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A Sociotechnical Transition Beyond Electric Mobility LANCE NOEL, GERARDO ZARAZUA DE RUBENS, JOHANNES KESTER, AND BENJAMIN K. SOVACOOL
ENERGY, CLIMATE AND THE ENVIRONMENT
Vehicle-to-Grid
Energy, Climate and the Environment
Series Editors David Elliott The Open University Milton Keynes, UK Geoffrey Wood School of Law University of Stirling Stirling, UK
he aim of this series is to provide texts which lay out the technical, environmental and political issues relating to proposed policies for responding to climate change. he focus is not primarily on the science of climate change, or on the technological detail, although there will be accounts of this, to aid assessment of the viability of various options. However, the main focus is the policy conlicts over which strategy to pursue. he series adopts a critical approach and attempts to identify laws in emerging policies, propositions and assertions. In particular, it seeks to illuminate counter-intuitive assessments, conclusions and new perspectives. he intention is not simply to map the debates, but to explore their structure, their underlying assumptions and their limitations. he books in this series are incisive and authoritative sources of critical analysis and commentary, clearly indicating the divergent views that have emerged whilst also identifying the shortcomings of such views. he series does not simply provide an overview, but also ofers policy prescriptions. More information about this series at http://www.palgrave.com/gp/series/14966
Lance Noel · Gerardo Zarazua de Rubens Johannes Kester · Benjamin K. Sovacool
Vehicle-to-Grid A Sociotechnical Transition Beyond Electric Mobility
Lance Noel Department of Business and Technology Aarhus University Herning, Denmark
Benjamin K. Sovacool Department of Business and Technology Aarhus University Herning, Denmark
Gerardo Zarazua de Rubens Department of Business and Technology Aarhus University Herning, Denmark
and
Johannes Kester Department of Business and Technology Aarhus University Herning, Denmark
Science Policy Research Unit (SPRU) University of Sussex Unit Falmer, UK and Universiti Tenaga Nasional Kajang, Malaysia
Energy, Climate and the Environment ISBN 978-3-030-04863-1 ISBN 978-3-030-04864-8 https://doi.org/10.1007/978-3-030-04864-8
(eBook)
Library of Congress Control Number: 2018962250 © he Editor(s) (if applicable) and he Author(s), under exclusive license to Springer Nature Switzerland AG, part of Springer Nature 2019 his work is subject to copyright. All rights are solely and exclusively licensed by the Publisher, whether the whole or part of the material is concerned, speciically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microilms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. he use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a speciic statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. he publisher, the authors and the editors are safe to assume that the advice and information in this book are believed to be true and accurate at the date of publication. Neither the publisher nor the authors or the editors give a warranty, express or implied, with respect to the material contained herein or for any errors or omissions that may have been made. he publisher remains neutral with regard to jurisdictional claims in published maps and institutional ailiations. Cover credit: Tim Gainey/Alamy Stock Photo his Palgrave Macmillan imprint is published by the registered company Springer Nature Switzerland AG he registered company address is: Gewerbestrasse 11, 6330 Cham, Switzerland
Acknowledgements
he authors are appreciative to the Research Councils United Kingdom (RCUK) Energy Program Grant EP/K011790/1 “Center on Innovation and Energy Demand,” the Danish Council for Independent Research (DFF) Sapere Aude Grant 4182-00033B “Societal Implications of a Vehicle-to-Grid Transition in Northern Europe,” which have supported elements of the work reported here. Any opinions, indings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily relect the views of RCUK Energy Program or the DFF. We also thank Dr. Xiao Lin for her assistance in collecting some of the primary data for this book, as well as Prof. Willett Kempton and Assoc. Prof. Jonn Axsen for helping reine our thoughts on the topic.
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About This Book
his book deines and charts the barriers and future of an emerging low-carbon source of mobility that could dramatically reduce emissions, create revenue, and accelerate the adoption of battery electric cars: vehicle-to-grid technology. his technology connects the electric power grid and the transportation system in ways that will enable electric vehicles to store renewable energy and ofer valuable services to transmission operators. To understand the complex features of this emergent technology, this book explores the current status and prospect of vehicle-togrid and then individually details the sociotechnical barriers that may impede its fruitful deployment. Finally, the book concludes with a policy roadmap to advise decision-makers on how to optimally implement vehicle-to-grid and capture its beneits to society while attempting to avoid the impediments discussed earlier in the book. his combines the most up-to-date literature on vehicle-to-grid, mobility, transitions, sociotechnical systems, and electric power systems along with original data collected by the authors on the array of challenges and beneits to vehicle-to-grid. he examples in the book cut across technical integration of research, economic analyses, and sociopolitical challenges based on novel mixed methods (quantitative and vii
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About This Book
qualitative). hus, the book will ensure that readers from a variety of backgrounds will gain a more comprehensive understanding of vehicleto-grid and its potential for wide-scale implementation in the transport and electric systems.
Contents
1 History, Deinition, and Status of V2G 1.1 Deining V2G 1.1.1 Incorporating V2G to the EV 1.1.2 Aggregation 1.1.3 Auditing and Metering 1.1.4 V2G in Practice 1.2 V2G, Power Markets and Applications 1.2.1 Electricity Markets and V2G Suitability 1.2.2 Long-Term Storage, Renewable Energy, and Other Grid Applications 1.2.3 Beyond the Grid: Other Concepts Related to V2G 1.3 History and Development of EVs and V2G 1.4 Actors and Roles of V2G 1.4.1 Primary Actors: EV Owners, Aggregators, and the Electricity Grid 1.4.2 Secondary Actors: Government, the EV Industry, and Electricity Producers
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1.5 Conclusion References
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2 he Potential Beneits of V2G 2.1 Summarizing the Beneits of V2G 2.1.1 Technical Beneits: Storage Superiority and Grid Eiciency 2.1.2 Economic Beneits: EV Owners and Societal Savings 2.1.3 Environment and Health Beneits: Sustainability in Electricity and Transport 2.1.4 Other Beneits and Perceived Beneits 2.2 Beneits in Motion: From Fleets to Individuals and Beyond 2.3 V2G and the Grid 2.4 Conclusion References
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3 he Technical Challenges to V2G 3.1 Battery Degradation 3.2 Charger Eiciency 3.3 Aggregation and Communication 3.3.1 Aggregation and Scaling 3.3.2 Communication Standards 3.4 V2G in a Digital Society 3.5 Conclusion References
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4 he Economic and Business Challenges to V2G 4.1 Evaluating V2G Costs and Revenues 4.1.1 EV Costs and Beneits 4.1.2 Adding V2G Costs and Beneits 4.1.3 Additional V2G Costs 4.1.4 he Evolving Nature of V2G Costs and Beneits
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V2G Business Models 4.2.1 Pricing and Revenue Models 4.2.2 Ownership Structure: Aggregators and Other Actors 4.2.3 Deining the Evolving Market: Integration with Other Technologies 4.3 Conclusion References
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5 he Regulatory and Political Challenges to V2G 5.1 V2G and Regulatory Frameworks 5.1.1 Regulating V2G and Energy Storage 5.1.2 Ownership of V2G and Energy Storage 5.2 Market Design Challenges 5.2.1 Proper Valuation of Ancillary Services 5.2.2 Double Taxation, Curtailment and Capacity Markets 5.2.3 Clarifying Aggregator Roles and Responsibilities 5.3 Other V2G Regulatory and Legal Challenges 5.4 Political Challenges of V2G 5.4.1 Broader Policy Coordination and Political Will 5.4.2 Speciic V2G Policies 5.5 Conclusion References
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6 Consumers, Society and V2G 6.1 Consumer Perspectives of V2G 6.1.1 Ambivalence and Low Consumer Awareness 6.1.2 Intermediaries and V2G Difusion 6.2 Conceptualizing the Consumer in a V2G System 6.2.1 Difusion of Innovation 6.2.2 Social Construction of Technology 6.2.3 he Multi-level Perspective User-Typology 6.3 Increasing Consumer Knowledge and Acceptance 6.3.1 User Innovation and Tinkering
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6.3.2 Accruing User Experience and Involvement 6.3.3 Targeted Information Campaigns 6.3.4 Involving Users in Pilot Projects 6.3.5 Promoting V2G as a Conspicuous Good 6.4 Conclusion References
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7 V2G Deployment Pathways and Policy Recommendations 7.1 Synthesizing Barriers Across Actors 7.2 Toward a Stylized V2G Policy Mix 7.3 Five Global Development Pathways and V2G Futures 7.3.1 Conservative Backlash 7.3.2 V2G Remains a Niche 7.3.3 High V2G, Dirty Grid 7.3.4 High V2G, Renewables in a Traditional but Decarbonized Grid 7.3.5 he Super-Smart Grid 7.4 Conclusion References
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8 Realizing and Problematizing a V2G Future 8.1 Key hemes and Current Expert Perspectives: Beneits, Barriers, and Policies 8.1.1 Compelling Potential Beneits 8.1.2 Sobering Barriers and Challenges 8.1.3 Calibrating Policy Mixes 8.2 Problematizing V2G in the Context of Energy Transitions 8.2.1 Elitism and Inequitable Access 8.2.2 Loss of Privacy and Cybersecurity 8.2.3 Airming Conventional Automobility 8.2.4 Vulnerable Groups and Pollution 8.2.5 Toward a Just and Sustainable V2G Policy
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hematic Social Research Gaps 8.3.1 Carbon and Health Impacts of V2G 8.3.2 User Behavior 8.3.3 Visions and Narratives 8.3.4 Social Justice 8.3.5 Gender Norms 8.3.6 Urban Resilience, Disasters, and Emergency Capacity 8.4 Methodological Research Gaps 8.4.1 Broadening the Set of V2G “Cases” 8.4.2 Overcoming Transformative Failures 8.4.3 Toward Interdisciplinary, Multi-method Approaches 8.5 Conclusion References
Index
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212 212 214 216 220 221 222 223 223 224 225 228 230 235
About the Authors
Dr. Lance Noel is a Postdoctoral Researcher at Aarhus University, where he is a lead researcher on a $1.6-million grant on the sociotechnical beneits and barriers of electric vehicles and vehicle-to-grid in the Nordic region (NV2G). his research includes ive methods across the ive Nordic countries, including expert interviews, surveys, focus groups, and choice experiments. He received his Ph.D. at University of Delaware where his dissertation focused on the economic, political, and legal implications of large-scale renewable energy implementation and vehicle-to-grid technology. Additionally, he participated in the original vehicle-to-grid pilot project at University of Delaware and has published 17 journal articles that focus primarily on vehicle-to-grid and renewable energy integration. Gerardo Zarazua de Rubens is a Doctoral Fellow at Aarhus University working on the same NV2G grant that explores the social, technical, and economic barriers for electric vehicle and vehicle-to-grid implementation in the Nordic region. His research is focused on energy and climate policy, sustainable development, and economic and managerial science, and also has experience in undertaking a variety of research xv
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methods, from expert interviews, to focus groups and surveys. He has previously worked as a consultant on international electricity markets, and non-traditional business models of energy supply, as well as logistics and operations management. Gerardo received his M.Sc. in sustainable development from the University of St Andrews, Scotland, in 2014. He is currently leading and co-authoring 10 journal articles focused on electric mobility, power systems, and energy justice. Dr. Johannes Kester is a Postdoctoral Researcher at the University of Aarhus working on the NV2G grant. His primary interests lie in the governance of sociotechnical energy systems, drawing on social theory. Recent publications include “Torn Between War and Peace” (2017) in Energy Policy and “Energy Security and Human Security in a Dutch Gasquake Context” (2017) in Energy Research and Social Science. He defended his Ph.D. “Securing Abundance: he Politics of Energy Security” (2016) at the University of Groningen in the Netherlands. Dr. Benjamin K. Sovacool is the Principle Investigator of the NV2G project. He is Professor of Energy Policy at the Science Policy Research Unit (SPRU) at the School of Business, Management, and Economics, part of the University of Sussex in the UK. He is also Professor of Business & Social Sciences and Director of the Center for Energy Technologies at Aarhus University in Denmark, as well as Visiting Professor at the Institute of Energy Policy and Research (IEPRe), Universiti Tenaga Nasional, Malaysia. Professor Sovacool works as a researcher and consultant on issues pertaining to energy policy, energy security, climate change mitigation, and climate change adaptation. Professor Sovacool is the author of more than 400 refereed articles, book chapters, and reports, including solely authored pieces in Nature and Science. He is the author, coauthor, editor, or co-editor of 20 books, including Climate Change and Global Energy Security (MIT Press), Energy Poverty (Oxford University Press), Global Energy Justice (Cambridge University Press), he Political Economy of Climate Change Adaptation (Nature Publishing Group/Palgrave), Fact and Fiction in Global Energy Policy (Johns Hopkins University Press), and Enabling the Great Energy Transition (Columbia University Press). US President
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Bill Clinton, the Prime Minister of Norway Gro Harlem Brundtland, and the late Nobel Laureate Elinor Ostrom have endorsed his books. Additionally, Prof. Sovacool is the founding Editor-in-Chief for the international peer-reviewed journal Energy Research & Social Science, published by Elsevier, and he sits on the Editorial Advisory Panel of Nature Energy.
List of Figures
Fig. 1.1
Fig. 1.2 Fig. 1.3
Fig. 1.4 Fig. 1.5
Common schematic of a V2G System. Note ISO stands for Independent System Operator. he igure shows two potential means of dispatching V2G requests: from the ISO directly to a vehicle (shown in the upper right-hand corner), or from the ISO to a third-party aggregator of a leet (shown in bottom right-hand corner) Example communication diagram of a V2G System. he black line represents communication lows, whereas the red line represents bidirectional power lows Example of example metered data providing reliability of grid services over ive minutes. he blue line (Request) is the amount of energy requested from the electricity grid operator, while the red line (Response) is the energy provided by the EV. Average time delay is between 1 and 3 seconds Example electricity markets and their suitability for V2G Diagram of actors in a hypothetical V2G system. Note that some of the communication and power lows may difer depending on V2G service provided
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Fig. 2.1
Fig. 2.2 Fig. 2.3 Fig. 2.4 Fig. 2.5 Fig. 2.6 Fig. 3.1
Fig. 3.2 Fig. 3.3
Fig. 4.1 Fig. 5.1
Fig. 6.1 Fig. 6.2
List of Figures
Revenues over a 16-year period providing frequency regulation in US electricity grid regions. ISO-NE ISONew England, NYISO New York ISO, ERCOT Electricity Reliability Council of Texas, CAISO California ISO Estimated annual CO2 emissions avoided by V2G per electricity region, assuming 1% of EVs are V2G-capable hree scenarios of storage with large-scale renewable energy in the PJM interconnection. Left column: hydrogen storage, center: centralized batteries, right: V2G Renewable energy curtailed, based on percent penetration and level of grid lexibility Research focus (a) and Expert opinion (b) of Beneits of V2G systems Supergrid with high levels of renewable energy and a HVDC network Estimated battery capacity loss over time for EVs (no V2G included). Note that the diference between diferent levels of charging, as shown in the legend in the upper left corner, makes no discernable diference on the diference on capacity loss Battery degradation per cycle (N) as a function of temperature and depth of discharge (DOD) Average battery capacity losses over 10 years with V2G services, providing three diferent services (peak shaving, frequency regulation, net load shaping) in two usage scenarios (everyday for 10 years and 20 times per year) Potential V2G revenue, pricing, and power low models Inluence of fees and taxation on V2G operation. Note Graph represents Nuvve’s June 2017 settlement bills from NEAS Energy (their BPR), indicating how much of the bought electricity is used for driving and how much for grid operations as well as the distribution of taxes, tarifs, and fees Classic U-shaped difusion of innovations curve he MLP with description of user typologies
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List of Figures
Fig. 8.1 Fig. 8.2
Fig. 8.3
he diverse array of 25 V2G beneits identiied by expert interviews Dendrogram of top 9 most common barriers to V2G. Note Organized by Jaccard’s coeicient of similarity, colors denote cluster groupings (Italics represent Percent of Respondents Discussing Barrier ) Recent publishing trends in V2G research, January 2015–April 2017. Note n = 197 peer-reviewed articles
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List of Tables
Table 1.1 Table 2.1 Table 3.1 Table 3.2 Table 3.3 Table 6.1 Table 7.1 Table 7.2 Table 7.3 Table 8.1 Table 8.2 Table 8.3 Table 8.4
Deining the diferent conceptualizations of use cases of a bidirectional vehicle Technical attributes of various storage technologies, using the USA as an example. Ranges indicate diference in cost depending on technology or system used Percentage energy loss per stage in the V2G system for charging and discharging at two diferent current levels Diferences between the three V2G standards Potential security risks in a smart grid/V2G system Summary of various theories on the implications of users in a V2G system Impacts and roles of actors in across sociotechnical barriers Policy solutions aligned to address sociotechnical barriers Five imagined V2G futures and their characteristics Summary of V2G policy suggestions and our relection he interactive and potential positive and negative impacts of a V2G transition Policy mechanisms to minimize problematic V2G pathways Functional-symbolic and private-societal dimension of driver behavior
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Table 8.5 Table 8.6
List of Tables
Summary of visions, promises, and ideographs of EVs and V2G in the Nordics Illustrative summary and comparison of V2G model qualities
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Introduction: Vehicle-to-Grid and the Future of Electric Mobility
Vehicle-to-grid, often shortened to V2G, was irst introduced as a concept near the turn of the twenty-irst century to capitalize on the assumption that electric vehicles (EVs) would widely difuse in society, and thus, there would be a large amount of electric power capacity that could provide valuable storage services to electricity grids [1]. Since its introduction, many have elaborated on the potential beneits of V2G, detailing the large amounts of power capacity, various electricity grid services, and economic revenues potentially available to EV owners [2, 3]. Given the disappointingly slow difusion of EVs, V2G may prove useful to accelerate the adoption of EVs [4, 5]. While providing ancillary services for the grid, namely frequency regulation, and EV owner economic beneits are the most immediate beneits of V2G, the future beneits of V2G such as integrating renewable energy are also tantalizing. Indeed, a variety of papers have found that V2G can provide lowcost storage to integrate large-scale renewable electricity [6–8]), helping tackle the looming challenge of climate change as well as public health emissions from electricity and transportation sources. Consequently, there has been increasing interest in the concept among industry and scholars, which has resulted in a variety of novel xxv
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potential solutions within electricity grids and transportation. In a recent literature review [9], the authors found around 200 articles published on V2G, covering a wide variety of concepts, including, but not limited to renewable energy integration, ancillary services, local grid solutions, microgrids, and buildings (see more about these research gaps in Chapter 8, the Conclusion). While the academic focus on V2G has continued to accelerate, the difusion of the actual use of V2G has been more staggered historically, with current projects limited to only a few pilot projects within leets around the world [9]. Nonetheless, these pilot projects are entering commercial operations, and there has been recent activity in project development, for example, with the UK government investing £30 million in projects focused on V2G in 2018 [10]. Even the Pope has supported and adopted EVs, which also included a project involving V2G [11]. Indeed, the future of V2G looks bright, with some scholars predicting that V2G will be an essential form of storage for the electricity grid of the future. For example, it has been predicted that there will be massive increases in V2G capacity in the coming decades, as shown in Fig. 1 [12], where it becomes a dominant technology in the power system. For this reason, and with the potential to decarbonize the electricity and transport
Fig. 1 Installed capacity (left) and utilization per hour (right) during operation of a European grid optimized for different energy storage technologies, 2000– 2100. CAES compressed air energy storage (Reprinted from [12])
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sectors and drive EV adoption, the future of V2G is enticing to many actors. Speciically, experts envision V2G as a means to reach a future where there is a synergy between electricity and EVs, thereby feeding into imaginaries of synergy and seamless interconnectivity, as well of autonomy and self-determination [13]. While V2G exists today mostly in leet pilot projects, its potential future is far-reaching and substantial, particularly when tapping into personal vehicles, public transportation, and perhaps more. hus, it is conceivable that in the future, V2G capability will become the norm (or at least in some markets and regions) and will be available in a variety of vehicles, becoming a part of everyday life in society. Despite the possible pervasiveness and beneits of V2G, outside of academia (and even within it), current knowledge and understanding of V2G are relatively low. In a recent survey conducted by the authors in the Nordic region, fewer than 10% of the respondents had ever heard of V2G before taking the survey [14, 15]. At the same time, academic knowledge of V2G is highly specialized, with most of the research efort taking place in highly technical ields within science and engineering [9], such as control charging optimization algorithms, renewable energy integration, and battery degradation. Specialized knowledge alone, however, does not lead to broad difusion of a new technology. It is well established in the innovation and transition literatures that for a technology to difuse, knowledge about its beneits, use, and potential must be dispersed across a wider variety of actors than is currently the case for V2G [16]. Looking beyond academics and consumers, there will be an increasing number of other actors who will play an essential role in the difusion of V2G, such as local and national policymakers, marketers, energy sector practitioners, leet operators, or parking organizations, among various others. herefore, for these actors, a basic understanding of V2G is essential. For these reasons, we set out to write this extensive, comprehensive, and easily accessible reference on V2G. he book is aimed toward a wide audience including academics at the periphery of V2G, consumers interested in the technology that comes in their EV, policymakers who want to understand the technology to implement policies, and industry practitioners to understand the technology that may have
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been recently implemented in their local grid. As the only other broad introduction to V2G is almost 10 years old [17], this book ofers an up-to-date and more extensive introduction to a fast-moving technology that has changed substantially over the last 10 years. Moreover, to underscore the role played by the numerous sectors and actors in the complex sociotechnical system that V2G is interacting, we believe it is of the utmost importance to give a more comprehensive perspective of V2G. Consequently, as you make your way through the book, we will aim to provide the history and context of V2G, its potential future in better detail, and the challenges it may face from the variety of relevant perspectives. As the irst chapters will extensively discuss the conceptualization and background of V2G, this introduction will introduce our approach to V2G, ofer a brief introduction to the chapters, and describe the data, method, and theories that are used.
