Vehicle-to-Grid Technology: Campus Demonstrator Viability 3 rd Year, School of Engineering, University of Warwick. ES327 – Individual Project. Submitted 23/04/2012. Stephen Cordle
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Vehicle-to-Grid Technology:
Campus Demonstrator Viability 3rd Year, School of Engineering, University of Warwick.
ES327 – Individual Project. Submitted 23/04/2012. Stephen Cordle
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ACKNOWLEDGEMENTS
I would like to thank the many employees of the University and other organisations who have
taken the time to give facts, opinions and advice without which this project would not have been
possible. I would particularly like to thank Mark Jarvis, Graham Hine, Dominic Scholfield, Paul
Bostock, Sebastien Pelissier, Andrew McGordon, Philip Mawby, Gareth Haines, Leonard Beck,
Mike Simpson, Lilian MacLeod, Andy Walden and Graham Hardwick.
Special thanks go to the University of Warwick, Cenex and the Low Carbon Vehicle Procurement
Programme (LCVPP) for granting me access to a confidential, valuable and very extensive set of
primary data regarding the use of Electric Vehicles on the University of Warwick campus.
Specifically, I am grateful to Graham Hine and Dominic Scholfield, the individuals who allowed
this access. Dominic Scholfield also provided vital help in interpreting the data, for which I am
most appreciative.
Finally, I would like to thank my supervisor Dr. Ian Tuersley for his help, support and advice
throughout the project.
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AUTHOR’S SELF-ASSESSMENT
The author believes that this report has made a genuine contribution to the current discourse
concerning Vehicle-to-Grid (V2G) technology in the UK, and that the report contributes substantial
progress towards establishing whether a V2G demonstrator on the University of Warwick campus
would be viable. Information has been gathered from a wide range of research, news and personal
communications and summarised in a digestible format, with conclusions drawn concerning the
viability of a campus demonstrator. Both primary and secondary sources have been used, with a
wide range of stakeholders and relevant parties contacted including representatives of National
Grid, EDF Energy, npower, Jaguar Land Rover, AC propulsion, REV technologies, Cenex, MIRA
and the National Renewable Energy Laboratory (part of the United States’ Department of Energy).
Primary sources have included data covering University energy production and consumption, and
the usage of campus electric vehicles.
In national terms V2G technology is a relevant and important topic due to the convergence of major
public policy issues in environmental, energy and transport matters. The technology has
considerable momentum and is likely to increasingly impact upon the national consciousness. For
the University of Warwick, a campus demonstrator could enhance the University’s profile and
reputation, help to meet carbon reduction targets and potentially provide a revenue stream.
This report could be used to provide anyone with an understanding of the rationale behind V2G
technology and the way in which it works. It also lays a solid foundation for anybody seeking to
establish a V2G demonstrator on campus or wishing to further investigate whether such a
demonstrator would be viable.
This project has met all of its objectives (found in Section 1.3). The report provides a clear and
factual introduction to the case for V2G technology and delivers data and analysis assessing the
potential for a campus demonstrator. A particular highlight is the fact that as a result of this project
EDF Energy, a national energy company, has expressed interest in collaborating with the
University in order to establish a proof-of-concept trial.
Limitations in the time and space available have meant that many areas of the report were not
treated with the level of depth which would have been ideal, such as the technical requirements
and tendering process for balancing contracts with the National Grid. Time constraints also
prevented the contact with EDF Energy from being explored to a greater level of depth. This was
unfortunate as this could have been a very fruitful line of enquiry.
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EXECUTIVE SUMMARY
This report investigates Vehicle-to-Grid (V2G) technology, in which plug-in Electric Vehicles (EVs)
capable of bi-directional power flow communicate with the grid in order to provide balancing
services or, in the longer term, help to balance supply and demand. The report seeks to establish
the reasoning behind V2G technology, and then whether a viable V2G demonstrator could be
established on the University of Warwick campus.
In the UK the Climate Change Act 2008 set stringent emissions reduction goals. The need to find
alternatives to fossil fuels and move to more sustainable alternatives has caused upheaval in the
energy generation and automotive industries, and allowed the concept of V2G to emerge as an
opportunity that could benefit both vehicle owners and grid operators.
In the main body of this report, academic writing on V2G is critically reviewed and the
requirements and benefits of a V2G demonstrator are investigated. Data and information regarding
the University’s EV fleet, campus electricity production and demand, and the balancing services
purchased by the National Grid are then found and analysed. It is established that the University
meets the technical requirements for a V2G system.
Whilst analysis has shown that the current EV fleet is too small to provide significant V2G services,
a proof-of-concept demonstration could be worthwhile. A number of utility companies were
approached, and EDF Energy expressed interest in collaborating to establish such a demonstrator.
In order to determine whether a demonstrator providing substantial V2G services could be
achieved in future, projections are made about the size of the University fleet in 2020. The impact of
including staff and student vehicles parked on campus is also modelled. It is found that combining
optimistic predictions of University fleet growth and staff and student EV uptake, V2G services
could be provided on a significant scale by 2020. If the University were to encourage more rapid EV
uptake, then this could be expected to come sooner. These V2G services could be used internally to
balance campus electricity demand and supply, or could be sold to the National Grid. Revenue
could be approximately £12,600 - £23,400 per annum.
Overall, there is good potential for a proof-of-concept demonstrator in the near term, particularly if
collaboration with commercial partners such as EDF Energy is fruitful. In the longer term, by 2020
the University may well be in a position to sell significant V2G services to National Grid.
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LIST OF FIGURES
Figure 1: The UK Challenge – Current emissions compared to 2050 objective. ................. 3
Figure 2: An illustrative scenario for power sector decarbonisation to 2030. .................... 3
Figure 3: Change in installed capacity 2010/11 to 2020/21 ........................................... 4
Figure 4: Overview of the smart grid technology landscape (© EG&S KTN, 2011). ........... 5
Figure 5: Sectoral contributions to UK CO2 emissions in 2005 ........................................ 6
Figure 6: University of Warwick projected emissions to 2020. ....................................... 20
Figure 7: October 2007 demonstration ...................................................................... 22
Figure 8: Method used to produce Figures 9 and 10 .................................................... 25
Figure 9: Graphical representation of electricity purchased from the grid during 2011 ..... 26
Figure 10: Graphical representation of electricity generated by CHP plant during 2011 .... 26
Figure 11: Electricity Demand of typical campus office and accommodation buildings ...... 27
Figure 12: Total Campus Electricity Demand and Current and Future CHP Production ...... 28
Figure 13: Illustration of the principle of frequency regulation. Source ........................... 29
LIST OF TABLES
Table 1: Comparison of battery technologies. Data from (35). ...................................... 15
Table 2: Requirements of balancing services in the UK. Data from (39) ......................... 29
Table 3: Average prices of all successful tenders for provision of FFR services ................ 31
Table 4: Average prices of successful tenders for provision of 3MW of FFR services ......... 31
Table 5: Average accepted STOR bids from most recent tender round. Data from (58). ... 33
Table 6: Electric Vehicles owned by the University of Warwick ...................................... 34
Table 7: Total battery capacity of University of Warwick owned Electric Vehicles ............. 34
Table 8: Data regarding University of Warwick Smith EVs ............................................ 35
Table 9: Charging information for University of Warwick Smith EVs ............................... 36
Table 10: Current University EV fleet - power ............................................................. 39
Table 11: Current University EV fleet - energy storage capacity .................................... 39
Table 12: 'Business as usual' University EV fleet - power ............................................. 40
Table 13: 'Business as usual' University EV fleet - energy storage capacity .................... 40
Table 14: '25% electrification' University EV fleet - power ............................................ 40
Table 15: '25% electrification' University EV fleet - energy storage capacity ................... 40
Table 16: Characteristics of University fleet plus staff and student vehicles under different
assumptions ........................................................................................................... 41
Table 17: Summary of National Grid balancing service requirements ............................. 43
Table 18: Suitability of current and projected scenarios for selling balancing services to
National Grid .......................................................................................................... 43
Table 19: Average accepted STOR bids from most recent tender round. Data from (58) .. 44
Table 20: Suitability of current and projected scenarios for internal provision of load-
balancing services ................................................................................................... 45
Table 21: Project costs ............................................................................................ 50
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CONTENTS
ACKNOWLEDGEMENTS ........................................................................................... I
AUTHOR’S SELF-ASSESSMENT .............................................................................. II
EXECUTIVE SUMMARY ......................................................................................... III
LIST OF FIGURES ................................................................................................. IV
LIST OF TABLES ................................................................................................... IV
CONTENTS ............................................................................................................. V
CHAPTER 1. INTRODUCTION ................................................................................. 1
1.1 POLICY AND PUBLIC AFFAIRS BACKGROUND .................................................................. 1
1.1.1 Climate change - The need for transformation ............................................... 1
1.1.2 The future of UK energy production .............................................................. 2
1.1.3 The future of personal transport .................................................................. 6
1.2 CONCEPT OF VEHICLE-TO-GRID (V2G) TECHNOLOGY ...................................................... 8
1.3 OBJECTIVES ....................................................................................................... 9
1.4 RESEARCH METHODOLOGY ...................................................................................... 9
CHAPTER 2. THEORY AND PRACTICE OF VEHICLE-TO-GRID DEMONSTRATORS ... 10
2.1 BACKGROUND ................................................................................................... 10
2.1.1 Development of the V2G concept ................................................................ 10
2.1.2 What does a V2G system look like? ............................................................. 10
2.1.3 Outlook for V2G ........................................................................................ 11
2.2 REQUIREMENTS FOR A V2G SYSTEM ......................................................................... 12
2.2.1 Energy balancing requirements ................................................................... 12
2.2.2 V2G capable vehicles ................................................................................. 13
2.2.3 Appropriate infrastructure .......................................................................... 13
2.3 MAJOR OBSTACLES FOR V2G .................................................................................. 14
2.3.1 Battery technologies ................................................................................. 14
2.3.2 Manufacturer attitudes ............................................................................... 16
2.4 V2G AND THE UK ............................................................................................... 17
2.4.1 Suitability of the UK for V2G ....................................................................... 17
2.4.2 Potential benefits of V2G for the UK ............................................................ 18
2.4.3 Benefits of a V2G demonstrator to the University of Warwick ......................... 19
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2.5 CURRENT AND PLANNED V2G DEMONSTRATORS ............................................................ 21
CHAPTER 3. OBSERVATIONS AND RESULTS ........................................................ 23
3.1 EXISTING KNOWLEDGE REGARDING CAMPUS SITUATION ................................................... 23
3.1.1 Previous Report ........................................................................................ 23
3.1.2 Basic information ...................................................................................... 23
3.2 ENERGY BALANCING REQUIREMENTS .......................................................................... 24
3.2.1 Using V2G services internally ..................................................................... 24
3.2.2 Selling services to the National Grid ............................................................ 28
3.3 V2G CAPABLE VEHICLES ....................................................................................... 33
3.3.1 The cost of increased battery wear .............................................................. 36
3.3.2 The cost of bi-directional charging and control electronics .............................. 37
3.4 INFRASTRUCTURE ............................................................................................... 38
CHAPTER 4. ANALYSIS AND DISCUSSION ........................................................... 39
4.1 DEMONSTRATOR OPTIONS ..................................................................................... 39
4.1.1 Demonstrator using only the campus fleet ................................................... 39
4.1.2 Demonstrator also using staff and student vehicles ....................................... 41
4.2 TECHNICAL VIABILITY .......................................................................................... 42
4.3 FINANCIAL VIABILITY ........................................................................................... 42
4.3.1 Revenue potential – selling services to the National Grid ................................ 42
4.3.2 Non-revenue producing options .................................................................. 44
4.4 NOTE ON ACCURACY AND RELIABILITY ........................................................................ 46
4.4.1 Reliability of referenced sources.................................................................. 46
4.4.2 Accuracy of calculated figures ..................................................................... 46
CHAPTER 5. CONCLUSIONS ................................................................................. 47
CHAPTER 6. RECOMMENDATIONS FOR FURTHER WORK ...................................... 49
CHAPTER 7. COSTING .......................................................................................... 50
REFERENCES ....................................................................................................... 51
APPENDICES ......................................................................................................... A
APPENDIX IA ............................................................................................................ A
APPENDIX IB ............................................................................................................ A
APPENDIX II ............................................................................................................ B
APPENDIX III ........................................................................................................... C
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CHAPTER 1. INTRODUCTION
This report aims to evaluate the case for Vehicle-to-Grid technology as a relevant and useful
technology with respect to the global and national situations regarding climate change, energy
supply and transport. The specific situation of the University of Warwick is then examined, in
order to explore the theoretical and real-world potential for a Vehicle-to-Grid demonstrator on the
University campus. This is achieved by synthesising the work of a previous report, the current
academic literature on the matter, and data and opinions regarding the specific case of the
University of Warwick.
1.1 Policy and Public affairs Background
Before investigating the potential for a Vehicle-to-Grid (V2G) technology demonstrator on the
University of Warwick campus, it is first necessary to define and explore what is meant by V2G
technology. Furthermore, an effort to provide a full understanding of V2G technology must first
build a picture of the issues that led to the concept of V2G technology emerging. The following
section of the report, which aims to explain V2G technology, therefore begins with a thorough
exploration of the current situation on a national and international level in areas such as climate
change, energy supply and transportation.
