BLEKINGE TEKNISKA HÖGSKOLA

BLEKINGE TEKNISKA HÖGSKOLA
BLEKINGE TEKNISKA HÖGSKOLA
Design of a Self-sufficient Micro-Grid with Renewable
Energy Production.
Advanced Technology & Research.
This thesis is presented as a part of Degree of Master of Science in Electrical Engineering
MD. EMDADUL HAQUE
Department of Electrical Engineering
BLEKINGE TEKNISKA HÖGSKOLA (BTH)
Karlskrona, Sweden, 2013
P age |i
Design of a Self-sufficient Micro-Grid with Renewable Energy
Production.
Advanced Technology and Research.
Volvo Group Truck & technology (GTT), Gothenburg
Sweden
Supervisors: Niklas Thulin, Senior Research Engineer at Volvo Technology, Gothenburg
Maria Erman, Department of Electrical Engineering at Blekinge Institute of
Technology
Examiner:
Dr. Sven Johansson, Head of Dept. of Electrical Engineering
Blekinge Institute of Technology, Karlskrona Sweden
P a g e | ii
ACKNOWLEDGEMENTS:
I would like to confess, and extend my heartfelt gratitude to all those who gave me the prospect to complete this
project successfully.
I am deeply grateful to my supervisor Thulin Niklas (Product Platform Manager Electromobility at Volvo
Group Truck & Technology) whose help, stimulating suggestions, knowledge, experience, encouragement and
support helped me in all the times of study and analysis of the project in the pre and post research period,
without whom this report was almost impossible. I also grateful to Mr. Adam Paul and Istaq Ahmed they
taught me for solar power and storage system respectively, which helped to a great extent in the project. Also I
would like to thanks to all Volvo employees that they helped and supported me lots during my study.
I would like to particular thank Maria Erman, supervisor, School of Engineering (ING) at Blekinge Institute of
Technology (BTH) and Dr. Sven Johansson, Head of the Department of Electrical Engineering, Blekinge
Institute of Technology (BTH). I have got lots of help from them about academic and research oriented
information. It was really good learning experience workings under them.
The practical guidance in the field of Project “Design of a self-sufficient micro-grid with renewable energy” that
gave is too valuable for me.
Also, I would like to give a very special thanks to Thulin Niklas, for providing me a golden opportunity to work
in this area in the company of Volvo Group.
Most particularly to my family and friends, and to God, he made all things possible for all of us.
Gothenburg, March 2013
Md.Emdadul Haque
P a g e | iii
ABSTRACT:
In power development technology there are pioneering various μ-grid concepts, that integrating multiple
distributed power generation sources into a small network serving some or all of the energy needs of
participating users can provide benefits including reduced energy costs, increased overall energy efficiency and
improved environmental performance and local electric system reliability.
In the fast progression of technology the electric vehicles, electric construction equipment and machinery such
as- road building or quarries would greatly benefited from electrification and the by this revolutions, they able
defending the environment from detrimental effect and potential energy (and local emission) reduction is
sufficient. These types of sites are often remotely located and it is much costly to meet the high voltage utility
grid or distribution grid, which are normally far-off from the sites. Hence, it would be advantageous to be able to
set up such sites without having to build long and expensive connections to high voltage transmission and
distribution grids.
In this project we have design and proposed a self-sufficient smart DC micro-grid providing renewable energy
resources to supply electric machinery is designed. This grid is capable of meeting energy as well as peak power
demands of machine site while offering the possibility to fully rely on locally produced renewable energy. In this
project we have included price and performance forecasting for solar and wind energy, charger, grid energy
storage system and micro-grid power electronics.
Therefore, with this design it is capable to provide efficient power supply to the site and can meet the demand at
peak loads. Grid modeling and simulating results (including loads, storage and energy production) are done by
MATLAB.
P a g e | iv
TABLE OF FIGURES
Figure: 2.1
Figure: 2.2
Figure: 2.3
Figure: 2.4
Figure: 2.5
Figure: 2.6
Figure: 2.7
Figure: 2.8
Figure: 2.9
Figure: 2.10
Figure: 2.11
Figure: 2.12
Figure: 2.13
Figure: 2.14
Figure: 2.15
Figure: 2.16
Figure: 2.17
Figure: 2.18
Figure: 2.19
Figure: 2.20
Figure: 2.21
Figure: 2.22
Figure: 2.23
Figure: 2.24
Figure: 3.1
Figure: 3.2
Figure: 3.3
Figure: 3.4
Figure: 3.5
Figure: 3.6
Figure: 3.7
Figure: 4.1
Figure: 4.2
Figure: 4.3
Figure: 4.4
Figure: 4.5
Figure: 4.6
Figure: 4.7
Figure: 4.8
Figure: 4.9
Figure: 4.10
Figure: 4.11
Figure: 4.12
Figure: 4.13
Figure: 4.14
Figure: 4.15
Basic conception of a micro-grid system………………….………………………………….....03
Intelligent Battery and Charger Integration System (BCIS) …………………………………....04
Charging Infrastructure of Electrical Vehicles…………………………………………………..05
System Configuration and function of BCIS……………………………………………………06
PQ Controller Architecture Diagram……………………………………………………………08
Block diagram of voltage and current dual-loop controller……………………………………..09
Power Controller Structure of the grid…..………………………………………………………10
Object reflect different amounts of sunlight from the Earth’s surface ……………………….....13
Power curve versus wind speed of a wind turbine………………………………………………15
Schematic diagram of a wind turbine……………………………………………………………16
Wind turbine internal views and devices………………………………………………………..18
Evaluation in the size of wind turbines since 1985………………………………………...……19
Wind turbine price index by delivery date 2004 to 2012………………………………………..20
Wind turbine prices index in the US and Chain compared to the BNEF, 1997-2012…………. 20
Classification of solar cells……………………………………………………………………...23
Electrical contacts of a solar cell………………………………………………………………...24
Grid contacts on the top surface of a cell………………………………………………………..25
Photovoltaic systems…………………………………………………………………………….25
Concentrated Solar Power (CSP) system………………………………………………………..26
Linear concentrator system……………………………………………………………………...27
Linear concentrator power plant using parabolic through collectors……………………………27
Linear Fresnel reflectors power plant……………………………………………………………28
A dish/ engine power plant………………………………………………………………………28
A power tower concentrating power plant ……………………………………………………...29
Steps in the developments of a research projects………………………………………………..30
Block diagram of our proposed micro-grid model………………………………………………32
Hybrid system model……………………………………………………………………………33
System model of the micro-grid…………………………………………………………………34
Sub- models of wind power system……………………………………………………………..35
Sub- models of solar power system……………………………………………………………...36
Sub- models of grid storage system……………………………………………………………..37
Hourly power production and consumption per day in the site…………………………………39
Hourly power productions per day in the whole system ………………………………………..40
Hourly power consumption in the whole system………………………………………………..41
After consumption rest of the power of the whole system……………………………………....41
Electricity generating costs in the European Union, 2015, 2020 and 2030……………………..43
Cost forecasting in the European Union, 2015 to 2030…………………………………………43
Ten biggest onshore wind farms in Europe……………………………………………………..45
New annual EU wind energy capacity (2011-2020) ……………………………………………45
Wind power production in the EU (2011-2020) ………………………………………………..46
Global wind market forecast 2011-2020………………………………………………………..47
Wind power production in the EU (2000-2020) ………………………………………………..47
Total increased wind power capacity EU-27, (2009-2020)……………………………………..48
Average wind speed of Thu. Sep-27, 2012 at Gothenburg…………………………………….. 49
Average wind speed sep-2012 at Gothenburg…………………………………………………...49
Yearly wind speed at Gothenburg City Airport…………………………………………………50
P age |v
TABLE OF FIGURES
Figure: 4.16
Figure: 4.17
Figure: 4.18
Figure: 4.19
Figure: 4.20
Figure: 4.21
Figure: 4.22
Figure: 5.1
Figure: 5.2
Figure: 5.3
Figure: 5.4
Figure: 5.5
Figure: 5.6
Figure: 5.7
PV cell efficiencies and array surface area……………………………………………………...50
Solar radiation at Gothenburg …………………………………………………………………..51
Monthly AC energy produced in Gothenburg …………………………………………………..52
Average daily sum of global irradiation received by a module ………………………………...52
PV estimate: Location: 57°42'31" North, 11°58'28" East ………………………………………53
Module price trend from Solar buzz ……………………………………………………………54
German spot market prices for solar modules …………………………………………………..55
Wind power produce at different size of turbines blades ……………………………………….58
Rotor efficiency versus Vd/Vu ratio has single maximum ……………………………………...59
Weibull probability distribution functions ……………………………………………………...60
Wind power generation cost for different turbine size and capacity factor …………………….63
Up-front costs as a function of energy produced at different sunlight hours …………………...67
Up-front costs as a function of energy produced at different system lifetime…………………..67
Life- cycle costs as a function of energy produced at different sunlight hours …………….......68
ABBREVIATIONS:
PHEV
PEV
BEV
PMS
EES
PV
AC
DC
TX-Line
EM
ICE
MPPT
BMS
EMS
€
£
$
¥
Wp
KWh
KW
Li-ion Battery
BOS
BCIS
CI
CSP
- Plug-in Hybrid Electric Vehicle
- Plug-in Electric Vehicle
- Battery Electric Vehicle
- Power Management System
- Electrical Energy Storage
- Photovoltaic
- Alternating Current
- Direct Current
- Transmission- Line
- Electric Machine
- Internal Combustion Engine
- Maximum Peak Power Tracker
- Battery Management System
- Energy Management System
- Symbol of Euro
- Symbol of British Pound
- Symbol of US dollar
- Symbol of Chinese Yuan
- Watt-peak
- Kilowatt-hour
- Kilowatt
- Lithium-ion Battery
- Balance of System
- Battery& Charger Integration System
- Charging Infrastructure
- Concentrated Solar Power
P a g e | vi
P a g e | vii
TABLE OF CONTENTS
1. INTRODUCTION…………………………………………………………………………………………….01
2. LITERATURE STUDY………………………………………………………………………………………02
2.1 Micro-grids…………………………………………………………………………………..02
2.1.1 Charger Integration………………………………………………………04
2.1.2 DC grids………………………………………………………………….07
2.1.3 Intelligent Grid Control….……………………………………………….08
2.1.4 Renewable Integration…...………………………………………………10
2.1.5 Energy storage in Micro-grids……………………………………...……11
2.2 Wind Power………………………………………………………………………………….12
2.3 Solar Power………………………………………………………………………………….22
3. MODELING APPROACH…………………………………………………………………………………...30
3.1 Methodology…………………………………………………………………………….......30
3.2 High Level Site Model………………………………………………………………………31
3.2.1 Proposed model…………………………………………………………..32
3.2.2 System model of the micro-grid………………………………………….34
3.3 Sub-Model Wind Power……………………………………………………………………..35
3.4 Sub-Model Solar Power……………………………………………………………………..36
3.5 Sub-Model Grid Storage Energy…………………………………………………………….37
4. CASE STUDIES…........………………………………………………………………………………………38
4.1 Site Descriptions…………………………………………………………………………….38
4.1.1 Site Specification…………………………………………………….…..38
4.1.2 Simulation data and results………………………………………….…...38
4.1.2.1 Total power production and consumption…………....40
4.2 Input Data……………………………………………………………………………………42
4.2.1 Wind Power Data…………………………………………………….…..42
4.2. 1 Forecasted Data………………………………………...43
4.2.2 Solar Power Data……………………………………………………...….50
4.2.2.1 Solar Module cost Data………………………………………………...53
5. RESULTS……………………………………………………………………………………………………...56
5.1 Wind Power site…………………………………………………………………………......56
5.1.1 Cost……………………………………………………………………....56
5.2 Solar Power site ………………………………………………..............................................63
5.2.1 Cost……………………………………………………………………....63
5.3 Calculated total cost…………………………………………………………………………69
6. DISCUSSIONS………………………………………………………………………………………………..70
7. CONCLUSIONS………………………………………………………………………………………………71
8. REFERENCES………………………………………………………………………………………………..72
APPENDIX
A-Electric Construction Machines……………………………………………………………74
APPENDIX
B-Energy Storage Technology…………………………………………………………………77
APPENDIX
C-Solar cell and Panels price Trends………………………………………………………....80
P age |1
1. INTRODUCTION
With the innovative improvement in the power industry Micro-Grid systems are prevailing technique that co-ordinate
numerous power generation sources through a small network serving some energy requirements of participating
users can optimizes one or many of the following: Power quality and reliability, sustainability and economic benefits
including reduced energy costs, increased overall energy efficiency, improved environmental performance and local
electric system reliability. In addition the growth of electric power generation shared with emerging technologies,
particularly renewable energy, storage devices, power electronic interfaces, and cost minimization are making the
conception of a micro-grid is the technological authenticity.
Alternating the aspect of the surviving power system, over the past several decades has witnessed a rising the
demand of cost-effective, reliable, quality requirements, and energy efficient in the power system, especially in
automotive industry the electric machines such as construction equipments, PHEV, BEV and PEV are promptly
changing the used of electrical energy as well.
In this project, a new scheme is proposed to evaluate a smart, cost effective, energy efficient and reliable design of a
self-sufficient DC micro-grid using renewable energy resources, to smart energy delivery for local utilization and
saving electrical energy capable of 2020 excellence. This grid would be capable to provide technical and economical
sustenance and optimize energy supply.
Therefore, by this prevailing grid design, we can mitigate the problem of local area power supply and save the
energy, which can use in electricity crisis to the site. Linear interpolation method is used to prediction the data’s and
to interpolate the future demand of energy estimate respectively. The whole simulation results are executed by
using MATLAB and Excel.
P age |2
2. LITERATURE STUDY
In this chapter we are going to discuss detail regarding the literature review such as: -on-going latest technology
related to the micro-grid design, planning, forecasted method, energy management and intelligent control
system, charging system and available renewable resources.
2.1 MICRO-GRID GENERAL
Source: Avago Technology
WHAT IS MEANT BY A MICRO-GRID?
A micro-grid is defined as a small power system with three primary mechanisms: distributed generators with
optional storage devices, autonomous load centers, and system capability to operate interconnected with or
islanded from the larger utility electrical grid [1], [2] and [3].
Numerous facility micro-grids span multiple buildings or structures, with loads typically ranging between 5 MW
and 50 MW, such as electric construction equipment and machinery and localization (small industry, electric
machines charging, municipal, etc.), electric vehicles, industrial and commercial complexes, and building
residential developments [4].
The fundamental conception of a micro-grid is shown in Fig.2.1. Normally, micro-grid can be a DC or an AC
grid. An AC micro-grid can be a single-phase or a three-phase system. To the power distribution networks it can
be linked to low voltage or medium voltage [4], [5].
In this paper we have consider one a DC micro-grid that is connected to a city utility power grid. In general, a
micro-grid includes four basic technologies for operation:
ƒ
ƒ
ƒ
ƒ
Distributed generation units
Distributed storage devices
An interconnection switch and
An intelligent control system.
P age |3
These technologies are the fundamental technology for design of an effective micro-grid to achieve expected
output.
UTILITY GRID/MAIN GRID
TRANSFORMER
SUBSTATION
CIRCUIT
BREAKER(CB)
INTELLIGENT
CONTROL
SYSTEM
AC
CONVERTER
DC
Micro Grid
DC bus
DC
DC
AC
WIND
POWER
DC
DC
SOLAR
POWER
DC
DC toAC
LOAD-1
DC toAC
LOAD-2
BATTERY
BANK
Figure: 2.1: Basic conception of a typical micro-grid scheme
Source: [7]
In this plentiful ways, a micro-grid is really just a small-scale version of the traditional power grid that the vast
majority of electricity consumers in the developed world rely on for power service today. So far the smaller scale
of micro-grids results in far fewer line losses, a lower demand on transmission infrastructure, and the ability to
rely on more localized sources of power generation and properly utilized the renewable resources to benefit with
electrical energy saving [4],[5].
All of these benefits are stimulating an increased demand for micro-grids on a worldwide basis, in a variety of
application areas including Electric Machines charging such as-PEV, BEV, PHEV, construction equipment,
remote/off-grid settings, community/utility systems, and commercial and industrial markets.
In future of micro-grid with high technology like Nano-super capacitor, Nano solar cell, Nano batteries and fuel
cell will make the ideal storage capacities reality Micro-grid. Advance in automation, intelligent control systems,
hybrid engine and bus plugged generating or storage sources device. In the vast area mini nuclear plants would
be the ideal sources of energy of Micro-grids.
P age |4
BENEFITS OF A MICRO-GRID:
There are some advantages of micro-grid system. The thought of Micro-grid, is not a substitution of the utility
grid, it has some especial aspects for to mitigate the demand of consumer with perfectly use sufficient renewable
resources [3].
ƒ
ƒ
ƒ
ƒ
ƒ
It is much smaller financial commitments.
Power produces with renewable resources for this reason it is more environmentally friendly with lower
carbon footprints.
Require fewer technological skills to maintenance and control more on mechanization.
It is isolated from any grid interruption or outage.
Set the consumer out of the hang on from the national utility generation networks.
2.1.1 CHARGER INTEGRATION
For suitable supervision and with cognitive quick charging system of Electric Vehicles, NEC has developed
Battery and Charger Integration System (BCIS). Interrupted, fluctuation of charging system and power shortage
has increased the need for reliable, efficient and stable intelligent management of power grid operations and
control.
Additionally, it is make crisis and required to prepare suitable countermeasures for the problems of the new
power demand and supply, such as the peak of power demands by charging the electric vehicles (EVs),
construction equipment and the instability of power grids by increase in power generation supplied from
renewable energy sources to the local area[5].Up to that time they have marketed for domestic energy storage
systems incorporating Li-ion batteries and has also developed EV quick chargers and EV charging systems by
optimally using cloud computing for member authentications, administration and billing settlements[5].
Figure: 2.2. Intelligent Battery and Charger Integration System (BCIS)
Source: NEC
P age |5
Later on Integrated with above these technologies, NEC has developed the BCIS system as we can see Fig 2.2
and is currently attempting to mitigate the detrimental effect as we can see above.
BCIS is like cognitive management systems that realize the reduction of the peak power consumption for EV
charging demands, and the shortening of the EV charging time because BCIS which is linked to the multiple
quick chargers and stationary batteries controls the power to be supplied to the EVs efficiently [5].
In addition, under this charging system there are some strategies in order to validate the effectively of BCIS for
the regional power demand and supply adjustment and modification, we have discussed these are in sort detail
that how and which infrastructure we need to this intelligent system.
CHARGING INFRASTRUCTURE (CI) OF ELECTRIC VEHICLES (EV):
Electric Vehicles (EV) are expected to grow attractiveness in the upcoming generation as a clean, zero emissions
sort of transportation. However right now, fully charging the EV is a time consuming procedure and that can
take more than a few hours using a household power supply. In electric vehicles there is some disadvantages and
shortcoming that these are not able to travel for long distance.
In addition, Electric Vehicles are only capable to drive short distance compared to gasoline engine vehicles. To
resolve or mitigate the issues with traveling, a charging infrastructure is needed on a national scale and a model
of charging infrastructure is shown in Fig: 2.3, and from this figure we can get fundamental perception of CI.
Figure: 2.3. Charging infrastructure of Electrical Vehicles,
sources: NEC
With rapid growth in automotive machinery, in the future Electric Vehicles (EV) fast charger would be expand
very fast beyond existing service stations and much updated technology would be used. We will find them in
roadside locations like convenience stores, shopping centers and industrial area etc., at leisure facilities like
theme parks and stadiums, and public facilities like airports, buss stations and train stations.
Like this situation to smoothly charging support of the electric vehicle charging infrastructure in essential with
smart charging station.
P age |6
SIGNIFICANTCONCERNSIN THE NEW POWER DEMAND/SUPPLY:
The distribution of EVs brings about increase in stable power demands. And renewable energy increases
unstable power generation. This means that the power supply arrangement facility with the conventional power
grid may not be able to maintain stable power supply [5].