Approach: V2G as a “Niche” in a “Sociotechnical System” To help understand the promise and challenges of V2G, the book largely views the related transport and electricity infrastructure connected to V2G as a “sociotechnical system”—looking at more than just the technical aspects of V2G to how it is part of and inluences society. he term sociotechnical system inds its origin rooted in multiple disciplines and approaches. One of the best known is homas Hughes’s work on the history of the electric utility system, wherein he argues that the generation, transmission, and distribution of electricity occurs within a technological system that extends beyond the engineering realm [18]. Such a system is understood to include a “seamless web” of considerations that can be categorized as technical, economic or inancial, political, environmental, and social, making it “sociotechnical.” Large modern systems integrate these elements into one piece, with system builders striving to “construct or … force unity from diversity, centralization in the face of pluralism, and coherence from chaos” [19]. If the managers succeed, the system expands and thrives while,
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Fig. 2 A sociotechnical system for personal automobile transportation (Reprinted from [20])
simultaneously, closing itself (both its meaning and set of relationships) for disruption, resistance, and change. In other words, the inluence of the outside environment on a sociotechnical system may gradually recede as the system expands its reach to encompass factors that might otherwise alter it. In other words, the concept of a sociotechnical system helps reveal that technologies, such as electricity grids and V2G, must be understood in their societal context and that the diferent values expressed by inventors, producers, managers, regulators, and consumers shape technological change all in their own way. System builders, it follows, must overcome a complex milieu of sociotechnical obstacles to reap beneits. A salient insight from the sociotechnical approach is its focuses on the interrelationship of linkages between elements and co-evolutionary processes, e.g., that a system never stands on its own but is nested in other equally complex sociotechnical systems. Figure 2 ofers an illustration of the sociotechnical system that surrounds modern, conventional, carbased land transport [20]. he book takes a sociotechnical approach, as such an analytical framework encourages scholars to look beyond single dimensions without
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Table 1 Overview of sociotechnical dimensions of a V2G transition Dimension
Inclusive of
Example(s)
Technical
Technology, infrastructure, and hardware
Financial
Price signals, economics, regulatory tariffs
Socioenvironmental
Broad social costs and beneits
Behavioral
Consumer and user perceptions, attitudes, and behavior
Vehicle performance, grid interconnection, communication, battery degradation Capital cost of V2G charging stations, hardware, batteries and interconnectors, revenues, cost savings, business models Mitigated greenhouse gas emissions, air pollution, integration with renewable sources of energy, externalities Consumer perceptions of all of the above, including beneits, inconvenience, distrust, confusion, range anxiety
losing the complexity of the system and doing injustice to the many interactions and relationships that shape it. Speciically, we investigate V2G across the various sociotechnical categories summarized in Table 1. hese include, irst, the technical or technological elements such as batteries and charging infrastructure, tires on vehicles, and interconnections to the electricity grid. Next are the inancial or economic elements that encompass the cost of the technology as well as the availability of fuel and any ailiated cost savings and revenues that can be generated. A third category is socioenvironmental, and how the technology relates to the overall beneits (or costs) to society. A inal category focuses on the individual behavior of consumers and users, namely the owners and operators of EVs that might take part in V2G programs. We see each of these dimensions at play in diferent parts of our chapters. In laying out the following chapters below, it is not our intent to suppose that demarcations between “technical,” “inancial,” “socioenvironmental,” and “behavioral” dimensions really exist in distinct, separate classes. he entire point of the sociotechnical systems approach is that
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such impediments are seamlessly interconnected; dividing the “social” from the “technical,” or even the “economic” from the “environmental” is counterproductive and dangerous, since it misses the point that such factors exist in an interstitial and interdependent network. In other words, it is a heterogeneous combination of sociotechnical factors that determine whether V2G technologies will achieve widespread acceptance or face consumer rejection. hus, while reading each chapter, the readers are heavily encouraged to consider the seamless connections to other chapters of the book. Within well-established ield of sustainability transitions studies, one particularly strong framework often utilized is that of the multi-level perspective, or MLP [21]. Borrowing from a mix of disciplines, including history, evolutionary economics, institutional theory, and science and technology studies (STS), the approach suggests that difusion or transitions occur through interactions among three levels: the niche, the regime, and the landscape. he niche refers to a radical innovation that is emerging to gain difusion or adoption, to move from invention and innovation to viable market introduction [22]. he regime level refers to the incumbent sociotechnical system that the niche is potentially afecting or replacing; such regimes contain cognitive, regulative, and normative institutions [23]. he “landscape” refers to exogenous developments or shocks (e.g., economic crises, demographic changes, wars, ideological change, major environmental disruption like climate change) that create pressures on the regime, which in turn create windows of opportunity for the difusion of niche-innovations. Figure 3 illustrates how the three scales interact. A key term of art within the MLP framework is that of a “transition pathway.” Analytically, the claim is that diferent kinds of interactions among niche, regime, and landscape result in diferent kinds of alignments. Geels and Schot [24] construct a typology based on combinations between two dimensions: the timing and nature of multi-level interactions. his leads them to distinguish four transition pathways: (1) technological substitution, based on disruptive niche-innovations that are suiciently developed when landscape pressure occurs, (2) transformation, in which landscape pressures stimulate incumbent actors to gradually adjust the regime, when niche-innovations are not suiciently developed, (3) reconiguration, based on symbiotic niche-innovations
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Fig. 3 Niches, regimes, and landscapes in sociotechnical transitions (Reprinted from [24])
that are incorporated into the regime and trigger further (architectural) adjustments under landscape pressure, (4) de-alignment and re-alignment, in which major landscape pressures destabilize the regime when niche-innovations are insuiciently developed; the prolonged co-existence of niche-innovations is followed by re-creation of a new regime around one of them. he core lesson from these four pathways is that transitions can be conlictual—many niches fail—and that existing energy systems and infrastructure can dominate and suppress threatening innovations. As we will see throughout the book, V2G clearly falls within the “niche” or even “pre-niche” category, meaning it must compete with
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these other sources of mobility and electricity grid actors. While these are not the only theories that we will utilize, we urge the readers to consider this framework as we move through the individual sociotechnical barriers, and how these may inluence the transition of V2G from a niche to a regime, and perhaps even to the landscape level.
Chapters to Come he book has eight remaining chapters, each focusing on a diferent facet of V2G, and thus analyzing diferent subcomponents of the sociotechnical system. While acknowledging the interconnected nature of the topics discussed in each individual chapter, we endeavor to atomize V2G as a technology into its most basic portions. First, in Chapter 1, we focus on the history of V2G, to provide context for the remainder of the book. Additionally, given the lack of knowledge and confusion over exactly what V2G is, we will carefully deine V2G, what is included in its conceptualization, and what is not V2G, but related to it, deining other concepts, such as vehicle-to-home (V2H), vehicle-to-building (V2B). As V2G takes place in a complex sociotechnical system, this chapter next looks beyond the speciics of the technology and deines the potential actors and their roles in the various V2G set-ups. Finally, we will summarize the current status of V2G around the globe and ofer an overview of some of the pilot projects and plans in place. Next, in Chapter 2, we focus on the beneits and potential of V2G. We start with an exploration and summary of all the potential beneits of V2G, from economic revenues, to grid eiciency, to renewable energy integration, and everything in between. We then place these beneits in the larger transportation and electricity systems, irst focusing on how V2G’s current status in leets can transfer to personal consumers and others. From the other side, we also will detail the interactions of V2G with a quickly changing grid, particularly with the potential advent of smart grids and super grids. Finally, we end the chapter with the conceptualization of the future of V2G.
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Moving beyond the status and beneits of V2G, the next several chapters detail the challenges that V2G faces, from a plethora of perspectives. First, in Chapter 3, we begin with a narrow perspective and focus on the challenges of the technology itself. hat is, we focus on the technical challenges, including battery degradation, charger eiciency, and communication. Beyond the snapshot, we will also take a prospective approach and discuss the potential challenges that V2G may face as it difuses across society, such as scaling, privacy, digitalization, and transparency of data. In Chapter 4, we then turn to the economic and business challenges of V2G. First, we will review that main costs of V2G, such as bidirectional chargers and increasing the vehicle’s communication capacity, and its revenue potential, from the various electricity markets in which it can participate. Additionally, we will also review other economic barriers stemming from the electricity market, such as double taxation and its impact on V2G revenue streams. On the other hand, we will also discuss how these costs and revenues translate into the potential business models of V2G, a topic that is currently very understudied [9], and may be essential to the smooth difusion of V2G as the technology itself. Within this discussion, we will explore the pricing and revenue models of V2G, how ownership could work within aggregation, as well as deining the market as it evolves. We next examine the regulatory and political challenges in Chapter 5. First, focusing on regulations, we will discuss how relevant decisionmakers and actors interact, before moving onto market regulations, such as the development and deinition of the storage market, net metering, and taxation regulations. he second half of the chapter will focus on the relevant policies to V2G, and how policymakers can incentivize and encourage the development of V2G. Of course, a policy discussion of V2G would not be complete without a discussion of the interconnectedness of policies between V2G and EVs. More speciic to V2G, we also discuss the development of V2G niches in pilot projects, as well as the galvanization of grid operator projects, and how policy can help deine the storage market.
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he inal set of challenges we discuss is from the perspective of the consumer and social barriers in Chapter 6. First and foremost, consumers are expected to be a major barrier to the difusion of V2G, as many experts believe that consumers will resist or at least express reluctance to the technology. To understand this resistance, we discuss consumer perspectives on battery degradation, reliability, as well as the general lack of consumer knowledge and awareness of V2G (and its beneits) that may assuage this resistance. We then propose certain strategies to increase consumer knowledge and acceptance of V2G, including education, experience, as well as more novel approaches, such as tinkering. In order to understand the consumer as an actor in the difusion of V2G, we then conceptualize the consumer in a variety of theories, drawing on difusion studies, sociotechnical transitions, and science and technology studies. he chapter concludes by commenting on current research gaps within the social aspects of V2G, including user behavior, externalities of V2G, visions and expectations, social justice, gender, and urban resilience and disaster capacity. After reviewing the challenges of V2G, in Chapter 7 we then resynthesize the knowledge gained in the previous four chapters, recognizing the seamless interconnectedness of these attributes in a sociotechnical system. With this knowledge, we then propose the pathways for V2G to develop, and detail recommendations for how each of the actors discussed in Chapter 1 can take actions to help progress V2G in the sociotechnical system. From a policy perspective, we then provide roadmaps for a generalized country to transition toward a V2G system. he chapter also relects on the global difusion of V2G and the role that internationalization plays in the development of V2G. Finally, we summarize the book in Chapter 8 by iterating the key themes of V2G, and relecting upon the lessons learned in regards to the technology. In addition, we comment on the potential futures of V2G, particularly within the context of energy transitions and decarbonization. We conclude the book by setting future research objectives and goals for V2G.
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Data, Method, and Other Theories As shown by the chapters we set out above, our goal of this book is to provide a complete perspective of V2G as a technology in society, funded by a fairly large three-year grant looking at electric mobility and V2G in the Nordic region, but also in connection with global market trends and technical contexts, to ensure generalizability. In order to do so, we will principally rely on the most relevant literature that has been published. However, in addition to this, and given our expertise as researchers on V2G and our wealth of empirical data collected, we also use a dataset of four original empirical methods based on recent work in the Nordics. hese empirical methods include expert interviews, consumer focus groups, an online survey, and simulated “mystery shopping” experiences at automobile dealerships. We will provide some information on these methods now and refer to them occasionally throughout the rest of the book. First, we conducted 227 semi-structured expert interviews with 257 participants across the ive Nordic countries. A brief summary is presented in Table 2. Data collection lasted from September 2016 until May 2017 and centered on the sociotechnical beneits and barriers of both EVs and V2G, though we will focus primarily on their discussion of V2G in the remainder of the book. Upon completion of the interviews, each was fully transcribed and then coded in NVIVO with grounded theory in mind (meaning there were no pre-determined themes). Later these arguments were bundled in larger themes and topics, like costs or taxation. hroughout the book, reference is made to these coded themes, such as an expert’s views on V2G beneit and barriers, as well as cite individual quotes from the experts (anonymized using respondent number, e.g., R54). Second, to complement the expert perspective with a consumer perspective, we also conducted consumer focus groups across the ive Nordic countries concomitantly. In total, eight focus groups were conducted, with a total of 61 participants across six Nordic cities, summarized in Table 3. Additionally, two of the eight focus groups were exclusively a single gender (one all-female, the other all-male) and were asked additional questions about perceived impact of gender on EVs
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Table 2 Overview of expert interviews Classiications
Interviews (n = 227)
Respondents (n = 257)
% of respondents
Country Iceland (September–October 2016) Sweden (November–December 2016) Denmark (January–March 2017) Finland (Machr 2017) Norway (April–May 2017) Gender
14.0
29
36
42
44
17.1
45
53
20.6
50 61
57 67
22.2 26.1
160 40 27
207 50
80.5 19.5
Transport or logistics Energy or electricity system Funding or investment Environment or climate change Fuel consumption and technology Other EVs and charging technology Sector
73 63 10 12 22
81 75 12 16 23
31.5 29.2 4.7 6.2 8.9
13 34
14 36
5.4 14.0
Commercial Public Semi-public Research Non-proit and media Lobby Consultancy
68 37 40 37 12 23 10
70 46 51 39 13 25 10
27.2 17.9 19.8 15.2 5.1 9.7 3.9
Male Female Group Focus
Source Authors. Focus represents the primary focus area of the organization or person in question, sector represents the sector the company was working in (semi-public referring to commercial companies owned by public authorities, like DSOs)
and V2G. Each of the focus groups was asked similar questions that were asked to the experts, namely about the main transport and energy challenges, the perceived beneits and barriers of EVs and V2G, and what should change to speed up the acceptance and adoption of these respective technologies. Each focus group was fully transcribed and
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Table 3 Overview of focus groups Classiications
Participants (n = 61) % of participants
F1: Iceland (October 2016) F2: Sweden (November 2016) F3: Denmark [mixed gender] (February 2017) F4: Finland 1 (March 2017) F5: Finland 2 (March 2017) F6: Denmark [male] (June 2017) F7: Denmark [female] (June 2017) F8: Norway (September 2017) Male Female Have driver’s license Currently own a car Experienced an EV Own an EV
5 6 10 9 7 7 8 9 29 32 50 29 8 0
8 10 16 15 12 12 13 15 48 52 82 48 13 0
Source Authors
coded in NVIVO as well, again with grounded theory in mind. In the remainder of the book, we will primarily utilize quotes from individual participants in focus groups, only referring to the focus group in which they participated in (e.g., “one participant from F5 suggested…”). hird, to complement these two in-depth qualitative methods, we also conducted an online survey with a focus to collect quantitative data. Responses were collected via both a random sample (distributed by Qualtrics) and a non-random convenience sample to target speciic populations such as Icelanders or current EV owners. A total of 5894 responses were collected, however, after iltering incomplete surveys, the inal responses totaled to 5067, nearly evenly distributed across the ive Nordic countries. he survey consisted of 44 questions total questions and split into 4 sections, including (i) vehicle history and background, (ii) vehicle preferences, (iii) an electric vehicle choice experiment, and (iv) demographics. As with the other two methods, our focus will be mostly on the V2G aspects of the survey, though we will use other statistics to provide context. Finally, to assess in particular potential business dimensions to V2G as perceived by commercial entities such as automotive dealerships and car salespersons, we visited 126 car dealerships between October 2016
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and June 2017 across 15 cities in the countries of Denmark, Finland, Iceland, Sweden, and Norway. he visits where conducted typically in the capital, the second most populous city and the largest rural town of each country: Aalborg (Denmark), Aarhus (Denmark), Akureyri (Iceland), Copenhagen (Denmark), Gothenburg (Sweden), Helsinki (Finland), Malmo and Lund (Sweden), Oslo (Norway), Oulu (Finland), Reykjavik (Iceland), Stockholm (Sweden), Tampere (Finland), Tromsø (Norway), and Trondheim (Norway). After the visit, the mystery shoppers recorded three sets of data in an audio ile including (1) characteristics of the salesperson based on a ive-point Likert scale (2) characteristics of the dealership visited (such as location, brands available, or type of dealership), and (3) their shopping experiences; noting individual thoughts and relevant quotes said by the salesperson. Other data collected were promotional material provided by dealers (lealets and price lists), dealer’s business card, and in some cases photographs of advertisement, charging infrastructure, and location of dealership. Looking beyond the data and methods employed in the book, we will also take a variety of other theoretical perspectives in the coming chapters to ofer context, explain, and relect on the multitude of subject areas covered in them. Some chapters, particularly the irst chapter about the history and potential of V2G, are light on theoretical frames, while subsequent chapters use simple economic and policy analyses. hroughout the book, but especially in the later chapters, we begin to place more emphasis on V2G in the context of sociotechnical studies, and additional theories are used such as difusion of innovation [16], the aforementioned MLP [25], the social construction of technology [26]. We use these theories with the understanding that V2G is in the process of difusing across society and to provide more than just a snapshot of V2G—instead to show, understand, relect, and guide the potential development of V2G during a societal transition. Ultimately, we aim to show both the promise V2G has to ofer, but to temper that promise with likely problems that need to be addressed. We test and validate numerous ideas, concepts, and even conceptual frameworks about mobility, automobility, electric mobility, and prosuming as we do so, given that V2G must compete and co-evolve with conventional
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and emerging mobility services and technologies. What results (we hope) is a rich, multidimensional, multi-conceptual, multi-method, and grounded approach that sparkles the pages to come with unique insights not yet introduced by any other research project. We won’t profess that our book alone will determine the future of V2G. But we certainly hope to inform, debate, deliberate, and critically relect on it.