1.1.1 Climate change - The need for transformation
During the second half of the 20th century levels of atmospheric CO2 began to be observed and
were found to be steadily increasing. Links between the increases in atmospheric CO2 and climate
changes such as global warming began to be fully explored and gained increasing levels of interest
(1). The first major international climate science conference was held in 1979, and in 1988 the
International Panel on Climate Change (IPCC) was set up by the United Nations Environment
Programme and the World Meteorological Organization to provide a scientific view on the extent
of climate change and its potential impact. In 1992 the United Nations Framework Convention on
Climate Change (UNFCCC) was signed by 154 nations. The objective of the UNFCCC was to
stabilize the atmospheric concentration of greenhouse gasses. It included voluntary targets for the
reduction of emissions, and allowed for the addition of future protocols to set mandatory
targets. The Kyoto Protocol was agreed in 1997 and as of January 2012 192 states have signed and
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ratified the protocol (2). Notable non-participants are the USA, which was a signatory but has not
ratified the treaty, and Canada, which withdrew from the protocol in December 2011. The protocol
represented the first legally binding agreement to reduce greenhouse gas emissions, and developed
countries ratifying the protocol committed to an average reduction of 5.2% of emissions relative to
1990 levels, to be carried out over the first commitment period, 2008-2012. International talks on
climate change have continued, with recent developments coming at the Copenhagen Accord of
2009, the Cancun agreements in 2010 and the Durban Climate Change Conference of 2011. The
Copenhagen Accord contained targets including an
overall temperature rise of less than 2°C. The Durban
talks produced an agreement for developing countries to
also commit to targets for cutting carbon, with a further
protocol that will be decided in 2015 and come into force in 2020.
The UK signed both the UNFCCC and the Kyoto protocol, and is on track to achieve its Kyoto
target. The Stern Review on the Economics of Climate Change was published in 2006 by HM
Treasury. The Review states that climate change is the greatest and widest-ranging market failure
ever seen, and concludes that “stabilization … requires that annual emissions be brought down to
more than 80% below current [2006] levels”. The Review recommends that rich countries reduce
CO2 output by 60-80% from 1990 levels by 2050. In 2008 the Climate Change Act was passed,
committing the UK to reduce emissions by 80% relative to 1990 levels by 2050.
This is an extremely challenging target, and will require a huge transformation of the way that
energy is produced and delivered in the UK. The Royal Academy of Engineering concludes in its
report ‘Generating the Future’ that meeting emissions reduction targets “will require nothing short
of the biggest peacetime programme of change ever seen in the UK” (3).
1.1.2 The future of UK energy production
As we have seen, the UK has committed to reduce emissions by 80% relative to 1990 levels by 2050.
Policy objectives include an aim to have achieved a 34% reduction by 2022, and for renewable
sources of energy to supply 15% of UK energy by 2020 (currently ≈3%) (4). Other policy objectives
cover reduction of emissions due to transport, improvements in energy efficiency, and security,
economic and social concerns. Figure 1 below shows the huge scale of the challenge.
Climate change is one of the great
challenges of the 21st century.
- IPCC (73)
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Figure 1: The UK Challenge – Current emissions compared to 2050 objective.
The production of energy is one area that will see a particularly disruptive change, as Renewable
sources of energy become ever more important. Figure 2 shows a graph produced by the
Committee on Climate Change showing an illustrative scenario for power sector decarbonisation to
2030, in which decarbonisation is achieved by gaining 40% of power used from Renewable sources
and 38% from Nuclear power.
Figure 2: An illustrative scenario for power sector decarbonisation to 2030.
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As the graph shows, the vast majority of Renewable Energy produced in the UK in 2030 is expected
to come from wind energy. This is reinforced by Figure 3 below, produced by UK Energy Research
Centre (UKERC), which shows the change in installed capacity over the decade from 2010 to 2020.
Clearly, there is expected to be a huge increase in the absolute and proportional amount of UK
power produced by wind turbines. According to Professor John Loughhead, Executive Director of
the UKERC, the growth in energy production from now to 2030 will come almost entirely from
wind (4).
The transient nature of wind energy, and indeed most forms of renewable energy (the primary
exception being hydroelectric generation) presents serious problems to the aim of providing a
dependable supply of electricity to UK households whenever demanded.
Figure 3: Change in installed capacity 2010/11 to 2020/21. From (4).
This is because of the nature of the electricity generation industry. Electricity is not stored by the
grid and therefore must constantly be matched to demand; electricity is a commodity that is
produced and consumed simultaneously (9). This requires many generators to be on reserve or
running below full capacity, which is inefficient. More pertinently, in a future energy generation
industry where a very significant proportion of power will come from intermittent sources
(primarily wind) this could become infeasible, as the amount of energy produced by a wind farm
cannot be controlled according to the level of demand for electricity. Despite the relatively low
share of energy currently produced by wind turbines, there have already been some problems
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accommodating wind power. An example of this is the £1.2 million paid in compensation to a wind
farm in September 2011 because the grid was unable to absorb the energy being produced and the
wind farm was therefore shut down during a period of strong winds (5).
An important concept that has arisen from the necessarily flexible nature of a future grid that
integrates diverse and intermittent sources of electricity is that of the ‘Smart Grid’. This is a concept
that is widely seen as s necessary response in order to continue to provide a reliable supply of
electricity in a low-carbon future. Much academic work has been carried out exploring the theory
and practice of a Smart Grid, and the ‘UK Smart Grid Capabilities Development Programme’ was
published by the Government’s Technology Strategy Board late in 2011. It describes the task of
creating a Smart Grid as a challenge of strategic importance (6).
The report identifies Energy Storage as one of 5 areas which are highly critical to the deployment of
a Smart Grid but are also areas of low current capability (6). The report later states that Grid-scale
storage of electricity is one of the biggest challenges for the future and that the potential benefits are
immense.
Figure 4: Overview of the smart grid technology landscape (© EG&S KTN, 2011). From (6).
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The purpose of storage media would be to provide ancillary services to the grid by absorbing
energy at times when the supply of energy exceeds demand, and then providing energy during
times of high demand. This could involve responding quickly to provide energy to cover for a
failure elsewhere in the grid (known as ‘Spinning Reserves’), or it could involve smaller inputs to
help to keep frequency and voltage steady (known as ‘Regulation’). Part of the elegance of using
vehicles to fulfill this need is the fact that peaks in electricity demand are always going to occur
when the majority of cars are parked and can therefore provide V2G services, because people are
not using household or office electrical goods when travelling in the car.
Despite the research being conducted into energy storage solutions for a Smart Grid, Professor
Loughhead of the UKERC has stated “We don’t have any realistic and effective storage media
available at the moment.” (4)
1.1.3 The future of personal transport
Following on from the 2006 Stern Review mentioned previously, it was announced by the British
Government in 2007 that Professor Julia King, vice-chancellor of Aston University, would lead a
review of the options for decarbonizing road transport in the UK, especially cars. The interim
report was published in October
2007. In 2005, passenger cars
accounted for 13 per cent of UK
CO2 emissions. In a ‘Business as
usual’ scenario road transport
emissions could be expected to
double by 2050 (7). Long term, it
is widely envisaged that low-
carbon road transport will take
the form of electric vehicles
and/or hydrogen fuel cell
vehicles. Both of these technologies have zero emissions at point of use, but obviously the manner
in which the hydrogen or electricity is produced would also need to have low or zero emissions in
order to ensure overall emissions are reduced. The King Review states that shifting from petrol and
Figure 5: Sectoral contributions to UK CO2 emissions in 2005
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diesel to electricity is therefore only as CO2-efficient as the marginal means of generating that
electricity.
In order to reduce emissions from cars to 20 per cent of 2000 levels we would actually need to
achieve a 90 per cent reduction in per-kilometer emissions by 2050 to offset the effect of traffic
growth.
The King Review considers the various fuel types available to replace fossil fuels in the short,
medium and long term. In the short term emissions are to be reduced through increased efficiency
of the internal combustion engine, meaning fossil fuels are still used but increasingly sparingly. In
the medium term battery-electric
hybrids and biofuels could achieve
significant savings in CO2, although
biofuels must be treated with caution
due to issues surrounding deforestation
and food supply; deforestation emits
more CO2 globally than all transport,
whilst the rush to produce biofuels has “significantly contributed” to global food price rises (8). It is
in the long term that Electric Vehicles (EVs) or hydrogen fuel cell vehicles are likely to be widely
adopted, with the potential to almost completely decarbonise road transport.
In the Royal Academy of Engineering’s 2010 report ‘Electric Vehicles: charged with potential’, it is
stated that since 2008 Electric Vehicles “have appeared to be the preferred policy option to ensure
long-term sustainable mobility” (9), and it is widely believed that Electric Vehicles will be in wide
use in the medium to long term future. The King Review states that “Fully electric, battery-
powered vehicles … offer the most direct opportunity to decarbonise road transport over the
longer term.”
However, this presents challenges, particularly in that it moves the energy demand of transport
onto the electricity grid, presenting a huge load. According to Willet Kempton, plug-in cars
represent the largest new load to appear on the nation’s power grid in a generation (10).
In the long term, carbon-free road transport fuel is the
only way to achieve an 80-90 percent reduction in
emissions, essentially “decarbonisation”. Given biofuels
supply constraints, this will require a form of electric
vehicle, with novel batteries, charged by “zero-carbon”
electricity (or, possibly, hydrogen produced from zero-
carbon sources).
- King Review (7)
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1.2 Concept of Vehicle-to-Grid (V2G) Technology
We have seen that:
1) With the 2008 Climate Change Act the UK has set a very challenging, legally binding target
to reduce CO2 emissions by 80% relative to 1990 levels by 2050.
2) This presents a huge challenge to the UK’s energy industry, which will need to implement
some form of Smart Grid in order to accommodate a high proportion of intermittent
sources of energy. Energy storage is a critical aspect of a successful Smart Grid, for which
there is currently low capability.
3) The emissions target also presents a major challenge for road transport in the UK, with a
target of effectively decarbonizing road transport by 2050. In order to achieve this target, a
large proportion of cars in the UK in the medium- to long-term are likely to be Electric
Vehicles of some sort, with a battery on board and a plug-in connection to the grid.
Vehicle-to-Grid technology is essentially the idea of making the link between Electric Vehicles and
the grid a two way system. This allows excess energy to be absorbed when supply exceeds
demand, and then recovered by the grid when demand exceeds supply.
This will help to counteract the negative impact of the large extra load on the grid caused by
Electric Vehicles, as well as providing a means to accommodate the high proportion of intermittent
sources of energy expected to be supplying the grid in the medium to long term.
As it is generally envisaged that V2G car owners will be paid for the services they provide to the
grid, it is also hoped that V2G technology could also help to accelerate the uptake of Electric
Vehicles by providing a financial incentive.
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1.3 Objectives
This project has four main objectives:
To investigate the rationale behind V2G technology, examining the convergence of issues in
environmental, energy and transport policy. (Chapters 1 and 2)
To summarise and review the body of research and relevant literature in the field of V2G
technology, exploring the issues associated with V2G implementation and the success of
existing V2G technology demonstrators. (Chapter 2)
To summarise and review the report written last year which began to explore the possibility
of a V2G demonstrator on campus. (Chapter 3)
To build on last year’s report in order to establish a deeper insight into the technical and
financial issues that would need to be overcome in order to establish a V2G demonstrator
on the University of Warwick campus. (Chapters 3 and 4)
1.4 Research methodology
In order to carry out these objectives, information will have to be gathered from many sources. The
primary methods which will be used to collect information are:
Finding and reading books containing relevant information, journals containing academic
articles concerning relevant research and news articles covering V2G related stories.
Face to face interviews, telephone interviews and e-mail communication with internal and
external stakeholders and key sources of knowledge in the University, the automotive
industry, the energy industry and the fledgling V2G industry.
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CHAPTER 2. THEORY AND PRACTICE OF VEHICLE-TO-
…………… GRID DEMONSTRATORS
2.1 Background
2.1.1 Development of the V2G concept
The concept of Vehicle-to-Grid (V2G) was first formulated by Willet Kempton of the University of
Delaware in 1996 as he wrestled with the problem of peak times of renewable energy output
differing from peak times of consumer demand (11). The first academic work on the idea was co-
authored by Kempton and Steven Letendre and published in 1997, entitled “Electric Vehicles as a
new power source for electric utilities” (12). This paper considered V2G primarily as a means of
absorbing excess or off-peak electricity supply and discharging this electricity at peak times or at
times when demand exceeded supply. This was the main focus of V2G discussion and research for
some time, but more recently frequency regulation has received more attention (13), in which far
smaller and more frequent increases in demand or supply are needed in order to keep the grid
frequency within ±1% of the nominal frequency (50 Hz in the UK). Whilst the first concept has
greater significance from a national strategic perspective, the second is more practical with
currently available technology and may offer the better option for a demonstrator in the near
future. More recent work by Kempton calls frequency regulation and similar services the “most
economic entry” for V2G technology, describing large-scale energy storage as “a later application,
when parked V2G-capable cars are connected and aggregated in large numbers” (14). Other papers
confirm that the current consensus in the V2G research field is that frequency regulation is the most
promising and practical near-term use of V2G (15) (16). This is due to the need for instant response,
the shallower battery cycling and the higher value nature of frequency regulation. For a full
discussion of the different energy markets relevant to V2G, see Section 2.2.1.
2.1.2 What does a V2G system look like?
A V2G system consists of a number of V2G capable plug-in electric vehicles connected to a smart
electricity grid. Measurement of electricity flow and the use of control algorithms can then be used
to decide when batteries charge and discharge. At times when supply exceeds demand and
electricity is cheap, the vehicle batteries can be charged. When demand exceeds supply and
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electricity is more expensive, the batteries can be discharged at a profit. A 2002 paper by Kempton
and Letendre entitled “The V2G Concept: A New Model For Power?” observes that utilities could
be disinclined to deal with hundreds or thousands of individual owners. The paper therefore
envisages a large number of individual vehicles being dealt with by utility companies through an
intermediary ‘aggregator’, allowing utilities to deal with fewer transactions (17). The paper also
states that whilst the availability of an individual vehicle is unpredictable, the availability of
thousands or tens of thousands of vehicles is highly predictable. In more recent V2G research, the
presence of an aggregator is seen as a requirement (15), with a 2009 paper written on the subject by
C. Quinn et al. of Colorado State University concluding that use of an aggregating entity improves
the scale and reliability of V2G ancillary services (18). Corporate vehicle fleets could be ideal
pioneers of V2G technology because there is no need for a third party aggregator, as the fleet-
owner would automatically fill this role (19).