ƒ
ƒ
ƒ
Increased power demand due to the dissemination of EVs
Unstable power generation due to renewable energy
Battery and Charger Integration System (BCIS)
SYSTEM CONFIGURATION AND OPERATION:
In BCIS incorporates there is six components mainly considered as we can see in the figure. The system
configuration and the function of each component with briefly description we can see in Fig: 2.4 [5].
........
CEMS
Remote
operation&
management
Energy
management
Map of
charging
station
Authentication Billing
BCIS
BCIS Manager
BCIS
Power controller
Grid
powerreceiving
Battery
control
section
BCIS Power control
Battery
control
section
Battery Units
............................
Quick chargers
Network
Figure: 2.4 System Configuration and function of BCIS system.
Power line
Source: [5]
P age |7
In this system there is some fundamental part these are pointed out below as we can see:
ƒ
ƒ
ƒ
ƒ
ƒ
ƒ
Grid power receiving section
Battery control section
Battery unit system
Quick charger system
Power controller unit
BCIS manager
BCIS FEATURES FUNCTION:
BCIS has some amazing features first one is a power output control function for the quick charger that would be
used electric power efficiently, and next features is a power demand and supply adjustment function as well that
contributes to stable and efficient regional power supply.
(1). Power output control function for quick charger
(2). Power demand and adjustment function
2.1.2 DC GRIDS AND AIDS
The micro-grid is divided into AC micro-grid and DC micro-grid, which is classified by whether, distributed
sources and loads are connected on the basis of AC or DC grid. AC micro-grid has a benefit to utilize existing
AC grid technologies, protections and standards, but synchronization, stability, need for reactive power are
inherent demerits [6].
On the other hand, DC micro-grid has no such demerits of AC micro-grid and satisfies the demand of today
because most of environment-friendly distributed generation sources such as photovoltaic, fuel cells and variable
speed wind power generate DC power and most of digital loads need DC power.
In addition, DC micro-grid can eliminate DC-AC or AC-DC power conversion stage required in AC micro-grid
for the above renewable sources and loads, and thus has advantages in the stand of efficiency, cost and system
size. However, DC micro-grid needs further research about proper operating range of DC voltage and protection
apparatus for DC circuit [6].DC micro-grid consists of uncontrolled distributed sources such as wind power,
photovoltaic generation and controlled fuel-cells source, energy storage elements such as super-capacitor and
battery, DC load and grid-tied converter.
Large electrical grids are based on AC for two important reasons. First, changing voltage is simple and cheap;
this allows energy to be transported over long distances at high efficiency and relatively low cost. Second, AC
motors and generators are more cost-effective than DC counterparts. However, for a localized application such
as residential or commercial usage with a large DC power source such as a solar PV array, it is actually more
cost-effective to use a DC power distribution system for DC loads such as lighting and a local AC grid for the
remaining AC loads.
This is because changing DC to AC is relatively expensive and inefficient, while regulating DC or changing AC
to DC is both cheap and efficient. Inverters for converting DC to AC are quite complex; DC regulators for DCto-DC conversion are relatively simple; and AC-to-DC rectifiers are extremely simple. Therefore, it is quite easy
to import both DC and AC power into a DC power distribution system but relatively difficult to import DC
power into an AC grid [7], [8].
P age |8
2.1.3 INTELLIGENT GRID CONTROL
CONTROL SYSTEM OF MICRO-GRID:
Control of micro-grid should ensure that any tiny source of access does not affect the system, the ability to
correct voltage and system and to separate the active and reactive control. When micro-grid system start, there
must be one or more distributed power playing the role of the main grid, supporting the voltage and frequency
for the micro-grid system, such as diesel, battery power, can issue a large number of active and reactive, is
relatively easy to achieve.
In situations of requiring for high power quality, we can combine the storage system and distributed power as the
primary control unit, making full use of rapid charging and discharging function of energy storage systems and
diesel engines to get the advantages of longer time maintaining of micro-grid system running.
Micro-sources such as wind power and PV cells, their power output size, more affected by the weather, power
generation has an obvious intermittent, and usually only issued a constant active power or the performance of
maximum power point tracking [9].
A. PQ CONTROLLER DESIGN
Design of PQ controllers shown in Figure 2.5, there will be decoupled active and reactive power, we can get the
inductor current reference value, and compared with the actual values we obtain error signal, and then use the
instantaneous current loop proportional - integral (PI) controller as inverter to modulating voltage signal [9].
+
Pref
/
2/3
Idref
+
+
PI
Controller
Vd
+
+
WLf
Vfdd
Id
Abc/b
q0
Iq
WLf
Vfdq
+
Oref
-2/3
/
Iqref
+
+
PI
Controller
+
+
Vq
+
Figure: 2.5. PQ controller architecture diagrams
Source:[9]
P age |9
Where Pref and Qref respectively are reference values for active power and reactive power; Idref and Iqref
respectively for the reference current value of d, and q axes by decoupling; Vd and Vq respectively are
modulated voltage signals of d, and q axes by the current loop control; w is the frequency of power grid.
B. V/F CONTROLLER DESIGN
In this paper, V / f are used to control energy storage system and diesel engine, the controller includes voltage
and current dual-loop controller and power controller.
1. THE VOLTAGE AND CURRENT DOUBLE-LOOP CONTROLLER:
In Figure 2.6 where the outer ring is the voltage ring to provide a steady load. Output voltage is compared with
the reference voltage to get error signal, then by PI controller it is given as the reference of current loop, inverter
output filter inductance current compared with the reference signal to get the error signal, and for inverter
modulation voltage signal through the instantaneous current-loop PI controller. Filter inductance current as the
inner loop, can improve the dynamic response of the system [9].
Itd
+
V”tdd
+
+
PI
controller
+
+
-
-
Vtdd
I”d
+
+
PI
controller
+
+
Vd
+
-
WLf
WCf
Id
Vtdq
Iq
WCf
+
-
V”tdq
+
+
PI
controller
+
WLf
I”q
+
+
+
+
PI
controller
+
+
Vq
+
+
Itq
Figure: 2.6 Block diagram of voltage and current dual-loop controller
Source: [9]
2. POWER CONTROLLER:
As the frequency signal is easier to measure, we use frequency control instead of phase angle. The power of
control loop is the instantaneous power of the output of distributed power supply. The P and Q of micro-source
output must satisfy the following two conditions: 0≤P≤PmaxˉQmax≤Q≤QmaxOutput power of the controller as
the reference voltage of double-loop control. The design of the structure shown in Figure-2.7: [9].
P a g e | 10
Pn
+
V
+
-
+
1/a
+
Vn
+
Vnef
+
PI
controller
V”1dd
V”
Vߜ/dq0
Q
1/a
+
+
+
+
fn
fnef
+
PI
controller
ߜ”v
2n
V”1dq
1/s
-
W”
f
Figure: 2.7: Power controller structure
Source: [9]
2.1.4 RENEWABLES INTEGRATION:
Source: http://www.greenpowerconferences.com
RENEWABLE ENERGY INTEGRATION
Renewable Energy Integration focuses on integrating renewable energy sources, distributed generation, energy
storage, thermally activated technologies, and demand response into the electric distribution and transmission
system [10]. A systems approach is being used to ways integration development and demonstrations to address
economic, technical, monitoring, and institutional barriers for using renewable and distributed systems.
The main objective of Renewable energy integration is to design an advance system and support, planning and
estimating, operation of the electric grid and to set the intelligent control and management system:
ƒ
Decrease carbon emissions and emissions of other air pollutants through increased use of renewable
energy and other clean distributed generation.
ƒ
Increase benefit use through integration of distributed systems and reduce customer peak loads and thus
lower the costs of electricity in the daily life.
P a g e | 11
ƒ
Support reaching of renewable selection standards for renewable energy and energy efficiency.
ƒ
Enhance reliability, security, and resiliency from micro-grid applications in critical infrastructure
protection and highly reserved areas of the electric grid.
ƒ
Reductions of dependency in oil use by supporting plug-in electric vehicle (PHEV) and electric
construction equipment’s operations with the grid.
2.1.5 ENERGY STORAGE IN MICRO-GRIDS
Source: http://panasonic.net/energy/storage_battery/index.html
ENERGY STORAGE SYSTEMS FOR SMART GRIDS:
In presently the environmental concerns such as global warming and CO2 emissions have become world-wide is
a great issues. As a result, deployment of the distributed power sources increasing rapidly, which utilize
renewable forms of energy such as solar power and wind power system, fuel cell and Micro-Grids, which are
effectively utilize all types of power sources, are considered highly promising technologies in the world.
Power grids recognize the supply and demand of stable power by optimally balancing. But as the use of solar
power and other renewable energy sources, which have unpredictable power supply to the entire grid could
become unstable. This presents there is like diversity of challenges should be mitigate.
To overcome this type of challenges, we need an operative technology that could be “stores electrical power.”
Through storing electrical energy in energy storage systems, we could match electrical load and encouraging the
efficient use of energy as our demand. Energy storage systems serve as back-up power sources in an emergency
supply as well [11], [12].
P a g e | 12
PROPERTIES OF DEEP- CYCLE
ACID BATTERY
LEAD-
APPLICABILITY 10 MW AND SMALLER
PROPERTIES OF LITHIUM- ION BATTERY
APPLICABILITY 10 MW AND SMALLER
SYSTEMS
SYSTEMS
Charge rate 0.1–1.5 kW per battery
Charge rate 0.2–2 kW per battery
Discharge rate 0.5–2 kW per battery
Discharge rate 0.5–10 kW per battery
Lifetime
Lifetime
Time 3 to 10 years
Cycles 500–800 cycles
Time 10–15 years
Cycles 2,000–3,000 cycles
Initial capital cost
Initial capital cost
Cost/discharge power $300–$800/kW
Cost/discharge power $400–$1,000/kW
Cost/capacity $150–$500/kWh
Cost/capacity $500–$1,500/kWh
Table: Cost and other comparison, Lead-acid and Li-ion storage battery
Grid energy storage i,e, large scale energy storage refers to the strategy used to store electricity on a large scale
within an electrical power grid. Electrical energy is stored during times when production (from grid) exceeds
consumption and the stores are used at times when consumption exceeds production.
Generally Li-ion and Lead-acid battery used for grid storage system but Lead acid is more preferable because of
its cheaper than Li-ion from all over the cost.
2.2 WIND POWER PRODUCTION:
CHARACTERISTICS OF WIND POWER GENERATION:
In this segment we are going to discuss in extra detail wind as a renewable power generation source, including
its fluctuating character and the physical boundaries for utilizing this natural resource.
WHAT IS MEANT BY WIND?
Wind is simply as we can define air in motion and it is produced by the irregular heating of the Earth’s surface
by energy spreads from the sun. Since the Earth’s surface is made of very different forms of land and water, it
absorbs the sun’s radiant energy at different rates, because all of the absorbing objects are not same characteristic
to absorb. Most of this energy is usually converted into heat as it is absorbed by land areas, bodies of water, and
the air over these formations [13], [15].
PHYSICS OF WIND:
The wind energy comes from the sunlight radiation form sun. When the sun shines, some of its light (radiant
energy) reaches the Earth’s surface and the Earth near the Equator receives more of the sun’s energy than the
North and South Poles. Generally some parts of the Earth absorb more radiant energy than others parts and some
energy reflect more of the sun’s rays back into the air. The fraction of light which is striking a surface that gets
P a g e | 13
reflected is called Albedo as we can see in the figure below and also we can see which objects probably how
much percentage energy reflects [13].
Figure: 2.8 Earth´s surface and objects reflects different amount of sunlight.
Source: [13]
When the Earth’s surface absorbs the sun’s energy by the different objects, it turns the light into heat energy.
This heat on the Earth’s surface warms the air above it. The air over the Equator gets warmer than the air over
the poles, the air over the desert gets warmer than the air in the mountains. The air over land usually gets warmer
than the air over water and we know that fair getting warms, it must expand. We know from the physics that the
warm air is less dense than the air around it and rises into the atmosphere. This moving air is what we call wind
and which is caused by the uneven heating of the Earth’s surface [13], [15].
The power of an air mass that flows at wind speed V through an area A can be calculated by the following
equation:
ଵ
ܲ‫݀݊݅ݓ݊݅ݎ݁ݓ݋‬ǡ ܲ ൌ ߩ‫ ܸܣ‬ଷ ሺ‫ݏݐݐܽݓ‬ሻ
ଶ
2.3.1
Where,
ߩ ൌ ܽ݅‫ݕݐ݅ݏ݊݁݀ݎ‬ǡ
݇݃
‫݁ݎݑݏݏ݁ݎ݌݀݊ܽ݁ݎݑݐܽݎ݁݌݉݁ݐݐܾ݊݁݅݉ܽ݀ݎܽ݀݊ܽݐݏ‬
݉ଷ
‫ ܣ‬ൌ ‫ܽ݁ݎܽݐ݌݁ݓݏ‬ǡ ݉ଶ ሺ‫ ܣ‬ൌ ߨ‫ ݎ‬ଶ ሻ
P a g e | 14
‫ ݎ‬ൌ ‫݈ܾܾ݁݀ܽ݁݊݅ݎݑݐ݄݁ݐ݂݋ݏݑ݋݅݀ܽݎ‬ǡ ݉
ܸ ൌ ‫݀݁݁݌ݏ݀݊݅ݓ‬ǡ ݉Ȁ‫ݏ‬
The power in the wind is directly proportional to the air density, by the capturing area A (e.g. the area of the
wind turbine blades) and the cube of the velocity V.
The air density as we can see in the following equation and which is a function of the height above sea level of
both air pressure and air temperature:
ߩሺ‫ݖ‬ሻ ൌ
௉బ
ோ்
‡š’ ቀ
ି௚௭
ோ்
ቁ
2.3.2
Where,
ߩሺ‫ݖ‬ሻ ൌ ܽ݅‫݁݀ݑݐ݅ݐ݈݂ܽ݋݊݋݅ݐܿ݊ݑ݂ܽݏܽݕݐݏ݅ݏ݊݁݀ݎ‬ሺ݇݃݉ିଷ ሻǢ
ܲ଴ ൌ ‫ݕݐ݅ݏ݊݁݀ܿ݅ݎ݄݌݄ݏ݋݉ݐ݈ܽ݁ݒ݈݁ܽ݁ݏ݀݁ݎܽ݀݊ܽݐݏ‬ሺͳǤʹʹͷ݇݃݉ିଷ ሻ;
ܴ ൌ ‫ݎ݅ܽݎ݋݂ݐ݊ܽݐݏ݊݋ܿݏ݂ܽ݃ܿ݅݅ܿ݁݌ݏ‬ሺʹͺ͹ǤͲͷ‫ି݃݇ܬ‬ଵ ‫ି ܭ‬ଵ ሻǢ
݃ ൌ ݃‫ݐ݊ܽݐݏ݊݋ܿݕݐ݅ݒܽݎ‬ሺͻǤͺͳ݉‫ି ݏ‬ଶ ሻǢ
ܶ ൌ ‫݁ݎݑݐܽݎ݁݌݉݁ݐ‬ሺ‫ܭ‬ሻǢ
‫ ݖ‬ൌ ݈ܽ‫݈݁ݒ݈݁ܽ݁ݏ݁ݒ݋ܾܽ݁݀ݑݐ݅ݐ‬ሺ݉ሻǤ
The kinetic power in the air is the amount of total available energy per unit of time and which is converted into
the mechanical into rotational energy of the wind turbine rotor, which results in a reduced speed in the air mass.
The power is produced in the wind cannot be extracted 100% by a wind turbine, as the air mass would be
stopped completely in the capturing rotor area [15].
The theoretical optimum power for utilizing in the wind by reducing its velocity was first published by the
German scientist Betz, in 1926. According to Betz, theory the theoretical maximum power that can be extracted
from the wind is:
ଵ
ଵ
ଶ
ଶ
ܲ஻௘௧௭ ൌ ߩ‫ ܸܣ‬ଷ ‫ܥ‬௣ǡ௕௘௧௭ ൌ ߩ‫ ܸܣ‬ଷ ͲǤͷͻሺܹܽ‫ݏݐݐ‬ሻ2.3.3
Where, Cp, betz is the turbine coefficient or Betz coefficient.
Therefore, even if power extraction without any losses were possible, only 59% of the wind power could be
possible to utilize by a wind turbine [11c].
THE POWER CURVE:
ƒ
ƒ
ƒ
Power curve versus wind speed
Below rated: Maximizing power extraction (Rigion-2)
Above rated: Constant power produce (Rigion-3)
As explained by Equation (2.3.1), the available energy in the wind varies with the cube of the wind speed. Hence
a 10% increase in wind speed will result in a 30% increase in available energy.
P a g e | 15
The power curve of a wind turbine build a relationship between cut-in wind speed (the speed at which the wind
turbine starts to operate) and the rated capacity, approximately (see also Figure 2.9). The wind turbine usually
reaches rated capacity at a wind speed of between 12-16 ms-1, depending on the design of the individual wind
turbine [13], [15], and [16].
Below rated
Above rated
Power
captured
ܸ௖௨௧ି௜௡
ܸ௥௔௧௘ௗ
ܸ௖௨௧ି௢௨௧
Wind speed
Figure: 2.9 Power curve versus wind speed of a wind turbine
At wind speeds higher than the rated wind speed, the maximum power production will be limited. The power
output regulation can be achieved with pitch-control (i.e. by feathering the turbine blades in order to control the
power) or the aerodynamic design of the rotor blade will be regulating the power of the wind turbine).
Therefore, a wind turbine produces maximum power within a certain wind interval that has its upper limit at the
cut-out wind speed. The cut-out wind speed is the wind speed where the wind turbine stops production and turns
out of the main wind direction. Typically, the cut-out wind speed is in the range between 20 to 25 ms-1.
The power curve depends on the air pressure or in other words we can say the power curve varies depending on
the height above sea level as well as on changes in the aerodynamic form of the rotor blades, which can be
caused by dirt or ice. The power curve of fixed-speed, stall-regulated wind turbines can also be influenced by the
power system frequency.
Finally, the power curve of a wind farm is not automatically made up of the scaled-up power curve of the
turbines of this wind farm, owing to the shadowing or wake effect between the turbines. For instance, if wind
turbines in the first row of turbines that directly face the main wind direction experience wind speeds of 15 ms -1,
the last row may ‘get’ only 10 m/s in figure: 2.9.
P a g e | 16
WIND POWER BACKGROUND:
The kinetic energy in the air is a more powerful and promising source of renewable energy with extensive
potential in many parts of the world [16]. This energy which can be captured by wind turbines is vastly
dependent on the weather and mainly on local average wind velocity. The regions that usually the most attractive
potential are located near coasts, inland areas with open terrain or on the edge of bodies of water. Some
mountainous areas also have good potential [16] for the renewable energy.
Over the past 30 years wind is the most prevailing source of the renewable energy, and the wind power has
become a mainstream source of electricity generation all over the world. However, the future of wind power will
be governed by a great deal on the capability of the industry to continue to achieve the minimization of cost of
energy [17].
The wind turbines convert the kinetic energy in moving air into revolving energy, which in turn is converted to
electricity. Since wind speeds vary from month to month and second to second depending on the climate, the
amount of electricity wind can make varies constantly. Sometimes a wind turbine will make no power at all. This
variability of the wind does affect the value of the wind power, but not in the way many people expect.
DESCRIPTION OF WIND TURBINES
Wind turbine technology has extended an advanced status during the past 15 years as a result of international
commercial competition, mass production and continuing technical success in research and development (R&D).
The previous concerns that wind turbines were expensive and unreliable have largely been calmed. Wind energy
project costs have declined and wind turbine technical availability is now consistently above 97%. Wind energy
project plant capacity factors have also progressed from 15% to over 30% today, for sites with a good wind
management [16].