References 1. Kempton W, Letendre SE. Electric vehicles as a new power source for electric utilities. Transp Res Part Transp Environ. 1997;2(3):157–75. 2. Kempton W, Tomić J. Vehicle-to-grid power fundamentals: calculating capacity and net revenue. J Power Sources. 2005;144(1):268–79. 3. Kempton W, Tomić J. Vehicle-to-grid power implementation: from stabilizing the grid to supporting large-scale renewable energy. J Power Sources. 2005;144(1):280–94. 4. Zarazua de Rubens G. Who will buy EVs after early adopters? Using machine learning to identify EV mainstream buyers and their characteristics. Rev Energy. 2018. 5. Sovacool BK, Hirsh RF. Beyond batteries: an examination of the beneits and barriers to plug-in hybrid electric vehicles (PHEVs) and a vehicle-togrid (V2G) transition. Energy Policy. 2009;37(3):1095–103. 6. Noel L, Brodie JF, Kempton W, Archer CL, Budischak C. Cost minimization of generation, storage, and new loads, comparing costs with and without externalities. Appl Energy. 2017;189:110–21. 7. Budischak C, Sewell D, homson H, Mach L, Veron DE, Kempton W. Cost-minimized combinations of wind power, solar power and electrochemical storage, powering the grid up to 99.9% of the time. J Power Sources. 2013;225:60–74. 8. Lund H. he implementation of renewable energy systems: lessons learned from the Danish case. Energy. 2010;35(10):4003–9. 9. Sovacool BK, Noel L, Axsen J, Kempton W. he neglected social dimensions to a vehicle-to-grid (V2G) transition: a critical and systematic review. Environ Res Lett. 2018;13(1):013001. 10. GOV.UK. £30 million investment in revolutionary V2G technologies [Internet]. 2018 [cited 2018 Jun 25]. Available from: https://www.gov.uk/government/news/30-million-investment-inrevolutionary-v2g-technologies.
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11. May L. Pope Francis drives an electric car—Vatican to become the 1st zero-emission state [Internet]. he Mobility House. 2017 [cited 2018 Jun 28]. Available from: http://www.mobilityhouse.com/en/ pope-francis-drives-electric-car-vatican-become-1st-zero-emission-state/. 12. Després J, Mima S, Kitous A, Criqui P, Hadjsaid N, Noirot I. Storage as a lexibility option in power systems with high shares of variable renewable energy sources: a POLES-based analysis. Energy Econ. 2017;64:638–50. 13. Wentland A. Imagining and enacting the future of the German energy transition: electric vehicles as grid infrastructure. Innov Eur J Soc Sci Res. 2016;29(3):285–302. 14. Sovacool BK, Kester J, Noel L, de Rubens GZ. he demographics of decarbonizing transport: the inluence of gender, education, occupation, age, and household size on electric mobility preferences in the Nordic region. Glob Environ Change. 2018;52:86–100. 15. Noel L, Carrone AP, Jensen AF, Zarazua de Rubens G, Kester J, Sovacool BK. Willingness to pay for electric vehicles and vehicle-to-grid applications: a Nordic choice experiment. Rev Energy Econ. 2018. 16. Rogers EM. Difusion of innovations. 5th ed. New York: Free Press; 2003. 551 p. 17. Beck LJ. V2G-101: a text about vehicle-to-grid, the technology which enables a future of clean and eicient electric-powered transportation. Newark, DE: Leonard Beck; 2009. 332 p. 18. Hughes TP. Networks of power: electriication in Western society, 1880–1930. In: Softshell Books, editor. Baltimore, MD: Johns Hopkins University Press; 1993. 474 p. (Softshell Books history of technology). 19. Hughes TP. he evolution of large technological systems. In: Bijker WE, Pinch TJ, editors. he social construction of technological systems: new directions in the sociology and history of technology. Cambridge, MA: MIT Press; 1987. p. 52. 20. Geels FW. he dynamics of transitions in socio-technical systems: a multi-level analysis of the transition pathway from horse-drawn carriages to automobiles (1860–1930). Technol Anal Strateg Manag. 2005;17(4):445–76. 21. Geels FW. A socio-technical analysis of low-carbon transitions: introducing the multi-level perspective into transport studies. J Transp Geogr. 2012;24:471–82. 22. Grin J, Rotmans J, Schot J, Geels FW, Loorbach D. Transitions to sustainable development: new directions in the study of long term transformative
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change. First issued in paperback. New York and London: Routledge; 2011. 397 p. (Routledge studies in sustainability transitions). Geels FW. From sectoral systems of innovation to socio-technical systems. Res Policy. 2004;33(6–7):897–920. Geels FW, Schot J. Typology of sociotechnical transition pathways. Res Policy. 2007;36(3):399–417. Geels FW. Technological transitions as evolutionary reconiguration processes: a multi-level perspective and a case-study. Res Policy. 2002;31(8–9):1257–74. Kline R, Pinch T. Users as agents of technological change: the social construction of the automobile in the rural United States. Technol Cult. 1996;37(4):763.
1 History, Deinition, and Status of V2G
In this chapter, we start with the basics; deining what V2G is, the technology behind it, and how it works, along with key terms such as “aggregation,” “auditing,” and “metering”. We then move onto the conceptualization of V2G and the other related, yet distinct, applications of this technology and describe why these distinctions matter. Next, we describe the history and current status of V2G implementation in academia and in practice. Finally, we conclude by placing V2G in the larger context, looking beyond the technology by deining the actors and their roles in a V2G system.
1.1
Deining V2G
he idea of V2G, irst formally introduced to our knowledge by Kempton and Letendre [1], is relatively simple sounding—it merely stipulates using the battery within an EV to provide storage for the electricity grid. EVs are by default already connected to the grid when they recharge their battery; however, without V2G, they cannot return power back to the grid. For this reason, several additions to the EV are needed, as well as development of a V2G system, to enable bidirectional communication and power © he Author(s) 2019 L. Noel et al., Vehicle-to-Grid, Energy, Climate and the Environment, https://doi.org/10.1007/978-3-030-04864-8_1
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low between the EV and the power grid. Using the framework deined by Kempton, among others, there are three key elements to a V2G system: (1) a power connection to the electricity grid, (2) communication that controls charging and discharging, such as an aggregator combining a leet of EVs, and (3) a means to audit the services rendered to the grid [2–4]. Such a V2G system is commonly displayed as Fig. 1.1, and each of these elements and the system will be explained below.
Fig. 1.1 Common schematic of a V2G system. Note ISO stands for Independent System Operator. The igure shows two potential means of dispatching V2G requests: from the ISO directly to a vehicle (shown in the upper right-hand corner), or from the ISO to a third-party aggregator of a leet (shown in bottom right-hand corner) (Reprinted from [5])
1.1.1 Incorporating V2G to the EV In order to build a V2G system, the EV thus requires three things: a specialized charger, power bidirectionality, and communication capacity. Of course, in order to have a connection to the grid, the EV needs to have a charger to which connect with. In this respect, there are several important attributes of a charger, including its power capacity, whether the charger is on-board the vehicle or of-board within the charging station, and its communication and bidirectional capacities
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[6]. hough V2G is possible with any power level, the power capacity of the charger is important to the economics and aggregation of EVs. Electric vehicle supply equipment (EVSE), which supply electricity to a charger on-board the EV, are commonly distinguished between three levels: Level 1, typically using the lowest available power outlets, resulting in low power capacities, e.g., ~1–2 kilowatts (kWs), Level 2, which uses higher power capacities ranging from 4 kW to around 20 kW, and Level 3, also known as fast or quick chargers, which, unlike the previous two levels, commonly uses direct current (DC) of-board chargers to provide substantially higher power capacities, such as 50 kW and above [6]. Since batteries require DC power in order to be charged, Level 1 and 2 chargers that use alternating current (AC) use an on-board power inverter to convert delivered AC power into DC power to the battery. While technically any of these charger levels would suit V2G, it is widely expected that most of the V2G projects will likely occur with Level 2 chargers, at least in the short term, given the balance between suicient power capacity and the more afordable cost of such chargers for an average consumer at home or work [7]. On the other hand, certain other V2G use cases, such as leets [8] may be more likely to use chargers closer to the Level 3 standard, especially as the cost of high capacity chargers (both AC and DC versions) decrease in price. Once the EV has established a power connection to the electricity grid via some type of EVSE, the next step is for the EV to provide bidirectional power and the capacity for communication. Neither of these provide overwhelming technical or economic challenges, however, it is important to note that, from the perspective of the EV, these are integral changes that need to be made at the design stage of the vehicle. Bidirectionality of power simply requires that an EV can provide power back through the EVSE onto the grid, which is essentially the same process as charging the EV’s battery to drive, but now discharged onto the grid. As an aside, unidirectional low—also called managed charging, V1G, or smart charging—requires only adding communication to the EVSE and only controls the charging level. But since this has less value as compared to V2G, we focus the rest of the book on bidirectional power lows and V2G (while recognizing that smart charging may be a “stepping stone” to V2G). Of course, the process of V2G requires that
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not only the EV but also the EVSE are bidirectionally enabled. More importantly, apart from the physical low of power, it also requires a communication pathway in order to direct the power lows. From a vehicle perspective, the communication ability is most commonly manifested as a simple addition of another communication chip on-board the vehicle. For example, some of the early projects use a communication software component called a vehicle smart link (VSL), irst developed by University of Delaware for projects that include a variety of diferent vehicle types such as converted Scion XB’s and Mini-E’s [9]. It is worth noting that communication technologies such as VSL are quite expensive to design and develop, but once developed, actual construction and inclusion of the chip is substantially cheaper, estimated to be only a few hundred dollars. Despite the development and commercial availability of VSL-type technologies, most EVs purchased today do not currently include such V2G capability, with a few notable exceptions such as Nissan [8]. Nonetheless, a VSL is essential to the V2G system by directing power lows in and out of the EV. Once this capacity to control bidirectional power is in place, the next step is a means to provide messages to the EV instructing it what power lows the grid currently requires. As such, there needs to be a communication channel between the EVSE (which is connected to the internet and receives the power low instructions from a third party such as an aggregator or utility) and the vehicle. Currently, there are a variety of ways to enable this communication ability though, with competing national and international standards of communication that vary slightly in their implementation. For example, previous projects have used control pilot line communication speciied in IEC 61851 Annex D, or power line communication through Open Charge Point Protocol (OCPP) and Smart Energy Proile 2.0 (SEP 2.0), while future standards are contested between ISO 15118, SAE J2847, among others [9–11]. Some of these systems of communications are potentially better suited for diferent types of V2G systems and services, and the adoption of these standards may be essential to the difusion of V2G services. However, for the time being, the important aspect is that there are some means of communicating through the charger. Furthermore, we will discuss the speciic technical aspects of the communication standards in greater detail in Chapter 3.
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1.1.2 Aggregation With a bidirectional power connection and a means to receive communication signals, the EV itself is ready to participate in a V2G system. his brings us to the next aspect of the V2G system, the aggregator, often taking the form of a CPU system. As shown in Fig. 1.1, strictly speaking, an aggregator is not essential to the technical functioning of a V2G system. Instead, an individual EV could theoretically receive communication signals directly from an electricity grid operator. In practice, and to-date, V2G projects overwhelmingly rely on aggregators to combine individual vehicles into a single resource to participate on an electricity grid operator’s markets [8, 9]. he aggregator receives a main signal from the electricity grid operator, and the aggregator subsequently disseminates this signal to each individual vehicle within its aggregated pool. Considering that EVs are not physically connected to the grid (through the charging cable) at all times, the aggregator must coordinate and estimate the number of EVs that are connected as well as the available power that can be used for grid services required at particular times. here are several reasons for why an aggregator is preferred instead of a direct communication from the electricity grid operator to an individual EV. First and foremost, many of the markets that V2G can make the most economic value participating in (such as frequency regulation), requires a minimum power capacity in order to participate. In many cases, in order to bid on an ancillary services market, the minimum bid is 100 kW, or worse yet, 1 megawatt (MW). As shown in our discussion of chargers above, if an individual V2G-capable EV is using a Level 2 charger, a V2G system would require approximately 6–9 EVs together to reach 100 kW, depending on actual power capacity of the charger. On the other hand, a Level 3 charger would only require 1–2 V2G-capable EVs, though this would be a substantially more expensive system (and still insuicient for markets with a minimum capacity of 1 MW). hus, an aggregator can ofer a more economically eicient means for a V2G system to participate on electricity grid markets by creating a pool of V2G-capable EVs.
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Beyond the technical and market required grouping capacity of an aggregator, an aggregator with a leet of V2G-capable EVs can also ofer stability and lexibility as a market participant through the implementation of predictive and/or control algorithms. First and foremost, an aggregator can optimize its aggregated capacity and develop a control strategy that balances energy lows between diferent vehicles and their driver’s needs and maximize revenues by choosing to participate among the various electricity grid services, such as frequency regulation [12]. Likewise, since EVs are also used for driving and charging, aggregator algorithms can use statistical predictions in order to account for EV behavior patterns [13], thus optimizing energy lows among vehicles (charging the vehicle that is about to leave, but relying on others to discharge). Aggregators also have the opportunity to learn from previous EV charging behavior in order to predict the maximize available V2G resources during future market participation [14]. here are many more other algorithmic constructions that have potential beneits to a V2G system, and as with the technical details of V2G, we will similarly go into deeper detail regarding aggregators in Chapter 3. In short, aggregators provide many advantages and will play an important role in the V2G system. Aggregators are the key connection between the grid and the vehicle, as they receive the power dispatch signal from the electricity operator, and then send the relevant information to the V2G-capable EVs in the leet. his process is summarized in Fig. 1.2, though in practice, there can be slight variations (such as where the central communication chip is located, either on the EV or the EVSE). With the EV, the charger and the aggregator in place, the irst two elements of the V2G framework set out by Kempton [2] can be satisied, as there is a bidirectional power connection to the grid and several layers of communication throughout the diferent levels shown in Fig. 1.2. hus, with these elements in place, V2G is possible and can provide the diferent services to the electricity grid we discuss in the next subsection. But before we do so, the inal element of the V2G framework, auditability of the V2G systems will be discussed.
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Fig. 1.2 Example communication diagram of a V2G System. The black line represents communication lows, whereas the red line represents bidirectional power lows (Source Authors, partially adapted from [5])
1.1.3 Auditing and Metering he primary requirement for the third element of a V2G framework is a precision meter [2, 4]. Since the fastest electricity markets require reliability within the individual second-time frame, the meter needs to have high precision and granularity. his level of energy metering, sometimes referred to as Advanced Metering Infrastructure (AMI), provides practically real-time data and information to the aggregator and the electricity grid operator. Given this data, AMI can help improve grid quality, ensure reliability of the V2G systems, and optimize the management of the system [9]. But what exactly are meters (and AMI) actually measuring? In short, as shown in Fig. 1.2, electricity grid operator is requesting power both onto the grid and from the grid, and they require that the V2G system, and the aggregator acting on its behalf, is actually doing the service that is being requested. Among a variety of other attributes (such as voltage, EV status, state-of-charge), the primary measurement will be power consumption, typically both provided to the grid and drawn from the grid, depending on the service provided, over time. An example of the data from a precision meter being used is shown in Fig. 1.3. In this igure, the power requested from the electricity grid operator and the power response from the V2G-capable EV should closely correlate. As one can tell from the slight discrepancy between the request and the
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Fig. 1.3 Example of example metered data providing reliability of grid services over ive minutes. The blue line (Request) is the amount of energy requested from the electricity grid operator, while the red line (Response) is the energy provided by the EV. Average time delay is between 1 and 3 seconds (Reprinted from [11])
response, there will be limited amounts of lag between the request from the electricity grid operator and the response from the EV, given the time required to communicate. However, this will typically be limited to a few seconds, and generally outperforms other older ancillary service participants, which can sometimes take several minutes to respond (though the market is changing quickly) [15]. As shown in Fig. 1.3, precision metering thus focuses on two aspects: power capacity provided and accuracy over time. Essentially, this can be seen as vertical (power) and horizontal (accuracy) matching of request versus response, respectively. As we discuss below, V2G can provide a variety of diferent types of services, where the power request from the electricity grid operator varies signiicantly from what is shown in Fig. 1.3. Nonetheless, authentication of the services provided by the V2G system will be an important attribute throughout all of these services. Indeed, the auditing and authentication of a V2G system’s capability to provide these services will likely provide the basis for both their permitting process and their regulated economic remuneration (e.g., see [16]). We will discuss the regulatory implication of V2G systems further in Chapter 5.