There is a large, active and rapidly expanding body of research on the subject of V2G technology.
Particularly active research areas include optimisation of the power electronics allowing bi-
directional charging (20) (21) (22) (23) and system algorithms and control models (24) (25) (26).
2.1.3 Outlook for V2G
Forecasts of the future market for V2G services vary. It has been estimated by Pike Research that
globally almost 100,000 V2G enabled vehicles will be on roads by 2017, generating revenue for the
services they provide to the grid of $18 million (13). Business research firm Global Data, on the
other hand, has “conservatively” predicted that globally $40 billion would be paid to Electric
Vehicle owners for electricity services in 2020 (27). Pike Research expects that V2G as a consumer
offering won't hit the mainstream for another 4-5 years (13).
Whilst the overall outlook for V2G technology is highly relevant to this report, the ultimate aim is
to determine whether a viable V2G demonstrator could be established on the University of
Warwick campus. Therefore, the rest of this chapter is concerned with the theoretical requirements
for a V2G demonstrator, methods of analyzing V2G systems and examples of real-world V2G
demonstrators. The potential benefits of establishing a V2G demonstrator are explored in Section
2.5.
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2.2 Requirements for a V2G system
The elements of a V2G system are energy balancing requirements, V2G capable vehicles and
appropriate infrastructure. These three components of a V2G system are now analysed in order to
gain further insight into what is required to establish a V2G demonstrator.
2.2.1 Energy balancing requirements
The wholesale electricity market can in general be divided into three main areas: baseload power,
peak power and ancillary services.
Baseload power is the constant supply of electricity produced by large nuclear, coal power stations,
usually on a long term contract. These facilities tend to be large and run at near-capacity in order to
maximize efficiency. This market is not relevant to V2G technology, as V2G is not concerned with
the constant, large scale production of electricity.
Peak power is the power that is required by the Grid at times of particularly high demand, when
the capacity of the baseload power stations is insufficient. Peak power services are typically needed
for a few hundred hours a year (28), making it economically sound to meet the need with lower
capital cost, higher unit-energy cost power plants such as gas turbines. Peak power services are
generally required for 3-5 hours, which means that whilst it may be economical to meet peak power
demand with V2G services this may not always be viable due to the limitations of battery size (28).
Ancillary services include spinning reserves and frequency regulation. Spinning reserve power
refers to backup services that can provide power very quickly (under 10 minutes) in the incident of
an unplanned energy shortage due to a sudden spike in demand or a grid failure. Spinning
reserves are typically called upon 20 times a year, for up to 1 hour at a time (28). Compensation
typically includes payment for the time spent available even when electricity was not being
provided, in order to compensate for the unused capacity. Frequency regulation is required to
constantly maintain the frequency and voltage of the grid by helping to match demand and supply
of electricity. If demand is exceeding supply, voltage and frequency will drop. In order to allow for
this, regulation services are controlled in real time by the grid in order to regulate frequency and
voltage up or down. Regulation services could be called upon in the order of 400 times a day and
must be able to respond in less than a minute, usually for a few minutes at a time (28).
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According to Pike Research, early discussion of the V2G concept mainly concerned peak power but
focus has now shifted to the use of vehicles for frequency regulation. This is because frequency
regulation has less impact on batteries and is therefore looked upon more favourably by car
manufacturers (13).
2.2.2 V2G capable vehicles
In order for a vehicle to be V2G capable it must have three elements: a connection to the grid for the
bi-directional flow of electricity; a control or logic connection for communication with utilities or
the grid operator; and a meter on-board the vehicle to measure the power flows into and out of the
vehicle (29). This general definition allows the inclusion of fuel cell vehicles (FCVs, of which the
most prominent are Hydrogen FCVs) in the V2G concept, but FCVs are unlikely to achieve
significant market penetration in the near future. The University of Warwick also owns no FCVs,
and has no immediate plans to procure any. They are therefore considered to be outside of the
scope of this report.
2.2.2.1 Bi-directional charging and control electronics
All plug-in EVs will already have at least two converters on board. An AC-DC converter is
required to convert AC electricity delivered by the grid into DC electricity to be stored by the
battery. A DC-DC converter is then required to alter the electricity’s voltage so that it is an
appropriate voltage for storage in the battery. In a V2G capable vehicle, these converters would
need to be bi-directional. According to Professor Philip Mawby, an expert in power electronics at
the University of Warwick’s School of Engineering, these converters are usually of a design that
could be expected to easily allow bi-directional charging capabilities to be added (30). The addition
of electronics to control the flow of electricity would also be expected to be simple.
2.2.3 Appropriate infrastructure
A V2G system requires metering technology in order to monitor the flow of electricity back into the
grid, and a smart grid system capable of instantaneously matching demand to supply drawing
upon a range of resources including V2G technology. Most charging points are likely to already
possess the control electronics necessary to measure flow of electricity in order to bill customers. It
is also necessary that the Grid be smart in order to allow the connection of many distributed loads.
Smart metering technology is due to be installed in all UK homes by 2020 (18), and the rollout of a
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smart grid is seen as a priority by government (6). A precedent for the integration of distributed
generation into the UK Grid can be seen in the establishment of feed-in tariffs to allow households
to produce renewable energy on a small scale and sell this to the Grid.
2.3 Major obstacles for V2G
When the first paper on V2G was published in 1997, the reaction was swift and negative (31).
Automotive manufacturers argued that V2G would exacerbate existing issues with Electric Vehicle
range and battery lifetime. Utilities believed that vehicles would not be available at times of peak
demand when their ability to provide electricity would be most useful. Analysis has since shown
that vehicles are in fact idle for much of the day, meaning that this is not a significant problem (see
Section 2.4.1), and utilities are now often strong supporters of V2G technology (32). However,
issues of battery capacity and lifetime are still among the primary obstacles to V2G (and indeed all
EV) uptake. Other obstacles include the cost of retrofitting EVs to provide V2G capabilities, and the
possibility that consumers will not be willing to adopt V2G technology. It is also known that the
attitude of automotive manufacturers is not always positive towards Vehicle-to-Grid technology
(33). The issues of battery technology and manufacturer attitudes will now be discussed.
2.3.1 Battery technologies
As well as the necessary power and control electronics for bi-directional charging, V2G vehicles
require batteries that have high energy density and long life, with high resistance to degradation
caused by cycling.
Lead-acid, lithium-ion, and nickel-metal hydride (NiMH) are generally considered to be the top
three contending technologies for EV batteries due to a combination of performance capability,
safety, life, and cost (34). These technologies are briefly outlined below.
Lead-Acid
Lead-Acid batteries are the oldest type of rechargeable battery. Already ubiquitous in the
automotive industry due to their use as SLI (starter, lighting and ignition) batteries, they were
initially the favoured choice for EV applications due to safety, reliability and familiarity. Lead-Acid
batteries have a low energy-to-weight ratio and a low energy-to-volume ratio, but a relatively large
power-to-weight ratio. They are inexpensive relative to other battery types.
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NiMH
NiMH is a mature battery technology, widely used in current hybrid vehicles. Energy density is
slightly better than lead-acid batteries, but considerably worse than Li-ion batteries. Power density
is far better than lead-acid and comparable with Li-ion. Due to the cost advantage over Li-ion,
NiMH is currently the dominant battery technology for non-plugin hybrid vehicles, but this is
expected to change in the short to medium term as Li-ion increases in volume and decreases in cost
(35).
Li-ion
Li-ion batteries are widely used in mobile phones and mobile computers, and have very high
power and energy densities. However, the technology is considered to be somewhat immature for
automotive applications. It is the most actively researched automotive energy storage technology
and is expected to dominate in plug-in hybrid and fully electric vehicles (35). Current and planned
fully Electric Vehicles almost exclusively use Li-ion batteries.
Table 1: Comparison of battery technologies. Data from (35).
Battery Type Energy Density (Wh/kg) Power density (kW/kg) Cycle life (no. cycles)
Lead-Acid 30-40 0.05 500-800
NiMH 40-65 0.4 4000
Lithium-Ion 70-200 0.5 500-5000
Despite the levels of research and investment into the field, the limitations of battery technologies
are considered the primary factor preventing EVs from becoming competitive with Internal
Combustion (IC) engine vehicles in terms of cost, range, convenience and product lifetime (36). The
batteries in an Electric Vehicle account for more than 50% of the total vehicle cost (34). This helps to
explain automotive manufacturers’ inclination to avoid anything that could shorten battery life,
and also means that future advances in technology could significantly help to make EVs more
affordable.
A potential difficulty with the large-scale production of automotive batteries is that resource
limitations could constrain the supply and cost of vital materials. Materials identified as potentially
scarce include lithium, nickel, cobalt, vanadium, cadmium, lead, rare-earth elements, platinum and
ruthenium (37). Different battery technologies have varying levels of exposure to problems of
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resource availability. Nickel based batteries such as NiMH are deemed to be the most constrained,
whilst lithium based batteries are unlikely to face significant issues (35) (38).
2.3.2 Manufacturer attitudes
It is widely reported that automotive
manufacturers have resisted the idea of
V2G because of concern regarding
reductions in battery life due to the
increased battery cycling (39). The previous report on the potential for a campus demonstrator of
V2G technology found that company representatives of Tata Motors did not see the benefit of V2G
technology (33). The University of Warwick works closely with Jaguar Land Rover (JLR) as well as
Tata Motors, the parent company of JLR.
In order to further understand the perspective of automotive manufacturers contact was made with
Paul Bostock, who works in the Hybrids & Electrification Strategy department of Jaguar Land
Rover (JLR). Mr. Bostock agreed to meet to discuss the issue and give an insight into the
perspective of automotive manufacturers (32).
From this meeting, it was clear that however it is viewed, V2G technology is very much on the
radar of manufacturers as an upcoming technology. JLR are actively liaising with various power
companies with interests in V2G, including EDF Energy and RWE npower. As expected, a major
concern from the manufacturer’s perspective is the effect of V2G on battery life. With battery
limitations already a barrier to EV adoption and with manufacturers offering warranties for battery
lifetimes, it is felt that anything that limits battery life further is to be avoided as far as possible.
Another concern was that the cost of adding V2G capabilities to all production cars would incur
extra expense for a feature not everybody would wish to use. In the current economic climate and
with EVs already carrying a considerable price premium over petrol or diesel vehicles,
manufacturers would be reluctant to pass on the cost to consumers and reduce the competitiveness
of EVs further. This is especially the case for V2G, which is not considered to be marketable. The
alternative to increasing the vehicle price would be manufacturers absorbing the cost, but this is
also felt to be infeasible.
The electric industry said, ‘Yes, this is incredible. Yes,
we’ll pay for it,’ but the car industry said, ‘Not with our
batteries you don’t.’
- Willet Kempton (11)
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Overall, it seems that the perception is that V2G technology provides significant gains for utility
companies but little or no gains to vehicle manufacturers. However, the longer term view is
considerably more positive. It is expected that EVs will definitely go into full scale production at
some point in the relatively near future, and when this happens the increase in battery volumes and
the increased investment will result in battery costs decreasing rapidly. This will make V2G a much
more attractive proposition for manufacturers, especially if consumers are properly educated on
the potential benefits.
2.4 V2G and the UK
2.4.1 Suitability of the UK for V2G
According to the original paper on V2G technology from Kempton and Letendre, the mechanical
power of all of the vehicles on the road in 1997 in the US exceeded the power of all US electricity
generating plants by a factor of 10. Private vehicles were also idle 96% of the time (12). This led to
the conclusion that when much of the vehicle fleet is grid-connected, proper utilization of this
resource would represent a significant opportunity.
Carrying out similar analysis for the UK, it can be seen that the mechanical power in the UK vehicle
fleet is approximately 2868 GW (2.87 TW)1. The capacity of the UK grid is 82.5 GW as of 2010/11
(40), and therefore the nominal mechanical power in the vehicle fleet is approximately 35 times
larger than the capacity of the UK grid. This is a very rough figure, but the order of magnitude
gives a reasonable indication. The average UK car is used for only 45.8 minutes of the day,
therefore sitting idle 96.7% of the time2. This analysis shows that the UK is at least as suitable for
V2G as the USA. Indeed, the fact that the UK is situated on an island with extremely good wind
energy resources only adds to this.
One of the pieces of literature most relevant to this project is the report commissioned by National
Grid and delivered jointly by National Grid and Ricardo, entitled “Bucks for balancing: Can plug-in
vehicles of the future extract cash – and carbon – from the power grid?” (41). This was published in May
1 Full methodology and calculations are detailed in Appendix Ia. 2 Full methodology and calculations are detailed in Appendix Ib.
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2011. Being co-produced and published by the body that operates the electricity transmission
system in Great Britain, this report carries with it considerable authority. It also demonstrates the
acceptance of V2G into the UK mainstream.
According to the report, simply using demand-side management could, based on estimates of the
penetration of plug-in vehicles (PIVs) in 2020, provide 6% of the GB grid’s daily average balancing
requirements (41). In this scenario, the financial return to vehicle owners would be very modest – in
the region of £50 per year. However, demand-side management does not require anything more
than a PIV and smart metering technology, which is due to be installed in all UK homes by 2020
(42). As no extra cycling occurs, demand-side management does not increase battery degradation.
Also whilst the benefit to the individual owner is small, the benefit to the grid operator is estimated
to be £30.8 million (41), helping to build the case for a ‘smart grid’.
Regarding the potential impact of full V2G in 2020, it is predicted that if all PIVs have V2G
capabilities and a charge/discharge power of 22kW then a peak of 100% of balancing requirements
could be met, with the average across the day being 79%. Annual earnings are predicted to range
from £600 pounds for a 3kW system (the output of a standard UK household connection) to £8000
for a 50kW three phase installation (41). However, V2G on an individual basis faces problems with
the level of investment required, whilst if V2G was taken up on a bigger scale there would be
heavily diminished returns due to market saturation.
