4,10
35,80
2,30
6,42
188,20
17,50
9,30
78,00
3,10
3,97
444,00
33,00
7,43
47,20
3,90
8,26
21,70
2,00
9,22
296,00
20,70
6,99
5,60
0,10
1,79
101,20
3,50
3,46
36,50
4,00
10,96
145,50
7,60
5,22
360,80
31,50
8,73
2.410,30
157,70
6,54
62,10
3,60
5,80
89,00
4,50
5,06
531,00
21,00
3,95
36,80
2,40
6,52
218,20
19,90
9,12
85,40
3,30
3,86
479,00
36,00
7,52
54,20
4,60
8,49
26,80
2,50
9,33
330,00
23,10
7,00
5,90
0,10
1,69
110,90
3,80
3,43
42,80
4,70
10,98
147,80
7,60
5,14
393,00
34,30
8,73
2.612,90
171,40
6,56
67,30
3,80
5,65
94,50
4,80
5,08
547,00
21,00
3,84
37,70
2,50
6,63
246,70
23,20
9,40
92,10
3,40
3,69
516,00
38,00
7,36
63,40
5,40
8,52
32,10
3,00
9,35
360,00
25,20
7,00
6,30
0,10
1,59
121,50
4,10
3,37
49,00
5,10
10,41
152,30
7,70
5,06
425,70
36,20
8,50
2.811,60
183,50
6,53
2,60
1,44
-1,12
2,76
2,33
-0,41
1,69
1,96
0,27
2,57
0,47
-2,05
3,61
3,30
-0,30
4,56
2,35
-2,12
3,46
4,46
0,96
4,03
6,13
2,02
3,19
0,87
-2,24
2,74
0,31
-2,36
1,75
0,00
-1,72
2,71
2,17
-0,52
5,07
5,92
0,81
4,05
1,27
-2,67
1,57
1,43
-0,13
2,67
2,29
-0,37
1,69
1,92
0,23
3,26
1,71
-1,51
3,50
4,32
0,78
1,82
0,00
-1,78
2,44
0,15
-2,24
2,06
0,68
-1,36
2,60
2,02
-0,56
3,61
1,99
-1,56
4,76
4,56
-0,18
2,11
1,42
-0,68
3,00
0,00
-2,91
2,81
2,46
-0,35
3,14
0,62
-2,45
0,35
1,66
1,30
1,34
2,74
1,38
2,39
2,11
-0,28
2,55
0,00
-2,49
2,45
2,70
0,25
1,42
-4,76
-6,10
3,26
9,09
5,64
3,05
2,17
-0,85
1,59
0,00
-1,57
4,51
5,44
0,90
4,38
3,12
-1,20
7,32
13,33
5,61
0,73
-3,98
-4,67
0,00
0,00
0,00
4,35
2,86
-1,43
5,46
6,06
0,57
0,21
0,00
-0,21
3,99
3,86
-0,13
2,69
1,53
-1,13
1,99
0,75
-1,22
1,90
1,92
0,01
0,59
1,23
0,63
0,71
-1,06
-1,76
2,73
5,55
2,75
2,71
0,82
-1,83
1,69
1,58
-0,11
3,90
4,26
0,35
5,37
4,15
-1,17
3,01
5,20
2,13
2,37
0,00
-2,31
2,00
-0,70
-2,65
4,25
3,39
-0,82
0,49
-6,86
-7,31
1,21
1,57
0,36
1,69
1,88
0,18
1,87
1,15
-0,71
1,85
1,88
0,03
0,73
0,00
-0,73
0,55
0,85
0,30
3,00
2,60
-0,39
1,83
1,26
-0,56
1,53
1,76
0,22
2,80
3,36
0,54
4,31
4,56
0,24
2,20
2,22
0,02
1,05
0,00
-1,04
1,85
1,66
-0,19
3,24
3,28
0,04
0,31
0,00
-0,31
1,72
1,72
-0,01
1,63
1,68
0,05
1,62
1,09
-0,53
1,21
1,30
0,09
0,60
0,00
-0,59
0,48
0,82
0,33
2,49
3,12
0,62
1,52
0,60
-0,91
1,50
1,09
-0,41
3,19
3,26
0,07
3,68
3,71
0,04
1,76
1,76
0,00
1,32
0,00
-1,30
1,84
1,53
-0,31
2,74
1,65
-1,07
0,60
0,26
-0,34
1,61
1,08
-0,52
1,48
1,37
-0,10
1,82
1,01
-0,79
1,64
1,68
0,05
0,64
0,35
-0,29
0,57
0,29
-0,28
2,74
3,62
0,86
1,97
0,90
-1,05
1,56
1,46
-0,10
3,25
3,58
0,32
4,39
4,14
-0,24
2,27
2,89
0,61
1,52
0,00