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Finally, it is important to note that the typical ancillary service market participant is not an aggregated pool of resources, and thus metering is much simpler—each participant only needs one meter, typically one that is approved and developed by the local utility. However, the metering a V2G system can be much more complex, as with any aggregated resource, since it can be comprised of a leet of tens if not thousands (and perhaps one day, millions) of individual EVs. Requiring a costly utility-grade precision meter per individual EV would be overly burdensome to a V2G system, especially since the EVSE will likely already have a (non-utility) meter already installed to ensure reliability from the aggregator’s perspective. Consequently, allowing the use of certiied but non-utility meter data, already in place in some regions, would allow for easier aggregation and combination of resources [9]. Such a meter policy may prove indispensable as V2G leets shift from the current tens of vehicles to thousands of individual consumer vehicles.
1.1.4 V2G in Practice In the above three sections, we have described the system that needs to be developed in order to suice the three elements of a V2G framework: (1) bidirectional power connection to the grid, (2) communication capability to control charging and discharging of the EV, and (3) precision metering to audit services provided to the grid [2]. With this V2G system in place, an EV would be ready to provide V2G services to the grid. It is important to note that V2G can be done by a variety of different vehicles, more than just the average consumer personal vehicle. In fact, the concept of V2G can be incorporated to a myriad of other vehicles, especially leet vehicles such as vans [8], school buses [17], delivery trucks [18], and other public services vehicles like garbage trucks and city buses [19]. Indeed, it is not inconceivable that with the electriication of other modes of transportation, such as motorcycles, boats, even airplanes, the scope of V2G will likewise continue to grow. Nonetheless, the primary focus will still likely be on personal vehicles, albeit not the only one. In addition, the sections so far highlight how the aggregator plays an important role in the development of the system. Importantly, given
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that much of the value of V2G is in markets that require substantial capacities, the socioeconomic value of individual EVs depends on the aggregation of resources to capture such beneits. And as the V2G capacity increases, the lexibility of the aggregator to provide a variety of grid services concomitantly increases. In the next section, we will discuss the lexibility and the potential grid services that a V2G aggregator can provide.
1.2
V2G, Power Markets and Applications
A key aspect of V2G is, obviously, the grid. However, the grid itself is quite complex, and a basic understanding of its structure is necessary in order to understand how V2G can provide a beneit. To review, the advantages of a V2G system are that it has high capacity at a low price, has high availability, and can react quickly. On the other hand, the disadvantages of a V2G system are that, compared to other electricity market participants, it has a more limited energy production capacity and that the cost per unit of energy is comparatively higher. With this in mind, we next look at typical electricity markets and then discuss how V2G its these markets.
1.2.1 Electricity Markets and V2G Suitability hough electricity systems globally can vary from each other quite signiicantly, there are many commonalities shared between them. We summarize the three diferent generic markets, baseload, peak load, and ancillary services in Fig. 1.4. First, the most pertinent market for an electricity system would be the baseload power market. In this market, wholesale energy is produced continuously, typically coming from large nuclear or coal power plants that have low production costs and limited lexibility (though hydro ofers baseload but also has more lexibility). Given the continuous energy demand, long-time frames of market participation, and very competitive costs per kilowatt-hour (kWh) of energy, V2G has been argued to a bad it for this type of market [5].
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Fig. 1.4 Example electricity markets and their suitability for V2G (Source Willett Kempton, as based on discussion in [5])
Second, since electricity demand varies substantially throughout the day, occasionally baseload power is insuicient to meet increasing electricity demand. At the same time, these peaks tend to occur only infrequently as these peaks can occur daily, weekly, or even less frequently, depending on the size of the peak. As such, the characteristics of the market participants active on day-ahead peak power markets difer signiicantly from baseload power. Instead of low-cost and wholesale production, peak power participants tend to have higher energy production costs, but ofer high lexibility and low technology capital costs, such as gas turbines. To avoid scarcity pricing, these markets are sometimes supplemented with capacity markets, wherein operators pay producers to have idle capacity available at certain times. his helps ensure better investment and planning for power capacity that is only occasionally needed [20]. In relation to V2G, this is considered an acceptable (but certainly not great) match with V2G, even though it has perhaps a too strong focus in the literature [8]. hough peak power can be of high value, it is infrequently used, and when used, is very energy intensive. In other words, V2G participation runs the risk of draining the energy from an EV’s battery, preventing EV owners from completing trips, or
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when peak power is not used, the V2G system typically does not receive any economic remuneration. his brings us to the third type of market, that best matches up with the attributes of V2G, ancillary services. hough diferent electricity markets have a variety of ancillary services, the most common are frequency regulation and spinning reserves (both shown in Fig. 1.4). Compared to the previous two electricity markets, both frequency regulation and spinning reserves coincide better with V2G’s advantages, namely high availability and a higher valuation of power over energy capacity. First, spinning reserves, also known as synchronized reserves, is a market that helps an electricity grid respond to unexpected outages or other contingency events [21]. Power capacity is bought by the grid operator throughout the entirety of the day with the participant always being available, and when needed, the participant must generally respond within 10–15 minutes [5, 21]. he capacity costs are highly amenable to V2G, as EVs can provide capacity continuously due to their high availability and fast response rate. However, because spinning reserves are used infrequently, and, more importantly, can drain batteries when used due to the larger amount of energy required in such instances (e.g., a failing coal plant), the overall it for V2G is considered to be good, but not great. Finally, this brings us to frequency regulation. Frequency regulation goes by a variety of other names, such as automatic generation control (AGC), frequency control, frequency containment reserves. As shown in Fig. 1.4, the main idea behind frequency regulation is that grid quality and stability require a constant ine-tuning of the frequency of the grid. Because actual power delivered can be either too much or too little as compared to electricity consumed, frequency regulation requires the participant to provide energy both to and from the grid, depending on the ever-changing diference between generation and load around standardized frequencies of 50 or 60 Hz. Consequently, the value of frequency regulation to V2G is that it is continuously needed and used, requires high power capacity but limited energy capacities, and requires quick reactions, all of which coincide with the advantages of V2G described above. As a result, frequency regulations is considered the highest value service that V2G can participate in [5], at least for the time being.
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Consequently, V2G is and will be inextricably tied to frequency regulation in early pilot projects [8, 9]. Frequency regulation also sheds light on the V2G system which we described above in Sect. 1.1. he communication signal coming from the electricity grid operator will be a frequency regulation signal that is continuously changing every second. In addition, because frequency regulation is a 24/7/365 market, the aggregator must account for the availability of the V2G leet over time, to ensure that the capacity exists to follow the signal from electricity grid operator. In other markets, such as peak power, availability is only required for a few hours and the aggregator in such a set up would therefore only be concerned with the capacity during that time period. Nonetheless, the V2G system participating in a frequency regulation market requires a richer and more comprehensive information low. In addition to the ancillary services discussed above and depending on characteristics speciic to local grids, there are a variety of other services commonly employed in electricity markets. hese include services such as non-spinning reserves (same as spinning reserve, but not synchronized with the grid and basically oline), black-start capabilities, reactive supply and voltage control and other energy imbalance services (see, e.g. [21]). Moreover, since energy storage is relatively novel to the electricity grid, a variety of other potential services that V2G could provide to integrate renewables or provide lexibility to local grids that do not currently have markets [22]. In other words, when V2G becomes a more mature technology, its impact, use, and business cases may change. Indeed, many of the proponents of V2G are particularly hopeful that V2G can provide services beyond the ones that are currently deined as we will discuss in the next section.
1.2.2 Long-Term Storage, Renewable Energy, and Other Grid Applications hough the central focus in the short term of V2G will likely be ancillary services, the concept of V2G is often discussed in much broader terms. Indeed, when reviewing the literature, the most common subject that V2G research focuses on is its connection to renewable energy integration,
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which was discussed twice as frequently as V2G’s participation in existing electricity grid markets described above [8]. hough this academic connection between V2G and renewable energy is well-developed, it has not actually been put into practice for the reasons described above and the fact that these types of markets do not exist (yet). From a conceptual perspective, therefore, using V2G to integrate renewable energy would likely be slightly diferent than the conceptualization presented above. In this respect, the main issue with the most common renewable energy technologies, wind and solar energy, is that these have an intermittent nature and are therefore not as controllable as conventional electricity sources which creates energy-balancing issues. It is expected that, as wind and solar energy become more common, the mismatch between generation and electricity demand will increase and with it there is an increased need of services to balance the diferent power markets described above. his can manifest itself in a variety of ways. First, the increase in renewable energy can increase the need of ancillary services, including frequency regulation [21], thus making V2G more valuable in the markets it already participates in. On the other hand, as renewable energy becomes the primary source of electricity in grids, the larger concern is more fundamental than ancillary services: that is, the intermittency of renewable energy can greatly decrease the predictability of matching generation and load, sometimes requiring rapid backup generation when wind and solar generation unexpectedly decrease. Such lulls in renewable energy generation may last from minutes, hours to even days. When combined with the times that there is over-generation of wind and solar, V2G is said to be able to provide a cost-efective means of backup generation during times of renewable electricity production shortfall [7, 23]. However, such a service will likely be very diferent than how V2G operates in a system performing frequency regulation services, as it will require substantially more EVs and energy capacity to provide long-term storage. A market to incorporate this concept may resemble something similar to the existing markets of spinning reserves or peak power, though it may likely depend on the regulatory framework of the local electricity grid and will evolve as the electricity system increases in renewable electricity capacity and V2G capability.
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In addition to timescale, renewable energy integration and V2G also depends on the geographic scope of the analysis as well. While much of the research investigates the role of V2G integrating renewable energy on large, regional electricity grid systems [7, 24–26], V2G can also help integrate renewable energy on other scales, such as in microgrids. Similar to the potential services V2G can provide for large-scale renewable energy on a regional electricity grid, V2G can improve grid reliability and provide long-term storage for microgrids that rely primarily on renewable energy [27–29]. We will discuss the beneits of V2G to renewable energy in more detail in the next chapter, and the actual implementation of V2G with regard to renewable energy integration remains to be seen. In addition to renewable energy and longer-term storage, V2G can also provide a variety of the grid services of which there are not developed as markets yet, particularly on a more local level. For example, V2G can delay costly transformer upgrades, reduce line congestions and voltage violations, improve power supply, and avoid critical situations [8, 22]. However, these local service markets do not exist and the options to create them from a regulatory perspective are at best uncertain, which we discuss further in Chapter 5.
1.2.3 Beyond the Grid: Other Concepts Related to V2G he local and regional electricity grids are not the only things to which a bidirectional vehicle can be pointed toward. Instead, many have conceptualized various uses of a bidirectional vehicle, including by connecting such a vehicle to homes (V2H), to buildings (V2B), to loads (V2L), to anything (V2X). To many of the experts who are only partially aware of V2G, the idea has been conlated with a variety of these other uses and applications. While it is true that bidirectionality of an EV can provide a variety of new uses, which we summarize in Table 1.1, each of the diferent concepts has speciic use cases and their own beneits, and while some overlap, the distinctions in use case and beneits are important to understand individually in comparison to V2G. Among all the various conceptualizations of a bidirectional capable vehicle, certainly, the most common in the literature is V2G, with
V2L
V2B
V2H
V2G
Primary beneits
Highest economic value to – Frequency regulation, EV owners can contribute ancillary services to decarbonization of elec– Improve grid lexibility – Renewable energy storage tricity sector Backup power during – Independence from grid blackouts or when grid – Integration of home solar interconnection is overly PV expensive, smooths home – Emergency backup power energy demand, higher personal utilization of solar PV – Optimize building energy Buildings can reduce their Vehicle-to-Building: Using electricity costs by manconsumption the vehicle to provide – Demand side management aging both power and power and energy to a energy demands throughbuilding, decreasing use of – Reduce peak power out the day, can also be charges the electricity grid integrated with renewable – Emergency backup power energy – Providing power at a con- Provides power to area Vehicle-to-Load: Using the where electricity grid is difstruction site or hospital vehicle as the sole energy icult or cost prohibitive to – Providing power to elecproduction source to an connect to, or the power tric appliances, such as a isolated power load demand is temporary or power tools mobile
Vehicle-to-grid: Using the vehicle to provide storage services on an electricity grid market Vehicle-to-home: Likely the second-most common topic, using the vehicle to provide storage and power to one’s home
Examples
Deining the different conceptualizations of use cases of a bidirectional vehicle
Concept Deinitions
Table 1.1.
[37–39]
[34–36]
[31–33]
(continued)
[5, 7, 24, 30]
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(continued)
V2X
V2C
V2V
Primary beneits
Can ensure vehicles have enough energy to make trips, often while providing other services such as V2B or V2G Vehicle-to-community: Using – Using leets to create short Can increase resiliency and utilization of solar energy and long-term storage on the vehicle to provide on a local level, helping a local grid, often constorage for a local grid, to integrate solar at low costs nected to community solar create a self-suficient and resilient community Vehicle-to-X: Often used as – Can be any of the concepts – Can provide opportunity for novel uses for EV above a catch-all for any other owners, provide electricity – Using the EV to power imagined use other than in mobile situations where small mobile loads, such as V2G, it has also been conelectricity grid is unable to telescopes ceptualized as using the connect EV’s power to provide to mobile loads
Examples
Vehicle-to-Vehicle: Using the – Using one vehicle to balance energy in other vehicle to provide energy vehicles to other vehicles
Concept Deinitions
Table 1.1.
[38, 44]
[42, 43]
[31, 38, 40, 41]
Exemplary citations
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a wealth of literature focusing on the various aspects of EV grid integration. Other concepts, namely V2H and V2B, are also commonly used, though not as much as V2G. Finally, the other concepts like V2L, V2V, and V2C are less commonly (or rarely) used, while V2X is a concept that is growing in popularity as it hints at the many new potential uses. Nonetheless, these novel constructions of potential uses relects the interpretive lexibility of bidirectional EVs (i.e., that consumers can interpret the technology diferently, see [45]), as well as the innovation’s wide problem-deinition (i.e., that the problem that bidirectional EVs are seeking to solve is not narrowly deined, see [46, 47]). It is worth noting a few distinctions and similarities between these various conceptualizations. Of course, there are some ready connections, such as the renewable energy integration theme that runs in various concepts, such as V2G, V2H, and V2C, though it depends on the scope. Indeed, the idea of V2C and a V2G application to a microgrid are essentially the same idea. Additionally, the use of a bidirectional EV to provide mobile loads is shared in both constructions of V2L and V2X. However, an important distinction is that V2G includes the medium and high voltage electricity grid, whereas the other conceptualizations focus on low voltage, local and behind-the-meter uses. Moreover, the scale of V2G in terms of economic beneit and long-term renewable energy integration is much larger [7], though the others are perhaps more immediate. While many of the experts we interviewed appeared to conlate V2H with V2G, V2G is likely to provide much larger societal beneits. hus, experts were perhaps underestimating the potential beneits of V2G, underscoring the importance of understanding the distinctions between the various concepts presented in Table 1.1. hat said, a consumer may be interested in one use case over another. For example, a purely economic incentive would favor V2G, where consumers are likely to get the most value out of their EV in participation of a frequency regulation market. Similarly, a consumer mostly concerned about environmental impacts may be most motivated to do V2G along with V2H, in order to help integrate the grid (and their own) renewable energy. On the other hand, a consumer who is concerned primarily with grid independence (likely for non-economic
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reasons) may focus solely on V2H. Alternatively, a tinkerer may be interested in the mobile applications of V2X. However, given the environmental, socioeconomic advantages of V2G, its preponderance in actual use and the academic literature, we focus primarily throughout the book on V2G but will occasionally refer to these other conceptualizations, especially as the sociotechnical barriers that V2G faces likely are similar to the ones V2B, V2H, etc., will also face.
1.3
History and Development of EVs and V2G
Admittedly, the promise of EVs has been touted by supporters for decades, with even early advocates at the turn of the previous century discussing the beneits of electricity as a transport fuel. EVs, in contrast to horses, bicycles, trains, steamers, and gasoline vehicles, held many beneits, and became vehicles of choice in the early 1900s. heir quieter operation enabled them to run in noise-restricted areas and more aluent neighborhoods. Many women also preferred push button electrics as they did not require the shifting of gears or turning of hand cranks to start [48, 49]. By 1905, Mom reminds us that “more than half of all commercial vehicles in the United States were electric powered” [50]. In short, EV proponents believed in technological optimism and placed faith in human ingenuity to overcome lingering technical problems. Despite these high hopes, the use of EVs slowly declined and then sharply dropped of, so much that by 1920 they constituted less than 2% of the overall market. Even the commercial sector slowly abandoned them: In 1913, ten percent all commercial vehicles were electric powered but by 1925 the number had dropped to less than 3% [51]. A more recent wave of EV development was driven by motivations about sustainability and aggressive policies in places such as Europe and California. In the late 1980s, there was a general acknowledgment among automobile manufacturers that EVs need not be conined to the narrow markets of delivery vans, golf carts, and homemade cars [52]. As one team of transport researchers predicted in the early 1990s, “By the turn of the century, electric passenger vehicles could be viable as second cars in multicar households … No longer does successful
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commercialization depend on technical breakthroughs” [53]. General Motors similarly declared that electric propulsion for passenger vehicles was “suitable for mass production at afordable costs” [54]. As the IEEE wrote, “he 1990s are likely to be the decade in which the long-sought practical, economical electric vehicles will begin to be realized” [55]. However, despite such hype (and research expenditure), almost all of those EV models failed to meet sales targets. EVs as a whole for passenger transport had truly dismal sales and production igures, with major European manufacturers Renault, Citroen, and Peugeot all selling only 100–200 models, to say nothing of General Motors losing roughly $1 billion on their endeavor promoting the EV-1 in the USA [56]. Indeed, the collapse of EV markets in the mid-1990s may have even stigmatized electric mobility to the point where irms were overly reluctant to reinvest in electric propulsion as a proitable strategy. EVs remained conined to niche markets and a few large-scale demonstration projects across Europe and the USA for most of that decade. And thus enters the concept of V2G in the late 1990s, as a way to reverse this trend and make EVs more viable. hough the introduction of the concept of V2G was in 1997 [1], the irst V2G-capable EV was not developed until ten years later, where the University of Delaware retroitted a Scion xB into a V2G-capable EV, renamed the eBox in 2007 [9, 57]. Since then, there have been several pilot projects around the globe. However, many of these pilot projects, such as V2G/V2B pilot project in Japan or a US Department of Defense pilot project at the Los Angeles Air Force Base [8] showcase the technology but do not actually provide services to an electricity grid market. Indeed, there have only been a few examples of projects actually participating and making revenue on an electricity grid market. he irst example of which was also at University of Delaware, when in addition to the original eBoxes, BMW Mini-E were added to the leet to provide frequency regulation in the PJM Interconnection [58]. In addition, since that original pilot project, a variety of companies have formed in order to perform V2G services on the grid. Among these companies include: OVO Energy, which claims to have the world’s irst widely available V2G charger [59], Kisensum, which
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conducted the L.A. Air Force Base project [9], among others. However, the most successful V2G company thus far, in terms of actual projects participating in V2G, has been Nuvve, which has developed the second project actually participating on an electricity grid market in Denmark, the irst fully commercial V2G project [60]. Looking forward, Nuvve has projects in development in San Diego, California [61], as well as the irst V2G project in Japan [62]. Finally, both Nuvve and OVO Energy are expected to participate in the myriad of V2G projects in which the UK government invested £30 million [63]. Nonetheless, outside of a few scattered, comparatively small projects throughout the globe, V2G remains within a niche market. Compared to the hundreds of academic journal articles published within only the last few years [8], the actual implementation of V2G lags behind its academic focus. Yet, at the same time, V2G is also posed to potentially accelerate its difusion across the globe, to which only time will tell.