SWEPT AREA
OF THE
ROTOR
DIAMETER
ROTOR
NACELLE WITH
GEARBOX AND
GENERATOR
TOWER
UNDERGROUND
ELECTRICAL CONNECTION
(front view)
Figure: 2.10. Schematic diagram of a wind turbine
HUB
FOUNDATION (side
view)
P a g e | 17
Modern wind energy systems operate automatically. The wind turbines depend on the same aerodynamic forces
created by the wings of an aero-plane to cause rotation. An anemometer that continuously measures wind speed
are part of most wind turbine control systems. When the wind speed is sufficient to overcome friction in the
wind turbine drive train, the controls consent the rotor to rotate, hence generating a very small amount of power.
The cut-in wind speed is usually a gentle drift of about 3 m/s.
Power output increases rapidly as the wind speed rises. When output reaches the maximum power the machinery
was designed for, the wind turbine controls govern the output to the rated power [16]. The winds speed at which
rated power generate is called the rated wind speed of the turbine, and is commonly a strong wind of about 15
m/s. eventually, if the wind speed increases further, the control system shuts the wind turbine down to prevent
damage to the machinery. This cut-out wind speed is usually around 25 m/s.
The main equipment of modern wind energy systems typically consist of the following:
ƒ
ƒ
ƒ
ƒ
ƒ
Turbine rotor, with 2 or 3 blades, but at present most of the turbines are used 3 blades, which converts
the kinetic energy in the wind into mechanical energy into the rotor shaft.
Gearbox to match softly turning rotor shaft to the electric generator.
Hightower which supports the rotor high upstairs the ground to capture the higher wind speeds.
Concrete foundation to prevent the wind turbine from blowing over in high winds and icing conditions
and
Intelligent Control system to start and stop the wind turbine and to monitor for properly operates of the
machinery.
In figure 2.10 we can see the arrangement of a typical “Horizontal Axis Wind Turbine” or HAWT wind energy
system. A “Vertical Axis Wind Turbine” or VAWT is an equally feasible alternative design, although it is not as
common as the HAWT design in modern projects implemented around the world.
MODERN WIND RYRBINES AND WORKING PRINCIPLE:
Currently, wind is converted into electricity using machines which is known as wind turbines. Turbine produces
the amount the electricity that depends on its size of the turbine and speed of the wind.
Most large wind turbines have the identical basic parts: blades, a tower, and a gear box. All of these parts work
together to convert the kinetic energy into rotation that generates electricity. Below we have discus in brief
detail the process works like this [13]:
o
o
o
o
o
Initially, the moving air spins the turbine blades.
The blades are connected to a low-speed shaft. When the blades spin, the shaft turns
slowly.
The low-speed shaft is joined to a gear box. Inside the gear box, a large slow-moving
gear turns a small gear rapidly.
Inside this small gear turns another shaft at high speed.
The high-speed shaft is connected to a generator to produce electricity. Since the highspeed shaft turns the generator, it produces electricity.
P a g e | 18
o
The produced electric current is transmit through cables down the turbine tower to a
transformer that changes the voltage of the current before it is sent out on transmission
lines.
Figure: 2.11 Wind turbine internal views and devices
Source: [13]
GROWTH AND SIZE OF THE WIND TURBINE:
In figure 2.12 as we can see the evaluation of typical wind turbine, the modern era of wind power began in 1979
with the mass production of wind turbines by Danish manufacturers Kuriant, Vestas, Nordtank and Bonus. These
early wind turbines typically had small capacities (10 kW to 30 kW) by today’s standards, but pioneered the
development of the modern wind power industry that we see today.
The current average size of grid-connected wind turbines is around 1.16 MW (BTM Consult, 2011), while most
new projects use wind turbines between 2 MW and 3 MW. Even larger models are available, for instance RE
Power’s 5 MW wind turbine has been on the market for seven years. When wind turbines are grouped together,
they are referred to as “wind farms”. Wind farms comprise the turbines themselves, plus roads for site access,
buildings (if any) and the grid connection point [14], [18].
P a g e | 19
Figure: 2.12. Growth in the size of wind turbines since1985
Source: upwind [14]
Wind power technologies arise in a numerous of sizes and styles and can usually be categorized by whether they
are horizontal axis or vertical axis wind turbines (HAWT and VAWT), and by whether they are positioned
onshore or offshore. The wind power generation by turbines is determined by the capacity of the turbine (in kW
or MW) and depend on the wind speed, and the height of the turbine and the diameter of the rotors blades.
The turbine size and the type of wind power system are usually interrelated. Today’s utility-scale wind turbine
generally has three blades, sweeps a diameter of about 80 to 100 meters, has a capacity from 0.5 MW to 5 MW
and is part of a wind farm of between 15 and as many as 150 turbines that are connected to the grid [14].
WIND TURBINE PRICE INDEX:
The wind turbine is the largest single cost component of the total installed cost of a wind farm. Between 2000
and 2002 turbine prices for onshore wind farms averaged USD 700/kW, but this had risen to USD 1 500/kW in
the United States and USD 1 800/kW in Europe in 2009 in figure 2.13. This increase was due to rising costs for
materials and civil engineering, high profit margins for wind turbine manufacturers, and larger turbines that cost
more but achieve higher capacity factors. [18], [19].
P a g e | 20
WIND TURBINE PRICE INDEX
Wind turbine prices, (2010 USD thousands/kW)
2
1.73 1.71
1.8
1.6
1.35 1.37
1.4
1.2
1.13
1.23
1.43 1.47 1.46
1.57 1.57
1.51
1.46
1.4
1.4
1.4
1.38
1.26
1
0.8
0.6
0.4
0.2
0
2004 2004 2005 2005 2006 2006 2007 2007 2008 2008 2009 2009 2010 2010 2011 2011 2012 2012
H1 H2 H1 H2 H1 H2 H1 H2 H1 H2 H1 H2 H1 H2 H1 H2 H1 H2
Yearly turbine price index
Figure: 2.13 Wind turbine price index by delivery date, 2004 to 2012
Source: IRENA 2012
Since the peak prices of around USD 1 800/kW in Europe and USD 1 500/kW in the United States for contracts
with a 2008/2009 delivery, wind turbine prices have started to fall. Preliminary data for 2012 projects suggest
quotes between USD 900 and USD 1 270/kW in the United States, which would represent a decline of around
a quarter, compared to peak prices. This is in line with the BNEF Wind Turbine.
Price Index, which indicates average turbine, prices outside Asia of around USD 1 200/kW for 2012 in figure
2.14.
Figure: 2.14 Wind turbine price in the United States and China compared to the BNEF wind turbine price index,
1997-2012
Source: IRENA 2012, Renewable power generation cost.
P a g e | 21
These cost reductions are occurring at the same time as the yield of a given turbine is being improved by
increased average hub heights and rotor diameters. In addition, a more buyerfriendly market has meant that
better terms and conditions are being offered by manufacturers, including longer initial O&M
contracts, improved warranty terms, better performance guarantees and shorter lead times for delivery.
The increased competition in the wind turbine market is partly due to the rise of Chinese and other emerging
market manufacturers. Chinese manufacturers have increased capacity significantly above domestic demand,
resulting in domestic turbine prices averaging USD 658/kW in 2010 and falling to between USD 580 and
USD 610/kW in 2011 (CWEA, 2012), before rebounding slightly to an average of USD 630/kW in 2012.
Chinese manufacturers are therefore very competitive potential suppliers in the international market, although
not all Chinese manufacturers’ products are necessarily suited to international markets. [19].
OPERATIONS AND MAINTENANCE COSTS (ONSHORE) BY COUNTRY:
In this section we are going to discuss the fixed and variable operations and maintenance (O&M) costs, which
are a significant part of the overall LCOE of wind power. European countries tend to have higher cost structures
for O&M for onshore wind projects (Table 4.4) where an average value of between USD 0.02 and
USD 0.03/kWh is the norm [18],[19].
Country
AUSTRIA
DENMARK
FINLAND
GERMANY
ITALY
JAPAN
THE NETHERLANDS
NORWAY
SPAIN
SWEDEN
SWITZERLAND
UNITED STATES
Table: 1
Variable (2011
USD/kWh)
Fixed (2011 USD/kW)
0.038
0.0144 - 0.018
35 - 38
64
47
71
35
0.013 – 0.017
0.020 – 0.037
0.027
0.010 – 0.033
0.043
0.010
Source: IRENA, Renewable power generation cost, 2012
O&M costs for offshore wind farms are significantly higher than for onshore wind farms due to the higher costs
involved in accessing and conducting maintenance on the wind turbines, cabling and towers. Maintenance costs
are also higher as a result of the harsh marine environment and the higher expected failure rate for some
components. Overall, O&M costs are expected to be in the range of USD 0.027 to USD 0.054/kWh (ECN, 2011)
[18], [19].
P a g e | 22
2.3 SOLAR POWER PRODUCTION
In this section we will extant the detail concerning of the solar technology and energy production from solar
system.
The output power of each PV system, with respect to the solar radiation power, can be calculate by the following
equation:
ܲ௏ ൌ ߝ௚ ܰ‫ܣ‬௠ ‫ܩ‬௧
(7)
Where,
ߝ௚ =is the instantaneous PV generator efficiency (dimensionless)
‫ܣ‬௠ =is the area of a single module used in a system (m2)
‫ܩ‬௧ = is the global irradiance on the titled plane (W/m2) and
ܰ=is the number of module, which is used in the system
SOLAR ENERGY TECHNOLOGIES:
Solar system is the promising technologies to produce electricity from the energy of the sun by using photo
electric effect. There is variety size of solar energy systems which can provide electricity for homes, businesses,
and remote power supply in small solar system and larger solar energy systems provide more electricity for
contribution to the industries, heavy electric power system site and so on.
PHOTOVOLTAIC:
The Photovoltaic (PV) materials and strategies convert sunlight into electrical energy, and PV cells are
commonly known as solar cells. Photovoltaic can accurately be translated as light-electricity.
First used in about 1890, "photovoltaic" has two parts first one is: photo, derived from the Greek word for light
and the second one is volt, relating to electricity innovator Alessandro Volta. According to the French physicist
Edmond Becquerel discovered as early as 1839,photovoltaic materials and devices which is convert light energy
into electrical energy.
Becquerel discovered that the procedure of using sunlight how to produce electric current in a solid material.
This process had recognized by more than another century to truly understand this process.
PV systems are by this time a significant part of our daily lives in world wide. The PV systems provide power
for small electronic devices such as calculators and wristwatches and in complicated systems provide power for
communications satellites, water pumps, and the lights, appliances, and electric machines in construction site and
workplaces. Numerous road and traffic signs also are now powered by PV. In several cases, PV power is the
least expensive form of electricity than other technology to produce electrical energy [19] ,[20] and [22].
PHOTOVOLTAIC CELLS:
Photovoltaic (PV) cells, or solar cells, produce electricity taking benefit of the photoelectric effect. PV cells are
the fundamental element of all PV systems for the reason that these are the devices that convert sunlight to
produce electricity.
P a g e | 23
Universally PV cells are electricity-producing devices which are made of semiconducting materials. There is in
many sizes and shapes of PV cells, it’s normally a several inches. They are often attached together to form PV
modules that may be up to several feet long and a few feet wide or according to power rating of the modules.
A small number of modules combined and connected to make PV arrays of different sizes and rated power
output. The modules of the array build up the major part of a PV system, after then include electrical
connections, mounting hardware, power-conditioning equipment, and batteries that store solar energy for use
when the sun is not shining as a backup power [19].
WORKING PRINCIPLE:
Light from sun incident on a PV cell, it may be reflected, absorbed, or pass right through according to the photo
electric effect; but only generates electricity from the absorbed light. The energy produced from the absorbed
light which is transferred to electrons in the atoms of the PV cell of semiconductor material. The brand-new
energy, these electrons escape from their normal positions in the atoms and in an electrical circuit these are turn
into part of the electrical flow, or current[21].
TYPES OF SOLAR CELLS:
The families of PV technologies and revolution are illustrating in the figure below. In this figure: 2.15 we have
focuses on crystalline silicon (c-Si) and thin films, i.e. mono- and multi-c-Si, and amorphous silicon, CdTe and
CIS/CIGS [21].
PHOTOVOLTICS/SOLAR CELLS
CRYSTALLINE SILICON CELLS
Monocrystalline
Multicrystalline
MULTIJUNCTION
THIN-FILM CELLS
Quasimono
Amorphous
Hybrid
Thinfilmsilicon
CIS/CIGS
Micro-crystalline
CdTe
Dye cells
Various III-V
Semi-conductor
combinations
Organic
cells
Micromorphous (tendem cells)
Figure: 2.15 Classification of solar cells
Figure source: [21]
CRYSTALLINE SILICON CELLS IN COMMERCIAL VIEW:
The universally used as a photovoltaic cells are the crystalline silicon PV cells. Hence, for a suitable example of
typical PV cell system the crystalline silicon solar cells are be responsible [22].
P a g e | 24
In large-scale, that means commercially PV power plants is dominated by crystalline silicon and cadmium
telluride and besides this crystalline silicon solar cells have many benefits: In commercially the poly and monocrystalline silicon modules now achieve to just over 20 percent efficiency [22].
ƒ
ƒ
ƒ
Outstanding to the relatively high efficiency than other modules.
A lesser amount of installation area is required per unit of output, that means fewer mounting frames
and cables are needed and
New “quasi-mono” wafers realize correspondingly high efficiencies to mono-crystalline solar cells.
Since thin-film modules are significantly less efficient, they need to cover up to 30 percent more surface area
than crystalline silicon modules to achieve the same output and needs to increase installation cost, support
frames and cabling. Conversely, the intensive research and development the efficiency of thin-film modules is
currently improving at a faster rate than that of crystalline silicon modules [23].Therefore, large-scale PV plants
equipped with thin-film modules can generally produce power just as cheaply as those constructed using
crystalline modules.
PV ELECTRICAL CONTACTS:
Layers on the outermost of photovoltaic (PV) cells are the electrical contacts and anti-reflective coating these are
the most important part in solar system. These layers are responsible for vital purposes to the cell's operation and
to produce electricity suitably.
ELECTRICAL CONTACTS:
In solar system electrical contacts are most vital part to PV cells because they link the connection between the
semiconductor device and the external electrical load.
The front contact to permit electrons to enter an electrical
circuit, a back contact to allow them to complete the circulation,
after in the semiconductor layers where the electrons begin and
complete their circulation.
In the back contact of a cell the entering sun lights relatively
simple than other. It commonly is made up of a layer of
aluminum or molybdenum metal alloy.
Figure: 2.16. Electrical contacts of a solar system.
Source: [22]
The back contact of a cell is side away from the incoming sun lights relatively simple. It commonly is made up
of a layer of aluminum or molybdenum metal alloy.
On the other hand the front contact the side ways in front of the sun is more difficult. Although sunlight shines
on a PV cell, a current of electrons flows over the surface. To collect the most current, contacts must be placed
across the surface of the cell. Nevertheless, placing a large grid, on top of the cell shades active parts of the cell
from the sun and reduces the cell's conversion efficiency.
P a g e | 25
The shading effects must be reduced
to increase conversion efficiency.
One more challenge in cell design when applying grid contacts to the solar cell
material is to reduce the electrical resistance losses. These losses are interrelated to
the solar cell material's property of opposing the flow of an electric current, which
results in thermal losses in the material. As a result, shading effects must be stable
against electrical resistance losses. The normal methodology is to design grids
with many thin, conductive fingers that spread to each part of the cell surface. The
fingers must be thick enough to conduct well with low resistance, but thin is not
sufficient to block too much entering sun light [22].
Figure: 2.17. Grid contacts on the top surface of a solar cell.
Source: [22]
PHOTOVOLTAIC SYSTEMS:
A photovoltaic (PV)system, is made up of several
photovoltaic solar cells. Separately a PV cell is
commonly small of size; typically contain about 1
or 2 watts of power to each cell. To get high the
power output of PV cells are combined together to
form larger units called modules. The modules
can be connected to arrangement even larger units
called solar arrays, which can be interconnected to
produce more power produce. In this approach,
PV systems can be built to meet any electric
power need, small or large scale to meet the
demand of the load [22].
Figure: 2.18 Photovoltaic (PV) or solar systems.
Figure source: [22]
Through just solar modules or arrays does not represent a complete PV system. In the solar system include
structures that plug them toward the sun and components that take the direct-current electricity produced by
modules and after then usually converting it to alternate current. PV systems may also include batteries to
storage electrical energy as comically. Also more component included these substances are denoted to as the
balance of system (BOS) components to complete structures of the solar system.
Well arrangements of modules with BOS components create a complete PV system. In this complete system is
usually all elements are required to meet a particular energy demand, such as powering in electric construction
equipment site, the appliances and lights in a home and electrical machines charging and so on[19],[20] [22].
P a g e | 26
CONCENTRATING SOLAR POWER
In modern technology the concentrating solar power (CSP) use mirrors or lenses to reflect and concentrate
sunlight by the receivers to collect solar energy and
convert this energy to heat energy.
This heat energy is used through a steam turbine that
drives to produce electricity.
Concentrating solar power deals with a utility-scale,
firm, dispatch-able renewable energy options that
can help meet our demand for electricity in daily
used. CSP system produce power by first using
mirrors to concentrate sunlight to heat a working
fluid in the system. Eventually, this high-temperature
fluid is used to spin a turbine and by an engine that
drives a generator and this ultimate product of this
process is electricity.
Figure: 2.19 Concentrated solar power (CSP) system and its structure.
Figure source: [19]
There are several varieties of CSP systems are used, there is some CSP system is briefly discussed:
ƒ
ƒ
ƒ
ƒ
Linear Concentrated System
Dish or Engine System
Power Tower System and
Thermal Storage System
P a g e | 27
LINEAR CONCENTRATING SYSTEMS FOR SOLAR POWER:
In this promising technology that means Linear concentrating
solar power (CSP) collectors capture the energy from the sun
with large mirrors that reflect and focus the sunlight onto a linear
receiver tube. The receiver holds a fluid that is heated by the
sunlight and this produce superheated steam which is spins a
turbine that drives a generator to produce electricity. On the other
hand, steam can be generated directly in the solar field that
removes the need for costly heat exchangers [19].
Figure: 2.20. Linear concentrator System,
Source: Sandia National Laboratory / PIX 14955
Linear concentrating collector that are usually aligned in a north-south orientation to maximize annual and
summer energy collection which is contain of a large number of collectors in parallel rows. Through a singleaxis sun-tracking system, this arrangement enables the mirrors to track the sun from east to west during the day,
which ensures that the sun reflects continuously onto the receiver tubes to smoothly power produce.
PARABOLIC TROUGH SYSTEMS:
In the United States the most common CSP system is a linear concentrator that uses parabolic holder collectors.
In this approach, the receiver tube is located along the focal line of each parabola-shaped reflector in
arrangement. The heated fluid either a heat-transfer fluid or water or steam flows through and out of the field of
solar mirrors to where it is used to create steam and the tube is fixed to the mirror structure.
Figure: 2.21. Linear concentrator power system using parabolic trough collectors.
Source: [21]
In these systems, the collector field is oversized to heat a storage system during the day which could be used in
during cloudy weather or when sunlight is not incident to generate extra steam to produce electricity. This
parabolic trough plants can also be designed as hybrid system that means they use fossil fuel to complement the
solar output during periods of low or zero solar radiation. In such way of a design, a natural gas-fired heater or
gas-steam boiler or reheated are used to produce electricity.
P a g e | 28
LINEAR FRESNEL REFLECTOR SYSTEMS
Other linear concentrator technology is the linear Fresnel reflector system. Slightly or flat curved mirrors
attached on trackers on the ground are to reflect sunlight onto a receiver tube which is fixed in space above the
mirrors. On other hand a small parabolic mirror is occasionally fixed on upper the receiver to further focus the
sunlight.