-1,50
1,89
0,93
-0,94
3,35
2,73
-0,60
0,47
-1,92
-2,37
1,54
1,45
-0,09
1,59
1,63
0,03
52
Appendix B
LIST OF COTREL MEMBERS
COMMITTEE OF ASSOCIATIONS OF EUR0PEAN
TRANSFORMER MANUFACTURERS
SECRETARIAT - Ing Tomasso Genova (ANIE)
AUSTRIA
Fachverband der Elektro und Electronikindustrie (FEEI)
Mariahilfer Strasse 37-39
1060 Vienna
Austria
Tel: +43 588 39 21
Fax: +43 1 586 69 71
BELGIUM
Federation des Entreprises de I'Industrie des Fabrications
Metalliques (FABRIMETAL)
Rue des Drapiers 21
1050 Bruxelles
Belgium
Tel:
+32 2 510 2540
Fax:
+32 2 510 2561
FRANCE
Groupement des lndustries de Materiels d'Equipement
Electrique et de I’Electronique lndustrielle Associee
(GIMELEC)
11 Rue Hamelin
75783 Paris - Cedex 16
France
Tel: +33 1 45 05 70 70
Fax: +33 1 47 04 68 57
GERMANY
ZVEI/Fachverband Transformatoren
Zentralverband Elektrotechnik und Elektronikindustrie e.v.
Stresemannallee 19
POSTFACH 70 12 61
60591 Frankfurt/Main 70
Germany
Tel: +49 69/6302 256
Fax: +49 69/6302 317
IRELAND
Irish Transformer Manufacturers' Association (ITMA)
(Irish Business & Employers Confederation) Confederation
House
84/86 Lower Baggot Street
Republic of Ireland
Tel: +353 1 660 1011
Fax: +353 1 660 1717
ITALY
Associazione Nazionale lndustrie Elettrotecniche
(ed Elettroniche) (ANIE)
Via Alessandro Algardi 2
20148 Milan
Italy
Tel:
+39 2 326 4242
Fax:
+39 2 326 4212
NETHERLANDS
FME HOLTRAM - Holland Transformer Manufacturers
Vereniging voor de Metaal - en de Elektronische industrie
Postbus 190
40 Boerhaavelaan
2700 AD Zoetermeer
Netherlands
Tel:
+31 79 353 11 00
Fax:
+31 79 353 13 65
PORTUGAL
Associacao Nacional des Industriais de Material
Electrico e Electronico (ANIMEE)
Av. Guerra Junqueiro, 11-20
1000 Lisbon
Portugal
Tel: +351 01 849 4521
Fax: +351 01 840 7525
UNITED KINGDOM
Westminster Towers
3 Albert Embankment
London SE1 7SL
Tel: +49 69/6302 256
Fax: +49 69/6302 317
53
Appendix C
References
18. Vast Amorphous Transformer Targets European Industry.
Tony Sacks. Electrical Review. 1st September 1998.
1. Energy Efficient Transformers. Barry Kennedy.
2 An Analysis of Energy Efficiency under the Energy Policy and
Conservation Act: A Case Study with Application to
Distribution Transformers. National Institute of Standards
and Administration.
3. Determination Analysis of Energy Conservation Standards for
Distribution Transformers. Oak Ridge National Laboratories.
4. J and P Transformer Book, S A Stigant and A C Franklin,
Newnes-Butterworth.