1.4
Actors and Roles of V2G
With the concept of V2G in place, we next describe the various actors and their roles in a hypothetical V2G system. Building upon our discussion above, there are several pertinent actors who play essential roles in the V2G system, as well as more periphery network of secondary actors. We summarize their interactions in Fig. 1.5, where we show the actors in a hypothetical V2G system. Of course, actual V2G systems may differ depending on the local context and the actual service that is provided. We next briely discuss the role of the primary and secondary actors on the overall V2G system.
1.4.1 Primary Actors: EV Owners, Aggregators, and the Electricity Grid First, Fig. 1.5 shows three diferent primary actors in the V2G system, each representing a part of the “V2G” abbreviation. First and foremost, of course, is the EV owner. Intuitively, the EV owner of course plays
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Fig. 1.5 Diagram of actors in a hypothetical V2G system. Note that some of the communication and power lows may differ depending on V2G service provided. Partially based on [64]
a vital role in the V2G system, as they provide the “V”—the vehicle. Beyond this, however, the role of the EV owner in most V2G systems is relatively passive. Once the EV owner connects their vehicle to the system, the EV owner no longer needs to actively participate in the system—indeed, the only other role they play is to notify the aggregator when they expect to leave, and most importantly, receive money for the services their vehicle rendered. At the same time, the EV owner’s vehicle is quite active in the process, as it communicates with the aggregator as well as provides the actual power to the grid for whichever service they provide, e.g., frequency regulation. Of the various roles in the system, the EV owner’s role is the simplest, but they also determine the amount of power capacity available and for how long it can be used, two of the most vital attributes to increase the system’s economic value. Next, the aggregator, which we discussed in detail above and which has the role of balancing communication and power sent between the grid and the vehicle or representing the “2” in V2G. he aggregator, likely operated by a third party (though in rare occasions may be
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owned by the electricity grid operator) manages the systems in a variety of ways. For example, the aggregator decides which electricity markets to participate and when to do so, which may depend on the available resources aggregated across EV owners. Once the aggregator has bid into a certain market, the aggregator must then be capable of receiving the communication signal for the services they agreed to provide from the electricity grid operator. his signal then will be split across the leet of EVs as described previously in Sect. 1.1.2, with power lowing to and from the electricity grid to the EVSE’s. During this process, the aggregator must monitor the status of the services provided by the leet to ensure reliability. Finally, the third primary actor is the electricity grid operator, representing the “G” in V2G. Of course, the electricity system is quite complex, but we have segregated this into two actors in Fig. 1.5. First is the larger regional or national electricity grid operator, which is known across regions and nations as either a transmission system operator (TSO), an independent service operator (ISO), or a regional transmission organization (RTO). Whatever they are called, their primary role on the electricity grid is transmission of large-scale electricity production to demand areas through high voltage transmission lines, and balancing of generation and load, typically over large regional areas. hese are the organizations in charge of the ancillary services described above and will be the entity that the aggregator actor will primarily interact with. Depending on the status of the grid, the electricity grid operator will purchase ancillary service capacity and subsequently send the signal to all participants, including the aggregator. he other grid operator is the local utility, also known as a distribution system operator (DSO) or sometimes a distribution network operator (DNO). he main purpose of these organizations is to receive the electricity transmitted by a TSO or ISO and then distribute it to end-users, such as industry or households. hough ancillary service markets will typically be conducted at the TSO level, EVs must also use the DSO network as EVs in the V2G system will be situated at the end-use of electricity (i.e., houses, etc.) and therefore both impact and interact with local grids. hus, V2G systems provide energy through the DSO network and often must be permitted to do so. In addition
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as market mature, it is likely that V2G systems will provide services directly to DSOs and help with balancing and congestion on local grids [22].
1.4.2 Secondary Actors: Government, the EV Industry, and Electricity Producers Beyond these primary actors of the V2G system, there are a variety of other important actors in the periphery to the main concept. hough these are not necessarily active participants in the V2G system, they nonetheless are vital in creating the space to allow V2G to contribute to the grid, as well as potentially increase its value. One of the most important secondary actors is the government and electricity market regulators. Primarily because they can regulate storage markets and develop the regulatory framework for aggregators to exist and participate on electricity grid markets. Policymakers can also encourage TSOs and DSOs to develop their own policies and regulations on storage. Beyond creating a regulatory space for storage, these types of policies can also determine things like the tax regulations on electric grid participants or both consume and produce electricity. Such general tax settings will determine the economic livelihood of V2G services. Finally, besides ofering direct support for storage options, government can also indirectly encourage the development of storage by requiring more renewable energy sources. As discussed above, renewable electricity sources like wind and solar will increase the need for energy storage, and decarbonization policies, like a carbon tax, will make other ancillary service participants like oil and natural gas less economically viable as compared to V2G systems. Another important secondary actor is the EV industry. Like governmental actors, the EV industry does not participate in the operation of the V2G system but they are important to the creation of bidirectional vehicles. For example, automakers play an inluential role in V2G systems by deciding whether or not to produce EVs (which government actors may also help determine), and of those EVs, whether or not they will be V2G-capable. Indeed, given the lack of EV models, and
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the further lack of V2G-capable EVs, this is a major obstacle the diffusion of V2G systems. Another group in the EV industry is the EVSE or charger developers, as they also decide whether an EVSE system is V2G-capable or not. Both the EV and the EVSE, built by diferent industry actors within the EV sphere, must be developed with V2G in mind. hus, their primary role is enablers of V2G systems. Finally, the third type of enabling actor we discuss is electricity producers and sales companies. Electricity production is a key determinant of the ancillary services required by the electricity grid operator. Moreover, renewable electricity developers may work in tandem with the advent of V2G systems and other energy storage options to ensure the reliability of the electricity grid. In smaller electricity grids, or ones with higher load and generation variability, the development of large-scale renewable energy may be dependent on the concomitant development of V2G systems and other energy storage capacity. hus, renewable electricity production actors may play a role of supporter of V2G system, both directly (such as lobbying for the development of storage in the electricity market) and indirectly (since renewable energy makes V2G services more valuable). Beyond these three secondary actors, it is worth noting that there may be other actors that could potentially play a role in the development of the V2G system, such as international standardization bodies (that set international and national agreements on V2G standards) or non-governmental organizations (NGOs) lobbying the government for more pro-environmental legislation. However, these are uncertain roles and are left out of Fig. 1.5 but may be further developed in the future.
1.5
Conclusion
In this chapter, we have set out to deine the basic deinition, conceptualization, and implementation of V2G. In summary, V2G is a system with aggregated EVs communicating with an electricity grid, providing a variety of storage-based services. hough V2G can potentially provide a variety of grid services, especially down the road as it difuses across society, the primary markets will be ancillary services, with frequency
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regulation being the most valuable and therefore economically viable. he chapter further discussed how V2G has been put into practice, ofered a short historical overview, and discussed the primary actors and their roles in and behind the V2G system. Beyond V2G, we showed that there is a plethora of other unique use cases for bidirectional vehicles that are similar to V2G, such as V2H, V2B, and V2X. It is important to be cognizant of the conceptual diferences. hese concepts are sometimes conlated, despite the fact that V2G provides the largest economic beneit to consumers as well as the largest environmental beneits to society, which we discuss in further detail in the next chapter.
References 1. Kempton W, Letendre SE. Electric vehicles as a new power source for electric utilities. Transp Res Part Transp Environ. 1997;2(3):157–75. 2. Tomić J, Kempton W. Using leets of electric-drive vehicles for grid support. J Power Sources. 2007;168(2):459–68. 3. Guille C, Gross G. A conceptual framework for the vehicle-to-grid (V2G) implementation. Energy Policy. 2009;37(11):4379–90. 4. Sovacool BK, Axsen J, Kempton W. Tempering the promise of electric mobility? A sociotechnical review and research agenda for vehicle-grid integration (VGI) and vehicle-to-grid (V2G). Annu Rev Environ Resour [Internet]. 2017 [cited 2017 Aug 24]. Available from: http://www.annualreviews.org/doi/abs/10.1146/annurev-environ-030117-020220. 5. Kempton W, Tomić J. Vehicle-to-grid power fundamentals: calculating capacity and net revenue. J Power Sources. 2005;144(1):268–79. 6. Yilmaz M, Krein PT. Review of battery charger topologies, charging power levels, and infrastructure for plug-in electric and hybrid vehicles. IEEE Trans Power Electron. 2013;28(5):2151–69. 7. Noel L, Brodie JF, Kempton W, Archer CL, Budischak C. Cost minimization of generation, storage, and new loads, comparing costs with and without externalities. Appl Energy. 2017;189:110–21. 8. Sovacool BK, Noel L, Axsen J, Kempton W. he neglected social dimensions to a vehicle-to-grid (V2G) transition: a critical and systematic review. Environ Res Lett. 2018;13(1):013001.
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9. Markel T, Meintz A, Hardy K, Chen B, Bohn T, Smart J, et al. Multilab EV smart grid integration requirements study [Internet]. Golden, Colorado: NREL; 2015 May [cited 2016 May 22]. p. 91. Report No.: NREL/TP-5400-63963. Available from: http://www.nrel.gov/docs/ fy16osti/60958.pdf. 10. Kester J, Noel L, Lin X, Zarazua de Rubens G, Sovacool BK. he coproduction of electric mobility: selectivity, conformity and fragmentation in the sociotechnical acceptance of vehicle-to-grid (V2G) standards. J Clean Prod. 2019; 207: 400–410. https://doi.org/10.1016/j. jclepro.2018.10.018. 11. Martinenas S, Vandael S, Andersen PB, Christensen B. Standards for EV charging and their usability for providing V2G services in the primary reserve market.pdf. In: Montreal, Canada; 2016. 12. Han S, Han S, Sezaki K. Development of an optimal vehicle-togrid aggregator for frequency regulation. IEEE Trans Smart Grid. 2010;1(1):65–72. 13. Jang S, Han S, Han SH, Sezaki K. Optimal decision on contract size for V2G aggregator regarding frequency regulation. In: IEEE; 2010 [cited 2018 Jul 4]. p. 54–62. Available from: http://ieeexplore.ieee.org/ document/5510464/. 14. Vandael S, Claessens B, Ernst D, Holvoet T, Deconinck G. Reinforcement learning of heuristic EV leet charging in a day-ahead electricity market. IEEE Trans Smart Grid. 2015;6(4):1795–805. 15. Marakov YV, Ma J, Lu S, Nguyen TB. Assessing the value of regulation resources based on their time response characteristics [Internet]. Richland, Washington: Paciic Northwest National Laboratory; 2008 Jun [cited 2018 Jul 5]. p. 83. Report No.: PNNL-17632. Available from: https:// www.pnnl.gov/main/publications/external/technical_reports/PNNL17632.pdf. 16. Federal Energy Regulatory Commission. Order No. 755 [Internet]. 137 FERC 61,604, Docket No. RM11-7-000, AD10-11-000 Oct 20, 2011. Available from: https://www.ferc.gov/whatsnew/comm-meet/2011/ 102011/E-28.pdf. 17. Noel L, McCormack R. A cost beneit analysis of a V2G-capable electric school bus compared to a traditional diesel school bus. Appl Energy. 2014;126:246–55. 18. Zhao Y, Noori M, Tatari O. Vehicle to grid regulation services of electric delivery trucks: economic and environmental beneit analysis. Appl Energy. 2016;170:161–75.
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30. Ota Y, Taniguchi H, Nakajima T, Liyanage KM, Baba J, Yokoyama A. Autonomous distributed V2G (vehicle-to-grid) satisfying scheduled charging. IEEE Trans Smart Grid. 2012;3(1):559–64. 31. Liu C, Chau KT, Wu D, Gao S. Opportunities and challenges of vehicleto-home, vehicle-to-vehicle, and vehicle-to-grid technologies. Proc IEEE. 2013;101(11):2409–27. 32. Shin H, Baldick R. Plug-in electric vehicle to home (V2H) operation under a grid outage. IEEE Trans Smart Grid. 2017;8(4):2032–41. 33. Colmenar-Santos A, de Palacio-Rodriguez C, Rosales-Asensio E, BorgeDiez D. Estimating the beneits of vehicle-to-home in islands: the case of the Canary Islands. Energy. 2017;134:311–22. 34. Nguyen HK, Song JB. Optimal charging and discharging for multiple PHEVs with demand side management in vehicle-to-building. J Commun Netw. 2012;14(6):662–71. 35. Van Roy J, Leemput N, Geth F, Buscher J, Salenbien R, Driesen J. Electric vehicle charging in an oice building microgrid with distributed energy resources. IEEE Trans Sustain Energy. 2014;5(4):1389–96. 36. Ioakimidis CS, homas D, Rycerski P, Genikomsakis KN. Peak shaving and valley illing of power consumption proile in non-residential buildings using an electric vehicle parking lot. Energy. 2018;148:148–58. 37. Tuttle DP, Baldick R. he evolution of plug-in electric vehicle-grid interactions. IEEE Trans Smart Grid. 2012;3(1):500–5. 38. hompson AW. Economic implications of lithium ion battery degradation for vehicle-to-grid (V2X) services. J Power Sources. 2018;396:691–709. 39. Kinomura S, Kusafuka H, Kamichi K, Ono T. Development of vehicle power connector equipped with outdoor power outlet using vehicle inlet of plug-in hybrid vehicle. In: 2013 [cited 2018 Jul 6]. Available from: http://papers.sae.org/2013-01-1442/. 40. Mohamed A, Salehi V, Ma T, Mohammed O. Real-time energy management algorithm for plug-in hybrid electric vehicle charging parks involving sustainable energy. IEEE Trans Sustain Energy. 2014;5(2):577–86. 41. Koufakis A-M, Rigas ES, Bassiliades N, Ramchurn SD. Towards an optimal EV charging scheduling scheme with V2G and V2V energy transfer. In: IEEE; 2016 [cited 2018 Jul 6]. p. 302–7. Available from: http://ieeexplore.ieee.org/document/7778778/. 42. Yamagata Y, Seya H, Kuroda S. Energy resilient smart community: sharing green electricity using V2C technology. Energy Procedia. 2014;61:84–87.
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43. Yamagata Y, Murakami D, Minami K, Arizumi N, Kuroda S, Tanjo T, et al. Electricity self-suicient community clustering for energy resilience. Energies. 2016;9(7):543. 44. Andersen PB, Marinelli M, Olesen OJ, Andersen CA, Poilasne G, Christensen B, et al. he Nikola project intelligent electric vehicle integration. In: IEEE; 2014 [cited 2016 May 23]. p. 1–6. Available from: http:// ieeexplore.ieee.org/lpdocs/epic03/wrapper.htm?arnumber=7028765. 45. Kline R, Pinch T. Users as agents of technological change: the social construction of the automobile in the rural United States. Technol Cult. 1996;37(4):763. 46. Rogers EM. Difusion of innovations. 5th ed. New York: Free Press; 2003. p. 551. 47. Rice RE, Rogers EM. Reinvention in the innovation process. Knowledge. 1980;1(4):499–514. 48. Why Volti R. Why internal combustion. Inven Technol. 1990;6(2):42–47. 49. Franz K. Tinkering: consumers reinvent the early automobile. Philadelphia: University of Pennsylvania Press; 2011. 50. Mom G. he electric vehicle: technology and expectations in the automobile age. Baltimore: Johns Hopkins University Press; 2004. p. 423. 51. D’Agostino S. he electric car: a historical survey on the motives driving its existence. Inst Electr Electron Eng Potentials. 1993;1993:28–32. 52. Cowan R, Hultén S. Escaping lock-in: the case of the electric vehicle. Technol Forecast Soc Change. 1996;53(1):61–79. 53. DeLuchi M, Wang Q, Sperling D. Electric vehicles: performance, life-cycle costs, emissions, and recharging requirements. Transp Res Part Gen. 1989;23(3):255–78. 54. Rajashekara K. History of electric vehicles in general motors. In: IEEE; 1993 [cited 2018 Aug 7]. p. 447–54. Available from: http://ieeexplore.ieee. org/document/298962/. 55. Chan CC. Present status and future trends of electric vehicles. In: 1993 2nd International Conference on Advances in Power System Control, Operation and Management; 1993. p. 456–69. 56. Dijk M, Yarime M. he emergence of hybrid-electric cars: innovation path creation through co-evolution of supply and demand. Technol Forecast Soc Change. 2010;77(8):1371–90. 57. Fehrenbacher K. he father of vehicle-to-grid charges toward commercialization [Internet]. Gigaom.com; 2010 [cited 2018 Jul 5]. Available from: https://gigaom.com/2010/05/13/from-research-to-reality-using-electricvehicles-to-regulate-the-grid/.