Figure: 2.22: A linear Fresnel reflector power plant.
Source: [22]
DISH OR ENGINE SYSTEMS CONCENTRATING SOLAR POWER
The dish or engine system is a concentrating solar power (CSP) technology which is produces relatively small
amounts of electricity than other CSP technologies, usually in the small range of 3 to 25 kilowatts. These
systems use a parabolic dish of mirrors and concentrate sunlight onto a central engine to produces electricity.
There is two major parts of this system first on is the solar concentrator and the second one is the power
conversion unit, which is convert power.
Figure: 2.23: A dish/engine power plant
Source:[22]
POWER TOWER CONCENTRATING SOLAR PLANT
In power tower concentrating solar systems are used, various large, flat, sun-tracking mirrors, known as
heliostats focus sunlight onto the top of a tall tower of a receiver. In the receiver, heat transfer fluid heated is
used to generate steam which is used in a conventional turbine generator to produce electricity [22]. In another
P a g e | 29
advanced designs are investigating with molten nitrate salt because of its superior heat-transfer and energystorage capabilities. Separately commercial plants can be sized to produce electricity up to 200 megawatts.
Figure: 2.24: A power tower concentrating power plant.
Source: [22]
In Spain there are several power tower systems. There is Plant a Solar 10 and Plant a Solar 20 are water or steam
systems with capacities of 11 and 20 megawatts, respectively. Solar Park will produce some 15 megawatts of
electricity and it has the capacity for molten-salt thermal storage system to produce electricity.
P a g e | 30
3. MODELING APPROACH
3.1 RESEARCH METHODOLOGY
This chapter describes the process of scientific research, from recognizing and developing a topic for
investigation to replication of results. The first section we are going to briefly introduces the steps in the
development of a research topic.
In this chapter we are going to describes the processes involved in identifying and developing a topic for
research investigation to make a valuable result. It was submitted that researchers consider several sources for
potential ideas, including a critical analysis of normal situations for research.
In developing stage a topic for investigation naturally would be easier with experience, at the beginning of
research need to pay specific attention to material already available in existing work. We should not attempt to
throw extensive research questions, but should try to isolate a smaller, more practical subtopic for literature
study. We should improve an appropriate method of analysis and then continue, through data analysis and
interpretation, to a clear and concise presentation of results during study [23].
The rigorous observation and experiment are characteristic of the scientific method to make better result. To
meet this goal, researchers should follow the prescribed steps shown in Figure 3.1. This research model is
suitable to all areas of scientific research to precise research result [23].
RESEARCH METHODOLOGY STEPS
selection a
problem
review of
existing
research and
theory
statment of
hypothesis or
research
questionn
determinatio
n of
approperiate
methodology
and rearch
design
Data
collection
Analysis and
interpretatio
n of data
Presentation
of results
Replication
Figure: 3.1 Steps in the development of a research project
Source: [23]
P a g e | 31
3.2 HIGH LEVEL SITE MODEL
MODELING
The persistence of this chapter is to introduce the research strategies applicable to this thesis work and the
empirical techniques applied. This chapter defines the scope of high level model of the micro-grid design, and
situates the research amongst existing research traditions in information systems.
This chapter is divided into three sections. In the first, High Level Site Model of the grid model in the field of
design information and modeling. In the next section is about the sub-model strategy of different machines load.
In the third section would be the sub-model of renewable energy sources-wind and solar power. Finally, section
three deals with sub-model of the storage energy of the Micro-grid system and covers the reason for selecting the
technology.
3.2.1 PROPOSED MODEL:
In this micro-grid design we have integrated five sections, which are fundamental part of the micro-grid. Hence,
this micro-grid system possesses the flexible ability to accomplish the efficient energy delivery to the site loads.
ƒ
Renewable energy sources
ƒ
Utility grid energy
ƒ
Storage energy
ƒ
Output loads and
ƒ
Intilligent control system
Renewable energy sources: In these units the power generation sources are interconnected to the micro grid bus
and intelligent control system.
Utility grid energy: The micro grid bus is also connected to the utility grid to get emergency power supply, but
this is optionally connected.
Storage energy: Generally, we can not 100% used of total produced energy, so excess energy we have to store
that which could be use needed more power.
Output loads: There is some electric construction equipments as loads (DC/AC) and there could some small
industries as well.
Intelligent control system: In our design we have included a intelligent control system, which would be control
and monitor the whole grid.
P a g e | 32
Figure 3.2:- Proposed micro-grid model:
11KV AC TX-Line
Transformer
SUB STATION
48V DC Loads
AC feedin 1KV
Ac to Dc
rectifire
Local PV
panels
Local Wind
Power
MPPT
AC/DC
Site:DC
Auxiliaries
DC/DC
Lighting
Fans
Laptop/Desktop
LED lighting
.
480V DC Bus
DC/DC
DC/DC
AC/DC
Machine
ESS
Grid ESS
Power units
ICE Genset (diesel, gas,
biogas etc)
Power
management
system (PMS)
Charger
DC/DC
Charger
DC/DC
Charger
DC/DC
Commercial Machines
1-߮ 460V AC
DC/AC
Loads with
230V AC
DC/AC
P a g e | 33
HYBRID SYSTEM MODEL
In this section we are going to discuss about the beneficial points and side, the renewable energy sources became one of the most pleasing issues in modern industry, as they
benefit both global economy and social business.
Solar
Module
Array
GENSET
Interconnections
Load
AC
or
DC
Charge Controller/
Inverter
Wind
Turbine
Array
Figure: 3.3 Hybrid system model
Battery
Battery
Battery
Battery
Battery
Battery
Battery
Battery
Storage
Battery
P a g e | 34
In this section we are going to discuss about the beneficial points and side, the renewable energy sources became
one of the most pleasing issues in modern industry, as they benefit both global economy and social business. A
big number of countries have already realized successful projects of solar, wind and tidal power plants, using the
possibilities provided by local natural conditions. Mostly it is related to highly developed states, which have
technological achievements and great financial support, but, amazingly, they do not refuse from usage of fossil
fuels totally.
In actual fact, renewable energy is not so constant and it depends on the local environment, as people may think.
There are some hour to hour and even daily changes, which obstruct total confidence on solar or wind stations.
In reason of their rational usage, certain countries constructed hybrid power stations that unite energy generation
from different sources.
All things in figure 3.3 we have that considered, hybrid power systems are referred to as perspective ones
nowadays regardless provided examples. This technologies might be consist as a transitive stage between usage
of conventional fuels and larger distribution renewable energy sources, the long-standing goal of global society
to effectively power supply.
3.2.2 SYSTEM MODEL OF MICRO-GRID
This is system or power flow model, by using this diagram we can observe that which type of energy sources are
connected and total how much power going to produce.
SITE-1(wind)
SITE-2(solar)
SITE-3(ICEDC)
AC/
DC
DC/
DC
DC/
DC
TOTAL
POWER
GENERATE,
∑P
SITE-4(Fuell
Cell)
DC/
DC
SITE-5 (AC
Tx-Line)
AC/
DC
DC/
AC
POWER
MANAGEMENT
SYSTEM
DC/
AC
LOAD
BALANCING
SYSTEM
DC/
DC
DC/
DC
BACK-UP
POWER
DC/
DC
DC/
DC
DC/
DC
LOAD-1
LOAD-2
LOAD-3
LOAD-4
LOAD-5
STORAGE
POWER
Figure: 3.4 System Model Of the micro-grid
Also from this diagram we can understand the types of loads are consuming in the site. And there is some
optional energy sources, which are mostly would be inactive, if necessary in emergency cases then will be used.
P a g e | 35
3.3 SUB-MODELS OF WIND POWER
STEP UP
TRANSFORMER
+
ADDER
Wind Turbine Array
(AC)
Figure: 3.5 Sub-Model of wind power system
P a g e | 36
3.4 SUB-MODEL OF SOLAR POWER
Solar Module Array (DC)
+
ADDER
+
CONVERTER
(DC/ DC)
+
Figure: 3.6 Sub-Model of solar power system
In our design the solar array should be arrangement like above figure 3.6.This alignment would be easy
deployment and for wiring system than other and it is more effective design as well.
If we set-up the solar module as round that means circular form then it will be less efficient for grounding
system, but in concentrating solar system its more efficient and more effective to produce solar power.
P a g e | 37
3.5 SUB-MODEL GRID STORAGE ENERGY:
In this figure: 3.7 we have showed the battery pack sub model of the energy storage system. There are 40
batteries of 12Volt rating individual and the current rating 80Amp. The battery pack voltage 480 volt DC
designed because of the bus voltage of the micro-grid is 480 Volt DC.
STORAGE BATTERY ARRAY
(80Ah) 12VX40=480Volt
CHARGE
CONTROLLER
Figure: 3.7 Sub model of grid storage system
P a g e | 38
4. CASE STUDIES
4.1 SITE DESCRIPTIONS:
In this project we have indicate a site with some electric machines for case studies. Below the table we have put
machines details and during the working hour how much power consumed as well. With this machine we have
made a site load distribution and plotted the curve. From this figure as we can see that, total power consumption
in a day. According to these machines requirements we have design micro grid, which is capable to fulfill the
electricity demand of the site machines.
Source: www.volvo.com
4.1.1 SITE SPECIFICATION
MACHINES SPECIFICATIONS OF WHOLE LOAD:
Machines Types
Designation
Electric
Energy
Consumption
Average Power
During
operation/charging
(kWh/week)
(kW)
No. of
Machine
s
Excavator
electric
5600
200
2
Hauler
Crushing &sorting
station
Wheel loader
Conveyor belt
hybrid
2250
26000
80
525
2
1
electric
1400
600
50
20
2
8
10000
400
1
Mobile crusher
station
Charge
Power
(kW)
Cable
connected
240
Cable
connected
240
Cable
connected
Cable
connected
No. of
Charger
s
1
1
Total energy used: 59300 kWh per week
Total average power: 1745 kW
Peak power: 2225 kW
We have considered Monday to Friday (7am to 5pm),
10 hours in a day
Energy consumption per day=59300/5=11860kWh
Table: 2
4.1.2 SIMULATION DATA AND RESULTS:
In this table we have putted all the simulation data and identification of the micro-grid. There is wind and turbine
data which is used to execute the output of the simulated results and solar data such as module rating, surface
area of the module as well. We have selected a single 3MW because of at this combination we have got a
optimum generating cost.
P a g e | 39
STATION IDENTIFICATION
City: Gothenburg
Country/ province: Sweden
Latitude: 57.670 N
Longitude: 12.300 E
SYSTEM CONFIGURATION (V112-3.0MW turbine)
PV SYSTEM SPECIFICATION
Wind class
Power Regulation
Module efficiency, ߝ
Type of cell
IEC IIA/IIIA
Pitch regulated with
variable speed
OPERATION DATA
Number of Turbine, N
Rated power
Cut-in wind speed
Rated wind speed
Cut-out wind speed
Re Cut-out wind speed
Operating temperature range
Air density
Hub height
Turbine co-efficient, Cp
ROTOR
Rotor diameter
Swept area
ELECTRICAL
Frequency
Generator type
1
3000kW
3m/s
13m/s
25m/s
23m/s
-30o to -40o
1.225kg/m3
84m
0.30
13%-19%
Mono-crystalline
silicon
5-8m2
8*3000=24000m2
15000
200Wp
5*200=1000Wp
Climate-SAF-PVGIS
Surface area per kWp
Surface area of plant
Number of module, n
Module power rating, Ps
Solar array size, Pr
Solar irradiance database
112 m
9852 m2
50/60Hz
Permanent magnet
Table:3
SIMULATION RESULTS:
In this graph we have plotted our simulation results. In our design we have considered some renewable micro
sources such as wind and solar power to produce electricity in Gothenburg. According to our site load
requirement around 1745 kW average power demand and peak power demand is 2225 kW.
POWER PRODUCTION AND CONSUMPTION
Total power produce (kW)
10000
Average power demand (kW)
9000
Exces power produce (kW)
8000
Mean of the total power (kW)
Power, kW
7000
Mean of exces power (kW)
6000
5000
4000
3000
2000
1000
0.15
0.55
1.35
2.15
2.55
3.35
4.15
4.55
5.35
6.15
6.55
7.35
8.35
9.35
10.35
11.35
12.15
12.55
13.35
14.15
15.15
15.55
16.35
17.35
18.15
18.55
19.35
20.15
20.55
21.35
22.15
22.55
23.35
0
Figure:4.1. Hourly power production and consumption per day in the site
P a g e | 40
In this simulation we have considered 112-3.0MW wind turbine, because of this turbine is standard size for
medium power site and it can power produce at the different wind class according to the VESTAS turbine
specification.
And about 15000 modern technologies that is mono-crystalline solar module of 200Wp rating. From these
sources total average power produces around 2702.7 kW, which is exceeds peak power demand, from this
produced power 1745 kW will consumed and rest of this power we can store, which would be used at the peak
power demand.
4.1.2.1 POWER PRODUCTION AND CONSUMPTION DATA (wind and solar):
In the figure 4.1 we have used theoretical data both of wind and solar power. This is the hourly total (wind and
solar) power produce per day in our selected site according to our site load demand as we can see in figure: 4.2.
HOURLY POWER PRODUCES PER DAY
10000
9000
8000
Power Pi, MW
7000
6000
5000
4000
3000
2000
1000
0.15
0.55
1.35
2.15
2.55
3.35
4.15
4.55
5.35
6.15
6.55
7.35
8.35
9.35
10.35
11.35
12.15
12.55
13.35
14.15
15.15
15.55
16.35
17.35
18.15
18.55
19.35
20.15
20.55
21.35
22.15
22.55
23.35
0
Hour of the day
Figure: 4.2. Hourly power production in the whole system (with real data)
P a g e | 41
HOURLY POWER POWER DEMAND PER DAY
2000
1800
Power Pc, MW
1600
1400
1200
1000
800
600
400
200
0.15
0.55
1.35
2.15
2.55
3.35
4.15
4.55
5.35
6.15
6.55
7.35
8.35
9.35
10.35
11.35
12.15
12.55
13.35
14.15
15.15
15.55
16.35
17.35
18.15
18.55
19.35
20.15
20.55
21.35
22.15
22.55
23.35
0
Hour of the day
Figure: 4. 3. Hourly power consumption in the whole system (with real data)
In figure 4.3 plotted the site demand curve and the load distribution done by author. In our site there is some
electric construction equipments, they are run generally 7am to 5pm that means 10 hour per day. Theoretically
1745kW average power will be consumed but according to this distribution it’s about 1700kW. Therefore, we
can say this load distribution is well fit to the site load demand.
AFTER CONSUMPTION AVAILABLE POWER
9000
8000
7000
Power
Pr, MW
6000
5000
4000
3000
2000
1000
0.15
0.55
1.35
2.15
2.55
3.35
4.15
4.55
5.35
6.15
6.55
7.35
8.35
9.35
10.35
11.35
12.15
12.55
13.35
14.15
15.15
15.55
16.35
17.35
18.15
18.55
19.35
20.15
20.55
21.35
22.15
22.55
23.35
0
Hour of the day
Figure: 4.4: After consumption rest of the power in the whole system (with real data)
P a g e | 42
And the last graph that means figure: 4.4 is the excess power that we can store to use at the maximum demand.
The maximum demand in the site is around 2225kW per day. With the excess power we can supply or the meet
the demand of peak loads.
4.2 INPUT DATA
4.2.1 WIND POWER DATA:
In this section we have discussed regarding the latest wind energy production, wind turbine installation, wind
speed and generating cost etc.
TOTAL INSTALLED COSTS OF ONSHORE
The cost reductions in wind turbine prices are taking some time to flow into installed project costs. Initial data
for 2012 from the United States suggest that total installed costs in 2012 have fallen from an average of around
USD 2 100/kW in 2011 to USD 1 750/kW in the first half of 2012 (for 2.6 GW of projects), with the most
competitive projects still around USD 1 500/kW [19].
COUNTRY
Chain
Australia
Austria
Brazil
Denmark
Europe (weighted average)
Ireland
Italy
Japan
Mexico
Norway
Portugal
Spain
United States
COSTS
OF THE
YEAR
2011
2011
2011
2010
2010
2011
2011
2011
2011
2011
2011
2011
2009
2011
COSTS
RANGE(USD/KW)
1114-1273
1600-3300
2368
1650-2850
1600-1700
~1600
2000-2600
1941-2588
3900
2000
1900-2000
1810
2000
2100
Table 4: Typical total installed costs for wind farms by country
Average installed costs in 2011 in China
were among the lowest in the world
(Table 4), as overcapacity in
manufacturing, a large domestic market,
low commodity (steel and cement) costs
and an everincreasingly competitive
development industry drives down
costs[20].
Source: [19]
P a g e | 43
4.2.1 FORECASTED DATA
ELECTRICITY GENERATING COSTS IN THE EUROPEAN UNION, 2015, 2020 AND 2030
ELECTRICITY GENERATING COSTS IN THE EUROPEAN UNION, 2015, 2020 AND 2030
120
113
107
101
100
82
75
€/MWh
80
71
80
79
68
60
40
20
0
Wind Energy
Gas Energy
Coal Energy
2015
75
101
82
2020
71
107
80
2030
68
113
79
Data source: IEA world energy outlook
Figure: 4.5. Electricity generating costs in the European Union, 2015, 2020 and 2030
ELECTRICITY GENERATING COSTS IN THE EUROPEAN UNION, 2015 TO 2030
76
74
€/MWh
72
70
68
66
64
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
Wind energy(spline)
Wind energy(linear)
Wind energy(nearest)
Wind energy(cubic)
Figure-4.6. Cost forecasting in the European Union, 2015 to 2030
2027
2028
2029
2030
Source: [25]
P a g e | 44
In IEA edition of World Energy Outlook, the IEA revised its assumptions on both fuel prices and power plant
construction cost. As a result, it increased its estimates for new-build cost. Figure-4.5 shows the IEA’s
assumption on future generating cost for new coal, gas and wind energy in the EU in 2015 and 2030. In the
above figure it shows that the IEA expects new wind power capacity to be cheaper than coal and gas in 2015 and
2030 and more reliable power supply [25]. In figure we have interpolate the data based on the figure: 4.5.
TEN BIGGEST ONSHORE WIND FARMS IN EUROPE:
City or Town
Country
No. of
Turbines
Capacity
(MW)
Turbine
Manufacturer
Developer
Date of
Installation
Romania
240
600
GE
CEZ
Whitelee
United
Kingdom
215
539
Siemens
Scottish
Power
Viking
United
Kingdom
United
Kingdom
United
Kingdom
Portugal
Portugal
Austria
103
371
Siemens
152
350
Siemens
76
256
tbd
SSE
Renewables
SSE
Renewables
Vattenfall
2012
(second
phase under
construction)
2012
(second
phase under
construction)
2018 (fully
permitted)
2012
120
120
79
240
240
237
Enercon
Enercon
Enercon
Spain
United
Kingdom
104
59
208
177
Gamesa
Vestas
1,268
3,218
Fantanele and
Cogealac
Clyde
Peny Cymoedd
Alto Minho
Vento Minho
Andau
Maranchón
Dorenell
TOTAL 10
Table: 5
n/a
n/a
BEWAG,
ImWind,
Püspök
Iberdrola
Infinergy
2016 (fully
permitted)
2008
2009
2014 (under
construction)
2007
2018 (fully
permitted)
Data source: EWEA strives to publish the most up-to-date and accurate data possible.
The tabulated data are estimated wind electricity production, during a normal wind year, of the ten biggest
onshore wind farms in Europe, once completed, is 6.8 TWh, the equivalent to the consumption of 1,778,790
average European homes and industry. Moreover there is some small industry and electric machines these are
getting energy. The above tabulated data are plotted in the figure-4.7 and from the plot we can get an
understandable depiction in the European Union.