19. Demonstration of Energy Saving in Distribution Transformers
with Amorphous Metal Cores. THERMIE Demonstration
Project E1 395/91. European Commission.
20. Energy Star Transformer Programme. Promoting
Competitiveness and Environmental Quality for America’s
Electricity Utilities. US EPA.
5. Distribution Transformers. Pauwels.
21. Three-phase Oil-immersed Transfomers…not exceeding
24kV. Information Sheet. HD 428. November 1992. CENELEC.
6. Energie-Sparpotentiale bei Motoren und Transformatoren.
Deutsches Kupfer-Institut.
22. Cut Your Losses to the Core. Tony Sacks. Electrical Review.
Vol 227 No 11.
7. Distribution Transformer Cost Evaluation Model (DTCEM).
US EPA.
23. ABB will Build First High Temperature Superconductor
Transformer. Electrical Review. Vol 228 No 3.
8. Energy Star Transformer Program. US EPA.
9. Current Developments in Grain-Oriented Electrical Steels.
Alan Coombs. European Electrical Steels.
10. M R Daniels. Modern Transformer Core Materials. Physics
World 1. 1988.
11. Amorphous Metal Cored Transformers, Jusifying their Use.
Brian Richardson. GEC Alsthom Transformers Ltd.
12. Transformatoren.
Anlagentechnik
Verteilungsnetze. VWEW.
fuer
Elektrische
13. Making Transformers Even More Reliable and Efficient. John
Dymott. International Power Generation. March 1996.
14. Report on Distribution and
Performance, 1997/98. OFFER.
Transmission
System
15. Economical Choice of Transformers. Pauwels. January 1997.
16. A New medium/low Voltage Transformer for Use in Rural
Public Distribution Networks. B Guilbert and J F Faltermeier.
Power Engineering Journal. June 1994.
17. Euro Growth Forecast. Power in Europe. 20th September
1996.
54
OPET NETWORK:
ORGANISATIONS FOR THE PROMOTION OF ENERGY TECHNOLOGIES
The network of Organisations for the Promotion of Energy Technologies (OPET), supported by the European Commission, helps to disseminate new, clean
and efficient energy technology solutions emerging from the research, development and demonstration activities of ENERGIE and its predecessor
programmes. The activities of OPET Members across all member states, and of OPET Associates covering key world regions, include conferences,
seminars, workshops, exhibitions, publications and other information and promotional actions aimed at stimulating the transfer and exploitation of improved
energy technologies. Full details can be obtained through the OPET internet website address http://www.cordis.lu/opet/home.html
OPET
ADEME
27, rue Louis Vicat
75737 Paris, France
Manager: Mr Yves Lambert
Contact:
Ms Florence Clement
Telephone: +33 1 47 65 20 41
Facsimile: +33 1 46 45 52 36
E-mail:
[email protected]
ASTER-CESEN
Via Morgagni 4
40122 Bologna, Italy
Manager: Ms Leda Bologni
Contact:
Ms Verdiana Bandini
Telephone: +39 051 236242
Facsimile: +39 051 227803
E-mail:
[email protected]
BEO
BEO c/o Projekttraeger Biologie,
Energie, Umwelt
Forschungszentrum
Juelich GmbH
52425 Julich
Germany
Manager: Mr Norbert Schacht
Contact:
Mrs Gillian Glaze
Telephone: +49 2461 615928
Facsimile: +49 2461 61 2880
E-mail:
[email protected]
BRECSU
Bucknalls Lane, Garston
WD2 7JR Watford