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58. Fitzgerald M. Electric vehicles sell power back to the grid. Wall Str J [Internet]. 2014 Sep 28 [cited 2018 Jul 7]. Available from: https://www. wsj.com/articles/electric-vehicles-sell-power-back-to-the-grid-1411937796. 59. Field K. OVO energy drops 4 product Bombshells, including new vehicle-to-grid charger. CleanTechnica [Internet]. 2018 Apr 19. Available from: https://cleantechnica.com/2018/04/19/ovo-energy-drops-4-productbombshells-including-new-vehicle-to-grid-charger/. 60. Nuvve. Nuvve operate world’s irst fully commercial vehicle-to-grid hub in Denmark [Internet]. Nuvve: Western Europe; 2017 [cited 2018 Jul 7]. Available from: http://nuvve.com/portfolio/nissan-enel-and-nuvve-operate-worlds-irst-fully-commercial-vehicle-to-grid-hub-in-denmark/. 61. Margoni L. Nuvve and UC San Diego to demonstrate vehicle-to-grid technology through energy commission grant [Internet]. UC San Diego News Center; 2017 [cited 2018 Jul 7]. Available from: https://ucsdnews.ucsd.edu/pressrelease/nuvve_and_uc_san_diego_to_demonstrate_ vehicle_to_grid_technology. 62. Nuvve. First V2G project deined for Japan [Internet]. Nuvve Corp; 2018 [cited 2018 Jul 7]. Available from: http://nuvve.com/2018/06/ irst-v2g-project-deined-for-japan/. 63. GOV.UK. £30 million investment in revolutionary V2G technologies [Internet]. 2018 [cited 2018 Jun 25]. Available from: https://www. gov.uk/government/news/30-million-investment-in-revolutionary-v2gtechnologies. 64. O’Rielly T. Adopiton of vehicle-to-grid in South Australia [Internet]. Aalborg, Denmark: Aalborg University; 2017 [cited 2018 Jul 7]. Available from: https://projekter.aau.dk/projekter/iles/267987414/Adoption_of_ Vehicle_to_Grid__in_South_Australia___Tom_ORielly___Final.pdf.
2 The Potential Beneits of V2G
One of the main reasons that V2G is enticing as a technology is that it potentially represents a scenario where all parties involved beneit. In this chapter, we go over the variety of potential beneits that V2G can ofer EV owners, the grid, and society at large. We irst move through categorizing the beneits of V2G in speciic topics, and how these beneit the diferent actors described in Chapter 1. After deining the various beneits, the chapter then turns to how these beneits can be captured, especially as V2G as a technology moves from a select few leets in pilot projects to personal and public vehicles in wider society. In addition, as the grid becomes smarter and more encompassing we next postulate how V2G can and will interact with the grid.
2.1
Summarizing the Beneits of V2G
he beneits of V2G are quite wide in scope and, given its niche status, are not completely deined yet. Nonetheless, in this section we summarize the beneits of V2G into three main themes, which coincide with diferent dimensions of a sociotechnical system: technical, © he Author(s) 2019 L. Noel et al., Vehicle-to-Grid, Energy, Climate and the Environment, https://doi.org/10.1007/978-3-030-04864-8_2
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economic, and environmental. Additionally, these beneits impact different actors and levels of society diferently, which we discuss within each subsequent subsection. Beyond these three central themes, we also acknowledge the wide variety of other potential beneits that V2G, and the related concepts described in the previous chapter such as V2X or V2H, can also provide. However, these should still be put in context that the three other themes of beneits are larger and more beneicial to society. Before moving onto the actual beneits, throughout this section (as well as other portions of the book) it is important to reiterate the interconnectedness of the concept of V2G to EVs themselves. Obviously, since EVs are antecedent to V2G, the beneits of V2G could be seen as a subset of the beneits of EVs. Conversely, though, V2G can be construed as a means to increase the adoption of EVs, i.e., the additional inancial beneits of V2G will encourage more consumers to choose EVs. In this sense, V2G may also help “unlock” the beneits that EVs can ofer society, so with this in mind our discussions below demarcate both beneits that V2G can directly contribute to, as well as indirectly contribute to, through the increased adoption of EVs. While it is important to recognize both of these potential beneits in order to fully contextualize the beneits of V2G, readers making their way through this chapter should also be careful to understand the distinctions between V2G’s direct and indirect beneits. Finally, this section describes a wide variety of beneits which can be described in another two ways. hat is, many of the beneits are presently available, whereas others are expected to occur down the road, depending on the circumstances in the future energy and transportation system. We discuss these potential developments in the inal chapter, but it is also important to understand the temporal aspects of these beneits. For example, economic beneits to EV owners participating in frequency regulation are readily available in most areas, but the decarbonization of the electricity grid is likely to occur over both a short- and long-term time frame. his temporal distinction matters, as some of the V2G beneits are antecedent on other aspects in the sociotechnical system.
0
1500–3200
1100–2500
870
850
V2G
Hydrogen
Purpose-built batteries
Flywheels
Power-to-gas
40–109
68
Pumped hydroelectric
N/A
4800
Compressed air 900–1300 energy storage
50
94
A few seconds to minutes
70–82
9–12 minutes 70–90
Seconds to minutes
A few seconds
70–90
40
70–85
Round-trip eficiency (%)
$4300
$2800
$2300
$41,200
$7020
$6200
N/A
Cost to match U.S. V2G capacity ($bn)
By far the cheapest system, diffusion process long and complex, depends on consumers Lowest eficiency and high capacity costs Without secondary use, battery energy capacity is very high cost Highly eficient but cost limits overall energy capacity, preferred for short-term storage Low eficiency, gas infrastructure must preexist, contributes to gas-related emissions Dependent on local geology to compress air into, proven technology Most prevalent storage, but geographically dependent, environmental implications
Other notes
Note Round-trip eficiency is the amount of energy that is retained after energy is put into the storage system and subsequently retrieved, expressed as a percentage
1400
A few seconds
Response time
260–540 Seconds to minutes 500–800 A few seconds
0–40
Cost of storage $/kW $/kWh
Storage technology
Table 2.1 Technical attributes of various storage technologies, using the USA as an example. Ranges indicate difference in cost depending on technology or system used. Data based on [1–5]
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2.1.1 Technical Beneits: Storage Superiority and Grid Eficiency First, the primary beneit V2G ofers is its technical beneits to the power grid through storage, since V2G is comparatively low cost, has a high potential power capacity, and can react quickly, and thereby is able to serve diferent types of power markets. But, to completely understand the beneit that V2G ofers to the grid, it should be placed in the context of other commonly used energy storage options. Here in Table 2.1, we compare the technical attributes of V2G to other commonly discussed forms of electricity storage. he technologies presented in Table 2.1 all have their own beneits and downsides. While some may be preferred for speciic roles, such as lywheels for short-term ancillary service storage or compressed air energy storage for large-term renewable energy storage, here we argue that V2G ofers the most valuable storage overall. Clearly, V2G’s most substantial beneit is that, in theory, it can be “free” if EV owners agree to use the already existing storage and power capacity in the EVs for V2G (though some include a cost for battery degradation, hence the upper limit of $40/kWh). In addition, assuming per-car averages of a 10 kW charger and a 30 kWh battery, the total capacity of the US vehicle leet would be 2.7 terawatts (TW) of power and 8.1 TWh of energy [6]. his capacity is substantial compared to the existing US electricity capacity, which is just over 1 TW [7]. In short, if the entire US vehicle leet converted to V2G-capable EVs, it would be a substantial resource for storage to the electricity grid. Of course, the same capacity can be built in the form of any of the other storage technologies in Table 2.1 (perhaps other than pumped hydroelectric), but this would also come at a signiicantly higher cost. For example, in the best case, the V2G system essentially is available for free, whereas Table 2.1 shows that this same capacity (using the lowest cost range for each technology) would cost trillions of dollars if constructed with the other technology systems. In addition to the potential cost-efectiveness of V2G technology, there are several other technical advantages compared to its alternatives. V2G has a fast response time and relatively high eiciency, while
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many of the alternatives have only one or the other (e.g., hydrogen is fast responding, but ineicient, and compressed air energy storage has high eiciency but takes several minutes to respond). In addition, it is expected that charger eiciency can be improved, making V2G even more amenable [4]. Of course, V2G isn’t the perfect solution (if it were, it is likely we would not need to write this book). here are several disadvantages of V2G compared to the other technologies in Table 2.1, which may post obstacles in the future development of V2G systems. First, the most signiicant challenge is that, unlike the other technologies, the development of V2G systems depends almost entirely on end-use consumers’ decision to adopt a V2G-capable EV and agree to participate in an aggregator’s V2G system. As an example, if a hypothetical electric grid operator required 1000 MW of storage, V2G would be the cheap option, but also would require convincing roughly 100,000 individual consumers or several hundred vehicle leet operators in their electrical grid region to participate in a V2G program, which would likely take a long time to implement and potentially face consumer resistance. Alternatively, a grid operator could convince one industry actor to construct pumped hydroelectric or a centralized, purpose-built battery plant, both of which could be inished within a few years and not rely on consumer decisions. Secondly, in its current form, batteries in general are best suited for shorter-term storage, especially depending on the overall system capacity. Hence current V2G pilot projects focus on services that require seconds to minutes worth of storage time [8, 9], but future storage markets like renewable energy integration may require storage time of days to weeks. While the latter three examples in Table 2.1 (power-to-gas, compressed air energy storage, and pumped hydroelectric) are already suitable for such long-term storage, V2G systems would likely require substantially higher capacities before it can meaningfully participate in such markets. If the storage-related barrier discussed above is resolved, then V2G (or storage in general) can ofer the grid a variety of technical advantages. For example, Eyer and Corey [10] found 17 general beneits that storage could provide the grid. Briely, some of these beneits include
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improved power quality, voltage support, transmission congestion relief, energy demand shifting, increased electricity reliability, and wind and solar integration. As V2G capacity increases, it is expected that a V2G system can provide a variety of these services all at the same time. However, the most alluring economically are the ancillary services such as the frequency regulation market (as discussed in Chapter 1), and the most alluring societally is likely to be renewable energy integration. While we focus primarily on these two beneits, we recognize that there are a plethora of secondary beneits V2G systems could provide to improve grid operation. In addition to making the grid technically more eicient, these beneits can also provide economic beneits to both the EV owner and society, which we discuss next.
2.1.2 Economic Beneits: EV Owners and Societal Savings More pertinently, V2G can produce economic savings on a variety of scales and a variety of actors, such as individual EV owners, grid operators, and society as a whole. However, the perspectives are slightly diferent for each of them. For consumers, V2G can open up new revenue sources, whereas for grid operators and society, V2G can provide a cheaper alternative to current market participants. We will show this below, irst by calculating potential V2G revenues in ancillary service markets and then by discussing how these beneits can make the grid more cost-efective. From the perspective of the consumer, the primary means of economic beneits are remuneration from participating in ancillary markets services. As we discussed in Chapter 1, the primary and most valuable ancillary services market in which V2G currently participates in is frequency regulation. However, we have not yet discussed the speciics of how consumers are compensated for frequency regulation participation. In short, the value of frequency regulation is primarily the power capacity, meaning that compensation is generally given for each megawatt (MW) of power capacity over the period of an hour, in line with Eq. 2.1. After the service is provided over that hour, the participants are
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then also compensated for the energy, i.e., megawatt-hour (MWh). For simplicity’s sake, however, we ignore this aspect in Eq. 2.1 as the remuneration for the actual energy delivered tends to be of substantially less value than the capacity itself. Many of the other services that V2G may provide in the future, such as spinning reserves, will likely have compensation schemes of similar structure. R = PrFREQ × PMW × A
(2.1)
Equation 2.1. Calculating the Annual Revenue of Frequency Regulation Participation, where R = Annual Revenues, PrFREQ = Frequency regulation price (in $/MW-h), PMW = power capacity (in MW), and A = Availability to provide V2G (in hours). Using Eq. 2.1, we can calculate an example of how much frequency regulation participation could beneit an EV owner. Let us assume that a Nissan Leaf owner in the PJM Interconnection (the largest electricity grid in the world, operating roughly from Chicago to New Jersey) can participate in frequency regulation using their home charger. Assuming use of some kind of Level 2 charger (see Chapter 1), let us assume that the capacity for this Nissan Leaf owner is 10 kilowatts (kW), or 0.01 MW. Next, acknowledging that there would be additional revenue if there was also a work charger, we assume that the EV is available to provide V2G services only at home, for 15 hours during weekdays and 23 hours during weekends [11], adding up to about 6300 hours per year (~72% of the time). Finally, the average price (as of May 2018) for frequency regulation in PJM was $34 per MW-h [12]. Multiplying these out, per Eq. 2.1, the annual revenue that our hypothetical Nissan Leaf owner can earn is $2140 (though a portion of this revenue would in reality likely go to an aggregator). Adding a V2G-capable charger at work increases this annual revenue by about $600/year, which may be cost-efective for our hypothetical Nissan Leaf owner to invest in. hus, depending on the time frame, V2G revenues can add up to tens of thousands of dollars over the life span of a vehicle. For example, the 2018 Nissan Leaf costs a consumer in the USA as low as $22,490 after federal tax rebates [13]. In theory, it would take only 10.5 years for an owner to recapture that value in V2G revenues (not accounting for other beneits of EV ownership, like reduced fuel costs). At the same
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time, it is important to note that frequency regulation prices are highly variable over time and electricity grids. Figure 2.1 shows the total revenues of a V2G owner providing frequency regulation over 16 years in the ive electricity grid operators in the USA, where total revenues can range from just under $20,000 to over $45,000 [14]. Of course, these revenues rely on the three factors in Eq. 2.1: frequency regulation price, power capacity, and EV availability. Frequency regulation price may vary signiicantly over time, hence the relatively large error bars in Fig. 2.1. At the same time, power capacity and EV leet availability can be increased, which both will increase the revenue potential. In a previous study, we have found that power capacity and variations in frequency regulation price are the most pertinent variables in overall revenue of V2G [15]. Either way, and depending on the time frame, the potential of V2G to reduce the cost of ownership over the life span of the vehicle could be quite enormous. Moving onto whether these revenues can incentivize further EV adoption, it is important to note that these revenue calculations have
Fig. 2.1 Revenues over a 16-year period providing frequency regulation in US electricity grid regions. ISO-NE ISO-New England, NYISO New York ISO, ERCOT Electricity Reliability Council of Texas, CAISO California ISO (Reprinted from [14])
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not been discounted to their net present value (NPV). Briely, for those unfamiliar, discounting is an economic concept that computes future costs and beneits to their value in the present. Essentially, the main idea is that $100 today is worth more than $100 one year from now. he amount discounted, known as a discount rate, depends on its use, but in economic analyses, typically ranges from 3 to 7% [15, 16]. Applying a discount rate of 5% to V2G revenues, we can calculate that in our example above, the NPV of V2G to our hypothetical Nissan Leaf owner over 16 years would be $23,000 (whereas undiscounted it would be $34,000). Still, when discounted, the potential revenues of V2G are quite substantial, even in comparison with the capital cost of the EV. Unfortunately, one of the main issues with technologies like V2G or fuel eiciency, as well as energy eiciency problems in general, is that consumers tend to greatly discount future costs and savings, well beyond typical discount rates. Known as an implied discount rate, consumers have been shown to discount future beneits and savings by as much as 15% [17, 18]. Applying such a discount rate to our example above reduces the beneit nearly in half, resulting in an NPV of $12,800. While still substantial, consumer implied discount rates would clearly inluence the valuation of V2G. hus, the use of V2G revenues to incentivize EV adoption may very well depend on how consumers view the technology’s beneits, and how they calculate future savings. In addition, the lack of business models, V2G-capable EV models, as well as other social barriers to EV difusion could limit the possibility of V2G revenues incentivizing EV adoption in the short term. We discuss these potential barriers further in Chapters 4 and 6. In the meantime, beyond consumers, the beneit of frequency regulation market revenues is even more compelling to other types of EV owners and users. As is the case currently with pilot projects [8, 9], V2G revenues may be especially enticing to leet managers, who tend to be more cost-sensitive than consumers, can be more easily aggregated than individual consumers, and can more easily integrate EVs (model availability, less range limitations, trips already scheduled). In some cases, V2G capability has successfully incentivized the adoption of EVs in leets, and in the short term will likely incentivize marginal EV adoption in leets next in a variety of uses, such as vans, buses, even garbage
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trucks [15, 19, 20]. While V2G revenues can more easily be integrated into leet EVs, they may act as a short-term bridge to the wider market of private consumers. In this thread, one can construe leets as small market niche, or a “protected space” where V2G can develop before moving onto the regime or landscape levels [21]. Beyond the economic beneit of providing a new revenue stream for EV owners, V2G can also increase the cost-efectiveness of ancillary services, which reduces expenses for grid operators and society overall. For example, in the USA, it is estimated that the frequency regulation market alone costs approximately $400 million per year, and spinning reserve markets cost another $200 million per year [22]. Given the limited operating costs of a V2G system, which is essentially zero once the system has already been developed, increasing V2G capacity can greatly reduce these costs, saving grid operators (and thus electricity payers) potentially hundreds of millions of dollars per year. At the same time, the assumption that V2G can greatly reduce the cost of ancillary services beneits society, but also entails a decreasing revenue stream for EV owners as more V2G capacity is added to the system, reducing cost and pushing overall revenue downward. hus, in the long term, the opening of new markets (such as DSO services or renewable energy integration) may be key to maintaining the revenue potential of V2G. Nonetheless, V2G can greatly reduce electricity grid costs, especially in the ancillary service market. Moving toward the future, it is likely that V2G can help reduce grid operating costs in other ways as well, though those ways have not yet been monetized [23]. For example, as often discussed, V2G is a cost optimum way of integrating renewable energy, especially compared to other storage options, as we showed in Table 2.1. Previous work focusing on high-penetration renewable scenarios in the PJM electricity grid has found that compared to other storage options, V2G can save $419 billion over a 25-year time frame, or approximately $24 billion per year [2]. Once society chooses to commit to large-scale renewable energy development, V2G can save society billions of dollars per year providing storage in a variety of scales and contexts—from improving ancillary services, local utility storage, to renewable energy integration.