2.4.2 Potential benefits of V2G for the UK
V2G technology could have significant benefits if it becomes widely used in the UK. Energy storage
is an essential component of a smart grid, which could be provided by V2G capable vehicles. This
would allow the increased utilisation of intermittent, renewable sources of electricity such as wind
turbines and solar power. The compensation that vehicle owners could expect to receive for the
provision of balancing services to the grid could encourage the uptake of electric vehicles, helping
to achieve the decarbonisation of road transport by 2050.
Further to these benefits, there are potentially considerable economic benefits should the UK be an
early adopter of V2G and other low-carbon technologies and therefore cultivate a strong
technology and skills base. The 2010 Energy Market Assessment, produced by the Department of
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Energy and Climate Change and published by HM Treasury, gives an overview of this subject (43).
The report states that the transition to a low-carbon economy will transform the economy, and
require new services, technologies and industries. This change provides a chance to invest for
growth in these sectors, creating new business opportunities and developing highly skilled jobs.
The Government wants to make the UK a world leader in the low-carbon and environmental
sector, which is worth £3 trillion globally. The report predicts that by 2015 the sector could be
worth £150 billion in the UK alone, and employ around 1.3 million people.
V2G is a low-carbon technology with a bright future, with many requirements of V2G technology
such as widespread EV usage and the establishment of a smart grid highly synergistic with existing
government priorities. The technology could therefore play a noteworthy part in the transition to a
low-carbon economy.
2.4.3 Benefits of a V2G demonstrator to the University of Warwick
A Vehicle-to-Grid demonstrator could potentially provide considerable benefits to the University of
Warwick. If the financial reward of frequency regulation and peak response outweighs the cost of
providing the infrastructure, retrofitting vehicles and increased battery degradation then the
demonstrator could be profitable. This would hopefully be the case in the long term, but in the
short term a demonstrator may require subsidy. If this is the case, there is still much to gain,
including the increased international profile of the University. Since January 2009, the English
language Wikipedia page has listed the University of Warwick as one of 5 institutions in the world
conducting research into V2G technology. This page has received 89,950 views since then,
promoting the University of Warwick to a wide audience as an innovative institution and an
academic leader. The University has also received positive publicity for similar reasons in the past,
being highly commended in Business in the Community's 2010 Regional Excellence Award for
Sustainable Travel implemented as a result of its Green Travel Plan (44).
Significantly, V2G
technology could play a
key part in a low-carbon
future. The University
of Warwick is committed to be becoming a ‘low-carbon University’ by 2020 (44). In April 2005, the
“It is incumbent on all members of Warwick’s community to take
responsibility for reducing carbon emissions and to consider ways of
enhancing our future performance in a carbon-constrained world.”
- Professor Nigel Thrift, Vice Chancellor - March 2011 (44)
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University of Warwick joined 19 other UK Universities in the Higher Education Carbon
Management Programme, which is overseen by the Carbon Trust. In the 2005 document ‘Higher
Education Carbon Management Programme: University of Warwick Case for Action’ (45), four key
drivers are given for embarking on a Carbon Management Programme:
Increased awareness of climate change between staff and students.
Increasing fuel prices making a large impact on utilities budgets.
The ability to reduce the negative impact of the University on the local and global
environment.
Improved corporate image of University.
In the University’s 2011 document ‘2020 Carbon Management Implementation Plan’, the target is
set of achieving a 60% reduction in emissions by 2020/21 relative to a base year of 2005/06 (44). The
Higher Education Funding Council for England (HEFCE) considers that a target of 43% reduction
in emissions by the Higher Education sector 2020/21 compared to 2005/6 should be considered
equivalent to the existing UK Government target (44). It is estimated that energy costs for the
University will be £19.6 million in 2020/21 and that this could be reduced to £8.7m if the carbon
reduction target is met. This would represent a saving of £10.9m (44).
Figure 6: University of Warwick projected emissions to 2020. From (39)
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There are various sources of funding available to achieve the target. £150,000 per year is allocated
by the University through the Estates Office for general energy saving projects; £650,000 from the
HEFCE/Salix Finance Revolving Green Fund and currently £857,000 in loans; an additional sum of
£660,000 over the next eight years for general energy efficiency measures in residences, conference
venues and retail areas is included in the Estates Commercial Group 10 year plan; and, subject to
approval of viable projects, the University has made an outline commitment to £2M per annum for
“Energy Efficiency Related Improvements” over a five year period. It is therefore possible that
funding could be found to cover or contribute towards the cost of establishing a campus V2G
demonstrator.
There is a precedent of a major capital investment project being undertaken by the University as
part of the overall programme of carbon management, with a thermal storage scheme being
undertaken during 2007/08. This scheme uses large water vessels to store excess heat from the
campus Combined Heat and Power (CHP) plant at times when the heat required is less than the
electricity required. The heat can then be used at times of high heat demand.
2.5 Current and planned V2G demonstrators
AC Propulsion
AC Propulsion is a California based manufacturer of battery and propulsion systems for electric
vehicles. The company has worked closely with Willet Kempton since his concept first emerged,
and is credited with having coined the term ‘Vehicle-to-Grid’ in 2001 (46). In 2002 AC Propulsion
undertook a study in which an EV was retrofitted to add V2G capabilities and a grid interface. The
study demonstrated the technical feasibility of the concept but raised issues related to cost,
estimating that battery costs due to the cycling constituted 20-60% of the gross value created (47). In
2006, AC Propulsion created the eBox, the world's first vehicle-to-grid (V2G) capable electric
vehicle.
Delaware
The University of Delaware was the original home of the V2G concept, and remains a world leader.
A proof-of-concept was demonstrated on October 18 2007 (Figure 7) in which an eBox was
successfully connected to the grid, being used as a regulation resource (14).
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In October 2011 the University of Delaware
formed a partnership with NRG Energy, one of
the largest power operators in the U.S.A (48).
The company to emerge is called eV2g, and is
expected to emerge from the R&D phase into
commercial markets in a few years' time at the
earliest.
Denmark
Perhaps the most significant V2G demonstrator currently underway is the EDISON (Electric
vehicles in a Distributed and Integrated market using Sustainable energy and Open Networks)
scheme in Denmark. The Danish government has set a target of wind power supplying 50% of the
country’s energy needs by 2025 (49). It is also expected that in the near future upwards of 10% of
vehicles could be electric or hybrid. Even now, more than 50% of the country’s energy production
is from wind turbines or CHP plants (49). The demonstrator is based on the island of Bornholm,
which has a population of just over 40,000. Nuvve, a company created by the University of
Delaware team, will act as an aggregator in the system.
Others
A number of other demonstrators have been identified, all of which are located in the USA. In
order to find out more about current V2G demonstrators in the USA, contact was made with Mike
Simpson, a Vehicle Systems Engineer at the Center for Transportation Technologies and Systems,
which is part of the National Renewable Energy Laboratory (NREL). Mr. Simpson described a
number of programs, including a demonstrator at NREL facilities (50) and three at military and
government sites (51) (52) (53). Pacific Gas & Electric in San Francisco and Xcel Energy in
Minneapolis also launched smaller V2G demonstrations several years ago, but they never moved
out of the pilot stage (48).
Overall less than 10 V2G demonstrators could be identified globally, with no demonstrators
currently being located in the UK. This emphasizes the increased international profile and
reputation that the University of Warwick could enjoy if a V2G demonstrator was established in the
near future.
Figure 7: October 2007 demonstration
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CHAPTER 3. OBSERVATIONS AND RESULTS
3.1 Existing knowledge regarding campus situation
3.1.1 Previous Report
During the 2010-11 academic year, a report was written exploring the theoretical possibility of a
Vehicle-to-Grid technology demonstrator on the University of Warwick campus. This report sought
to determine what is already in place on campus and investigate what changes are required to
make the campus V2G capable.
Regarding the first objective, it was observed that charging points are already available on campus.
It was reported that 14 vehicles of the 177 in the University fleet were EVs, with plans for future
expansion in numbers of EVs.
The main changes required were considered to be the conversion of charging points to V2G capable
points, and the conversion of the EVs in the University fleet to provide V2G capabilities. The
conversion to V2G capable charging points is considered to be “a fairly easy and cheap process”.
There is no conclusion regarding the ease of converting the EVs to provide V2G, and the topic is
not treated in depth.
The report noted that the University of Warwick could be particularly well placed to host a V2G
demonstrator, as the main components of a national V2G system are present. This includes the
presence of electricity demand from both residential and office buildings, an electricity generation
facility, and electric vehicles. This could allow the University campus to act as a useful model for
the national situation.
3.1.2 Basic information
In order to establish basic information regarding the campus situation Mark Jarvis, Utilities
Technical Assistant at the University’s Estates Office, was contacted. Mr. Jarvis explained that the
University of Warwick generates electricity and heat in a Combined Heat and Power (CHP) Plant.
The CHP plant runs on natural gas and consists of three turbines, which have a combined output of
1.4MW of electricity and 1.7MW of heat, and a combined consumption of approximately 3.8MW
Gas (54). There are plans to construct a new CHP plant with a 3MW electrical output in the future.
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The University’s tariffs for the purchase of electricity and gas are complicated, varying with day
rates, night rates, standing charges, capacity/transmission charges and also varying between
different suppliers. The average cost of purchasing gas from the grid was 2.65p/kwh and the
average cost of purchasing electricity from the grid was 7.79p/kwh (54).
In the 2010/11 fiscal year, using the CHP rather than purchasing electricity and gas from the grid
saved the University approximately £1.3m. Total expenditure on electricity and gas including CHP
production totaled £6.7m over the same period.
3.2 Energy balancing requirements
As discussed in Section 2.2.1, energy balancing is one of the components of a V2G system. As the
University of Warwick generates its own electricity, there is the option of using a V2G
demonstrator only internally in order to complement the University’s energy generation facilities.
However, there is also the option of selling energy balancing or frequency regulation services to the
National Grid. The possibility of providing frequency regulation and balancing services are
investigated in both of these contexts.
3.2.1 Using V2G services internally
Frequency regulation
The use of V2G technology to provide frequency regulation internally is not applicable to the
University of Warwick’s situation, as the University does not act as a grid operator and therefore is
not responsible for maintaining system frequency. The electricity distribution network on campus
is part of the National Grid, which as grid operator has ultimate responsibility for frequency
regulation in the UK (55).
Load balancing
The appropriateness of V2G load balancing for the University of Warwick can be assessed by
examining the campus electricity demand and consumption.
There are two main power lines feeding electricity into the University, one of which is linked to the
CHP plant. The Estates policy is to try and keep the consumption on this feeder to a set amount
(54). Therefore if the demand on the campus increases, the CHPs run harder until they are running
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at maximum capacity, with the remaining demand met by the grid. If the demand falls, the CHPs
start scaling back generation and even shut down so that they don’t “over generate” and export
back to the grid; the University does not have a feed-in-tariff for the CHP and therefore cannot sell
excess power to the grid. The other feed to the University is independent of the CHPs and as little
power as possible is put through this (54).
Through contact with Mark Jarvis, data regarding the campus energy production and consumption
was obtained. The data is logged in kWh consumed per half hour. The volume of data is such that
displaying the entirety of the figures is impractical, but an overview can be communicated
graphically. The full dataset can be obtained from the Estates Office of the University of Warwick.
Over the page, Figure 9 and Figure 10 show an accurate graphical representation of the quantity of
electricity purchased from the grid and produced by the CHP plant during 2011, with data points
at half hour periods. Each figure shows 17,520 individual data points. In order to make the data
easily digestible, the values (which are in kWh per half hour) are shown as a colour rather than a
number. Each value is assigned a colour on the spectrum from white to red. The lowest value from
both data sets, 0, is assigned the colour white and the highest value from both data sets, 4069, is
assigned the colour red. This is illustrated in Figure 8 below.
A number of patterns can be seen from Figure 9 and Figure 10. For example, it can be seen that
during 2011 grid electricity mainly needed to be purchased between approximately 6:00 and 18:00
throughout the year, with less being purchased in November and December. Also, it can be seen
from the figure on the right that CHP electricity generation is constrained by the level of demand
for heat, being consistently high throughout winter months and consistently low in summer. CHP
production is far less responsive than grid electricity.
Figure 8: Method used to produce Figures 9 and 10
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The total consumption of electricity by the University of Warwick during 2011 was 51,230,666 kWh
or approximately 51 GWh. Of this, 28,890,957 kWh (29 GWh) was purchased from the grid, whilst
22,339,709 (22 GWh) was produced by the CHP plant.
Figure 9: Graphical representation of electricity
purchased from the grid during 2011, at half-hour
intervals. (own work)
Figure 10: Graphical representation of electricity
generated by CHP plant during 2011, at half-hour
intervals. (own work)
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In order to gain insight into the daily electricity demand profile of the University, two sources of
demand are considered: the demand from a typical residential building, and the demand from a
typical office building. The Heronbank and Lakeside residences are considered, alongside the
Argent Court office building. The electricity demand from these two sources can be seen in Figure
11 below, along with the total demand from both sources. Data points were obtained by finding the
average electricity demand over the whole year for each 30 minute period during a day.
Figure 11: Electricity Demand of typical campus office and accommodation buildings. (own work)
The sum of these two example sources of demand is very similar in shape to the average daily
campus demand from all sources, which can be seen in Figure 12. This is above current levels of
CHP production, but when the new 3MW CHP plant is installed in future, production will be at
approximately the level of the purple line ‘Future CHP Production’. As Figure 12 shows, total
campus demand fluctuates above and below the level of future CHP production, giving an ideal
environment for campus vehicles using V2G technology to provide large-scale storage of energy.
Whether or not campus vehicles would be able to provide the energy storage capacity to make this
a reality is explored in the analysis in Chapter 4.