United Kingdom
Manager: Mr Mike Trim
Contact:
Mr Mike Trim
Telephone: +44 1923 664754
Facsimile: +44 1923 664097
E-mail:
[email protected]
CCE
Estrada de Alfragide, Praceta 1
2720 Alfragide
Portugal
Manager: Mr Luis Silva
Contact:
Mr Diogo Beirao
Telephone: +351 1 4722818
Facsimile: +351 14722898
E-mail:
[email protected]
CLER
28 rue Basfroi
75011 Paris
France
Manager: Ms Liliane Battais
Contact:
Mr Richard Loyen
Telephone: +33 1 46590444
Facsimile: +33 1 46590392
E-mail:
[email protected]
CMPT
Exploration House
Offshore Technology Park
Aberdeen AB23 8GX
United Kingdom
Manager:
Mr Jonathan Shackleton
Contact
Ms Jane Kennedy
Telephone: +44 870 608 3440
Facsimile: +44 870 608 3480
E-mail: [email protected]
CORA
Altenkesselerstrasse 17
66115 Saarbrucken
Germany
Manager: Mr Michael Brand
Contact:
Mr Nicola Sacca
Telephone: +49 681 9762 174
Facsimile: +49 681 9762 175
E-mail: [email protected]
FAST
2, P. le R. Morandi
20121 Milan
Italy
Manager: Ms Paola Gabaldi
Contact:
Ms Debora Barone
Telephone: +39 02 76 01 56 72
Facsimile: +39 02 78 24 85
E-mail: [email protected]
Irish Energy Centre
Glasnevin
9 Dublin
Ireland
Manager: Ms Rita Ward
Contact:
Ms Rita Ward
Telephone: +353 1 8082073
Facsimile: +353 1 8372848
E-mail: [email protected]
CRES
19 km Marathonos Ave
190 09 Pikermi, Greece
Manager: Ms Maria Kontoni
Contact:
Ms Maria Kontoni
Telephone: +30 1 60 39 900
Facsimile: +30 1 60 39 911
E-mail:
[email protected]
ICAEN
Avinguda Diagonal, 453 bis, atic
08036 Barcelona
Spain
Manager:
Mr Joan Josep Escobar
Contact:
Mr Joan Josep Escobar
Telephone: +34 93 4392800
Facsimile: +34 93 4197253
E-mail:
[email protected]
LDK
7, Sp. Triantafyllou St.
113 61 Athens, Greece
Manager:
Mr Leonidas Damianidis
Contact:
Ms Marianna Kondilidou
Telephone: +30 1 8563181
Facsimile: +30 1 8563180
E-mail:
[email protected]
Cross Border OPET- BavariaAustria
Wieshuberstr. 3
93059 Regensburg
Germany
Manager: Mr Johann Fenzl
Contact:
Mr Toni
Lautenschlaeger
Telephone: +49 941 46419-0
Facsimile: +49 941 46419-10
E-mail:
[email protected]
ENEA-ISNOVA
CR Casaccia
S Maria di Galeria
00060 Roma, Italy
Manager:
Mr Francesco Ciampa
Contact:
Ms Wen Guo
Telephone: +39 06 3048 4118
Facsimile: +39 06 3048 4447
E-mail:
[email protected]
Energy Centre Denmark
DTI
P.O. Box 141
2630 Taastrup, Denmark
Manager: Mr Poul Kristensen
Contact: Cross Border OPET
Bavaria
Mr Nils Daugaard
Telephone: +45 43 50 70 80
Facsimile: +45 43 50 70 88
E-mail:
[email protected]
ICEU
Auenstrasse 25
04105 Leipzig
Germany
Manager: Mr Jörg Matthies
Contact:
Mrs Petra Seidler /
Mrs Sabine Märker
Telephone: +49 341 9804969
Facsimile: +49 341 9803486
E-mail: [email protected]
ICIE
Via Velletri, 35
00198 Roma, Italy
Manager: Mariella Melchiorri
Contact: Rossella Ceccarelli
Telephone:
+39 06 8549141-8543467
Facsimile: +39 06 8550250
E-mail:
[email protected]
IDAE
Paseo de la Castellana 95,
planta 21
28046 Madrid, Spain
Manager:
Mr José Donoso Alonso
Contact:
Ms Virginia Vivanco Cohn
Telephone: +34 91 456 5024
Facsimile: +34 91 555 1389
E-mail:
[email protected]
ETSU
Harwell
Didcot
OX11 0RA Oxfordshire
United Kingdom