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As such, V2G can make the EV sociotechnical system even more alluring from a socioeconomic perspective. In addition to the hundreds of millions, or even billions of dollars that V2G can save directly in electricity grid operation annually, if it incentivizes further EV adoption, then indirectly society can gain another set of socioeconomic beneits, the chief one being reduced fuel and maintenance costs. Assuming a full transition from the current system to EVs, societal expenditure on fuel and maintenance is expected to likewise decrease substantially. For example, the USA consumes 142.8 billion gallons of motor gasoline, costing an average of $2.33 per gallon in 2017 [24], resulting in a total fuel cost of $332 billion dollars per year. If these same vehicles had travelled using EVs, using average electricity costs [7], the approximate cost would be about $95 billion. So, in addition to the grid eiciency savings from V2G, EVs can ofer additional socioeconomic savings in the hundreds of billions annually. To the extent that V2G can indirectly incentivize the further adoption for EVs, the total socioeconomic value of V2G can be quite expansive, anywhere from hundreds of millions per year to hundreds of billions. Clearly, if properly implemented, a V2G-EV sociotechnical system can ofer substantial economic beneits to both consumers and society as a whole.
2.1.3 Environment and Health Beneits: Sustainability in Electricity and Transport hirdly, in addition to economic beneits, V2G also provides other societal beneits through reductions in environmental and health damages in both the electricity and transportation sectors. Looking at the electricity sector irst, the environmental and health beneits can be divided into two main prongs: displacing current ancillary service market participants and large-scale renewable energy integration. Before quantifying the extent of these beneits, let’s irst briely review how the existing system damages the environment and current electricity generators, namely coal and natural gas, generate emissions during the production process that causes damages to the environment and public health. he relevant emissions include climate change-causing
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gases, carbon dioxide (CO2) and methane, as well as those related to health-damaging particulate matter (PM), including nitrogen oxides and sulfur oxides (NOx and SOx). While climate change damages are self-explanatory, gaseous emissions can cause health damages by directly emitting PM, or by emitting NOx and SOx, which subsequently turn into PM. he most damaging is PM that is under 2.5 microns in diameter, known as PM2.5, as these can bypass the iltration system of the lungs and cause cardiopulmonary diseases, and premature deaths [25–29]. In addition to the gaseous emissions, electricity production also causes a wide variety of other impacts, such as impacts to wildlife, land use, and water resources [30, 31]. In order to understand the trade-ofs of electricity production and potential alternatives, one avenue is to monetize the climate change and public health damages of electricity production.1 However, the process of doing so is quite complex, as the main things being damaged by climate change and public health emissions, the entire planet’s environment and human lives, respectively, are necessarily diicult to value properly Still, in order to give some context to our indings below, we briely describe how these damages are monetized in the literature (in equivalent MWh of production), by looking at the cost estimates of the damages of respectively CO2 and health-related emissions. First, climate change damages are estimated over the time frame of several hundred years in integrated assessment models (IAMs) that attempt to capture the full damage of unabated climate change, and then discount the value into a NPV, typically in dollars per ton of CO2 [16, 32]. his estimate, called a social cost of carbon, relies on several key aspects, including the type of damages that are included, the relative risks of climate-related catastrophes, and the discount rate used, among other variables [33]. Since valuation of planetary devastation can be diicult, studies have produced a wide variety of estimates of the social cost of carbon, anywhere from $10 per ton to several tens of thousands [34, 35]. However, the US government uses a method that takes
1It
is worth noting that wildlife and water damages, despite being substantial impacts on the environment, have not been monetized and would likely be very high in costs if they were [30].
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averages from a variety of modeling methods and concludes an average of just about $50/ton of CO2, which we use in our monetization throughout this book [16, 32]. hus, to estimate the economic impact avoided by V2G, one can multiply this social cost of carbon by the carbon emissions that were avoided from coal and natural gas. Using average carbon intensities and 2016 production rates (the most recent year available) [7], coal and gas climate change damages amounted a total of $94 per MWh per year from these two sources totaling to $62 billion and $32 billion, respectively. Secondly, the exposure of particulate matter to the public causes a variety of negative consequences, such as lung cancer, asthma, and other cardiopulmonary diseases, resulting in increased sickness and premature death [25, 26]. From an economic perspective, increased sickness leads to reduced productivity, while the valuation of premature death is even harder and based on statistical estimates. Speciically, in order to estimate the cost of loss of life, economists use a metric termed the value of a statistical life (VSL), which is generated based on the valuation of increased risk of death and used by policymakers to estimate beneits of lifesaving technology [36]. However, since exposure, and thus damages, is dependent on geographic factors as well as the direction of the wind carrying the particulate matter and the impacted population density, a universal cost estimate of emissions is diicult. Instead, air quality modeling is typically utilized to estimate these damages from electricity production, which are then monetized and divided by total energy production per generation type [27, 28]. For example, coal-related health damages in the USA have been found to range from $0.02 to $1.57 per kWh [27] (the average being $0.14/kWh), while natural gas has been found to have damages about half the costs of coal, roughly $0.05/ kWh [28]. Applying these average health damage costs to 2016 production rates [7], it is estimated that coal caused $173 billion in damages, and natural gas caused $69 billion, for a total of $242 billion per year. Combining this with the climate damages above, the coal and natural gas system cause approximately $336 billion in environmental and health damages each year. If these damages were included in the electricity price, then it would essentially double the cost of electricity [7].
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Fig. 2.2 Estimated annual CO2 emissions avoided by V2G per electricity region, assuming 1% of EVs are V2G-capable (Reprinted from [14])
From an economized environmental and health perspective, and plain common sense, it is thus of the utmost importance to move away from these actors and their impacts in the electricity market. his will certainly require a substantial transition with a variety of diferent systems, only one of which is V2G. However, V2G can play an important part in the short term and long term. he most immediate way that V2G can reduce the environmental and health damages from electricity production is through participation in the ancillary services market. he most relevant ancillary service market competitor to V2G is natural gas, and the addition of V2G can displace both its carbon and health emissions [14]. For example, using an agent-based model to estimate the amount of V2G-capable EVs in each region Noori et al. estimate that hundreds of thousands of climate change emissions can be avoided in the frequency regulation market, depending on the region and EV penetration level, as shown in Fig. 2.2. hus, assuming a relatively modest V2G system in the near future, the USA can avoid almost a million tons of CO2 by 2030, which would equate to an avoided damage of $50 million per year using the social cost of carbon discussed above, only from displacing some of the natural gas in the frequency regulation market. Unfortunately, studies have yet to characterize the full beneit of V2G entirely displacing all conventional fuel participants in the ancillary services market. In addition, there are
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no studies on the avoided health damages from V2G participation on the ancillary service market. Using the carbon content of natural gas [37], the implied total production of natural gas based on carbon emissions in Fig. 2.2, and the estimated health damages from natural gas [28], we estimate that there should be approximately $106 billion in avoided health damages in the scenario of 1% V2G modeled by Noori et al. [14], totaling approximately $150 million per year. hough not thoroughly studied, assuming V2G expanded to capture the entire ancillary services market (not just frequency regulation shown here), then the climate and health damages avoided could be even more substantial, especially considering that the entire value of these services is $600 million per year [22]. In sum, V2G can provide a very large value to society by avoiding carbon and health emissions in the ancillary service market, but deserves a lot more study than the rough estimates presented here. Moreover, an optimist’s vision for V2G entails more than just the decarbonization of ancillary services. Instead, the larger environmental and health beneits to be captured are to help integrate the largescale implementation of renewable energy. he majority of the damages caused by coal and natural gas happen not on the ancillary service market, but instead as a result of wholesale energy production. Of course, V2G cannot replace wholesale energy production (for extended periods of time) given limits on storage to produce energy. However, V2G can provide storage and lexibility for renewable energy to displace conventional fuel sources. But to understand how V2G assists renewable energy integration one must also understand the challenges of renewable energy integration in general. In short, the initial challenge of the primary sources of renewable energy, wind and solar, is that energy production cannot be controlled to the same extent as previous conventional electricity production actors, like coal and natural gas. In order to meet load demands, electricity grid operators must deal with the intermittency of renewable energy, that is, that the sun doesn’t always shine and the wind doesn’t always blow. Intermittency in turn leads to two central challenges for electricity reliability: sudden changes in generation which require rapid responses from other electricity producers, and lack of suicient supply to meet demand. he irst challenge requires high levels of lexibility
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Fig. 2.3 Three scenarios of storage with large-scale renewable energy in the PJM interconnection. Left column: hydrogen storage, center: centralized batteries, right: V2G (Reprinted from [38])
and responsiveness on the grid, whereas the second challenge requires either backup storage or generation or building additional renewable energy (which would likely lead to over-generation at other times). he general mismatch between generation and load is shown in Fig. 2.3, based on modeling work of large-scale renewable energy. Figure 2.3 shows the modeling of very high levels of renewable energy in the PJM grid, as compared to the historical load. As one can see, the wind generation (shown in the blue and pink in the top half of the igure) is very unpredictable, and over the course of only a few hours ranges from half of the load to several times over the needed load. hus, in the bottom half of the igure, one can see the need of backup storage and generation, shown in the gray and red. his is the generation that is needed to ill in the wind lulls and lack of solar production to ensure that there are no interruptions in electricity provision. So, if there is enough V2G capacity present in the electricity grid operator’s system,
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then one can utilize V2G storage to essentially perform peak shaving for a few hours until the wind lull is over. Without the use of storage, this extra needed generation would be produced most likely by coal or natural gas sources. Furthermore, in addition to obviating the need to rely on conventional fuel sources, storage like V2G has the additional beneit of being able to store excess generation (shown in gold in Fig. 2.3), which is expected to increase as wind and solar become the main source of electricity production [2, 38]. However, at the times where a large amount of backup generation is needed and storage cannot meet all of the generation on its own, grid operation runs into another problem: that conventional power plants cannot respond quickly enough to ill short term generation needs. he rate at which conventional generation plants can increase their generation of electricity, known as the ramp rate, can vary signiicantly from the type of production source. Depending on the technology and age of the power plant as well as its minimum load and start-up condition, coal can take about 3 hours to reach 100% production, whereas natural gas would need about half an hour to an hour (worse yet, nuclear would need at least a day or more) [2, 39]. In contrast, V2G and other battery storage have only a couple of seconds delay and almost no ramp-up time. But given that wind and solar generation can luctuate rapidly within an hour, or even minutes [40], there needs to be lexibility in the grid to allow conventional fuel power plants enough time to ramp up production, especially if the need for production is unforeseen. In this case, V2G can act as a temporary shoulder, which can help ill in generation gaps until slower means of production are able to ill in the larger generation gaps. Also, conversely when wind and solar generation picks up again, V2G can provide storage capacity while slower generation ramps back down, preventing curtailment of renewable energy and ensuring grid stability. In this respect, Fig. 2.4 shows the beneit of lexibility to wind and solar photovoltaic (PV) and highlights that, as lexibility of the grid increases, the amount of curtailed (or wasted) renewable energy decreases substantially, as 100% lexibility (which a large V2G capacity could achieve) can help increase penetration by nearly 30% while only curtailing 10% of the energy (points A and B in Fig. 2.4). hus, in the
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Fig. 2.4 Renewable energy curtailed, based on percent penetration and level of grid lexibility (Reprinted from [41])
short term, where grids rely on a mix between renewable energy and slower, conventional sources, V2G can provide important lexibility services to help integrate renewable energy without interrupting electricity grid reliability [2]. And when renewable energy becomes the sole means of energy production, i.e., 90% or more of total production, then V2G may act less as a lexibility service and more as a wholesale backup storage service (obviating the need for fossil fuels). Comparing these two types of services that V2G may provide, both play an important role in the short-term and long-term scales of the large-scale renewable energy transition. Flexibility is a key turning point in the transition and coincides well with the characteristics of V2G, such as quick responsiveness that other electricity actors do not have. his type of service will indirectly lead to improvements to the environment and public health, as it can help integrate renewable energy without causing the system to fail. On the other hand, the second service of wholesale backup storage provides more direct environmental and public health beneits, as it is directly displacing fossil fuels, but this requires substantial amounts of energy capacity. As shown in our discussion of
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Table 2.1, an entire leet of V2G-capable EVs would likely have suicient storage capacity to provide this service, but this would take a long time to develop. Nonetheless, V2G may play an essential role in the decarbonization of the electricity sector in a variety of ways: ancillary services, increased lexibility, and backup storage. Secondly, it is important to remember that electricity production is not the sole source of climate change and public health emissions. Indeed, in the USA, electricity production and transportation sectors are equally liable, both representing 28% of total climate change emissions in 2016 [42]. In addition, consumption of gasoline and petroleum causes substantial damages to health [43, 44], leading to approximately 3800 premature deaths per year in the USA, or about $35 billion worth of economic damages per year [45]. To the extent that V2G can incentivize the adoption of EVs in the transport sector (as discussed above), then V2G can help the decarbonization and improvement of public health from the transportation sector as well. Indeed, combining these calculations with the monetization of environmental and health damages from electricity production, the current electricity and transportation sectors cause $470 billion in damages annually, or an equivalent of decreasing the US GDP by 2.5% per year [46]. Considering US GDP increased by 2.3% in 2017, if society used EVs with V2G to move away from fossil fuels in both electricity and transportation, society would beneit more that than the economic growth from all other types of activity [46]. Moreover, though we use the USA as an example, this type of calculation will be relatively similar in any region of the world. In conclusion, the environmental and health beneits that V2G could provide to the electricity and transportation sector are enormously important to the sustainability and economic activity of society.
2.1.4 Other Beneits and Perceived Beneits As discussed in Chapter 1, V2G (and its related concepts like V2H or V2X) technology can be applied in a wide variety of other useful applications, such as in microgrids or emergency backup in one’s home. However, as compared to the previously discussed three beneits,
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especially the latter two, the variety of other beneits that V2G could provide are notably less valuable to society. For example, V2G systems have been studied in the context of microgrids or community grids to integrate highly local renewable energy development [8, 47, 48]. While V2G has been found to be beneicial in these cases, the overall societal beneits as compared to large-scale renewable energy integration can be characterized as much more niche. Moreover, other beneits such as backup power to one’s home or being able to disconnect from the grid are individual beneits that are more diicult to monetize and likely do not provide much of a beneit to society as a whole. Likewise, V2X beneits, like using the vehicle to provide mobile loads (such as using the vehicle to provide energy to a telescope) may increase the advantageousness of a V2G-capable EV, but the beneits are not monetizable nor societal. While these should be studied, especially as they could encourage users to adopt V2G-capable EVs for personal beneits and then subsequently also use them in ways that beneit society as a whole, it is important to note who beneits from each use and what the scale is of these potential beneits. For example, in Fig. 2.5 we show how academics and experts view the beneits of V2G. On the left hands we show the research focus of recently published V2G papers, and on the right, is data from our expert interviews (described in the Introduction) and how they perceive the main beneits of V2G. Both the research papers and the expert interviews overwhelmingly focus on V2G as a means to integrate
Fig. 2.5 Research focus (a) and Expert opinion (b) of Beneits of V2G systems (a is reprinted from [8], b is based on author’s data)
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renewable energy, but this is often more on the technical aspects (as opposed to the environmental and economic aspects), as well as the variety of grid services that V2G could provide. However, noticeably absent from both lists is the public health beneits of V2G, reinforcing our indings that health and other societal beneits have been understudied by the literature (and go unrecognized by experts). While climate change appears as the 9th most common research topic, less valuable concepts, like emergency backup, microgrids, and V2H, are discussed more prevalently. his is not to say that the other beneits of V2G, V2H, and V2X should not be researched at all, nor discussed by experts. Indeed, some may argue that these concepts, such as V2X, may be also understudied by the literature and can provide a wide array of potential beneits to EV owners and society, even if they cannot be monetized yet. However, it is also true that the most valuable beneits of EVs, particularly environmental and health-related beneits are also understudied. And while V2X may provide some beneits to individuals, it is essential to understand that the main beneits of V2G have a substantial impact on society, from an economic, environmental, and health perspective. Importantly, we would push this argument even further and claim that these societal beneits provide valid reasons to the idea that policymakers and government should take an active role in encouraging the development of V2G. On the other hand, there is little reason for government intervention to encourage personal beneits like V2H and V2X. All in all, V2G systems include all of these beneits—large societal savings and novel personal beneits like powering telescopes.
2.2
Beneits in Motion: From Fleets to Individuals and Beyond
As the bundle of beneits has been described above, there remains the question of who will be doing V2G and how these beneits will accrue as the V2G system difuses and evolves. As mentioned previously, the status of V2G currently is entirely focused on leet vehicles performing
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frequency regulation [8, 9], however not to the degree that ancillary service prices are decreasing, thus the beneits are primarily accruing to the EV leet owners. Or rephrased, the overall V2G power capacity of these pilot projects is relatively low within their respective electricity markets (only a few hundred kW), there is not enough participation to capture the entire market, push ancillary service market prices down, nor to really decarbonize the market. he next step in V2G difusion is likely a push to move from leet pilot projects toward fully commercially developed V2G leets and subsequently to privately owned individual vehicles. hough the latter represents the largest capacity, difusion of EVs and V2G in the individual consumer market may be a slow and lengthy process. EVs themselves have faced a substantial amount of challenges in their difusion, and even after decades, only represent 0.2% of the global vehicle leet [49]. Considering the V2G-capable EVs in the world are in the tens or hundreds only, both EVs and V2G have a long way to go before capturing the capacities described in Table 2.1. Nevertheless, as EV prices decrease, it is expected that there will be a rapid transition to EVs, where adoption accelerates exponentially. For example, one study found that EU sales share of EVs in 2030 could range anywhere from about 8% to nearly 70% [50]. Even if EV market share was 70%, they estimate that EVs would still only represent just under 30% of the total vehicle leet [50]. Additionally, it is impossible to know what proportion of those EVs would be V2G-capable, as this would likely depend on a variety of the technical challenges and institutional barriers we discuss in the following chapters. If the EVs by 2030 were indeed all V2G-capable, this 30% would still represent a very large amount of power and energy capacity. his would likely be suicient to provide all ancillary services for electricity grid operators, decreasing the cost of grid operation and reducing climate change and public health emissions from the displaced electricity grid producers. On the other hand, most likely it remains insuicient to capture the larger economic and environmental beneits of large-scale renewable energy. For example, two studies on large-scale renewable energy integration found that to achieve 50 and 99.9% renewable energy integration of the PJM electricity grid, 70 and 100% of the vehicle feet would need to
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be V2G-capable EVs, respectively [2, 38]. hus, in order to capture the entirety of the economic and environmental beneits described above in regard to the renewable energy transition, it seems that V2G-capable EVs not only deserve but also require further policy support. Lastly, though personal EVs would provide the most capacity to the electricity grid, this is not to say that they are mutually exclusive with public transportation. Indeed, some types of public transportation such as buses can be electriied and provide the same V2G services [15, 19]. Indeed, the full decarbonization of transport would require the electriication of a wide variety of transportation methods, including personal vehicles, larger buses, among others. As such, given the wide need for storage capacity in future large-scale renewable energy scenarios, V2G capacity would be needed in all, not just some of the transport sector.