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Figure 12: Total Campus Electricity Demand and Current and Future CHP Production. (own work)
3.2.2 Selling services to the National Grid
3.2.2.1 Overview of National Grid balancing services procurement
The UK’s electricity transmission infrastructure is under the control of the National Grid, which has
a licence obligation to ensure that the system frequency remains within the limits specified in The
Electricity Supply Regulations 1988, i.e. ±1% of nominal system frequency (50Hz) save in abnormal
or exceptional circumstances (55). This is achieved by electronically synchronizing the speed of all
power station turbines connected to the grid, ensuring that they give the same output frequency of
50Hz, or 3000 revolutions per minute.
A single power generator must have its speed matched to the load being experienced or it will
gradually speed up or slow down, causing damage or stalling respectively. A similar concept
operates on the much larger scale of the grid, with synchronisation necessary to avoid damage to
electrical equipment connected to the network. The concept is illustrated simply in Figure 13.
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In order to regulate frequency, the National Grid must therefore ensure that sufficient generation or
demand is available to manage any circumstances that may arise. To do this, the National Grid
purchases three main types of balancing services: Frequency Response, Fast Reserve and Short
Term Operating Reserve (STOR) (41). The characteristics of these types of balancing can be seen in
the table below.
Table 2: Requirements of balancing services in the UK. Data from (41)
Speed of Response Min. Capacity Min. Delivery Period
Frequency Response < 30 seconds 3MW 30 min
Fast Reserve < 2 seconds 50MW 15 min
STOR Ideally < 20 min
(can be up to 4 hours)
3MW 120 min
The Procurement Guidelines Report, published by the National Grid, details information on the
balancing and other services purchased during a given year. The latest report available from the
National Grid covers the financial year 2009/10 (56), and figures from this report will be considered
a reasonable approximation to the current situation.
The total spent on balancing services in 2009/10 was £512m. During 2009/10, the total cost of
frequency response (both mandatory and commercial) was £112m. The cost of fast reserve services
(both tendered and non-tendered) was £54.3m. The cost of STOR payments was £95m. The average
STOR availability payment was £8.56/MW/h, whilst the total cost of utilization was £28m. The
remainder of the total spent on balancing services came from other areas such as inter-trips and
system-to-system services.
Figure 13: Illustration of the principle of frequency regulation. Source: (37)
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3.2.2.2 Frequency Response
The National Grid procures both dynamic and non-dynamic frequency response. Dynamic
frequency response is provided continuously and used to manage second by second changes on the
system. Non-dynamic frequency response is a discrete service usually triggered at a specific level of
frequency deviation. Frequency response is acquired through three mechanisms: Mandatory
Frequency Response, Firm Frequency Response (FFR) and Frequency Control by Demand
Management (FCDM) (57).
Mandatory Frequency Response is a service provided by generators larger than 100MW,
automatically adjusting output in response to system frequency changes. FFR is open to more
entities, and a firm agreement on the level of utilisation is made in advance of service provision. To
be eligible for FFR, a provider must be able to deliver 10 MW of response energy and pass a pre-
qualification assessment. FCDM provides frequency regulation by interrupting demand. To be
eligible for FCDM, the provider must be available for 24 hours a day, be able to provide the service
within two seconds of instruction, and deliver at least 3 MW. However, this does not preclude the
aggregation of multiple smaller sites that collectively meet or exceed the 3 MW minimum (41).
Mandatory Frequency Response can quickly be dismissed as not applicable to the University of
Warwick due to the size of generator involved, but the suitability of FFR and FCDM requires
further investigation. The financial rewards of FFR and FCDM are now explored.
Firm Frequency Response (FFR)
FFR is procured through a monthly tendering process. Providers could be compensated by up to
five different methods:
Availability Fee (£/hour) – for the hours which a provider has tendered to make the service
available for.
Window Initiation Fee (£/window) – for each window of provision.
Nomination Fee (£/hour) – a holding fee for each hour utilised within FFR nominated
windows.
Tendered Window Revision fee (£/hour) - payable if National Grid revises the time of
energy provision.
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Response Energy Fee (£/MWh) – based upon the actual response energy provided.
As providers are selected via a competitive tendering process, it is not possible to guarantee a
specific rate for any of these parameters, and significant assumptions will have to be made. An
approximation can be found by taking the average prices set for each of the tenders currently active
as of February 2012, which can be found on the National Grid’s website3 (58). This gives the
following values:
Table 3: Average prices of all successful tenders for provision of FFR services
Payment type Average price offered by successful tenders active as of
February 2012
Availability Fee (£/h) £768.86/h
Nomination Fee (£/h) £556.25/h
However, this does not account for the variable levels of power offered by individual providers.
The successful tenders provide a range of power levels, from 3 MW to 170 MW, and the
compensation rises with the level of power provided. Furthermore, there are two tenders providing
3MW of power, which is the order of magnitude that a V2G demonstrator at the University of
Warwick might hope to achieve. Investigation revealed that these tenders are from a company
called RLtec, a company that uses aggregates household appliances to provide dynamic demand
balancing services (59). This means that these tenders form an ideal model of how a V2G tender
might look. The tenders that offer 3 MW both have the pricing shown in Table 4:
Table 4: Average prices of successful tenders for provision of 3MW of FFR services
Payment type Price offered by successful tenders offering 3 MW as of
February 2012
Availability Fee (£/h) £15.72/h
Thus, these contracts involve simply a payment of £15.72 for each hour in which 3MW is available
to the grid for frequency response. This is a fair approximation of how any future tender by the
University of Warwick would be likely to be priced.
3 This is also included in Appendix II for reference.
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Frequency Control by Demand Management (FCDM)
FCDM operates a simpler pay structure than FDR, with providers paid an availability fee (£/MWh)
but not a utilisation fee. When FCDM providers are called upon, demand is usually interrupted for
30 minutes at a time. Interruptions are likely to occur between 10-30 times annually.
Through discussion with Andy Walden, Senior Account Manager at National Grid, it was found
that FCDM services are provided through bilateral contracts between the provider and National
Grid, and data on the prices offered are not in the public domain. Direct enquiries would therefore
need to be made in order to establish a dialogue with National Grid about the possibility of the
University of Warwick providing FCDM services via V2G technology. However, the University is
too far away from realising this goal for this dialogue to begin at the present time.
3.2.2.3 Fast Reserve
Fast Reserve delivers increased output from generation or a reduction in demand. It is used, in
addition to other energy balancing services, to control frequency changes that might arise from
sudden or unpredictable changes in generation or demand. This may be due to a problem with
equipment or the failure of a generator.
Active power delivery must start within 2 minutes of the instruction being received at a delivery
rate in of at least 25MW/minute, and the reserve energy should be sustainable for a minimum of 15
minutes. The provider must be able to deliver a minimum of 50MW.
Fast Reserve is procured via a monthly process. However, information regarding the prices of
successful tenders is not available online. As providers of Fast Reserve must be able to deliver at
least 50MW, this is unlikely to be a service that the University of Warwick could provide via V2G
technology for the foreseeable future.
3.2.2.4 Short Term Operating Reserve (STOR)
Short Term Operating Reserve (STOR) is a similar service to Fast Reserve, with the primary
difference being the tolerance of slower response times for STOR and the tolerance for smaller
minimum power deliveries. This is because STOR is used to cover for high demand or plant
breakdowns that are known about in advance.
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A STOR provider must be able to offer a minimum of 3MW of generation or steady demand
reduction, deliver full MW within 240 minutes or less from receiving instructions from National
Grid, provide full MW for at least 2 hours when instructed, have a Recovery Period after provision
of Reserve of not more than 20 hours, and be able to provide STOR at least 3 times a week.
Procurement is via a competitive tender with three tender rounds per year, and is divided into
Committed STOR and Flexible STOR. Committed service providers must offer service in all of the
required windows in each season and upon accepting the tender, National Grid commits to buy all
services offered. Neither party is obliged to offer or purchase services under the Flexible service.
Payment is in two forms:
Availability Payments (£/MWh) – payment for the time and capacity made available.
Utilisation Payments (£/MWh) – payment for the energy used.
The average bid accepted in the most recent tender round for availability payments and utilisation
payments for Committed STOR and Flexible STOR are shown in the table below.
Table 5: Average accepted STOR bids from most recent tender round. Data from (60).
Average accepted bid for availability
payments (£/MWh)
Average accepted bid for utilisation
payments (£/MWh)
Committed STOR £7.71/MWh £216/MWh
Flexible STOR £7.91/MWh £151/MWh
STOR could potentially be suitable for the University situation due to the relatively low power
requirements. However, a large fleet would be needed to provide significant storage capacity.
3.3 V2G capable vehicles
Last year’s report stated that the University of Warwick had a vehicle fleet of 177 of which 14 were
Electric Vehicles. As of January 2012, the University has a vehicle fleet of 163 of which 14 are
Electric Vehicles4 (61).
4 See Appendix III for a summary of the University’s vehicle fleet.
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Of these 14 Electric Vehicles, there are 6 different vehicle types, as shown in table 6:
Table 6: Electric Vehicles owned by the University of Warwick
Vehicle Manufacturer Vehicle Model No. of Vehicles
John Deere E-Gator Electric Utility Vehicle 1
Erider B2000 Electric Moped 2
Yamaha Golf Buggy 2
Aixam Mega Multitruck 600E dropside van 2
Nissan Leaf 5 Door Hatchback 2
Smith EV S001 Edison Panel Van MWB - Medium Roof 5
Total: 14
Table 7: Total battery capacity of University of Warwick owned Electric Vehicles
Vehicle Battery type Capacity (kWh) No. of Vehicles Total Capacity (kWh)
John Deere E-Gator Lead-acid 10.8 1 10.8
Yamaha Golf Buggy Lead-acid 8.16 2 16.32
Mega Multitruck 600E Lead-acid 6.72 2 13.44
Nissan Leaf Lithium-ion 24 2 48
Smith Edison Lithium-ion 50 5 250
Total: 338.56
As the table shows, the total battery capacity of the EVs currently owned by the University of
Warwick is 338.56 kWh, or 0.34 MWh. For the purposes of V2G analysis, the three small utility
vehicles can be discounted. These vehicles have lead acid batteries which are not cost effective in
V2G use due to limited cycle life (34). The total battery capacity of the Nissan Leaf and Smith
Edison vehicles is 298 kWh.
The Smith Edison vehicles were procured through the Low Carbon Vehicle Procurement Program
(LCVPP), a scheme established to subsidise public sector procurement of low carbon vehicles.
Analysis by Cenex of the 5 Smith Edison vehicles carried out during September and October 2011
produced the following results (62):
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Table 8: Data regarding University of Warwick Smith EVs
Among other tests carried out, the efficiency of delivering electricity to the batteries and then
extracting that electricity was measured. Tests produced estimates that the charger efficiency is 86%
and the battery efficiency is 93%, giving an overall efficiency of 80%. This means that the energy
measured leaving the battery is only 80% of the energy supplied when charging. However, this
estimate is subject to a potential error of around +/- 5% according to the researchers.
According to the University of Warwick’s Transport Manager, Graham Hine, the purchase of the
current Electric Vehicles was only made possible due to a significant grant from the Department of
Transport, and it would be difficult to justify the expenditure on such vehicles without financial
support. Regarding V2G technology, Mr. Hine does not have strong views on the matter but stated
that as an operator his priority is simply securing the energy necessary to operate the vehicles.
Knowledge of the times of charging of the current EVs is necessary in order to know when services
could be made available to the grid. An extensive dataset (containing 482,073 data points) has been
obtained through Cenex and the Low Carbon Vehicle Procurement Plan (LCVPP). The data is raw,
primary data collected from the University of Warwick’s Smith EVs using the onboard telemetry.
The data has been collected as part of a government programme. It is confidential and highly
valuable, being one of the most comprehensive datasets of its kind in existence (63).
Information has been extracted from the data regarding the charging times of the Smith EVs owned
by the University, shown in the table below:
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Table 9: Charging information for University of Warwick Smith EVs
Vehicle 1 (NK60FYJ)
Vehicle 2 (NK60FYH)
Vehicle 3 (NK60FYM)
Vehicle 4 (NK60FPG)
Vehicle 5 (NK60FPJ)
Average
First log 14/02/2011 17/02/2011 14/02/2011 14/01/2011 21/01/2011
- Last log 01/12/2011 22/12/2011 22/12/2011 21/12/2011 22/12/2011
Days measured 289 308 311 341 333
Hours measured 6952 7395 7466 8187 8012
Total number of trips
1269 4496 1880 416 3155 2243.20
Total distance (km)
1718.61 2524.48 2271.62 1010.39 3451.94 2195.41
Average km travelled/day
5.95 8.20 7.30 2.96 10.37 6.96
Total time charging (hrs)
466.14 445.53 613.26 597.66 1072.18 638.96
Total time travelling (hrs)
3954.00 4626.46 3749.29 3719.77 3628.72 3935.65
Total time idle (hrs)
2998.00 2768.55 3716.71 4467.23 4383.28 3666.75
Time charging per day (hrs)
1.61 1.45 1.97 1.75 3.22 2.00
Time idle per day (hrs)
11.99 10.44 13.92 14.85 16.38 13.52
When calculating these values, the time spent charging per day was originally calculated as a
measure of the amount of time that the vehicles would be available to provide V2G services. On
average, vehicles were charged for 2 hours per day. However, it was then realized that if the
vehicles were part of the V2G system, they could be plugged in for all of the time they are not
travelling. This increases the average amount of time per day that vehicles could be available to
nearly 14 hours.
3.3.1 The cost of increased battery wear
Calculating the cost of increased battery wear due to V2G usage is not straightforward, due to the
fact that battery lifetimes published by manufacturers usually assume that the battery is fully
charged and discharged with each cycle (34). Battery cycle life is defined as the number of charge-
discharge cycles a battery can undergo before its capacity falls below 80% of its initial capacity.