Manager: Ms Cathy Durston
Contact:
Ms Lorraine Watling
Telephone: +44 1235 432014
Facsimile: +44 1235 433434
E-mail:
[email protected]
IMPIVA
Plaza Ayuntamiento, 6
46002 Valencia
Spain
Manager: José-Carlos Garcia
Contact:
Joaquin Ortola
Telephone: +34 96 398 6336
Facsimile: +34 96 398 6201
E-mail:
[email protected]
EVE
Edificio Albia I planta 14,
C. San Vicente, 8
48001 Bilbao, Spain
Manager: Mr Juan Reig Giner
Contact:
Mr Guillermo Basanez
Telephone: +34 94 423 50 50
Facsimile: + 34 94 435 56 00
E-mail: [email protected]
Institut Wallon
Boulevard Frère Orban 4
5000 Namur
Belgium
Manager: Mr Francis Ghigny
Contact: Mr Xavier Dubuisson
Telephone: +32 81 25 04 80
Facsimile: +32 81 25 04 90
E-mail:
[email protected]
NIFES
8 Woodside Terrace
G3 7UY Glasgow
United Kingdom
Manager: Mr Andrew Hannah
Contact:
Mr John Smith
Telephone: +44 141 332 4140
Facsimile: +44 141 332 4255
E-mail: [email protected]
Novem
Swentiboldstraat 21
P.O. Box 17
6130 AA Sittard
Netherlands
Manager: Mr Theo Haanen
Contact:
Mrs Antoinette Deckers
Telephone: +31 46 42 02 326
Facsimile: +31 46 45 28 260
E-mail: [email protected]
[email protected]
NVE
P.O. Box 5091, Majorstua
0301 Oslo, Norway
Manager: Mr Roar W. Fjeld
Contact:
Mr Roar W. Fjeld
Telephone: +47 22 95 90 83
Facsimile: +47 22 95 90 99
E-mail:
[email protected]
OPET Austria
Linke Wienzeile 18
1060 Vienna, Austria
Manager: Mr Günter Simader
Contact:
Mr Günter Simader
Telephone:
+43 1 586 15 24 ext 21
Facsimile: +43 1 586 94 88
E-mail: [email protected]
OPET EM
Swedish National Energy
Administration
c/o Institutet för framtidsstudier
Box 591
S- 101 31 Stockholm
Manager: Ms Sonja Ewerstein
Contact:
Mr Anders Haaker
Telephone: +46 70 648 69 19/
+46 85 452 03 88
Facsimile: +46 8 24 50 14
E-mail:
[email protected]
These data are subject to possible change. For further information, please contact the above internet website address or Fax +32 2 2966016
OPET Finland
Technology Development Centre
Tekes
P.O. Box 69,
Malminkatu 34
0101 Helsinki, Finland
Manager: Ms Marjatta Aarniala
Contact:
Ms Marjatta Aarniala
Telephone: +358 105215736
Facsimile: +358 105215908
E-mail:
[email protected]
OPET Bothnia
Norrlandsgatan 13, Box 443
901 09 Umea - Sweden
Blaviksskolan
910 60 Asele -Sweden
Manager: Ms France Goulet
Telephone: +46 90 16 37 09
Facsimile: +46 90 19 37 19
Contact:
Mr Anders Lidholm
Telephone: +46 941 108 33
Facsimile: +46 70 632 5588
E-mail: [email protected]
OPET Israel
Tel-Aviv University
69978 Tel Aviv
Israel
Manager: Mr Yair Sharan
Contact:
Mr Yair Sharan
Telephone: +972 3 6407573
Facsimile: +972 3 6410193
E-mail: [email protected]
Orkustofnun
Grensasvegi 9
IS-108 Reykjavik
Iceland
Manager:
Mr Einar Tjörvi Eliasson
Contact:
Mr Einar Tjörvi Eliasson
Telephone: +354 569 6105
Facsimile: +354 568 8896
E-mail: [email protected]
SODEAN
Isaac Newton s/n
Pabellón de Portugal - Edifico
SODEAN
41092 Sevilla
Spain
Manager:
Mr Juan Antonio Barragán Rico
Contact:
Ms Maria Luisa Borra Marcos
Telephone: +34 95 4460966
Facsimile: +34 95 4460628
E-mail:
mailto:[email protected]
CEEETA-PARTEX
Rua Gustavo de Matos Sequeira,
28 - 1 . Dt .