P a g e | 45
10 BIGGEST ONSHORE WIND FARMS IN EUROPE
700
600
500
Capacity, MW
400
300
200
100
0
Fantanele
Whitelee
&
Cogealac
Viking
Clyde
Pen y
Cymoedd
Alto
Minho
Vento
Minho
Andau
Maranchó
Dorenell
n
Capacity (MW)
600
539
371
350
256
240
240
237
208
177
No. of Turbine
240
215
103
152
76
120
120
79
104
59
Figure: 4.7. Ten biggest onshore wind farms in Europe
Source: EWEA
Figure -4.8 shows the annual market for wind power up to 2020, the data are calculated according to the previous
evidence of EWEA’s targets prediction. In the wind year 2010, the market for offshore wind is expected to
exceed 1 GW per year for the first time ever to reach the target 2020. For the duration of the second half of the
next decade, an increasing quantity of existing wind power capacity would be decommissioned.
The market forecasting for replacement is expected to increase from 1 GW in 2015 to 4.2 GW in 2020. Through
2020, 28% of the annual market for new wind power capacity will be offshore. Annual investment in wind
power will increase from €11 billion in 2008 to €23.5 billion in 2020. Yearly investment in offshore wind will
increase from €900 million in 2011 to €8.8 billion in 2020, equal to 37% of total investment.
NEW ANNUAL EU WIND ENERGY CAPACITY(2011-2020)
60
50
Power, GW
40
30
20
10
0
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
Total
11
11.6
12.5
13.4
14.5
15.8
17.6
20
22.5
24.8
New onshore
9.3
9.4
9.6
10
10.4
10.9
11.6
12.5
13.1
13.6
Onshore repowering
0.2
0.3
0.5
0.7
1
1.3
1.9
2.6
3.5
4.2
New offshore
1.5
2
2.4
2.7
3.1
3.6
4.1
4.9
5.9
6.9
0
0
0
0
0
0
0
0
0
0
Offshore repowering
Figure-4.8: New annual EU wind energy capacity (2011-2020)
Source: EWEA
P a g e | 46
In figure: 4.9. Shows the annual wind power production up to 2020; this figure shows that the in EU how much
wind power produces and projection of the wind energy in Europe from 2011 to 2020 targets.
For this prediction we have used some regression method according to the previous evidence of EWEA’s targets
prediction and also we are going to discuss the yearly growth rate of the power and energy.
WIND POWER PRODUCTION IN THE EU (2011-2020)
1400
Power Production , TWh
1200
1000
800
600
400
200
0
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
Total
205
234
265
299
335
375
419
467
522
582
Onshore
189
211
233
257
281
308
336
367
399
433
Offshore
16.4
23.4
32.3
42.3
53.7
67.1
82.4
100.5
122.4
148.3
Figure-4.9. Wind power production in the EU (2011-2020)
Source: EWEA
In the figure: 4.10. the outlook for the coming period is a bit compared with previous forecasts, but this reflects
the market realities from where we sit in late March 2011 Overall, we expect to see average annual market
growth rates of about 9% for the next five years, but with a strong 2011 and a substantial dip in 2020 we see total
installations for the 2011-2020 period of about 255 GW, and cumulative market growth averaging just under
17% This is well below the 28% average for the last 10 years, but substantial growth in difficult times Overall,
we see total capacity ending up at just under 500 GW by the end of 2020, with an annual market in that year of
just under 60 GW.
P a g e | 47
GLOBAL WIND MARKET FORCAST 2011-2020
800
25%
700
20.30%
19.40%
20%
600
Power , GW
16.20%
15%
500
14.60%
13.65%
15%
13.40%
400
11.90%
9.33%
300
9.11%
7.70%
9.25%
10%
6.49%
5%
4.94%
4.00%
100
9.43%
7.80%
7.26%
200 6%
8.45%
0
0%
2011
2012
2013
2014
2015
2016
2017
2018
2019
Annual installed capacity(GW)
Cumulative installed capacity(GW)
Annual growth rate(%)
Cumulative growth rate(%)
Figure-4.10: Global wind market forecast 2011-2020
2020
Source: EWEA
WIND POWER PRODUCTION IN THE EU (2000-2020)
Wind power production in the EU (2000-2020)
700
600
500
400
300
200
100
0
Onshore
2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020
32
44
55
Offshore 0.1 0.3
22
1
1.9 2.2 2.6 3.3 4.1 5.3 6.9 10.9 16.4 23.5 32.3 42.3 53.7 67.1 82.4 101 122 148
67
80
96 115 132 150 168 189 211 233 257 281 308 336 367 399 433
Figure: 4.11- Wind power production in the EU (2000-2020)
Source: [26]
P a g e | 48
TOP 10 EU COUNTRIES FOR
INCREASED WIND POWER CAPACITY
IN GW (2009-2020)
However, both the UK, which will add 22.8 GW by
2020 and France, which will add 19.6 GW are
closing in on the leaders [26].
Figure: 4.12 show the national breakdown of the
increase in wind power capacity, according to
EWEA’s 230 GW scenario. In total, wind energy
capacity in the EU will increase by 165 GW by
Others
Countries
2020. Germany and Spain will continue to be in the
lead over the next 12 years, increasing their
installed capacities by 25.1 GW and 23.3 GW
respectively –making up 29% of the total EU
increase. However, both the UK, which will add
22.8 GW by 2020 and France, which will add 19.6
GW are closing in on the leaders [26].
TOP 10 EU COUNTRIES FOR INCREASED WIND
POWER CAPACITY IN GW (2009-2020)
Sweden, Netherland Greece,
5.5 Ireland, 5
10.8
s, 7.3
Poland, 10
Others,
Italy,
26.8
11.8
France,
Germany,
19.6
25.1
UK, 22.8
Spain, 23.3
Figure: 4.12. Total increased wind power capacity
EU-27, (2009-2020)
Source: [26]
Portugal
Belgium
Romania
Denmark
Bulgaria
Austria
Finland
Czech Republic
Lithuania
Hungary
Slovakia
Slovenia
Estonia
Luxembourg
Cyprus
Latvia
Malta
Increased in
Wind Energy
Capacity 20092020
% of EU-27
increase in wind
energy capacity
2009-2020
4.6
3.5
3.0
2.8
2.8
2.5
1.8
1.5
0.9
0.8
0.8
0.5
0.4
0.3
0.3
0.2
0.1
2.8%
2.1%
1.8%
1.7%
1.7%
1.5%
1.1%
0.9%
0.6%
0.5%
0.5%
0.3%
0.3%
0.2%
0.2%
0.1%
0.1%
Source:EWEA
Table 6: Others countries
They are followed by Italy (11.8 GW), Poland (10
GW) and Sweden (8 GW). It is a positive sign that
the group labeled “others” has more than 25% of
the total increase in capacity, indicating a wide
deployment of renewable throughout the European
countries. Today, 24 EU Member States have wind
power. All 27 Member States are expected to have
operating wind farms by 2020 [26].
P a g e | 49
WIND VELOCITY IN THE SITE:
The preliminary site selected in Sweden at Gothenburg City Airport for 50 meter height, from the figure-4.13 the
maximum average wind speed in a day 8.2 m/s and minimum 2.6 m/s and so we can say the variation of wind
speed is much at end of the summer [27]. To the coming part of analysis we will discuss the class of wind speed
and will be decide at which speed the power output would be better.
AVERAGE WIND SPEED OF THU. SEP-27, 2012 AT GOTHENBURGE
9
8.2
8
7.2
Wind speed, m/s
7
5.7
6
5
7.2
5.7
5.7 5.7 5.7
5.1
4.6 4.6
3.6
4
4.1
6.2
6.7
5.7
5.1
4.6 4.6
4.1 4.1 4.1
3.6
3.1
2.6
3
2
1
12:00 AM
11:00 PM
10:00 PM
9:00 PM
8:00 PM
7:00 PM
6:00 PM
5:00 PM
4:00 PM
3:00 PM
2:00 PM
1:00 PM
12:00 PM
11:00 AM
10:00 AM
9:00 AM
8:00 AM
7:00 AM
6:00 AM
5:00 AM
4:00 AM
3:00 AM
2:00 AM
1:00 AM
12:00 AM
0
Hour of the day
Figure-4.13: Average wind speed of Thu. Sep-27, 2012 at Gothenburg
Source: [27]
And in the figure-(4.14) we have plotted the monthly average air speed at the same site. From this curve we
observed that the variation is approximately same with per day average wind speed.
AVERAGE WIND SPEED SEP-2012 AT GOTHENBURGE
8.5
9
8.2
8
6.8
Wind speed, m/s
7
5.9
6
7.2
6.8
6.1
5.4
5
5
4.7
4.4
5.9
6.2
5.9
4.3
4.2
4
3.3
2.9
2.8
2.7
5.3
5.1
5
4.7
3.5
4
3
6.9
6.8
6.3
2.4
2
30-Sep
29-Sep
28-Sep
27-Sep
26-Sep
25-Sep
24-Sep
23-Sep
22-Sep
21-Sep
20-Sep
19-Sep
18-Sep
17-Sep
16-Sep
15-Sep
14-Sep
13-Sep
12-Sep
11-Sep
10-Sep
9-Sep
8-Sep
7-Sep
6-Sep
5-Sep
4-Sep
3-Sep
2-Sep
0
1-Sep
1
Day of the month
Figure-4.14 Average wind speed sep-2012 at Gothenburg
Source: [27]
P a g e | 50
WIND-FORCE PER DAY (JANUARY 2012 - OCTOBER 2012)
6
5.28
5
4.25
4.00
Wind speed, m/s
4
3.92
4.03
3.70
4.00
3.95
3.53
3.00
2.99
3.09
Nov
Dec
3
2
1
0
Jun
Feb
Mar
Apr
May
Jun
Jul
Aug
Month of the year
Figure: 4.15. Yearly wind speed at Gothenburg City Airport
Sep
Oct
Source: [28]
The data of November and December is forecasted data.
4.2.2 SOLAR DATA
CELL MATERIALS AND EFFICIENCY:
CELL MATERIALS
MODULE EFFICIENCY
SURFACE AREA NEED FOR 1KWp
Mono-crystalline silicon
13-19%
5-8݉ଶ
Ploy-crystalline silicon
11-15%
7-9݉ଶ
Micromorphous tandem cell (a-Si/μc-Si)
8-10%
10-12݉ଶ
Thin film-copper-indium/galliumsulfur/diselenide(CI/GS/Se)
Thin-film- cadmium telluride (CdTe)
10-12%
8-10݉ଶ
9-11%
9-11݉ଶ
Amorphous silicon (a-Si)
5-8%
13-20݉ଶ
Figure: 4.16. Cell made from different materials has different efficiencies and PV array surface area depends on
the type of cell used.
P a g e | 51
PVGIS ESTIMATES OF SOLAR ELECTRICITY GENERATION IN GOTENBURG
Table: 7
STATION IDENTIFICATION
GoteborgòLandvetter
City:
SWE
Country/Province:
57.67° N
Latitude:
12.30° E
Longitude:
169 m
Elevation:
IWEC
Weather Data:
PV System Specifications
DC Rating:
DC to AC Derate Factor:
AC Rating:
Array Type:
Array Tilt:
Array Azimuth:
4.00 kW
0.770
3.08 kW
Fixed Tilt
57.7°
180.0°
Energy Specifications
Energy Cost:
1.2750 krona/kWh
Month
1
2
3
4
5
6
7
8
9
10
11
12
Year
RESULTS
Solar
AC
Radiation
Energy
(kWh/m2/day)
(kWh)
0.63
48
1.25
95
2.75
260
4.24
384
5.39
488
5.02
428
5.25
463
4.48
397
3.76
332
2.38
214
0.86
64
0.58
47
3.06
3218
Energy
Value
(krona)
61.20
121.12
331.50
489.60
622.20
545.70
590.32
506.17
423.30
272.85
81.60
59.92
4102.95
SOLAR RADIATION AT GOTHENBURGE
6
5.39
5.02
5.25
5
4.48
Radiation, kWh/m2/day
4.24
3.76
4
2.75
3
2.38
2
1.25
1
0.86
0.63
0.58
0
1
2
3
4
Figure: 4.17 Solar radiations at Gothenburg
5
6
7
8
9
10
11
12
Source: PVGIS
P a g e | 52
SOLAR AC ENERGY PRODUCED AT GOTHENBURG
600
488
500
463
428
AC Energy,kWh
397
384
400
332
300
260
214
200
95
100
64
48
47
0
1
2
3
4
5
6
7
8
9
Figure: 4.18 Monthly AC energy produced in Gothenburg
10
11
12
Source: PVGIS
DIFFERENT TYPES OF LOSSES IN THE SOLAR SYSTEM:
Solar radiation database used
Nominal power of the PV system
Estimated losses due to temperature
Estimated loss due to angular reflectance effects
Other losses (cables, inverter etc.)
Combined PV system losses
Inclination
System
: PVGIS-classic
: 1.0 kW (crystalline silicon)
: 8.3% (using local ambient temperature)
: 3.2%
: 14.0%
: 23.6%
: 35 degree
: Fixed system
AVERAGE DAILY SUM OF GLOBAL IRRADIATION RECEIVED BY THE MODULES
180
162
160
157
159
135
Irradiation, Kwh/m2
140
118
120
97.3
100
76.1
80
58.1
60
43.2
40
20
29.8
17.4
15.4
0
1
2
3
4
5
6
7
8
Figure: 4.19 Average daily sum of global irradiation received by a module
9
10
11
12
Source: PVGIS
P a g e | 53
AVERAGE DAILY ELECTRICITY PRODUCTION AT GOTHENBURG
4.5
3.88
4
3.85
3.76
3.5
3.2
3.04
3
Ed, Kwh
2.47
2.5
1.98
2
1.5
1.29
1.5
0.82
1
0.47
0.42
0.5
0
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Figure: 4.20 PV estimate: Location: 57°42'31" North, 11°58'28" East, Elevation: 7 m a.s.l.
Fixed system: inclination=35° and
orientation=0°
Month
Ed
Em
Hd
Jan
0.47
14.7
0.56
Feb
1.29
36.0
1.54
Mar
1.98
61.3
2.45
Apr
3.04
91.3
3.92
May
3.88
120
5.21
Jun
3.85
115
5.24
Jul
3.76
116
5.13
Aug
3.20
99.3
4.35
Sep
2.47
74.2
3.24
Oct
1.50
46.4
1.87
Nov
0.82
24.6
0.99
Dec
0.42
13.0
0.50
Yearly
2.23
67.7
2.92
average
Total for
813
year
Table: 8,
Hm
17.4
43.2
76.1
118
162
157
159
135
97.3
58.1
29.8
15.4
89.0
Dec
Source: PVGIS
Ed: Average daily electricity production from the given system (kWh)
Em: Average monthly electricity production from the given system
(kWh)
Hd: Average daily sum of global irradiation per square meter received
by the modules of the given system (kWh/m2)
Hm: Average sum of global irradiation per square meter received by
the modules of the given system (kWh/m2)
1070
Data source: PVGIS
4.2.2.1 SOLAR MODULE COST
RETAIL PRICE SUMMARY - MARCH 2012 UPDATE:
The extensive downward trend the retail of module prices sustained in March. Reductions in Europe were much
more noticeable than in the United States comparatively.
P a g e | 54
The extensive period trends in retail module prices can practically always be mark out to regulations at the
factory gate. The factory gate prices are depend on the global supply or demand balance or used, by cuts in
production costs, and by changes in government incentives motivating demand of the solar module.
MODULE PRICING TRENDS (per watt peak)
$2.29
United States
€2.17
Europe
329
Number of prices
(34% of survey)
൏ $2.00 or £1.54/Wp
$1.1
Lowest Mono-cSi
€0.81
Module price
$1.06
Lowest Multi-cSi
€0.78
Module price
$0.84
Lowest Thin-film
€0.62
Module price
During the last five years in the European
markets has been around 80% of global PV
demand. Conversely in recent months, exacting
decreases in incentives in Europe to reduce
demand growth and also the total funding cost of
those supports. This way of decrease are actually
an outcome of government programs that have
been successful in making demand, but also
significantly it bring down per unit cost of solar
photovoltaic in the competitive market.
Table: 9
Source: solar buzz-solar market research and analysis
Table: Solar module pricing trends (per watt peak)
In the recent month, there are 89 price declines and just 33 price growths, to some extent similar to the 107 price
reductions and 23 price increases the preceding month. We have seen the last time the number of price rises
more than decreases was November 2010.
LOWEST RETAIL PRICES ($/WP):
Presently, 329 solar module prices are below $2.00 per watt (€1.48 per watt) or 34% of the total survey
according to the solar-buzz. During February, there was 302 price points below $2.00 per watt (€1.52 per watt),
31% of the survey as well.
Figure: 4.21 Module price trend from solar buzz
Source: solar buzz.se
P a g e | 55
According to the solar buzz this lowest retail price of a multi-crystalline silicon solar module is $1.06 per watt
(€0.78 per watt) from a German retailer and for a mono-crystalline silicon is $1.10 per watt (€0.81 per watt), also
from a German retailer. On the other hand the lowest thin film module price is $0.84 per watt (€0.62 per watt)
from a Germany-based retailer. It is typical to expect thin film modules should be the price concession to
crystalline silicon and this thin film price is for a 105 watt module as well conferring to their statement.
PV SPOT MARKET PRICE (US$)
The price information provided by Energy Trend is primarily a result of periodical survey of a pool of major
manufacturers via telephone and site visits. Energy Trend cross-surveys major buyers and suppliers throughout
the supply chain and attempts to ensure all enclosed price information reflects actuality.
Generally Energy Trend takes a conventional approach toward the enclosed price facts. All surveyed
manufacturers are to be kept anonymous and Energy Trend will not respond to price enquiry about any
individual manufacturer. With the historical agreement price information in database and capability of
conducting fast and in-depth market analysis, Energy Trend is equipped to provide both price trend and market
intelligence to our valued members.
GERMAN SPOT MARKET PRICES FOR SOLAR MODULES-2012
0.8
Module price,€/watt
0.7
0.6
0.5
0.4
mono-crystalline
0.3
multi-crystaline
0.2
asian spot market
0.1
0
22 29 6 13 20 27 3 10 17 24 31 7 14 21 28 5 12 19 26 2
9 16 23 30 7 14
mono-crystalline 0.7 0.7 0.7 0.7 0.7 0.7 0.7 0.7 0.7 0.8 0.7 0.7 0.6 0.6 0.7 0.7 0.7 0.7 0.8 0.7 0.7 0.6 0.7 0.7 0.7 0.6
multi-crystaline
0.7 0.6 0.7 0.7 0.7 0.7 0.7 0.7 0.6 0.7 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6
asian spot market 0.7 0.7 0.7 0.7 0.7 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.5
Figure: 4.22 German spot market prices for solar modules [35]
source: photon.info
P a g e | 56
5. RESULTS:
In this chapter vastly discussed the simulated result of the wind and solar power production and their limitation
to estimate the cheapest production cost. Also analysis simulated result by plotting some graph of the output.
5.1 WIND POWER SITE:
5.1.1 COST
In this section we have calculated the electricity production cost per unit and before this calculation derived
some mathematical function, which is used to calculate the actual cost.