The level of charge in a battery is known as the State of Charge (SOC), and the depth to which the
battery is discharged is called the depth of discharge (DOD). The SOC delta is the difference in
maximum charge and discharge levels allowed by the manufacturer. In Hybrid Electric Vehicle
(HEV) applications the SOC delta can be very small in order to increase battery life. The battery of
the Toyota Prius (a Hybrid Electric Vehicle) cycles between 80-90% SOC, giving an SOC delta of
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just 10% (35). In order to achieve the range required of a fully electric vehicle, the SOC delta might
typically be 80% (with the battery cycling between 10-90% of capacity).
The extent to which changing the depth of discharge (DOD) impacts cycle life depends upon the
battery technology used. Lead-acid batteries show a linear relationship in which reduced DOD
results in an increased battery cycle life. Lithium-ion and NiMH batteries show a logarithmic
relationship, meaning that reducing DOD results in an exponentially increasing cycle life (34).
The charge-discharge profile of a battery used for frequency regulation would be comparable to the
charge-discharge profile of a battery used in a Hybrid Electric Vehicle: according to the 2011
Energy Storage Report published by IHS, a Hybrid Electric Vehicle battery could be expected to
have a SOC delta of 10% (35). Under these conditions the battery could be expected to have a cycle
life of 300,000 cycles. Under the charge-discharge of a full Electric Vehicle with an 80% SOC delta,
the battery could be expected to have a cycle life of 1000+ cycles.
Major attempts to attach a monetary value to the cost of battery degradation in the context of V2G
technology can be seen in Kempton’s paper ‘Electric vehicles as a new power source for electric
utilities' (12) and in Chengke Zhou et al.’s ‘Modeling of the Cost of EV Battery Wear Due to V2G
Application in Power Systems’ (34). However, attempting to analytically produce an accurate
prediction of the costs of increased battery wear due to V2G usage is highly complex and beyond
the scope of this report. Empirical data concerning battery degradation due to cycling will
eventually be available from the LCVPP programme monitoring the University’s Smith EVs, but
according to Dominic Scholfield the level of battery degradation seen thus far is small enough to be
statistically insignificant (63). Conclusions on the real-world impact of increased battery cycling
will therefore have to wait until further data has been collected.
3.3.2 The cost of bi-directional charging and control electronics
The Smith vans owned by the University are already fitted with a telemetry system which records
and communicates over 43 different variables for each trip made by each vehicle. This means that
additional control electronics are unlikely to be required.
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The conversion of the Smith vans to allow bi-directional charging should be straightforward,
incurring minimal cost (30) (33). The technical and financial details of this process would be a good
subject for further investigation, but were considered to be outside the scope of this report.
3.4 Infrastructure
There are currently 5 charging points for the Smith vans on campus, each rated at 32 amps and 240
volts. This means each one is capable of delivering 7680 watts (7.68 kW). There are a large number
of other, household style plugs on campus. These are rated at 13 amps and 240 volts, meaning that
each one is capable of delivering 3120 watts (3.12 kW). Some of these are for University fleet
vehicles, whilst some are for researcher use and others are available for staff, students or the
general public. The only ones of interest to this report are those used for the V2G-relevant vehicles
in the University fleet. There are two of these, serving the two Nissan Leaf vehicles. The total power
that could be delivered by all of the Nissan Leaf cars and Smith Edison vans discharging at once is
therefore 44.64 kW.
The charging points on campus are already capable of bi-directional power flow (33). They also
already have meters installed to measure electricity flows (54). Through discussion with Mark
Jarvis it was found that the campus electricity usage is already ‘smart’ to some extent, with
electricity generation controlled at half-hourly intervals in response to demand.
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CHAPTER 4. ANALYSIS AND DISCUSSION
The ultimate aim of this project is to assess whether a viable V2G demonstrator could be
established on the University of Warwick campus. A successful demonstrator would have to be
both technically and financially viable. In order for a demonstrator to be technically viable, the
three elements of a V2G system must be in place; V2G capable vehicles, appropriate infrastructure
and energy balancing requirements. For financial viability, the demonstrator must either operate on
a commercial basis by offering a useful service (whether internally to the University or externally
by selling services to the National Grid), or operate on a non-commercial proof-of-concept basis.
4.1 Demonstrator options
4.1.1 Demonstrator using only the campus fleet
If sufficient balancing services could be provided by the University’s electric vehicle fleet this
would be ideal, as it is simple and does not require payment of third parties. However the current
fleet is limited in size, and therefore future projections are made. Two projections are made of the
conditions in 2020; a ‘Business as Usual’ projection and a ‘25% electrification’ projection. To provide
context to the projections, the current campus situation is summarised below:
Table 10: Current University EV fleet - power
Vehicle Battery type Capacity (kWh) No. of Vehicles Total Capacity (kWh)
Nissan Leaf Lithium-ion 24 2 48
Smith Edison Lithium-ion 50 5 250
Total: 338.56
Table 11: Current University EV fleet - energy storage capacity
Charging point type Power (kW) No. of charging points Total Power (kW)
Normal charge 3.12 kW 2 6.24
Fast charge 7.68 kW 5 38.4
Total: 44.64
4.1.1.1 ‘Business as Usual’ 2020 campus situation
Through discussion with Graham Hine, it was clear that the purchase of further Electric Vehicles
would only be possible with the help of government financial support. It is assumed that as this is a
priority for government and there are already numerous schemes running offering such support,
such purchases might be possible at the rate of 1 Nissan Leaf (or equivalent vehicle) every two
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years, and 2 Smith vans (or equivalent vehicles) per year. This would lead to the following
situation:
Table 12: 'Business as usual' University EV fleet - power
Vehicle Battery type Capacity (kWh) No. of Vehicles Total Capacity (kWh)
Nissan Leaf Lithium-ion 24 6 144
Smith Edison Lithium-ion 50 13 650
Total: 794
Table 13: 'Business as usual' University EV fleet - energy storage capacity
Charging point type Power (kW) No. of charging points Total Power (kW)
Normal charge 3.12 kW 6 18.72
Fast charge 7.68 kW 13 99.84
Total: 118.56
4.1.1.2 ‘25% electrification’ 2020 campus situation
To achieve approximately 25% electrification of the University fleet, vehicles would need to be
purchased at the rate of 1 Nissan Leaf (or equivalent vehicle) per year, and 15 Smith vans (or
equivalent vehicles) every four years (3.75 such vehicles per year). Currently the percentage of cars
in the UK that are electric is 0.00369%5. The percentage of the University of Warwick vehicle fleet
consisting of V2G-appropriate electric vehicles is 4.29%. Forecasts of EV penetration in the UK in
2020 range from 1-10% of all vehicles (64). The Committee on Climate Change has officially
recommended that the Government aims for 1.7 million EVs to be on the roads by 2020 (65). This
would represent 5.6% of UK cars. To achieve this, the yearly percentage increase of EVs in the UK
would have to be approximately 150%. These figures help to provide some perspective to the target
of 25% electrification, as the nation as a whole is likely to be undergoing a proportionally far more
rapid uptake in EVs. 25% electrification would lead to the following situation:
Table 14: '25% electrification' University EV fleet - power
Vehicle Battery type Capacity (kWh) No. of Vehicles Total Capacity (kWh)
Nissan Leaf Lithium-ion 24 10 240
Smith Edison Lithium-ion 50 35 1750
Total: 1990
Table 15: '25% electrification' University EV fleet - energy storage capacity
Charging point type Power (kW) No. of charging points Total Power (kW)
Normal charge 3.12 kW 10 31.2
Fast charge 7.68 kW 35 268.8
Total: 300
5 There are 1,107 electric cars in the UK (77) and approximately 30 million cars in total (69).
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4.1.2 Demonstrator also using staff and student vehicles
In addition to the University owned vehicle fleet, it is likely that in the period to 2020 increasing
numbers of staff and students will drive electric vehicles and park them on campus. There are
currently 4974 parking space on campus, and these are generally filled to capacity during term time
(66). The University target is to have 5422 parking space on campus by 2018. As we have seen, the
Committee on Climate Change has officially recommended that the Government aims for 1.7
million EVs to be on the roads by 2020 (65), equal to approximately 5.6% of cars in the UK. If the
number of University staff and students owning EVs is proportional to the national average, this
would mean 303 cars parked on campus in 2020. It can be conservatively assumed these cars would
all charge using standard household connections and would have an average storage capacity of 24
kWh (the storage capacity of the Nissan Leaf, a current EV model). Given that it has been predicted
that V2G vehicles could become a mainstream consumer offering within 4-5 years (13), it is possible
that many of these vehicles could be V2G capable. Those that are not already V2G capable could be
converted or used for demand-side balancing. 303 vehicles discharging at 3.12 kW would deliver
power of 945 kW, whilst the vehicles’ total storage capacity would be 7272 kW (7.3 MW).
A more optimistic scenario can also be constructed. It is known that EV uptake is
disproportionately high among the affluent and well educated, and the University’s staff and
students can reasonably be expected to generally conform to this description (67) (68). If it is
assumed that the proportional uptake is double the national average, this would mean there were
607 EVs parked on campus. If three-quarters of the charging points serving these EVs were rated at
the standard 3.12 kW and one quarter were rated at 7.68 kW, the vehicles would provide 2586 kW
of power. At 24 kWh per vehicle, in total 14568 kWh of storage would be available.
Combing the lower- and higher-range estimates for the 2020 University-owned EV fleet size and
the 2020 staff and student-owned EV fleet size (henceforth shortened to ‘University V2G resources’)
produces the following data:
Table 16: Characteristics of University fleet plus staff and student vehicles under different assumptions
Storage capacity (kWh) Power (kWh)
2020 Combined lower-range estimate 8 066 1 064
2020 Combined higher-range estimate 16 558 2 886
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4.2 Technical Viability
From Chapter 3, the University’s situation regarding the three elements of a V2G system is as
follows:
Energy balancing requirements
The University’s electricity demand and generation profiles show an opportunity for large scale
storage to be useful. The range of balancing services purchased by the National Grid offer good
potential for commercialisation if the requirements for capacity and power provision can be met.
V2G capable vehicles
The University currently has a modest fleet of electric vehicles, with 5 Smith Edison vans and 2
Nissan Leaf cars alongside other utility vehicles that would not be suitable for V2G. The Smith
Edison vans are already fitted with advanced telemetry and monitoring equipment, and should be
reasonably easy to convert to allow V2G capabilities.
Appropriate infrastructure
There are currently an appropriate number of charging points around campus, some of which offer
power delivery of 7.68 kW. The charging points are already capable of bi-directional flow and can
monitor electricity flow. The campus electricity usage is already ‘smart’ to some extent, with
electricity generation controlled at half-hourly intervals in response to demand.
With the three elements of a V2G system present, a V2G demonstrator on the University of
Warwick campus is technically viable.
4.3 Financial Viability
In order to be successful, any demonstrator would need to be financially viable. Note that this does
not necessarily mean that the demonstrator would have to produce revenue; financial viability here
requires only that any demonstrator has enough funding to provide a useful proof-of-concept. Of
course, an ideal demonstrator would be profitable, but this may not be possible.
4.3.1 Revenue potential – selling services to the National Grid
As discussed in Section 3.2.2, the National Grid procures three main types of balancing service:
Frequency Response (including Mandatory Frequency Response, Firm Frequency Response (FFR)
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and Frequency Control by Demand Management (FCDM)), Fast Reserve and Short Term Operating
Reserve (STOR). Primary requirements are summarised in the table below:
Table 17: Summary of National Grid balancing service requirements
Balancing Service Power deliver requirements
Freq
uen
cy R
esp
on
se
Mandatory Frequency Response Only open to generators larger than 100 MW.
Firm Frequency Response (FFR) Stated minimum 10 MW. Some current providers offer 3
MW.
Frequency Control by Demand
Management (FCDM)
Minimum 3 MW of power. Must be available 24 hours a day.
Fast Reserve Minimum 50 MW of power at a rate > 25 MW/minute.
Short Term Operating Reserve Minimum 3 MW of power for at least two hours.
Comparing these requirements to the characteristics of the current University fleet and various
projections of the fleet in 2020 yields the following:
Table 18: Suitability of current and projected scenarios for selling balancing services to National Grid
Storage capacity
(MWh)
Power delivery
(MW) Appropriate balancing services
Current University fleet 0.34 0.04 n/a
‘Business as usual’
University fleet 2020
0.79 0.12 n/a
‘25% electrification’
University fleet 2020
2.0 0.3 n/a
Combined lower-range
2020 estimate
8.1 1.1 n/a
Combined higher-range
2020 estimate
16.6 2.9 Firm Frequency Response and Short
Term Operating Reserve
This shows that the only appropriate balancing services are Firm Frequency Response and Short
Term Operating Reserve, and even then only with the Combined higher-range 2020 estimate.
Firm Frequency Response (FFR)
From Section 3.2.2.2, tenders for FFR active as of February 2012 show current providers offering 3
MW in exchange for payment of £15.72 per hour they make their services available to the grid.
Assuming the combined higher-range 2020 estimate, there will be approximately 3 MW available.
This is likely to be available during the hours 9:00 – 17:00. Assuming that there only enough cars
parked to deliver this power on weekdays in the first and second terms of the academic year, the
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University could provide 8 hours per day for 100 days annually. This would provide gross revenue
of £12,576 per annum, regardless of the extent to which services were actually used – payment is
for the availability of the service. Some of this revenue would likely be used to compensate vehicle
owners, but there is still potential for profit.
If all of the charging points installed in campus car parks was of the faster charging type, delivering
7.68 kW, then the power produced would be 4962 kW (approximately 5MW). As of February 2012,
a tender providing 4 MW was being paid an availability payment of £20.96/h and therefore it can be
assumed that the University could bid to provide 5MW for the same availability payment. Using
the same assumptions as above, this would give gross revenue of £16,768.