1200-215 Lisboa
Portugal
Manager: Mr Aníbal Fernandes
Contact:
Mr Aníbal Fernandes
Telephone: +351 1 395 6019
Facsimile: +351 1 395 2490
E-mail: [email protected]
SOGES
Corso Turati 49
10128 Turin, Italy
Manager:
Mr Antonio Maria Barbero
Contact:
Mr Fernando Garzello
Telephone: +39 0 11
3190833/3186492
Facsimile: +39 0 11 3190292
E-mail: [email protected]
OPET Luxembourg
Avenue des Terres Rouges 1
4004 Esch-sur-Alzette
Luxembourg
Manager: Mr Jean Offermann
(Agence de l'Energie)
Contact:
Mr Ralf Goldmann
(Luxcontrol)
Telephone: +352 547 711 282
Facsimile: +352 54 77 11 266
E-mail:
[email protected]
RARE
50 rue Gustave Delory
59800 Lille, France
Manager: Mr Pierre Sachse
Contact:
Mr Jean-Michel Poupart
Telephone: +33 3 20 88 64 30
Facsimile: +33 3 20 88 64 40
E-mail: [email protected]
VTC
Boeretang 200
2400 Mol
Belgium
Manager:
Mr Hubert van den Bergh
Contact:
Ms Greet Vanuytsel
Telephone: +32 14 335822
Facsimile: +32 14 321185
E-mail:
[email protected]
Wales OPET Cymru
Dyfi EcoParc
Machynlleth
SY20 8AX Powys
United Kingdom
Manager: Ms Janet Sanders
Contact:
Mr Rod Edwards
Telephone: +44 1654 705000
Facsimile: +44 1654 703000
E-mail: [email protected]
FEMOPET
Black Sea Regional Energy
Centre —
(BSREC)
8, Triaditza Str.
1040 Sofia
Bulgaria
Manager: Dr L. Radulov
Contact: Dr L. Radulov
Telephone: +359 2 980 6854
Facsimile: +359 2 980 6855
E-mail: [email protected]
EC BREC - LEI FEMOPET
c/o EC BREC/IBMER
Warsaw Office
ul. Rakowiecka 32
02-532 Warsaw, Poland
Manager: Mr Krzysztof Gierulski
Contact: Mr Krzysztof Gierulski
Telephone: +48 22 484832
Facsimile: +48 22 484832
E-mail: [email protected]
Estonia FEMOPET
Estonian Energy Research
Institute
Paldiski mnt.1
EE0001 Tallinn, Estonia
Manager: Mr Villu Vares
Contact: Mr Rene Tonnisson
Telephone: +372 245 0303
Facsimile: +372 631 1570
E-mail: [email protected]
FEMOPET LEI - Lithuania
Lithuanian Energy Institute
3 Breslaujos Str.
3035 Kaunas, Lithuania
Manager: Mr Romualdas Skemas
Contact: Mr Sigitas Bartkus
Telephone: +370 7 35 14 03
Facsimile: +370 7 35 12 71
E-mail: [email protected]
Energy Centre Bratislava
c/o SEI-EA
Bajkalská 27
82799 Bratislava, Slovakia
Manager: Mr Michael Wild
Contact: Mr Michael Wild
Telephone: +421 7 582 48 472
Facsimile: +421 7 582 48 470
E-mail: [email protected]
FEMOPET Poland KAPE-BAPEGRAPE
c/o KAPE
ul. Nowogrodzka 35/41 XII p.