SPEED, DIAMETER AND POWER RELATIONS OF THE WIND TURBINE [25]:
The power content in a cylindrical line of free air moving at unvarying speed V is the flow rate of its kinetic
energy per second, therefore [30]
ܲ௦ ൌ
ௗா
(1)
ௗ௧
The kinetic energy of a mass “m” in air with the wind speed V is given by the following equation we have [26a],
ଵ
‫ ݕ݃ݎ݁݊ܧܿ݅ݐ݁݊݅ܭ‬ൌ ܸ݉ ଶ ݆‫ݏ݈ݑ݋‬
ଶ
(2)
Substituting the equation (2) in equation (1) we have,
ܲ௦ ൌ
݀‫ܧ‬
݀ ͳ
ͳ ݀
ൌ ൬ ܸ݉ ଶ ൰ ൌ ൤ ሺܸ݉ ଶ ሻ൨
݀‫ʹ ݐ݀ ݐ‬
ʹ ݀‫ݐ‬
Applying the succession rule of differentiation
݀
ܸ݀ଶ
ܸ݀ଵ
ሺܸ ǡ ܸ ሻ ൌ ܸଵ
൅ ܸଶ
݀‫ ݐ‬ଵ ଶ
݀‫ݐ‬
݀‫ݐ‬
Then we have,
ଵ
ௗ௏
ଶ
ௗ௧
ܲ௦ ൌ ቀʹܸ݉
൅ ܸଶ
ௗ௠
ௗ௧
ቁ
(2a)
For the constant wind velocity V, the first portion would be zero, therefore:
ܸ݀
ൌͲ
݀‫ݐ‬
And as a result the power equation (2a) can express in terms of its mass flow rate and velocity V as:
ଵ ௗ
ଵ ௗ௠
ଶ ௗ௧
ଶ
ܲ௦ ൌ ቂ ሺܸ݉ ଶ ሻቃ ൌ ቀ
ௗ௧
ଵ
ቁ ܸ ଶ ൌ ݉ሶܸ ଶ
ଶ
Therefore, we are able to state that,
ͳ
ܲ‫ ݎ݁ݓ݋‬ൌ ሺ݉ܽ‫݀݊݋ܿ݁ݏݎ݁݌݁ݐܽݎݓ݋݈݂ݏݏ‬ሻܸ ଶ
ʹ
If we define the parameters as,
ܲ ൌ ݄݈݉݁ܿܽ݊݅ܿܽ‫ݎ݅ܽ݃݊݅ݒ݋݄݉݁ݐ݊݅ݎ݁ݓ݋݌‬ǡ ‫ݐݐܽݓ‬
(3)
P a g e | 57
ߩ ൌ ܽ݅‫ݕݐ݅ݏ݊݁݀ݎ‬ǡ ݇݃Ȁ݉ଷ
‫ ܣ‬ൌ ‫ݏ݈ܾ݁݀ܽݎ݋ݐ݋ݎ݄݁ݐ݂݋ܽ݁ݎܽݐ݌݁ݓݏ‬ǡ ݉ଶ
ܸ ൌ ‫ݎ݄݅ܽ݁ݐ݂݋݀݁݁݌ݏ‬ǡ ݉Ȁ‫ݏ‬
Then, we can define the mass flow rate of the air in kilograms per second as:
݉ሶ ൌ ߩ‫ܸܣ‬
(4)
By substituting the equation (4) into equation (3) we have the power contain,
ͳ
ͳ
ܲ௦ ൌ ሺߩ‫ܸܣ‬ሻܸ ଶ ൌ ߩ‫ ܸܣ‬ଷ ܹܽ‫ݏݐݐ‬
ʹ
ʹ
This can also refer to as the power density of the site, and is given by the following expression [26a]:
ܵ‫݁ݐ݅ݏ݄݁ݐ݂݋ݎ݁ݓ݋݌݂ܿ݅݅ܿ݁݌‬ǡ ܲ௦ ൌ
ͳ ଷ
ߩܸ ‫݉ݎ݁݌ݐݐܽݓ‬ଶ ‫ܽ݁ݎܽݐ݌݁ݓݏݎ݋ݐ݋ݎ݄݁ݐ݂݋‬
ʹ
This is the upstream site power. It would be varies linearly with the density of the air sweeping the blades, and
with the cube of the wind velocity of the upstream site [30], [31]. The entire of the upstream wind power cannot
be extracted by the turbine blades according to the Betz limit, as some power is loose in the downstream air site
which continues to move with reduced wind velocity [31].
If the diameter of the turbine blades is D then the power expression would be,
ଵ
గ஽మ
ଶ
ସ
ܲ௦ ൌ ߩ
ܸଷ
(5)
The power contain in the upstream site of the blades is proportional to the square of its diameter, D and more
significantly to the cube of its air velocity V.
POWER EXTRACTED AS OF THE WIND IN THE DOWN-STREAM SITE [26]:
The actual wind energy produce by the rotor blades would be the difference between the upstream and the
downstream wind powers, therefore from the equation (3) we have,
ଵ
ଵ
ଶ
ଶ
ܲ௠ ൌ ݉ܽ‫݀݊݋ܿ݁ݏݎ݁݌݁ݐܽݎݓ݋݈݂ݏݏ‬Ǥ ሼܸ௨ଶ െ ܸௗଶ ሽ ൌ ݉ሶሼܸ௨ଶ െ ܸௗଶ ሽ
ܹ݄݁‫݁ݎ‬ǡ
(6)
ܲ௠ ൌ ݄݈݉݁ܿܽ݊݅ܿܽ‫ݎ݋ݐ݋ݎ݄݁ݐݕܾ݀݁ݐܿܽݎݐݔ݁ݎ݁ݓ݋݌‬ǡ ݅Ǥ ݁Ǥ ǡ ‫ܾ݁݊݅ݎݑݐ݄݁ݐ݂݋ݎ݁ݓ݋݌ݐݑ݌ݐݑ݋‬
ܸ௨ ൌ ‫ݏ݈ܾ݁݀ܽݎ݋ݐ݋ݎ݄݁ݐ݂݋݁ܿ݊ܽݎݐ݄݊݁݁ݐݐܽݕݐ݅ܿ݋݈݁ݒݎ݅ܽ݉ܽ݁ݎݐݏ݌ݑ‬
ܸௗ ൌ ݀‫ݏ݈ܾ݁݀ܽݎ݋ݐ݋ݎ݄݁ݐ݂݋ݐ݅ݔ݄݁݁ݐݐܽݕݐ݅ܿ݋݈݁ݒݎ݅ܽ݉ܽ݁ݎݐݏ݊ݓ݋‬
Now we can point out the mass flow rate of air through the rotating blades is derived by multiplying the density
with the average velocity.
݄ܶ݁݉ܽ‫݀݊݋ܿ݁ݏݎ݁݌݁ݐܽݎݓ݋݈݂ݏݏ‬ǡ ݉ሶ ൌ ߩ‫ܣ‬ሺ
௏ೠ ା௏೏
ଶ
ሻ
(7)
P a g e | 58
Then the mechanical power extracted by the rotor, which is output of the turbine generator and is therefore, from
equation (5) and (7) we have,
ͳ
ܸ௨ ൅ ܸௗ
ܲ௠ ൌ ൤ߩ‫ܣ‬ሺ
ሻ൨ ሼܸ௨ଶ െ ܸௗଶ ሽ
ʹ
ʹ
The above expression could be simplified as like:
௏
௏
ଶ
ቀͳ ൅ ೏ ቁ ൤ͳ െ ቀ ೏ ቁ ൨
ͳ
௏ೠ
௏ೠ
ଷ
ܲ௠ ൌ ߩ‫ܸܣ‬௨ ൦
൪
ʹ
ʹ
Wind power for different size of turbine blades
3.5
Pm1 for r=52m
Pm2 for r=54m
Pm3 for r=56m
Pm4 for r=58m
3
Power,P (MW)
2.5
2
1.5
1
0.5
0
0
1
2
3
4
5
6
Velocity of wind,v (m/s)
7
8
9
10
Figure: 5.1 Wind power produce at different size of turbines blades
The power extracted by the blades is customarily expressed as a fraction of the upstream wind power as follows:
ଵ
ܲ௠ ൌ ߩ‫ܸܣ‬௨ଷ ‫ܥ‬௣
(8)
ଶ
ೇ
ܹ݄݁‫݁ݎ‬ǡ ‫ܥ‬௣ ൌ
ೇ
మ
ቀଵାೇ೏ ቁቈଵିቀೇ೏ ቁ ቉
ೠ
ೠ
ଶ
ൌ
ሺଵା்ೞ ሻ൫ଵି்ೞమ ൯
ଶ
(9)
The ‫ܥ‬௣ is the fraction parameter of the upstream wind power site, which is captured by the rotor blades. The
remaining power is discharged or wasted in the down-stream wind site [31]. The factor ‫ܥ‬௣ is known as the
power coefficient of the rotor /the rotor efficiency. We have plotted equation (8) as a function of wind speed at
different blade size in figure-5.1.
P a g e | 59
Power coefficient or rotor efficiency
0.7
0.6
Power coefficient,Cp
0.5
0.4
0.3
0.2
0.1
0
0
0.1
0.2
0.3
0.4
0.5
Vd/Vu ratio
0.6
0.7
0.8
0.9
1
Figure-5.2 Rotor efficiency versus Vd/Vu ratio has single maximum. Rotor efficiency is the fraction of available
wind power extracted by the rotor and fed to the electrical generator.
௏
The value of ‫ܥ‬௣ depends on the ratio of the down-stream to the up-stream wind speeds, that isቀ ೏ ቁ. In the plot of
௏ೠ
௏೏
power coefficient versus velocity speed ቀ ቁ shows that ‫ܥ‬௣ is a single, maximum-value function (Figure -1b). It
௏ೠ
௏
has the maximum value of 0.59 when the ቀ ೏ ቁ is one-third [30]. The theoretically maximum power extracted
௏ೠ
from the wind, when the downstream wind speed equals one-third of the upstream speed. Therefore, for an ideal
case we can write as follows:
ܲ௠௔௫ ൌ
ͳ
ߩ‫ ܸܣ‬ଷ ͲǤͷͻ
ʹ
The maximum power output of the wind turbine could be express in an alternative expression:
ଵ
ܲ௠௔௫ ൌ ߩܸ ଷ ͲǤͷͻ‫݉ݎ݁݌ݐݐܽݓ‬ଶ ‫ܽ݁ݎܽݐ݌݁ݓݏ݂݋‬
ସ
(10)
P a g e | 60
WEIBULL PROBABILITY DISTRIBUTION OF WIND SPEED:
The variation in wind speed is properly described by the Weibull probability distribution function ‘f (v)’ with
two parameters. The probability density function of wind speed v during any time interval is given by the
following expression [31]:
௞
௩ ௞ିଵ
௖
௖
݂ሺ‫ݒ‬ሻ ൌ ቀ ቁ ቀ ቁ
ೖ
݁ ିሺ௩Ȁ௖ሻ For 0൏ ‫ ݒ‬൏ λ
(11)
Where, f (v) is the probability density function of wind speed, v, and k is the Weibull shape parameter
(dimensionless), and c is the Weibull scale parameter (m/s). Generally range of k from 1.5 to 3 for most wind
conditions is assumed [32].For wind speed distributions the Weibull shape parameter is in the range of 1.5-3 are
as we can see in Fig.5.3.
Weibull distribution or PDF
0.8
c1=0.5
c2=1
c3=1.5
c4=3
0.7
Probability Desity, %
0.6
0.5
0.4
0.3
0.2
0.1
0
0
0.5
1
1.5
2
2.5
3
Wind speed,m/s
3.5
4
4.5
5
Figure: 5.3 Weibull probability distribution function
The value of k determines the shape of the curve, hence is called the ‘shape parameter’ [31], [32].Summarizing
the characteristics of the Weibull probability distribution function:
K=1 makes it the exponential distribution, ݂ ൌ ߣ݁ ିఒ௩
Where ߣ ൌ ͳȀܿ
K=2 makes it the Rayleigh distribution, ݂ ൌ ʹߣଶ ‫ି ݁ݒ‬ሺఒ௩ሻ
మ
and
K>3 makes it approach a normal distribution, often called the Gaussian or bell-shape distribution,
మ
݂ ൌ ʹߣଶ ‫ି ݁ݒ‬ሺఒ௩ሻ
P a g e | 61
COST ANALYSIS OF THE WIND ENERGY
RATED POWER AND RATED SPEED:
Universally wind turbines are classified by their rated power at a specific wind speed. The rated power is defined
as the maximum power output of the turbine and the rated wind speed is the wind speed at which the turbine
reaches its rated power output [33].
EXPECTED LIFETIME OF A WIND TURBINE:
Modern wind turbines are generally considered to work for around 120000 hours of operation throughout their
design lifetime of 20 years. This would be the turbine operating for around 66% of the time for two decades.
The components of a wind turbine are usually designed to remain operational for twenty years. It would be quite
hardly any more costly to design and shape some of the components to remain operational for extreme longer.
Nevertheless, because most of the major components would be very expensive to build for a longer life span, it
would be a waste to have a whole turbine standing idle because one part failed years earlier than the rest [34].
By approving on a twenty year design lifetime, an economic compromise is met which guides the engineers who
develop new components for wind turbines. At what time arrangement a new components they know that it will
be expected to work reliably for twenty years. Also it has to show that their planned components will have less
chance of failing within twenty years of installation of the wind turbine [34].
WIND TURBINES INSTALLATION COST:
In 2012 the costs for an effectiveness scale wind turbine range from about $1.3 million to $2.2 million per MW
of nameplate capacity installed in the spot market. This cost has fallen down noticeably from what it was just a
few years ago [34].
The majority of the commercial-scale wind turbines installed at present are 2 MW in size and cost roughly $3-$4
million installed. Wind turbines have significant economies of scale. Residential scale or smaller size turbines
cost less in general, but more costly per kilowatt of energy producing capacity, because of device and installation
cost is high according to the energy production. According to the prediction of some web site wind turbines less
than 100 kilowatts cost roughly $3,000 to $8,000 per kilowatt of capacity. Normally a 10 kilowatt machine
might have an installed cost of $50,000-$80,000 (or more) depending on the tower type, height, and the cost of
installation and maintenance. Oftentimes there is tax and other incentives that can dramatically reduce the cost of
a wind project but in locally production we don’t have to pay the production tax [34].
CAPACITY OR INTERMITTENCE FACTOR (IF):
The capacity factor (CF) is greatly significant factor in energy production and its define for an energy generating
technology is equal to the ratio of the actual energy produced in a given period to the hypothetical maximum
energy production, running full time at rated power.
Capacity Factorǡ ‫ ܨܥ‬ൌ
௔௡௡௨௔௟௘௡௘௥௚௬௣௥௢ௗ௨௖௧௜௢௡௜௡௚௜௩௘௡௣௘௥௜௢ௗ
௧௛௘௢௥௘௧௜௖௔௟௠௔௫௜௠௨௠௘௡௘௥௚௬௣௥௢ௗ௨௖௧௜௢௡
P a g e | 62
Depending on the wind statistics for a specific site, the ideal capacity factors minimize the cost per kilowatt-hour
(KWh) of energy produced. Capacity factor would be very different for various turbines, but as well the prices or
cost of these turbines will be very different.
WIND TURBINE PRESENT VALUE COST ANALYSIS:
Firstly we are going to calculate investment for a single wind turbine Project:
ܶ‫ݎ݁ݓ݋ܲ݀݁ݐܴܾܽ݁݊݅ݎݑ‬ǡ ܲ௥௔௧௘ௗ ൌ ͵‫ ܹܯ‬ൌ ͵ͲͲͲܹ݇
‫݁݉݅ݐ݂݁݅ܮ݀݁ݐܿ݁݌ݔܧ‬ǡܶ௟ ൌ ʹͲ‫ݏݎܽ݁ݕ‬
ܶ‫ݐݐܽݓ݋݈݅݇ݎ݁݌݁ܿ݅ݎܾܲ݁݊݅ݎݑ‬ǡ ‫ܥ‬௧ǡ௣௘௥ି௞௜௟௢௪௔௧௧ ൌ ̈́ͳʹͲͲȀܹ݇
ܶ‫݁ܿ݅ݎܾܲ݁݊݅ݎݑ‬ǡ‫ܥ‬௧ ൌ ܲ௥௔௧௘ௗ ‫ܥ כ‬௧ǡ௣௘௥ି௞௜௟௢௪௔௧௧ ൌ ͵ͲͲͲ ‫ ͲͲʹͳ כ‬ൌ ̈́͵ǡ͸ͲͲǡͲͲͲ
‫ݐݐܽݓ݋݈݈݅݇ݎ݁݌ݐݏ݋ܥ݊݋݅ݐ݈݈ܽܽݐݏ݊ܫ‬ǡ‫ܥ‬௜ǡ௣௘௥̴௞௜௟௟௢௪௔௧௧ ൌ ̈́ͳ͸ͲͲȀܹ݇ሺ݈݅݊ܿ‫݊݋݅ݐܿ݁݊݊݋ܿ݀݅ݎ݈݃݀݊ܽ݀݊ܽ݃݊݅݀ݑ‬ሻ
‫ݐݏ݋ܥ݊݋݅ݐ݈݈ܽܽݐݏ݊ܫ‬ǡ‫ܥ‬௜௡௦௧௔௟௟ ൌ ܲ௥௔௧௘ௗ ‫ܥ כ‬௜ǡ௣௘௥ି௞௜௟௢௪௔௧௧ ൌ ͵ͲͲͲ ‫ͳ כ‬͸ͲͲ ൌ ̈́ͶǡͺͲͲǡͲͲͲ
݄ܶ݁‫ܥݏܾ݅݁݊݅ݎݑݐ݀݊݅ݓ݄݁ݐ݂݋ݐݏ݋݈ܿܽݐ݋ݐ‬௧௢௧௔௟ ൌ ‫ܥ‬௧ ൅ ‫ܥ‬௜௡௦௧௔௟௟ ൌ ̈́͵ǡ͸ͲͲǡͲͲͲ ൅ ̈́ͶǡͺͲͲǡͲͲͲ ൌ ̈́ͺǡͶͲͲǡͲͲͲ
ܱƬ‫ݐݐܽݓ݋݈݈݅݇ݎ݁ܲݐݏ݋ܥܯ‬ǡ ‫ܥ‬௢Ƭ௣ǡ௣௘௥ି௞௜௟௢௪௔௧௧ ൌ ̈́͸ͶȀܹ݇
ܱƬ‫ݐݏ݋ܥܯ‬ǡ ‫ܥ‬௢Ƭ௣ ൌ ܲ௥௔௧௘ௗ ‫ܥ כ‬௢Ƭ௣ǡ௣௘௥ି௞௜௟௢௪௔௧௧ ൌ ͵ͲͲͲ ‫ כ‬͸Ͷ ൌ ̈́ͳͻʹǡͲͲͲȀ‫ݎܽ݁ݕ‬
ܶ‫݁ݎݑݐ݅݀݊݁݌ݔ݈݁ܽݐ݋‬ǡ‫ܥ‬௘௫௣ ൌ ܶ‫ ܾ݁݊݅ݎݑݐ݄݁ݐ݂݋ݐݏ݋݈ܿܽݐ݋‬൅ ܱƬܲܿ‫݁݉݅ݐ݂݈݁݅݀݁ݐܿ݁݌ݔ݄݁݁ݐݎ݁ݒ݋ݐݏ݋‬
ൌ ‫ܥ‬௧௢௧௔௟ ൅ ‫ܥ‬௢Ƭ௣ ‫ ݏݎܽ݁ݕͲʹ כ‬ൌ ̈́ͺǡͶͲͲǡͲͲͲ ൅ ሺ̈́ͳͻʹǡͲͲͲȀ‫ݎܽ݁ݕ‬ሻ ‫ ݎܽ݁ݕͲʹ כ‬ൌ ̈́ͺǡͶͲͲǡͲͲͲ ൅ ̈́͵ǡͺͶͲǡͲͲͲ
ൌ ̈́ͳʹǡʹͶͲǡͲͲͲ
P a g e | 63
Electricity Generating Cost
0.25
CF1=0.2854
CF2=0.3254
CF3=0.3654
0.2
Cost,USD/kWh
CF4=0.3854
0.15
0.1
0.05
0
1000
2000
3000
4000
5000
6000
7000
Rated power,Pr (kW)
8000
9000
10000
Figure-5.4 Wind power generation cost for different turbine size and capacity factor
TOTAL EXPENDITURE PER YEARS:
‫ݎ݋ݐ݂ܿܽݕݐ݅ܿܽ݌ܽܥ‬ǡ‫ ܨܥ‬ൌ ʹͺǤͷͶΨ ൌ ͲǤʹͺͷͶ
‫ݎܽ݁ݕݎ݁݌݀݁ܿݑ݀݋ݎ݌ݕ݃ݎ݁݊ܧ‬ǡܹ௣௘௥ǡ௬௘௔௥ ൌ ܲ௥௔௧௘ௗ ‫͵ כ‬͸ͷ ‫ʹ כ‬Ͷ ‫ ܨܥ כ‬ൌ ͵ͲͲͲ ‫͵ כ‬͸ͷ ‫ʹ כ‬Ͷ ‫Ͳ כ‬Ǥʹͺͷ ൌ ͹ǡͶͺͻǡͺͲͲܹ݄݇Ȁ‫ݎܽ݁ݕ‬
‫݁݉݅ݐ݂݈݁݅݀݁ݐܿ݁݌ݔ݁݃݊݅ݎݑ݀݀݁ܿݑ݀݋ݎ݌ݕ݃ݎ݁݊ܧ‬ǡܹ௣ ൌ ܹ௣௘௥ǡ௬௘௔௥ ‫ܶ כ‬௟ ൌ ͹ǡͶͺͻǡͺͲͲܹ݄݇Ȁ‫ ݎܽ݁ݕͲʹ כ ݎܽ݁ݕ‬ൌ ͳͶͻ͹ͻ͸ͲͲͲܹ݄݇
݄ܶ݁‫݁ݎ݋݂݁ݎ‬ǡ ݈݁݁ܿ‫ݐݏ݋ܿ݊݋݅ݐܿݑ݀݋ݎ݌ݕݐ݅ܿ݅ݎݐ‬ǡ
‫ܥ‬௣௖ ൌ
‫ܥ‬௘௫௣
̈́ͳʹǡʹͶͲǡͲͲͲ
ൌሺ
ሻ ൌ ̈́ͲǤͲͺͳ͹ͳͳͳʹ͹Ȁܹ݄݇
ܹ௣
ͳͶͻ͹ͻǡ͸ͲͲͲܹ݄݇
We have plotted the cost curve in figure-3a as a function of output power of the turbine and from this curve we
observe that when we increase the output power then the production cost decrease.