Short Term Operating Reserve (STOR)
Short Term Operating Reserve (STOR) requires a minimum of 3 MW of power delivery. STOR
differs significantly from FFR in that rather than lots of small bursts of energy, sustained power
delivery is required. In a STOR contract, payment is made for both availability and utilization.
From Section 3.2.2.4, STOR payment levels in the most recent tender round are as follows:
Table 19: Average accepted STOR bids from most recent tender round. Data from (60)
Average accepted bid for availability
payments (£/MWh)
Average accepted bid for utilisation
payments (£/MWh)
Committed STOR £7.71/MWh £216/MWh
Flexible STOR £7.91/MWh £151/MWh
The University could bid for a committed STOR contract for the eight hours from 9:00 – 17:00 each
working day during the first and second terms of the academic year. If these services were used for
an average of four hours a week, this would result in payment of £23,448. The same parameters
under flexible STOR would result in payment of £18,408.
4.3.2 Non-revenue producing options
There are essentially two ways in which a non-revenue producing demonstrator could still be
financially viable. Balancing services could be provided internally, or a proof-of-concept
demonstrator could be set up in partnership with a commercial partner.
Page | 45
4.2.1 Using V2G services internally
As discussed in Section 3.2.1, internal frequency regulation is not relevant to the University’s
situation as the University is not responsibility for maintaining system frequency. The University’s
demand and energy production profiles show a potential for energy storage to be useful. The
storage capacity of the current University fleet alongside various projections of the fleet in 2020 is
shown below, alongside the storage capacity as a percentage of hourly demand on campus. The
average hourly demand on campus is 5.83 MWh. It is assumed that in order to provide any form of
demand balancing, the total storage capacity must be at least equal to one hour of campus demand,
and in order to be truly viable at least double this must be available.
Table 20: Suitability of current and projected scenarios for internal provision of load-balancing services
Total storage
capacity (MWh)
Storage capacity
as percentage of
hourly demand
Viable?
Current University fleet 0.34 5.8% No
‘Business as usual’ University fleet 2020 0.79 13.5% No
‘25% electrification’ University fleet 2020 2.0 34.3% No
Combined lower-range 2020 estimate 8.1 138.9% Possibly
Combined higher-range 2020 estimate 16.6 284.6% Yes
It can be seen from Table 20 that by combining the University fleet with staff and student vehicles,
internal demand balancing may be viable, particularly if the higher 2020 estimate is met.
4.2.2 Proof-of-concept demonstrator
An attractive near-term option could be the establishing of a proof-of-concept demonstrator with
the support of an external partner. The University has close links many companies including utility
companies, and very strong ties with Tata Motors and Jaguar Land Rover, both of which have some
facilities based on campus. A number of utility companies were contacted to gauge interest, and a
very positive response was received from Sebastien Pelissier of EDF Energy. Mr. Pelissier explained
that V2G ‘is of much interest for us as a utility’ because ‘we are deeply involved in the future shift
of the electricity generation to inflexible or intermittent source’. EDF Energy would therefore be
interested in collaborating with the University to establish a proof-of-concept trial. This could
involve EDF Energy contributing funding or assisting in other ways, in which case this could allow
a financially viable demonstrator. A proof-of-concept would likely require some funds from the
Page | 46
University, but as can be seen in Section 2.4.3 the University has funds available for carbon-
reduction related projects. EDF Energy’s expression of interest has been passed on to WMG
(Warwick Manufacturing Group) staff in order to continue the dialogue.
4.4 Note on accuracy and reliability
4.4.1 Reliability of referenced sources
Critical judgment has been exercised in the use of sources for this report. The vast majority of
sources are from either peer reviewed academic work published in reputable journals, official
governmental publications or directly from source (e.g. from official University of Warwick
documents or National Grid documents). Where news sources are used it has been ensured that
they are reputable sources, preferably from organisations such as Forbes or the BBC.
4.4.2 Accuracy of calculated figures
Where figures have been calculated, they have often been rounded to an appropriate number of
significant figures. As many of the calculations in this report are based on figures which themselves
originate in approximations and predictions, it would be inappropriate and give an illusion of
accuracy by providing calculated answers to a large number of decimal places.
In particular, whilst assessing likely revenue from selling balancing services to the National Grid
provides a useful order of magnitude estimate, each tender bid is considered on its own merits and
another provider offering a similar level of power or energy in no way guarantees that a similar bid
by the University of Warwick would be successful.
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CHAPTER 5. CONCLUSIONS
This report aimed to examine and explain the background of V2G technology, summarise and
review academic literature on V2G technology, and build on last year’s report by providing a
deeper analysis of the possibility of a V2G demonstrator on the University of Warwick campus.
It has been seen that environmental issues are a major national and international concern of the 21st
century. The UK has committed to extensive and legally binding reductions in carbon emissions by
2050. The resulting program of change is causing major upheaval in the energy and transport
industries, with penetration of renewable, intermittent sources of energy increasing and the
government targeting the complete decarbonisation of road transport by 2050. Vehicle-to-Grid
(V2G) technology, which links Electric Vehicles (EVs) with the grid in order to help to regulate
demand and supply of electricity, is well positioned at the convergence of these issues.
The primary applications of V2G technology are in frequency regulation and load balancing.
Frequency regulation uses many small bursts of power to regulate the frequency of the National
Grid to within ±1% of nominal system frequency (50Hz), whilst load balancing consists of the large
scale storage of electricity at off-peak times which can then be used to help to cover peaks of
demand during the day.
Major obstacles to the technology are the limitations of battery technology and the negative attitude
of manufacturers, which themselves stem largely from the technical and financial limitations of
battery technology. However, it is expected that EVs will go into full scale production at some point
in the relatively near future, and when this happens the increase in battery volumes and the
increased investment will result in battery costs decreasing rapidly. This is expected to make V2G a
much more attractive proposition for manufacturers, especially if consumers are properly educated
on the potential benefits.
On the national level, adopting V2G technology would help to maintain electricity supply despite
the large-scale integration of renewable, intermittent source of energy. Early adoption could also
entail significant economic benefits. For the University of Warwick, a V2G demonstrator could help
to meet carbon reduction targets, and potentially provide a source of revenue. A demonstrator
Page | 48
could also increase the international profile and reputation of the University; less than 10 V2G
demonstrators could be identified globally with no demonstrators currently located in the UK.
In order for a successful demonstrator to be established on campus, it would need to be both
technically achievable and financially viable. Three elements are necessary for a V2G system to
operate successfully; energy balancing requirements, V2G capable vehicles, and appropriate
infrastructure. It was found that the University campus fulfills these requirements. Analysis has
shown that the current University EV fleet is not large enough to provide significant V2G services,
and so projections are made about the fleet in 2020. The impact of including staff and student
vehicles parked on campus is also modelled.
It is found that combining optimistic predictions of University fleet growth and staff and student
EV uptake, useful V2G services could be provided by 2020. If schemes were introduced to
encourage more rapid EV uptake, then this could be expected to come sooner. These V2G services
could be used internally to balance campus electricity demand and supply, or could be sold to
National Grid. Frequency regulation services such as Firm Frequency Response (FFR) could earn
approximately £12,600 per annum whilst a load-balancing service such as Short Term Operating
Reserve (STOR) could earn £18,400 - £23,400 per annum. These constitute order of magnitude
estimates and revenue would vary widely according to the requirements of National Grid at the
time and the intensity of competition between providers.
Alternatively, a proof-of-concept demonstrator could be established with the current University
fleet. This would not be large enough to provide significant V2G services and as it would not be
able to pay for itself this would not be a long-term option. Despite this, such a proof-of-concept
could serve as a useful demonstration of the feasibility of V2G technology. EDF Energy have
expressed interest in collaborating with the University to establish such a demonstrator, and this
expression of interest has been passed on to WMG (Warwick Manufacturing Group) staff in order
to continue the dialogue.
Overall, there is good potential for a proof-of-concept demonstrator in the near term, particularly if
collaboration with commercial partners such as EDF Energy is fruitful. In the longer term, by 2020
the University could be in a position to sell significant V2G services to National Grid.
Page | 49
CHAPTER 6. RECOMMENDATIONS FOR FURTHER WORK
Key areas for further work are as follows:
A continuation of the dialogue between EDF Energy and University staff regarding the
possibility of a collaborative proof-of-concept demonstrator.
A more detailed analysis of the process of tendering to provide balancing services to the
National Grid, including technical requirements and the application process.
A more detailed analysis of what would be involved technically and financially in
converting the current Electric Vehicles to allow bi-directional charging and to allow an
interface with the National Grid to be established.
An analytical or empirical investigation into the costs of battery degradation incurred by
participation in V2G technology.
Maintaining and enhancing relationships with the stakeholders contacted in the course of
this project, including those in the automotive, energy and V2G industries.
Page | 50
CHAPTER 7. COSTING
The costing of this project uses the following assumptions:
The author’s time was costed at £15 per hour, including overheads.
The academic supervisor’s time was costed at £50 per hour, including overheads.
The time of other University staff (e.g. Graham Hine, Transport Manager and Mark Jarvis,
Estates Technical Assistant) was costed at £40 per hour, including overheads.
The time of external persons such as employees of Jaguar Land Rover, National Grid, EDF
Energy etc. was assumed to have no cost, as these people voluntarily gave their time to help
with the project.
The cost of the project is therefore given as:
Table 21: Project costs
No. units Cost/unit Cost
Author’s time 250 hours £15/hour £3750
Supervisor’s time 5 hours £50/hour £250
Other University staff time 8 hours £40/hour £320
External persons time 10 hours Assumed no cost -
Equipment/consumables 1 book £30 £30
Total Cost: £4350
The project is calculated to have cost £4,350 to undertake. This costing excludes the use of existing
infrastructure such as the computing facilities in the School of Engineering, the extensively used
University of Warwick Library and the author’s laptop. The use of the University Library allowed
access to books, journals and online resources that would have cost hundreds or thousands of
pounds to have accessed as an individual, significantly helping to reduce costs. It is also relevant
that the author would be unlikely to be earning £15/hour during time spent not working on this
project, and that this costing is therefore somewhat generous. As the author’s time was by far the
largest contributor to the cost of the project, this must be taken into account.
The cost of the project must be compared to the benefits gained to allow some insight into whether
the project was worthwhile. The benefits from the project are difficult to quantify, but it is believed
that the reasoning behind Vehicle-to-Grid technology has been summarised well and that
significant progress has been made in consideration of the potential for a V2G demonstrator on the
University of Warwick campus.
Page | 51
REFERENCES
1. A history of climate change. Directgov. [Online] [Cited: January 7, 2012.] http://www.direct.gov.uk/en/Environmentandgreenerliving/Thewiderenvironment/Climatechange/DG
_072901.
2. Status of Ratification of the Kyoto Protocol. United Nations Framework Convention on Climate Change. [Online] [Cited: January 8, 2012.] http://unfccc.int/kyoto_protocol/status_of_ratification/items/2613.php.
3. The Royal Academy of Engineering. Generating the Future: UK energy systems fit for 2050. s.l. : The Royal Academy of Engineering, March 2010. ISBN 1-903496-54-3.
4. Where is UK energy going – and will it get there? Professor John Loughhead. Executive Director
of the UK Energy Research Centre : Presentation. School of Engineering, University of Warwick, Andrew Little Lecture Series, December 1st, 2011.
5. Malnick, Edward and Mendick, Robert. Wind farm paid £1.2 million to produce no electricity. The Daily Telegraph. 17 September 2011.
6. TWI and the UK Energy Research Centre. UK Smart Grid Capabilities Development Programme. 2011.
7. King, Julia. The King Review of low carbon cars. Part I: The potential for CO2 reduction. October
2007. ISBN-13: 978-1-84532-335-6.
8. Renewable Fuels Agency. The Gallagher Review of the indirect effects of biofuels production. 2008.
9. The Royal Academy of Engineering. Electric Vehicles; charged with potential. May 2010. ISBN 1-903496-56-X.
10. The Networked Vehicle 1.0: Integrating Electric Cars with the Nation's Power Grid. Letendre,
Steven, Kempton, Willett and Tomić, Jasna. 4, s.l. : XRDS: Crossroads, The ACM Magazine for Students, 2011, Vol. 17.
11. Ferber, Dan. Vehicle-to-Grid: A New Spin on Car Payments. Miller-McCune. [Online] October 31, 2011. [Cited: January 19, 2012.] http://www.miller-mccune.com/environment/vehicle-to-grid-a-new-spin-on-car-payments-36697/.
12. Kempton, W. and Letendre, S. Electric vehicles as a new power source for electric utilities. Transport Research Part D 2 (3). 1997, Vol. 2, 3.
13. Pike Research. Vehicle to Grid Technologies. 4Q 2011.
14. Kempton, Willet et al. A Test of Vehicle-to-Grid (V2G) for Energy Storage and Frequency
Regulation in the PJM System. November 2008.
15. Optimal decision on contract size for V2G aggregator regarding frequency regulation. Jang, Soohyeong, et al., et al. s.l. : 2010 12th International Conference on Optimization of Electrical and Electronic Equipment (OPTIM), May 2010. ISSN: 1842-0133.
16. The Value of Plug-In Hybrid Electric Vehicles as Grid Resources. Sioshansi, Ramteen and
Denholm, Paul. 3, s.l. : The Energy Journal, Vol. 31.
17. The V2G Concept: A New Model For Power? Kempton, Willet and Letendre, Steven. 4, s.l. : Public Utilities Fortnightly, February 2002, Vol. 140.
18. The effect of communication architecture on the availability, reliability, and economics of plug-in hybrid electric vehicle-to-grid ancillary services. Quinn, Casey, Zimmerle, Daniel and Bradley, Thomas H. s.l. : Journal of Power Sources, 2009, Vol. 195 (2010).