PL-00-950 Warsaw
Poland
Manager: Ms Marina Coey
Contact: Ms Marina Coey
Telephone: +48 22 62 22 794
Facsimile: +48 22 62 24 392
E-mail: [email protected]
Energy Centre Hungary
Könyves Kálmán Körút 76
H-1087 Budapest
Hungary
Manager: Mr Andras Szalóki
Contact: Mr Zoltan Csepiga
Telephone: +36 1 313 4824/
313 7837
Facsimile: +36 1 303 9065
E-mail:
Andras.szalóki @energycentre.hu
FEMOPET Slovenia
Jozef Stefan Institute
Energy Efficiency Centre
Jamova 39
SLO-1000 Ljubljana
Slovenia
Manager: Mr Boris Selan
Contact: Mr Tomaz Fatur
Telephone: +386 61 1885 210
Facsimile: +386 61 1612 335
E-mail: [email protected]
Latvia FEMOPET
c/o B.V. EKODOMA Ltd
Zentenes Street 12-49
1069 Riga
Latvia
Manager: Ms Dagnija Blumberga
Contact: Ms Dagnija Blumberga
Telephone: +371 721 05 97/ 241
98 53
Facsimile: +371 721 05 97/ 241
98 53
E-mail: [email protected]
OMIKK
National Technical Information
Centre and Library
Muzeum Utca 17
H-1088 Budapest
Hungary
Manager: Mr Gyula Nyerges
Contact:
Mr Gyula Nyerges
Telephone: +36 1 2663123
Facsimile: +36 1 3382702
E-mail: [email protected]
FEMOPET Romania ENERO
8, Energeticienilor Blvd.
3, Bucharest 79619
Romania
Manager: Mr Alexandru Florescu
Contact: Mr Christian Tintareanu
Telephone: +401 322 0917
Facsimile: +401 322 27 90
E-mail: [email protected]
Sofia Energy Centre Ltd
51, James Boucher Blvd.
1407 Sofia
Bulgaria
Manager: Ms Violetta Groseva
Contact: Ms Violetta Groseva
Telephone: +359 2 96 25158
Facsimile: +359 2 681 461
E-mail: [email protected]
Technology Centre AS CR
Rozvojova 135
165 02 Prague 6
Czech Republic
Manager: Mr Karel Klusacek
Contact: Mr Radan Panacek
Telephone: +420 2 203 90203
Facsimile: +420 2 325 630
E-mail: [email protected]
FEMOPET Cyprus
Andreas Araouzos, 6
1421 Nicosia
Cyprus
Manager: Mr. Solon Kassinis
Contact: Mr. Solon Kassinis
Telephone: +357 2 867140/
305797
Facsimile: +357 2 375120/
305159
E-mail:
[email protected]
These data are subject to possible change. For further information, please contact the above internet website address or Fax +32 2 2966016
NOTICE TO THE READER
Extensive information on the European Union is available through the EUROPA
service at internet website address http://europa.eu.int/
The overall objective of the European Union’s energy policy is to help ensure a sustainable
energy system for Europe’s citizens and businesses, by supporting and promoting secure energy
supplies of high service quality at competitive prices and in an environmentally compatible way.
European Commission DGXVII initiates, coordinates and manages energy policy actions at
transnational level in the fields of solid fuels, oil & gas, electricity, nuclear energy, renewable
energy sources and the efficient use of energy. The most important actions concern maintaining
and enhancing security of energy supply and international cooperation, strengthening the
integrity of energy markets and promoting sustainable development in the energy field.
A central policy instrument is its support and promotion of energy research, technological
development and demonstration (RTD), principally through the ENERGIE sub-programme (jointly
managed with DGXII) within the theme “Energy, Environment & Sustainable Development” under
the European Union’s Fifth Framework Programme for RTD. This contributes to sustainable
development by focusing on key activities crucial for social well-being and economic
competitiveness in Europe.
Other DGXVII managed programmes such as SAVE, ALTENER and SYNERGY focus on
accelerating the market uptake of cleaner and more efficient energy systems through legal,
administrative, promotional and structural change measures on a trans-regional basis. As part
of the wider Energy Framework Programme, they logically complement and reinforce the impacts
of ENERGIE.
The internet website address for the Fifth Framework Programme is
http://www.cordis.lu/fp5/home.html
Further information on DGXVII activities is available at the internet website address
http://europa.eu.int/en/comm/dg17/dg17home.htm
The European Commission
Directorate-General for Energy DGXVII
200 Rue de la Loi
B-1049 Brussels
Belgium
Fax +32 2 2950577
E-mail: [email protected]
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