5.2 SOLAR POWER SITE:
In this section we have calculated solar power cost per units and total cost of the system.
5.2.1 COSTCOST ESTIMATION OF PHOTOVOLTIAC SYSTEMS:
In this chapter estimated solar power production cost including storage and inverter cost. There is mainly two
types of cost first one is the up-front cost where did not consider battery replacement cost and second one is the
life cycle cost, in this calculation considered the battery replacement cost during the life of the grid.
P a g e | 64
COST OF INVERTER AS FUNCTION OF PEAK POWER REQUIRED:
Generally power is defined as the rate at which energy is delivered (or captured), that is, energy per unit time:
ܲ‫ ݎ݁ݓ݋‬ൌ ‫ݕ݃ݎ݁݊ܧ‬Ȁܶ݅݉݁
ܲൌ
‫ܧ‬
ܹܽ‫ݐݐ‬
ܶ
There are two categories of power supplies needs to know to designing/planning a solar system:
ƒ
ƒ
The peak power delivered to the load, and
The peak power produced by the solar panels.
The peak power delivered as we can define the total maximum power which can draw by the site load.
ܲ௣௘௔௞ǡ௨௦௔௚௘ ൌ ʹʹʹͷܹ݇
The amount of peak power, that the system could be provide will be determined by the size of the system of the
inverter, inverter is the device which converts the DC battery power to AC power:
ܲ௣௘௔௞ǡ௨௦௔௚௘ ൌ ܲ௣௘௔௞ǡ௜௡௩௘௥௧௘௥
According to the Present market prices for inverters, the costs of an inverter is nearly $1 per watt is
‫ݐݏ݋ܥ‬௜௡௩Ǥ௣Ǥ௞௪ ൌ ̈́ͳͲͲͲȀܹ݇
Cost of the inverter, as a function of the peak power used, is therefore:
‫ݐݏ݋ܥ‬௜௡௩௘௥௧௘௥ ሺܲ௣௘௔௞ǡ௨௦௔௚௘ ሻ ൌ ሺܲ௣௘௔௞ǡ௨௦௔௚௘ ሻሺ‫ݐݏ݋ܥ‬௜௡௩Ǥ௣Ǥ௞௪ ሻ
We can write this equation in different form,
‫ݐݏ݋ܥ‬௜௡௩௘௥௧௘௥ ൌ ൫ܲ௣௘௔௞ǡ௨௦௔௚௘ ൯ሺ̈́ͳͲͲͲȀܹ݇ሻ
COST OF SOLAR PANELS AS A FUNCTION OF ENERGY USAGE:
To calculate the solar panel cost, we need to peak power produced by the solar panels is determined by the panel
rating and number of solar panels uses in the system:
ܲ௣௘௔௞௣௔௡௘௟௦ ൌ ܰܲ௣௘௥௣௔௡௘௟
Where, N is the number of panels and Pper panel is the power per panel
Even though the energy used by electric machines will of course be produced by the solar panels, it is not
required that the peak power output of the solar panels be equal the peak power used:
ܲ௣௘௔௞ǡ௨௦௔௚௘ ് ܲ௣௘௔௞ǡ௣௔௡௘௟௦
P a g e | 65
For the reason that the power generated by the solar panels is stored by batteries with respect to time, therefore it
is possible that the more peak power can be supplied by the inverter than is produced by the solar panels.
As an alternative, we have to calculate the peak power of the solar panels as well, therefore the number of solar
panels, from the total amount of energy we need them to generate each day.
We are going to specify energy in units of kilowatt-hours as we can see in following equation:
‫ ݕ݃ݎ݁݊ܧ‬ൌ ܲ‫ݎ݁ݓ݋‬ሺܹ݅݊݇ሻ ‫݁݉݅ܶ כ‬ሺ݄݅݊‫ݏݎݑ݋‬ሻ ൌ ܰ‫݄ܹ݂݇݋ݎܾ݁݉ݑ‬
Moreover, it is essential to know the sun shines hours each day on average. Let this be denoted by,
ܶ௦௨௡ ൌ ‫݁݃ܽݎ݁ݒܽ݊݋݄݁݊݅ݏ݊ݑݏ݂݋ݏݎݑ݋ܪ‬
ா௡௘௥௚௬
From the relation between power and energy,ܲ‫ ݎ݁ݓ݋‬ൌ ሺ
ܲ௣௘௔௞௣௔௡௘௟௦ ൌ ሺ
்௜௠௘
ሻ we have
‫ܧ‬௨௦௘ௗ
ሻ
ܶ௦௨௡
As our survey of existing market prices, purchase cost of the panel. Hence, the upfront cost of the solar panels
we can calculate as̈́଴Ǥ଻
‫ݐݏ݋ܥ‬௣௔௡௘௟௦Ǥ௣Ǥ௪ ൌ ሺ
ௐ
ሻ, where W is watt
Or, by multiplying numerator and denominator by 1000,
̈́͹ͲͲ
‫ݐݏ݋ܥ‬௣௔௡௘௟௦Ǥ௣Ǥ௞௪ ൌ ሺ
ሻ
ܹ݇
Thus, the cost of the solar panels as a function of Energy use would be
‫ݐݏ݋ܥ‬௣௔௡௘௟௦ ൌ ൫ܲ௣௘௔௞௣௔௡௘௟௦ ൯൫‫ݐݏ݋ܥ‬௦Ǥ௣ ൯ ൌ ൬
‫ܧ‬௨௦௘ௗ
൰ ሺ‫ݐݏ݋ܥ‬௦Ǥ௣ ሻ
ܶ௦௨௡
OR,
‫ܧ‬௨௦௘ௗ
൰ ‫̈́ כ‬͹ͲͲȀܹ݇
ܶ௦௨௡
‫ݐݏ݋ܥ‬௣௔௡௘௟௦ ൌ ൬
COST OF BATTERIES AS A FUNCTION OF ENERGY USAGE:
How much energy we can be used when solar power will not produce that means after dark or on a rainy day
determines by the amount of storage energy.
The number of kilowatt-hours we can store will be depend on the number of battery, type of the batteries, % of
DOD and SOC, but the amount of energy storage is determined is:
P a g e | 66
‫ܧ‬௦௧௢௥௘ௗ ൌ ሺ‫ݕݎ݁ݐݐܾܽݎ݁݌ݕ݃ݎ݁݊ܧ‬ሻሺܰ‫ݏ݁݅ݎ݁ݐݐܾ݂ܽ݋ݎܾ݁݉ݑ‬ሻ
Typical lifetimes of deep cycle batteries are fairly little (3 - 10 years) is used, and depend on how fine they are
maintained Normally, if a battery is discharged to 50% every day, it will last about twice as long as if it is cycled
to 80%. If cycled only 10%, it will last about 5 times as long as one cycled to 50%.
If we take responsibility, in order not to discharge the battery more than 50% that the batteries will be able to
store twice the amount of energy we use:
‫ܧ‬௦௧௢௥௘ௗ ൌ ʹ ‫ܧ כ‬௨௦௘ௗ
As determined the present market survey, the cost of batteries is nearby $300 per kilowatt-hour of storage and
we can do in mathematically as:
‫ݐݏ݋ܥ‬௕௔௧௧௘௥௜௘௦ ൌ
̈́͵ͲͲ
ܹ݄݇
Therefore, as a function of energy used, the cost of batteries
̈́͵ͲͲ
ሻ
‫ݐݏ݋ܥ‬௕௔௧௧௘௥௜௘௦ ൌ ʹ ‫ܧ כ‬௨௦௘ௗ ‫ כ‬ሺ
ܹ݄݇
Since we have contained within the factor of two, then we are probably safe to take on at least a six year lifetime
of the batteries:
‫݁݉݅ݐ݂݁݅ܮ‬௕௔௧௧௘௥௜௘௦ ൌ ͸‫ݏݎܽ݁ݕ‬
CALCULATION OF UPFRONT COST:
Adding all of the costs of the inverter, panels and batteries, we have
‫ݐݏ݋ܥ‬௨௣௙௥௢௡௧ ൌ ‫ݐݏ݋ܥ‬௜௡௩௘௥௧௘௥ ൅ ‫ݐݏ݋ܥ‬௣௔௡௘௟௦ ൅ ‫ݐݏ݋ܥ‬௕௔௧௧௘௥௜௘௦
ൌ ൫ܲ௣௘௔௞ǡ௨௦௔௚௘ ൯ ‫ כ‬ቆ
̈́ͳͲͲͲ
‫ܧ‬௨௦௘ௗ
̈́͹ͲͲͲ
̈́͵ͲͲ
ቇ൅൬
൰‫כ‬ቆ
ቇ ൅ ʹ ‫ܧ כ‬௨௦௘ௗ ‫ כ‬ቆ
ቇ
ܹ݇
ܹ݇
ܹ݇
ܶ௦௨௡
P a g e | 67
UP-FRONT COST ESTIMATION OF SOLAR SYSTEM
0.35
0.3
Cost, US$/kWh
0.25
0.2
0.15
0.1
0.05
0
0
10000
20000
30000
40000
50000
60000
70000
80000
Energy Produced, kWh
T_sun=5
T_sun=6
T_sun=7
T_sun=8
Figure: 5.5 Up-front costs as a function of energy produced at different sunlight hours
UP-FRONT COST ESTIMATION OF SOLAR SYSTEM
0.35
0.3
Cost, US$/kWh
0.25
0.2
0.15
0.1
0.05
0
0
10000
20000
30000
40000
50000
60000
Energy Produced, kWh
T1=20
T1=21
T1=22
T1=23
Figure: 5.6 Up-front costs as a function of energy produced at different system lifetime
70000
80000
P a g e | 68
CALCULATION OF LIFE-CYCLE COST PER KILOWATT-HOUR:
According to recent solar panels are expected to last at least 20 years in general. Therefore we are going to use
20 years lifetime to calculate the life-cycle cost, because of our site lifetime is also same as:
ܶ௦௬௦௧௘௠ ൌ ʹͲ‫ݏݎܽ݁ݕ‬
Generally we using a longer lifetime to decrease the life-cycle cost and production cost, and vice versa.
The total life-cycle cost per kWh is given by the following equation is as:
‫ݐݏ݋ܥ‬௞௪௛ ൌ ሺܶ‫ݐݏ݋݈ܿ݁ܿݕ݂݈݈ܿ݁݅ܽݐ݋‬ሻȀሺܶ‫݀݁ݏݑ݄ܹ݈݇ܽݐ݋‬ሻ
To calculate the total life-cycle cost, we require to periodic replacement of the batteries. We have considered the
lifetime of six years of the batteries and the number of times we have to replace the batteries we can calculate as
like:
ܰ௕௔௧௧௘௥௜௘௦ ൌ
ܶ௦௬௦௧௘௠
ൌ ʹͲȀ͸ ؆ Ͷ
‫݁݉݅ݐ݂݁݅ܮ‬௕௔௧௧௘௥௜௘௦
Therefore the total life-cycle cost of the batteries we have as like
‫ݐݏ݋ܥ‬௕௔௧௧௘௥௜௘௦ǡ௟௜௙௘ି௖௬௖௟௘ ൌ Ͷ ‫ݐݏ݋ܥ כ‬௕௔௧௧௘௥௜௘௦ ൌ ͺ ‫ܧ כ‬௨௦௘ௗ ‫ͲͲ͵̈́ כ‬Ȁܹ݄݇
LIFE-CYCLE COST ESTIMATION OF SOLAR SYSTEM
0.400
0.350
Cost, US$/kWh
0.300
0.250
0.200
0.150
0.100
0.050
0.000
0
10000
20000
30000
40000
50000
60000
Energy Produced, kWh
T_sun=5
T_sun=6
T_sun=7
T_sun=8
Figure: 5.7 Life- cycle costs as a function of energy produced at different sunlight hours
70000
80000
P a g e | 69
The total life-cycle cost of the system will therefore be
‫ݐݏ݋ܥ‬௟௜௙௘ି௖௬௖௟௘ ൌ ‫ݐݏ݋ܥ‬௜௡௩௘௥௧௘௥ ൅ ‫ݐݏ݋ܥ‬௣௔௡௘௟௦ ൅ ‫ݐݏ݋ܥ‬௕௔௧௧௘௥௜௘௦ǡ௟௜௙௘ି௖௬௖௟௘
ൌ ൫ܲ௣௘௔௞ǡ௨௦௔௚௘ ൯ ‫ כ‬ቆ
̈́ͳͲͲͲ
‫ܧ‬௨௦௘ௗ
̈́͹ͲͲͲ
̈́͵ͲͲ
ቇ൅൬
൰‫כ‬ቆ
ቇ ൅ ͺ ‫ܧ כ‬௨௦௘ௗ ‫ כ‬ቆ
ቇ
ܹ݇
ܹ݇
ܹ݄݇
ܶ௦௨௡
The above equation is similar to the upfront cost formula, apart from the extra factor of four in the last term we
have added.
Because we defined the quantity Eused to be the number of kilo-watt hours used per day, the number of kilowatthours used over the lifetime of the system will be:
ܶ‫ ݐݐܽݓ݋݈݈݅݇ܽݐ݋‬െ ݄‫ ݀݁ݏݑݏݎݑ݋‬ൌ ʹͲ‫͵ כ ݏݎܽ݁ݕ‬͸ͷ݀ܽ‫ܧ כ ݏݕ‬௨௦௘ௗ ൌ ͹͵ͲͲ ‫ܧ כ‬௨௦௘ௗ
We therefore have
‫ݐݏ݋ܥ‬௞௪௛ ൌ ‫ݐݏ݋ܥ‬௟௜௙௘ି௖௬௖௟௘ Ȁሺ͹͵ͲͲ ‫ܧ כ‬௨௦௘ௗ ሻ
5.3 CALCULATED TOTAL COST OF THE SITE:
Here we have calculate the total installation cost of the site per kWh including operation and maintenance cost,
design and thermal and system losses we considered as well. Therefore the total cost is defined and calculate as
like below.
Total cost
ܵ௧ ൌ ܵ௦ ൅ ܵ௪ ൅ ܵ௕ ൅ ܵ௚
ൌ ̈́͵͵ͲͲ ൅ ̈́ͶͲͺͲ ൅ ̈́͸ͲͲ ൅ ̈́ʹͲͲ
ൌ ̈́ͺͳͺͲȀܹ݇
Where,
ܵ௦ =Solar panels installation cost ($/kW)
ܵ௪ =Wind turbine installation cost ($/kW)
ܵ௕ =Storage batteries cost/discharge power ($/kW)
(Cost per capacityൎ$300/kWh)
ܵ௚ =Micro-grid design and others cost ($/kW)
P a g e | 70
6. DISCUSSIONS AND FUTURE WORK:
With this type of grid design we are going to develop the electric energy production in remote areas where the
transmission lines does not come. In our design we have considered some renewable micro sources such as wind
and solar power to produce electricity in Gothenburg. According to our site load requirement around 1745 kW
average power demand and peak power demand is 2225 kW.
In case studies and meet the demands of our electric site we have considered VESTAS V112-3.0MW wind
turbine and about 15000 mono-crystalline solar module of 200Wp rating. From these sources total average
power produces around 2702.7 kW (i.e. 64864.8 kWh energy per day) which exceeds peak power demand, from
this produced power 1745 kW will consumed and rest of this power will be stored. If we bring into play the
storage battery at 50% discharge rate then we can use energy from storage system around half of the total energy
that means 32432.4 kWh per day. Therefore, with this energy efficiently and reliably we can meet the demand of
the site load.
Typically there are four basic operation mode used in micro grid, the stage of operation we have discussed in the
section of intelligent control strategy. The charging system is the important part of this design, NEC and ABB
have developed intelligent charging devices and infrastructure to mitigate the hazard of the vehicle charge,
which is broadly used in modern electric machine charging system, we have discussed before in detailed.
We have estimated the electricity production cost including operation and maintenance costs and also we have
calculated individual cost per unit of the wind and solar power according to the recent market price of the
instrument and devices.
In this project we have design of micro-grid and specify the modeling, in future of this project should be
implement a controlled and power management system then this would be the more perfect micro-grid.
Also should be choosing more than one site and make more site specification with latest data of that specific site.
P a g e | 71
7. CONCLUSIONS
In this innovatory concept of μ-grids, as an alternative advancement to integrating small scale distributed energy
resources into electricity distribution networks in specific area, and more generally, into the existing wider power
system. A conventional strategy generally focuses on reducing the consequences for safety and grid performance
of a comparatively small number of individually interconnected micro generators or power production sources,
involve that safety requires they immediately disconnect in the event of system outage that means from any
unintentional situation.
All the way through differentiate, Micro-Grids would be designed to operate autonomously, usually operating
connected to the grid but is landing from it, as cost effective or necessary to maintain performance to supply
electricity.
In this project we have presented a DC new self-sufficient micro-grid system, which is completely design with
renewable energy production to fulfill the demand of our electric site the, there is some number of electric
construction equipment in remote area. This grid also provides intelligent electric machines charging system and
infrastructure, which is able to efficient and reliable power supply to charged machines.
We have chosen DC grid because of our electrification site requirement and easily control DC power in
distribution network.
In addition to supply the efficient energy to local areas to attain the demand of electricity in electric construction
equipment’s, electric vehicles and small industries. In this design we have integrates the renewable energy,
standby energy, storage energy and energy from AC utility grid. In this project we have calculated the
production cost of energy per unit of the solar farm and wind farm.
Therefore, this self-sufficient micro-grid would be able to efficient and high quality power supply to meet
demand of our electric site with a new strategy. The simulation of this whole project is done by MATLAB.
P a g e | 72
8. REFERENCES
[1]
Micro-grids: an assessment of the value, opportunities and barriers to deployment in New York State; final
report 10-35; September 2010.