19. Using fleets of electric-drive vehicles for grid support. Kempton, Willet and Tomic, Jasna. 2, s.l. : Journal of Power Sources, 1 June 2007, Pages 459–468, Vol. 168.
Page | 52
20. Multi-function bi-directional battery charger for plug-in hybrid electric vehicle application. Zhou, Xiaohu, et al., et al. FREEDM Syst. Center, North Carolina State Univ., Raleigh, NC, USA : Energy
Conversion Congress and Exposition, 2009. ECCE 2009. IEEE., 2009. ISBN: 978-1-4244-2893-9.
21. A Bidirectional Inductive Power Interface for Electric Vehicles in V2G Systems. Madawala, U.K. and Thrimawithana, D.J. 10, Univ. of Auckland, Auckland, New Zealand : Industrial Electronics, IEEE Transactions on, 2011, Vol. 58. ISSN: 0278-0046.
22. Bi-directional charging topologies for plug-in hybrid electric vehicles. Erb, D.C., Onar, O.C. and Khaligh, A. Electr. & Comput. Eng. Dept., Illinois Inst. of Technol., Chicago, IL, USA : Applied Power Electronics Conference and Exposition (APEC), 2010 Twenty-Fifth Annual IEEE, 2010. ISSN: 1048-2334 .
23. A V2G vector control model of electric car charging and discharging machine. Wang, Xiaolei, et al., et al. Sch. of Electr. & Inf., Zhongyuan Univ. of Technol., Zhengzhou, China : 2011 International Conference on Advanced Mechatronic Systems (ICAMechS), August 2011. ISBN: 978-1-4577-1698-0.
24. The Control Strategy Of V2G Participating in Peak Regulation in Power System. Wen Qi Tian et
al.;. s.l. : Advanced Materials Research, 2011, Vols. 383-390.
25. An optimal scheduling problem in distribution networks considering V2G. Soares, J., Sousa, T. and Morais, H. s.l. : 2011 IEEE Symposium on Computational Intelligence Applications In Smart
Grid (CIASG) , 2011. ISBN: 978-1-4244-9893-2.
26. Optimal control of the plug-in electric vehicles for V2G frequency regulation using quadratic programming. Han, Sekyung, Han, Soohee and Sezaki, K. Dept. of Inf. Sci. & Technol., Univ. of Tokyo, Tokyo, Japan : Innovative Smart Grid Technologies (ISGT), 2011 IEEE PES , January 2011. ISBN: 978-1-61284-218-9 .
27. GlobalData. Vehicle-to-Grid (V2G) - Global Market Analysis and Forecasts to 2020. Novemeber 2010.
28. Vehicle-to-grid power fundamentals: Calculating capacity and net revenue. Kempton, Willett
and Tomic, Jasna. 1, s.l. : Journal of Power Sources, 2005, Vol. 144.
29. Integration of renewable energy into the transport and electricity sectors through V2G. Lunda, Henrik and Kempton, Willett. 9, s.l. : Energy Policy, 2008, Vol. 36.
30. Professor Philip Mawby. Electronics Professor, University of Warwick. Discussion concerning EV control electronics. February 24, 2012.
31. Muller, Joann. A Light Bulb Goes On. Forbes.com. [Online] Forbes, July 1, 2008. [Cited:
February 14, 2012.] http://www.forbes.com/global/2008/0107/036.html.
32. Bostock, Paul. Hybrid Strategy and Integration, Jaguar Land Rover. Interviewed by Stephen Cordle. December 5, 2011.
33. Pascall, Emma. Vehicle to Grid Demonstrator Viability. 3rd Year, School of Engineering, University of Warwick : ES327 - Individual Project, 2011.
34. Modeling of the Cost of EV Battery Wear Due to V2G Application in Power Systems. Zhou,
Chengke, Qian, Kejun and Allan, M. 4, s.l. : IEEE Transactions on Energy Conversion, Dec. 2011, Vol. 26. ISSN: 0885-8969.
35. Knibb, Gormezano and Partners. Advanced Energy Storage and Distribution Report. s.l. : IHS Supplier Business, 2011 Edition.
36. IHS Supplier Business. The Electric and Range Extended Electric Light-Vehicle Report. s.l. : IHS Inc., 2012.
37. Råde, Ingrid. Requirement and Availability of Scarce Metals for Fuel-Cell and Battery Electric
Vehicles. Gothenburg : Department of Physical Resource Theory, Chalmers University of Technology and Göteborg University (2001), 2001. ISBN-13: 978-9171979902.
38. Metal resource constraints for electric-vehicle batteries. Andersson, Björn A and Råde, Ingrid. 5, Pages 297–324, Department of Physical Resource Theory, Chalmers University of Technology and
Göteborg University : Transportation Research Part D: Transport and Environment, 2001, Vol. 6.
Page | 53
39. Gartner, John. EVs Don't Have To Wait for V2G to Help Balance the Grid. Reuters. [Online] June 24, 2011. [Cited: January 11, 2012.]
http://www.reuters.com/article/2011/06/24/idUS24604452520110624.
40. National Grid. National Electricity Transmission System: Seven Year Statement, Appendix F.10. 2011.
41. Ricardo and National Grid. Bucks for balancing: Can plug-in vehicles of the future extract cash – and carbon – from the power grid? May 2011.
42. BBC. UK energy smart meter roll-out is outlined . BBC News. [Online] December 2, 2009. [Cited:
February 7, 2012.] http://news.bbc.co.uk/1/hi/business/8389880.stm.
43. Department of Energy and Climate Change. Energy Market Assessment. s.l. : HM Treasury, March 2010. ISBN 978-1-84532-701-9.
44. University of Warwick. 2020 Carbon Management Implementation Plan. March 2011.
45. —. Higher Education Carbon Management Programme: University of Warwick Case for Action. 2005.
46. Emadi, Ali. Handbook of Automotive Power Electronics and Motor Drives . s.l. : CRC Press , 2005. ISBN-13: 978-0824723613.
47. Brooks, Alec N. Vehicle-to-Grid Demonstration Project: Grid Regulation Ancillary Service with a
Battery Electric Vehicle. s.l. : AC Propulsion, 2002.
48. Gallucci, Maria. Vehicle-to-Grid Charging for Electric Cars Gets Lift from Major U.S. Utility. InsideClimate News. [Online] October 12, 2011. [Cited: February 1, 2012.] http://insideclimatenews.org/news/20111012/vehicle-to-grid-v2g-technology-electric-vehicles-charging-nrg-energy?page=1.
49. Vehicle-to-Grid for islanded power system operation in Bornholm. Pillai, Jayakrishnan R and
Bak-Jensen, Birgitte ,. Inst. of Energy Technol., Aalborg Univ., Aalborg, Denmark : Power and Energy Society General Meeting, 2010 IEEE, 25-29 July 2010. ISSN: 1944-9925.
50. Vehicle Testing and Integration Facility. National Renewable Energy Laboratory (NREL). [Online] January 2012. [Cited: March 2, 2012.] http://www.nrel.gov/docs/fy12osti/53297.pdf.
51. Fort Carson - Smart Power Infrastructure Demonstration for Energy Reliability and Security. US
CERT - United States Computer Emergency Readiness Team. [Online] February 15, 2011. [Cited: March 02, 2012.] http://www.us-cert.gov/control_systems/icsjwg/presentations/spring2011/ag_16c_ICSJWG_Spring_2011_Conf_Beary.ppt.
52. U.S. Army Garrison-Hawaii Public Affairs, News Release . Army's first smart-charging micro
grid unveiled. www.army.mil - The Official Homepage of the United States Army. [Online] March 22, 2011. [Cited: March 02, 2012.] http://www.army.mil/article/53628/first-ever-smart-charging-micro-grid-unveiled/.
53. Camron Gorguinpour and Arun Seraphin. Air Force Jumpstarts Electric Vehicle Program. The
White House Office of Science and Technology Policy. [Online] September 09, 2011. [Cited: March 02, 2012.] http://www.whitehouse.gov/blog/2011/09/09/air-force-jumpstarts-electric-vehicle-program.
54. Jarvis, Mark. Utilities Technical Assistant, University of Warwick. Personal Communications, mainly via e-mail. 2011-2012.
55. The Electricity Supply Regulations 1988. Part VI, Regulation 30(2)(b). ISBN-13: 978-0110870571 .
56. National Grid. Procurement Guidelines Report: 1 April 2009 to 31 March 2010. . Version 2 (30th April 2010).
57. —. Frequency Response. National Grid. [Online] [Cited: February 21, 2012.] http://www.nationalgrid.com/uk/Electricity/Balancing/services/frequencyresponse/.
Page | 54
58. —. Firm Frequency Response Post Assessment Tender Report - February 2012. National Grid. [Online] [Cited: February 22, 2012.] http://www.nationalgrid.com/NR/rdonlyres/6770CBBE-F5C0-
4C57-921D-36D0C76CFCE3/51561/FFR_Post_Assessment_TenderReport_Feb2013.pdf.
59. RLtec - case study. Carbon Trust. [Online] January 2011. [Cited: February 22, 2012.] http://www.carbontrust.co.uk/about-carbon-trust/case-studies/smart-grid/pages/rltec.aspx.
60. STOR Market Information Report: Tender Round 15. National Grid. [Online] November 2011. [Cited: January 22, 2012.] http://www.nationalgrid.com/NR/rdonlyres/3F56DE61-F432-41AC-9FD6-6CA3A6F4BE0B/50015/TR15_MIR_final.pdf.
61. Hine, Graham. Transport Manager, University of Warwick. Personal communication. January, February 2012.
62. Cenex. LCVPP Interim Fleet Report. Fleet: University of Warwick. 2011.
63. Scholfield, Dominic. University of Warwick Smith EV data. Personal Communication via e-mail and telephone. February 23, 24, 2012.
64. Parliamentary Office of Science and Technology. Electric Vehicles. POSTNOTE Number 365 : Houses of Parliament, October 2010.
65. Committee on Climate Change. Meeting Carbon Budgets – the need for a step change. Chapter 6 - Reducing surface transport emissions through low carbon cars and consumer behaviour change. October 2009.
66. University of Warwick. Planning Application: Transport Assessment. Coventry : University of Warwick Masterplan, June 2007.
67. SBI Energy. Electric Vehicle (EV) and Plug-In Hybrid Electric Vehicle (PHEV) Markets Worldwide. s.l. : SBI Reports, March 2010.
68. Vyas, Charul, Hurst, Dave and Gartner, John. Electric Vehicle Consumer Survey. s.l. : Pike
Research, 2011.
69. Department for Transport. Vehicle Licensing Statistics: 2010. published April 2011.
70. Creating cars that drive themselves. Oxford University. [Online] September 29, 2011. [Cited: January 7, 2012.] http://www.ox.ac.uk/research/research_impact/oxford_impacts/creating_cars.html.
71. Crowter, Stephen. Interview with owner of used car dealership. February 3, 2012.
72. Department for Transport. Average time spent travelling by main mode, Great Britain, since 1995/97. published July 2011.
73. Intergovernmental Panel on Climate Change. IPCC Special Report on Renewable Energy Sources and Climate Change Mitigation. s.l. : Cambridge University Press, 2011.
74. Sankey, P., Clark, D.T. and Micheloto, S. The End of the Oil Age. 2011 and beyond: a reality check. s.l. : Deutsche Bank, 2010.
75. Committee on Climate Change. 1st Progress Report. Technical Appendix to Chapter 6. s.l. : Committee on Climate Change, 2009.
76. Simpson, Mike. National Renewable Energy Laboratory (NREL). Vehicle to Grid Demonstrators in the United States. Personal communication via e-mail. January 26, 2012.
77. Vaughan, Adam. Electric car UK sales sputter out. The Guardian. [Online] October 21, 2011. [Cited: March 05, 212.] http://www.guardian.co.uk/environment/2011/oct/21/electric-car-uk-sales-sputter.
Page | a
APPENDICES
Appendix Ia
Calculating the power of the UK vehicle fleet.
At the end of 2010 there were 34 million vehicles licensed in Great Britain (69), of which
approximately 30 million were cars (70). The mean engine size of all cars registered in Great Britain
in 2010 was 1,750cc (69).
According to an owner of a used car dealership interviewed, 1,750cc could be expected to generally
produce approximately 130 hp (71). 1 hp is equal to 0.735 kW, and therefore 130 hp is equal to 95.61
kW. Multiplying the power of the average car by the number of cars in the UK gives an order of
magnitude estimate of the total power in the UK vehicle fleet. This is found to be 2868 GW. The
capacity of the UK grid is 82.5 GW as of 2010/11 (40), and the vehicle fleet therefore has
times the power of the grid. The UK vehicle fleet therefore has approximately 35 times
the power of the UK grid.
Appendix Ib
Calculating the average idle time per day of UK vehicles.
According to the Department for Transport, in 2010 the average UK individual spent 140 hours
driving (72). Multiplying this by the 2010 UK population of approximately 62 million gives a figure
of 8680 million hours driven in the UK in 2010. Dividing this figure by the approximate number of
cars registered in the UK at the end of 2010, 30 million (69), gives a figure for the annual time each
car spends travelling annually of 289.333 hours. Dividing this by 365 gives a daily figure of 0.793
hours per day, or 47.56 minutes.
The average UK car therefore spends approximately 47.56 minutes travelling per day, leaving it
idle 96.7% of the time.
Page | b
Appendix II
National Grid Firm Frequency Response tender report, February 2012.
Page | c
Appendix III
University of Warwick vehicle fleet summary.
Vehicle Type Engine Type No. of vehicles
Van Diesel 101
Van Petrol 1
Van Electric 5
Car Diesel 18
Car Petrol 3
Car Electric 2
Tractor Diesel 15
Utility Vehicle Petrol 6
Utility Vehicle Electric 3
Golf buggy Electric 2
4x4 Diesel 2
Moped Electric 2
Fork Lift LPG 2
Fork Lift Diesel 1
Total: 163
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