[2]
Control System for a Diesel Generator and UPS Based Micro-grid, Scientific Journal of Riga Technical
University, Power and Electrical Engineering.
[3]
“A New DC Micro-grid System Using Renewable Energy and Electric Vehicles for Smart Energy Delivery”
[4]
http://www.pikeresearch.com/research/microgrids (Jan, 2013)
[5]
http://www.nec.co.jp/techrep/en/journal/g12/n01/120105.html (Jan, 2013)
[6]
Lee, J.; Han, B.; Choi, N.; "DC micro-grid operational analysis with detailed simulation model for
distributed generation," Energy Conversion Congress and Exposition (ECCE), 2010 IEEE, vol., no.,
pp.3153-3160, 12-16 Sept. 2010.
[7]
Shenai, K.; Shah, K.; , "Smart DC micro-grid for efficient utilization of distributed renewable energy,"
Energytech, 2011 IEEE , vol., no., pp.1-6, 25-26 May 2011.
[8]
DC Power Productions, Delivery and Utilization DC Power Production, Delivery and Utilization; An EPRI
White Paper; , June 2006.
[9]
Liu Jianye; Liu Jia; Gu Xiao; Li Yunshan; , "Model and Control of a DC Micro-grid Made Up by Solar and
Wind," Computer Science and Electronics Engineering (ICCSEE), 2012 International Conference on , vol.1,
no., pp.437-441, 23-25 March 2012.
[10] http://energy.gov/oe/technology-development/renewable-energy-integration (Jan, 2013)
[11] http://www.nec.com/en/global/environment/energy/nec_aes/index.html (Jan, 2013)
[12] http://theenergycollective.com/ecsjessica/172961/energy-storage-systems-finally-getting-attention-theydeserve (Jan, 2013)
[13] Exploring Wind Energy; , Student Guide; , National energy education development project 2012-2013.
[14] UpWind; , Design limits and solutions for very large wind turbines; , A 20 MW turbine is feasible; ,March
2011.
[15] “Wind Power in Power system”, Thomas Ackermann, Royal Institute of Technology; Stockholm, Sweden
[16] Clean energy project analysis: RETScreen engineering & cases textbook; Minister of Natural Resources
Canada 2001 - 2004.
[17] IEA Wind Task 26; The Past and Future Cost of Wind Energy; Technical Report NREL/TP-6A20-53510;
,May 2012.
[18] Renewable energy technologies: cost analysis series; Volume-1: Power sector, International Renewable
Energy Agency (IRENA); Wind Power, June 2012.
[19] Renewable power generation cost in 2012: An overview; International Renewable Energy Agency (IRENA),
2012
[20] P Adams, 6120;"Photovoltaic Technologies; part 1 – Commercialized technologies", Volvo engineering
report, March 2011.
[21] http://www.eere.energy.gov/basics/renewable_energy/photovoltaics.html (March, 2013)
[22] "PV Power Plants 2012, Industry Guide"; Renewables Insight-Energy Industry Guides (RENI).
P a g e | 73
[23] http://www.pathways.cu.edu.eg/subpages/training_courses/Research%20Methods%208/Chapter2.htm (Feb,
2013)
[24] http://www.volvoce.com/constructionequipment/na/en-us/products/excavators/pages/excavators.aspx (Feb,
2013)
[25] "The Economics of Wind Energy" By the European Wind Energy Association (EWEA); , March 2009.
[26] "Pure Power Wind energy targets for 2020 and 2030"; A report by the European Wind Energy Association
(EWEA) - 2009 update.
[27] http://weatherspark.com/ (March, 2013)
[28] http://www.weatheronline.co.uk/ (March, 2013)
[29] http://www.areavibes.com/gothenburg-ne/weather/ (March, 2013)
[30]
"Theory of wind machines, Betz equation" by M Ragheb; Oct. 2010.
[31] "Wind and Solar Power Systems" by Mukund R. Patel, Ph.D., P.E.U.S. Merchant Marine Academy Kings
Point, New York.
[32] J. Waewsak1,*, C. Chancham1, M. Landry2and Y. Gagnon"An Analysis of Wind Speed Distribution at
Thasala, Nakhon Si Thammarat, Thailand" ; Journal of Sustainable Energy & Environment 2 (2011) 51-55.
[33] Urban wind turbines; Technology Review; A companion text to the Catalogue of European Urban Wind
Turbine Manufacturers by Intelligent Energy Europe (WINEUR).
[34] http://www.windmeasurementinternational.com/index.php (March, 2013)
[35] http://www.photon-international.com/newsletter/document/72697.pdf (March, 2013)
P a g e | 74
APPENDIX:
In the appendix there is some data and information, which is not research oriented information. These
information we have included from some reference papers and website just for understand effortlessly to the
readers about the project. There are some basic conception of storage technology costing factor, construction
equipments and their working principle and to get some idea of latest prices of the solar modules and cell.
APPENDIX – A: ELECTRIC CONSTRUCTION MACHINES
EXCAVATOR GENERAL:
Excavators are the heavy duty engineering vehicles which are mostly used for the use of digging trenches, holes
or foundations and other heave duty work as well. These are also used for other purposes such as destruction,
lifting and placing heavy materials especially pipes, for mining but not open pit mining, river dredging,
landscaping and conveying stones from one place to another.
These equipments are the most popular equipment’s in the construction industry, excavators have successfully
aided in reducing the involvement of human effort in heavy construction work and shave time.
BENEFITS TO USE EXCAVATORS:
ƒ
ƒ
ƒ
ƒ
ƒ
Industry leading fuel efficiency.
Ergonomic work environment makes it more safe, reliable and comfortable on the operator.
Safety through the new design Volvo Care Cab.
Feature built to last undercarriage, reinforced superstructure, and proven equipments that transport
every time.
Environmentally friendly such as low emissions levels, low noise and more than 95% of the machine is
recyclable.
GENERAL CLASSES OF EXCAVATORS:
1. COMPACT EXCAVATORS:
Volvo’s smallest line of excavators which is more cost efficient, effective and wonderful for working tight job
sites. These machines may be compact, but are huge on features, protection and reliability. Excellent visibility
and operator soothe combined with efficient Volvo engines equals increased efficiency. Easy access to service
points means more machine uptime for the future.
2. WHEELED EXCAVATORS:
While flexibility and digging performance are main, Volvo wheeled excavators is the response. These machines
can handle the whole thing from general construction to utility work with ease. High travel speed and a smooth
ride make them especially proficient, even as load sensing hydraulics and a high torque swing motor allows
faster cycle times.
P a g e | 75
3. CRAWLER EXCAVATORS:
This is the type of excavator; Volvo crawler excavators are ready for your biggest quarrying, mining, road
building and wide-ranging construction jobs. Feature a forceful undercarriage and a reinforced boom/arm and
superstructure; these machines are safe, efficient and durable. Enlarged time between simplified service intervals
keeps these Volvo crawler excavators on duty for longer than always.
Figure:4.1.1a Volvo crawler excavator example
source of picture: www.volvo.com
HAULERS:
All the Volvo Construction Equipment developed the dumpers conception and new idea. And in the region of
globe, we’re still the undeniable leader of dumper truck hauling in the most demanding conditions, terrain and
applications and implementations. There are some top features for the range of Volvo dumpers include:
ƒ
ƒ
ƒ
ƒ
ƒ
ƒ
ƒ
In the first feature all of the Volvo drive train developed in synchronization, from engine and
transmission to drop box and axles.
Self compensating, hydro-mechanical steering, this for safety and longer lasted.
6x4 and 6x6 modes, for the optimized effectiveness, put on life and off-road mobility.
Volvo Care Cab, with centrally-positioned operative station, for high visibility and more
space, soothe and safety as well.
Engine hood with swing-down grill platform, for the effortless service.
95% recyclable machine, helping to preserve our environment and safety.
And the final feature is care Track telemetric as standard
equipment, helps you to save fuel, decrease costs and maximize profitability.
P a g e | 76
Figure: 4.1.1b Articulated hauler example
source of the picture: www.volvo.com
THE CRUSHERS:
The crushing technology at the Martha Mine open pit consists of an arrangement of two types of crushers, a jaw
crusher and two different Stamler feeder breakers. The first one is the jaw crusher is capable of crushing material
with strength of over 150 megapascals (MPa). By way of similarity, concrete has strength of 20-30 MPa. The
Stamlers deal with the softer material normally. Conventionally, the crushers are placed below ground level, in a
slot to minimize noise and hazard effects.
Figure: 4.1.2a Crushing & sorting station with conveyor belt
source: http://www.rogranex.ro/
THE CONVEYING SYSTEM:
There is some number of conveyors essential to ensure that following crushing; rock is transported to its correct
target or destination. The biggest conveyor on site (the overland conveyor) transports the ore from the open pit to
the processing plant, and the waste rock to the waste rock embankments individually.
P a g e | 77
Transfer stations shift rock from one conveyor to the next one, such as a transfer station is sited near to the
processing plant, so that ore can easily bearing for from the main overland conveyor to the processing plant, and
waste can be directed to the waste rock embankments. In the same way a transfer station is sited at the surface
services area in the open pit to transfer rock from the crusher conveyor to the main overland conveyor.
Frequently the rock may contain steel and timber from the old workings. Electromagnets exist at a number of
points in the region of crushers and transfer stations to pick up steel, which can damage the conveyors. The wood
and steel detached is referred to as drifter material, and is transported off site by truck. While rock contains a
large proportion of timber and steel, it is normally hand sorted.
APPENDIX – B: ENERGY STORAGE TECHNOLOGY
OVERVIEW OF STORAGE TECHNOLOGIES:
Storage technology in electrical systems can take many forms. Energy can be stored in chemicals (e.g. batteries
or hydrogen), as potential energy (e.g. pumped hydro or compressed air), as electrical energy (e.g. capacitors) or
as mechanical energy (e.g. flywheels). Because of this multiplicity of technologies, the system of classification
and metrics used to compare them is abstracted from the underlying storage standard. Further complicating a
consideration of storage is the growth of new and novel technologies to store energy, which quickly adds new
and unverified products to the market place.
These new technologies often make appearance claims exact c to their technology that can be difficult to
compare to other technologies. In this chapter the metrics by which one can compare storage technologies, such
as capacity and discharge rate, are discussed. Then there is an overview of the many storage technologies with a
focus on the technologies that are at present commercially feasible. Particular thought is given to those storage
technologies that emerge especially promising for isolated, island and remote electricity systems.
Finally, a high-level survey of technologies that are at this time in the pilot project phase and those that are still
under early research and development is provided. These are included to give a view of what technologies are
not yet ready but may be available in the near future.
UNDERSTANDING STORAGE PERFORMANCE:
The fundamental metrics used to define a storage technology for most electricity grid systems include:
ƒ
ƒ
ƒ
ƒ
ƒ
ƒ
Energy storage capacity (kWh or Ah)
Charge and discharge rates (kW or A)
Lifetime (cycles, years, kWh life)
Roundtrip efficiency (%)
Initial capital costs ($/kW, $/kWh cap, and $/kWh life)
Operating costs ($/MWh, $/kW x yr) and
For transportable systems in which space is at a very high quality, the substantial size (m3) of the system may
also be significant:
ƒ
Energy density (Wh/kg and Wh/m3) and power density (W/kg and Wh/m3).
P a g e | 78
ENERGY STORAGE CAPACITY
Energy storage capacity is the amount of energy that can be stored at a given time (kWh). Some batteries will
presume an operating voltage (V) and provide energy capacity in a different form (Ah, where kWh = V × Ah /
1,000). The useful energy capacity will frequently be less than the stated total capacity based on a number of
factors described below as we can see. For some battery technologies, the capacity will appear less if power is
pulled out rapidly and greater if power is pulled out slowly. Many technologies also have restrictions on how
much of the storable energy may be used. Over discharging some technologies (in particular, lead-acid batteries)
can shorten their lifetime that is less lasting.
CHARGE AND DISCHARGE RATES
Charge/discharge rates of the batteries are measures of power (kW) indicating the rate at which energy is
added/removed from a storage system. Some systems will assume an operating voltage (V) and provide the
charge/discharge rates as a current in amperes (A) (where kW = V × A / 1000). For many technologies these
rates will not be constant values at all times; in practice, they will change with how much energy is in storage
and how long power has been continuously removed/added to storage. The charge rate is lower than the
discharge rate for most technologies. In general, a storage system will be described mainly based on in terms of
its discharge rate of the battery.
LIFETIME
Each storage technology has a restricted lifetime. Some technologies measure lifetime according to how much
they are charged and discharged (cycles), while other technologies will lose functionality due to time passing
(years) and yet others have lifetimes limited by total energy throughput (kWh life or Ah life). As they age, most
storage technologies will suffer from despoiled performance.
INITIAL CAPITAL COST
The capital costs provided here are estimates based on trained experience and unofficial surveys of openly
available prices. They are projected to provide a high-level thoughtful of the issues and are not intended as cost
inputs into a design. Costs for a specific system will be different across an extensive range of factors. These
factors include system size, location, local labor rates, market inconsistency, and intended use of the storage
system, local climate, environmental considerations and transport issues.
It is important to distinguish that installing storage will require additional costs, generally called balance-ofsystem (abbreviated BOS) costs. These include safety equipment (e.g. fuses, current fault protection),
inverters/rectifiers, system controllers, remote monitoring equipment and supplemental sensors. BOS equipment
can have a large impact on the total system cost, ranging anywhere from 100% to 400% more than the costs of
the storage technology unaccompanied for an example calculation that illustrates BOS costs).
OPERATING COSTS
Technologies require ongoing operation and maintenance to remain at peak performance. In reality, a number of
factors will influence ongoing O&M costs, including how often the storage equipment is used, ambient
temperatures, handling of the equipment, adherence to the recommended maintenance schedule, quality of
installation, protection from overcharging, protection from over discharging, the rate at which the equipment is
cycled and the quality of the storage equipment. For plainness, all of these factors are bundled in a conventional
annual cost based on the size of the tools ($/kW). Estimates of annual costs are given in Table 1 and some data
as well.
P a g e | 79
Leadacid
batteries
Li-Ion
batteries
NaS
batteries
Flow
batteries
Fly-wheels
Pumped
hydro
Largescale
CAES
Applicable
grid
system size
[kW/MW]
Lifetime
[years]
≤10 MW
≤10 MW
≥100 MW
25 kW–10
MW
100
kW–200
MW
Mostly
≥200 MW
≥500 MW
3–10
10–15
15
20
25+
20+
Lifetime
[cycles]
500–800
2,000–
3,000
4,000–
40,000
>100,000
>50,000
>10,000
Roundtrip
efficiency
[%]
Capital cost
per discharge
power
[$/kW]
70%–
90%
85%–95%
80%–90%
Cell stack:
5–15;
Electrolyte:
20+
Cell stack:
1,500–
15,000
70%–85%
85%–95%
75%–85%
45%–60%
$300–
$800
$400–
$1,000
$1,000–
$2,000
$1,200–
$2,000
$2,000–
$4,000
$1,000–
$4,000
$800–
$1,000
Capital cost
per capacity
[$/kWh cap]
Levelised
cost of
storage
[$/kWh life]
$150–
$500
$500–
$1,500
$125–$250
$350–$800
$1,500–
$3,000
$100–$250
$50–$150
$0.25–
$0.35
$0.30–
$0.45
$0.05–
$0.15
$0.15–
$0.25
N/A
$0.05–
$0.15
$0.10–
$0.20
Annual
operating
costs [$/kW
yr]
$30
$25
$15
$30
$15
$5
$5
TABLE-1: SUMMARY OF THE COMMERCIALLY AVAILABLE STORAGE TECHNOLOGIES.
Source: [5e][6f]
BATTERIES
Generally, batteries are a very modular technology and system. The useful storage capacity will amplify with
each battery added to a battery bank and, depending on the architecture; the charge/discharge rate will also
increase. A battery is composed of a number of cells. Every of these cells contain a cathode (positive plate),
anode (negative plate), positive electrolyte and negative electrolyte. Each cell usually has a voltage of around 1.5
to 2 volts even though this will depend on the chemicals and materials used. The life of batteries is dependent in
part on how much of their storage capacity is used at any one time, which is recognized as the “depth of
discharge” (DOD). Normally, the deeper a battery is cycled, the shorter it’s expected lifetime. For example, a
battery cycled down to 80% of its full capacity (an 80% DOD) will, in general, have an order of magnitude
shorter lifetime than a battery that is cycled only to a 10% DOD.
P a g e | 80
APPENDIX – C: SOLAR CELL AND PANEL PRICE TRENDS
ENF February 2013 Cell and Panel Price Charts
February 19, 2013
Panel
Average Price:
€ 0.45 /Wp
Price Change: +€ 0.0003 /Wp
Cell
Average Mono 125 Price:
¥2.72 /Wp
Price Change: +¥ 0.08 /Wp
Average Poly 156 Price:
¥2.23 /Wp
Price Change: +¥ 0.09 /Wp
Where, Wp= Watt-peak and ¥=Symbol of Chinese currency Yuan
ENF 12-Month Chinese Crystalline Panel Prices (Wp)
Source: [7g][8h]
n this chart contain the price that Chinese panel manufacturers are selling their crystalline panels for. To create
the chart, ENF calls over 100 panel manufacturers certified with IEC61215 or IEC61730 to check their price
every month. The price quotes are for 1MWp of panels FOB China port.
Note: Suppose a manufacturer is going out of business they may estimate very low prices in order to apparent
stock. ENF has kept these quotes as a legal indication of market prices.
P a g e | 81
ENF 12-Month Chinese Solar Cell Prices (Wp)
Source: [7g][8h]
In this second chart tracks the price that Chinese panel manufacturers are paying for their crystalline cells. To
make the chart ENF collects about 60 cell prices every month from Chinese cell and panel manufacturers or
company. Cell manufacturers companies quote the price they are selling to the Chinese market, and panel
manufacturers quote the price they would be buying from Chinese cell manufacturers. Because all prices are for
cells produced and sold internally they include 17% domestic VAT and are not focus to exchange rate
fluctuations.
PV-XCHANGE PRICE TRENDS
In assistance with PV X-change, the world’s leading brand-independent market place for solar modules and
inverters, solar server presents a monthly index of wholesale prices for thin film and crystalline PV modules.
PRICE TRENDS FEBRUARY 2013
Source: [7g][8h]
Module type,
origin
€/
Wp
Crystalline
Germany
0.78
0,0 %
- 27.1 %
Crystalline
China
0.53
0,0 %
- 32.9 %
Crystalline
Japan
0.82
- 1.2 %
- 21.9 %
Thin film
CdS/CdTe
0.54
- 3.6 %
- 20.6 %
Thin film a-Si 0.42
0,0 %
- 30.0 %
- 1.9 %
- 32.9 %
Thin film aSi/μ-Si
0,51
Trend since
2013-01
Trend since
2012-01
P a g e | 82
APPENDIX- BIBLIOGRAPHI
APPENDIX-A
[1a]
www.volvo.com (Feb, 2013)
[2b]
http://EzineArticles.com/657130 (Feb, 2013)
[3c]
http://www.waihigold.co.nz (Feb, 2013)
[4d]
http://www.rogranex.ro/ (Feb, 2013)
APPENDIX-B
[5e]
http://www.irena.org/home/index.aspx?PriMenuID=12&mnu=PriPriMenuID=12&mnu=Pri (March,
2013)
[6f]
“Electricity Storage and Renewable for Island”, May 2012; Power by International Renewable Energy
Agency (IRENA)
APPENDIX-C
[7g]
http://www.enfsolar.com/cell-panel-prices (March, 2013)
[8h]
http://www.solarserver.com/service/pvx-spot-market-price-index-solar-pvmodules.html?gclid=CIPp7OHFzrMCFZHEzAodQ0QA_A (March, 2013)
Was this manual useful for you? yes no
Thank you for your participation!

* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project

Download PDF

advertisement