2.3
V2G and the Grid
Storage in general and V2G are very valuable to the grid as it exists now, especially as more renewable energy is added to the system. However, as renewable energy is integrated into the electricity grid, many have called for substantial changes to the electricity grid itself. For example, some have argued that the integration of the electricity sector with the heat and transportation sector would increase the reliability of wind-dominated systems [2, 51, 52]. Of course, the integration of the transport sector coincides perfectly with V2G systems. On the other hand, integration of the heat sector will likely reduce the need for other types of storage, as excess generation can provide a substantial beneit to the eiciency of the heat system [52]. Indeed, the integration of new sectors into the electricity grids coincides with the concept of smart grids, which is essentially a means of increasing communication in the electricity grid to control electricity demand to improve the lexibility and dynamism of the electricity grid [53]. However, the smart grid goes beyond V2G and includes distributed electricity production (such as community solar), as well as other types of demand-response actors, like HVAC, water heaters, and other forms of electricity demand [54]. Nonetheless, these studies show that V2G will not be only actor
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participating in many of these services required for large-scale renewable energy and increased grid eiciency, but that V2G is likely to be the most valuable and possibly one of the largest actors on the smart grid. In short, the emergence of smarter grids would reinforce V2G. On the other hand, another way to increase the reliability of systems based largely on renewable energy is to geographically increase the scope of the electricity grid, particularly by construction of high-voltage direct current (HVDC) transmission lines connecting new forms of electricity generation [55, 56], often called a supergrid. One of the main beneits of connecting geographically disparate regions is that wind generation becomes more stable on average, and thus easier to manage [57]. On the other hand, HVDC networks can also connect diferent types of renewable energy sources, such as solar-rich areas with wind-rich areas, and deliver them to where electricity demand is located [55, 56]. For example, we show a proposed HVDC supergrid in the USA in Fig. 2.6.
Fig. 2.6 Supergrid with high levels of renewable energy and a HVDC network (Reprinted from [56])
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In theory, the supergrid ofers substantial beneits to renewable energy integration. Speciically, this type of supergrid can integrate large amounts of renewable energy at comparatively low costs by siting renewable energy projects with the best resource, as opposed to those that are close to the existing grid transmission lines, reducing overall costs. In addition, given a variety of renewable energy sources and the beneit of geographical variation, the supergrid is expected to not need as much grid lexibility and storage as the existing grid. In short, the supergrid can provide the infrastructure for large-scale renewable energy at prices cheaper than today with little or no storage [56]. However, as advantageous as the supergrid is, it still faces several substantial challenges. he most obvious of which is that a network of HVDC transmission lines across a large region (e.g., the USA or the E.U.) would require a substantial investment in capital costs (which would save money over decades). However, such megaprojects often run into a variety of inancial, regulatory, and social risks [58]. In addition to securing the billions of dollars in overnight investment to establish the HVDC network, supergrids face regulatory questions (i.e., who regulates and controls the supergrid), cost overrun concerns, lack of political support, and issues of public acceptability [59–61]. With these questions in mind, the supergrid may indeed face an uphill battle to be developed, despite its potential beneits. As such, the role of V2G in relation to the supergrid is relatively uncertain. If the supergrid is realized, then the need for backup storage is largely obviated. Yet, V2G may still play an important role in renewable energy integration on the supergrid that focuses on intra-regional energy balancing (as opposed to the inter-regional balancing done via HVDC transmission in the supergrid). In addition, V2G can provide a cheap means of ensuring reliability in the case of faults in the supergrid. hat is, if a solar or wind power plant in California went suddenly oline or an earthquake brought down a main HVDC line, it may have much further reaching impacts in the supergrid, possible afecting the entire geographical region. With V2G, such concerns could be mitigated as it reduces the overall operational risk associated with supergrids [59]. However, it is unlikely that V2G could assuage the regulatory,
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inancial, political, and social barriers that a supergrid would face previous to its construction. In the meantime, V2G may actually provide a bridge to the supergrid. As discussed above, of the two means of V2G to integrate renewable energy, lexibility, and backup storage, V2G is better suited to provide lexibility given its responsiveness and high levels of power but somewhat limited energy capacity. hus, as renewable energy is in middling levels with some conventional energy, V2G could help integrate renewable energy at lower costs, while the supergrid is being built for the highest level of renewable energy (e.g., 90% or more). his could help the business case of the supergrid, as it makes little sense to have a supergrid if only 30–50% of generation is renewable (and the other is conventional power plants that do not use the supergrid). But while V2G may be a stepping stone to a supergrid, the interaction between a supergrid and lexible storage services has not yet been studied rigorously by the literature. Given the comparatively cheap cost of V2G, and the value of storage to the electricity grid in general, it is reasonable to assume that under any supergrid or smart grid (or combination thereof ), that V2G can provide a diferent array of valuable services.
2.4
Conclusion
In this chapter, we have aimed to deine the potential beneits of a V2G system. hese beneits can be primarily categorized as technical, economic, and environmental. In sum, V2G ofers a cheap and technically advantageous form of storage, one that, in tandem with the beneits of a full EV difusion, has economic, environmental, and health-related beneits that are of immense value to society, since the current system causes hundreds of billions in unnecessary costs each year. While these societal beneits are vast, we also briely discussed other potential beneits of V2G, highlighting how these may provide novel and non-monetized beneits to individual EV owners. Such a distinction is important to understand the underlying impetus for policymakers to intervene and encourage the development of V2G for the beneit of society. In other words, while V2X could ofer new and interesting business models and services to consumers, those do not necessarily justify public support.
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However, we wholeheartedly argue that the societal system level promise of V2G validates the extensive and active support from public authorities and industry. Moreover, this chapter also discussed how these beneits would be realized as V2G difuses from its current state to, potentially, the entirety of the vehicle leet. Likewise, we hypothesized how the evolution of the electricity grid toward supergrids and smart grids would afect the role and potential of V2G. In line with sociotechnical thinking, this reminds us that V2G will coevolve not only with technical improvements in vehicle performance, but in a symbiotic relationship with other elements of the system including batteries and storage as well as non-technical issues such as user practices, political regulations, and economic incentives. We will explore these latter themes in the chapters to come.
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3 The Technical Challenges to V2G
Starting with this chapter, we next move onto the challenges that V2G currently face and will face as it difuses (or fails to do so). With the beneits described in the previous chapter in mind, understanding these challenges is essential to capturing the societal beneits that V2G ofers. While these challenges encompass the entire sociotechnical system and include economic, regulatory and social aspects, we irst start with the most immediate of them, the technical barriers to V2G. Speciically, we describe the three primary technical challenges to the implementation of V2G: battery degradation, charger and communication eiciency, and aggregation. While none of these barriers prevent a V2G system from operating, they do impact the eiciency and thus economic advantage of V2G systems. As a result, the challenges here are the basis for many of the other challenges described in Chapters 4–6. In order to understand those later challenges, a basic understanding of the technical nuances of these challenges is foundational.
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Battery Degradation
he irst and most compelling challenge to V2G systems is the degradation of the battery as the result of wear from increased use. Battery degradation can cause loss of capacity over time, which impacts an EV’s range capability. For instance, a 30% capacity fade in an EV that was originally able to drive 100 miles means that the EV can now only drive 70 miles. Obviously, given the concerns that already exist over range of an EV and range anxiety [1–3], further decreasing the range only worsens this perceived problem. he extent that V2G may degrade the battery is consequently expected to impact the potential adoption of V2G in two ways. On the V2G side, the potential battery degradation could afect consumer’s willingness to participate in V2G systems. Battery degradation also afects V2G’s business case, as the payment ofered to consumers will need to be high enough to compensate for potential battery degradation, or worse, if overall capacity fades, replacing the battery. Calculating the degradation of a battery’s capacity in general is not as intuitive as one may think, and instead is very complex, with the main causes being time (known as calendar aging) and the amount of cycling on the battery (known as cycling aging), which is the amount of energy discharged and then charged into the battery [4]. hese two types of aging in turn depend on a myriad of factors, including the number of cycles put through the battery, time, the operation temperature of the battery, power rates of charge and discharge, the depth of the discharge (DOD), the state of charge (SoC) of the battery, and the total energy withdrawn or energy throughput [5, 6]. Before moving onto V2G, understanding the degradation of a generic EV is complex and highly context dependent. Nonetheless, understanding typical battery degradation from typical non-V2G use provides important context to the additional degradation that V2G may cause. Because degradation is most contingent on time, temperature, and use, the degradation of a typical EV is highly dependent on the driving and charging characteristics of the EV user, as well as the weather conditions of where the EV is used. hen again, time does not depend on geography or use patterns and is less context dependent.
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Fig. 3.1 Estimated battery capacity loss over time for EVs (no V2G included). Note that the difference between different levels of charging, as shown in the legend in the upper left corner, makes no discernable difference on the difference on capacity loss (Reprinted from [7])
Some assumptions therefore need to be made in order to estimate the amount of degradation that EVs will face. As an example, using an average driving behavior, the degradation of battery over time only including typical EV use was estimated to be about 31% over 10 years [7], see Fig. 3.1. hough Fig. 3.1 shows that the degradation is not exactly linear, the capacity fade equates to roughly 3% per year. In this study, the authors ind that higher temperature leads to higher capacity losses due to calendar aging, while lower temperatures lead to higher losses from cycling aging [7]. From an average temperature, e.g., San Francisco, the 31% loss over ten years is about evenly due to calendar aging and cycling aging. While calendar and cycling aging are roughly equally responsible for battery degradation, temperature is one of the most inluential factors for both types of aging. hough lower temperatures cause a higher
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amount of cycling (given reduced eiciency in batteries [8]), which indirectly reduces battery capacity due to more energy throughput, in contrast, higher temperatures directly cause high capacity loss and battery degradation. For example, Fig. 3.2 shows that higher temperatures combined with high DODs lead to the most drastic degradation of the battery per cycle [9]. Meanwhile, Wang et al. ind similar impacts to degradation due to time with high temperatures [7]. As such, a key means to reduce battery degradation in general is the temperature management of the battery, to prevent the internal battery temperature from becoming too hot and degrading, but also preventing it from becoming too cold and reducing eiciency, especially while driving [8]. For example, all else the same, actively managing the thermal conditions of the battery can reduce capacity fade by 7 percentage points [10]. hus, improving battery management systems will have several beneits on the EV’s eiciency and on maintaining overall battery health and life. With these general concepts in mind, the battery degradation due to V2G is primarily because of cycling aging, of course, since calendar aging will occur either way. Since EVs that actually are performing V2G
Fig. 3.2 Battery degradation per cycle (N) as a function of temperature and depth of discharge (DOD) (Reprinted from [9])
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have not been around that long, it is not known based on actual experience how the overall degradation trends for frequency regulation (or any other grid service, for that matter) impact batteries. Instead, like many of the studies regarding general EV degradation, the estimation of V2G’s impact on batteries is modeled, often with some underlying empirical data, based on battery experiments in a lab that accelerates impacts (but not on actually EVs providing V2G services) [11]. However, as with the importance of individual driving patterns, the assumption of the type of electricity grid service that the assumed V2Gcapable EV provides, as well as the regularity of providing these services, are the most inluential on estimated degradation. For example, providing peak-shaving services will entail substantial amounts of DOD, while frequency regulation requires smaller amounts of DOD, but generally, is more active throughout the year. However, as discussed in previous chapters, frequency regulation is the primary market in which V2G will provide in the short-term, and will likely provide other more energy-intensive services only once there is a substantial amount of V2G capacity in the EV leet. With this in mind, Fig. 3.3 shows the estimated degradation from three diferent V2G services, assuming diferent amounts of participation rates. In the “extreme cases” (which we do not believe to be so extreme for frequency regulation), the authors ind that frequency regulation participation every day will further degrade the battery by 3.6% over ten years [7]. On the other hand, net load shaping (i.e., integrating solar electricity and avoiding duck curves) every day causes an additional degradation by over 20%, but it is highly unlikely that such services would be needed more than 20 times a year (perhaps an exception would be some V2H use cases). hus, an EV providing frequency regulation every day and some type of net loading or peak shaving occasionally would be expected to cause only minor degradation over 10 years (e.g., approximately 5% higher additional capacity loss). Of course, any additional degradation is undesired, but these numbers are not discouraging. In fact, given that even the minor degradation as modeled here is uncertain, the impacts to the battery may be even less damaging. Another study used actual frequency regulation performance to test a battery (as opposed to modeled behavior), and found
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Fig. 3.3 Average battery capacity losses over 10 years with V2G services, providing three different services (peak shaving, frequency regulation, net load shaping) in two usage scenarios (everyday for 10 years and 20 times per year) (Reprinted from [7])
that given limited DOD and energy throughput, there was essentially no additional degradation as the result of V2G [12]. he reason for this is that frequency regulation keeps the V2G-capable EV at a medium SoC, which reduces chemical wear [13], and the limited demand of energy throughout the hour of a typical frequency regulation signal is substantially less than driving (and related recharging) power and energy demand. As the V2G leet increases in the future, the expected energy demand per car can be expected to decrease, further leading one to conclude that battery degradation will continue to decrease as well. Indeed, as V2G increases in capacity and there is more lexibility within the V2G system to implement algorithms which can split the power and energy demands in more optimal ways, V2G may be used to actually decrease battery degradation. For example, using a smart grid algorithm to control for DOD and overall cycling, one study found that V2G can reduce overall battery degradation by 9.1% [14]. Essentially, while V2G participation (especially frequency regulation)
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has limited impacts due to low DOD and energy throughput, the communication and controlling of power lows allow aggregators the possibility to implement more intelligent practices that will reduce degradation. One such principle may be to limit the times when high power is used to recharge the battery as fast as possible, but instead control slower charging while providing frequency regulation over an allotted time. his, along with other principles would be available as a result of a V2G aggregation system and may not be able to implemented without some kind of aggregator. hus, in the best case, V2G can open new possibilities to the consumer to maintain the health of their EV’s battery. In sum, estimates of V2G’s impact on the battery can widely vary, with some estimating small (though signiicant) additional degradation to the battery’s capacity [7], while some ind very little to no impact given the limited energy throughput [12], and inally some ind that V2G will reduce degradation [13, 14]. It seems recent research, as well as evidence from the pilot projects, have rebuked earlier harsher estimates of substantial battery degradation (some of which suggested V2G would reduce a battery’s life to only two years) [5]. It is therefore very unlikely that any potential battery degradation caused by V2G will afect the technical feasibility of an EV from meeting daily driving range requirements or prevent further participation in V2G [15]. At the same time, it is important to remember that while the current literature’s in-depth modeling show positive results for V2G’s impact on batteries, these results are still largely hypothetical. Nonetheless, battery degradation is an important challenge once it is introduced to consumers and starts to afect their valuation of the battery. Even though degradation may be relatively minor (or even improve battery health), consumers may resist participating in V2G out of fear that the impacts will be worse than expected, especially given the high valuation of battery life and range in general [3, 5, 7, 16]. To be clear, the barriers we discuss in Chapters 4 and 6 originate out of technical concerns with regard to the degradation to the battery and may be resolved through technical solutions, i.e., showing V2G does not impact battery life or actually improves it.
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Charger Eficiency
he second key technical challenge in the V2G system is the overall eiciency of sending energy to and from the grid, particularly from the electric vehicle supply equipment (EVSE). hough in Chapter 2 we showed that V2G systems have a comparatively high eiciency (~70– 80%) compared to other energy storage systems, such as hydrogen systems (eiciency of 40–50%), eiciency still has substantial impacts on the cost-eicacy of V2G systems. Energy losses impact the amount of total energy that makes it from the grid to the battery, and vice versa, so when performing any type of V2G service, the round-trip losses of energy are essentially paid for by the V2G aggregator and EV owner. In addition to V2G, energy losses efect the amount of money an EV owner needs to pay just to charge their EV. As such, the energy losses that occur throughout the V2G system inluence the technical eiciency as an electricity grid participant, but more importantly, the economic cost-efectiveness of both EV ownership and V2G participation, reinforcing the importance of understanding the extent of energy losses. Starting at the grid connection, energy losses can occur at the transformers, the breaker panels, and the EVSE. Next, within the car itself, energy losses can occur at the charger or power electronics unit (PEU), and inally, within the battery, with the opposite order of losses when discharging energy [17]. Similar to calculating battery degradation, the amount of energy losses throughout the process is highly dependent on variable factors, including temperature, current (in amps), and the current SoC of the battery. Complicating these factors further is that the amount of losses at each stage for each attribute also changes depending on whether the system is charging or discharging energy from the grid. Using an actual V2G system as an experimental setting, ApostolakiIosiidou et al. [17] found the overall system losses, as well as energy losses at each stage of the V2G system, as shown in Table 3.1. As one can read in this table, the amount of losses depends on whether the system is currently charging or discharging as well as the current level (in amps). However, a few trends can be found, that the battery, breakers,
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Table 3.1 Percentage energy loss per stage in the V2G system for charging and discharging at two different current levels Total GIV system percentage losses: building and EV components Component AC current (A) Percentage losses (%) Charging EV battery EV PEU EVSE Breakers Transformer Total
10 40 10 40 10 ≈40 10 ≈40 10 ≈40 10 40
0.64 1.69 6.28 5.77 0.10 0.29 0.00 1.30 10.20 3.33 17.22 12.38
Discharging 0.64 1.91 16.67 19.23 1.42 1.39 2.80 0.60 14.60 6.65 36.13 29.78
Reprinted from [17]
and EVSE are responsible for a very limited amount of the losses. Another trend is that, for the most part, eiciency increases as higher amperages are used (though of course, even this conclusion depends on other factors, such as temperature and the battery’s SoC). However, most concerning is that energy losses are particularly high at the PEU and the transformer. Nonetheless, one should note two important points about the transformer losses found in this study: irst, that the transformer modeled had abnormally low power loads, which causes high energy losses, and if assuming normal energy loads, transformer losses were substantially lower; and second, that transformer losses are typically not included in the costs to the consumer of a V2G system [18] as they are usually not “behind the meter.” With the higher (and more typical) utilization of a transformer, the authors estimate a roundtrip eiciency would be closer to 70% (including transformer losses), not the 62% implied by adding up the losses shown in Table 3.1. Unlike the transformer, unfortunately, there are no extenuating circumstances that artiicially inlated PEU energy losses. Instead, the authors found that other EVs found even higher energy losses (though these too occurred at very low currents). Nonetheless, more focus
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should be put on PEU eiciency, a hard task considering the wide varieties of currents and voltages that PEUs typically are designed to operate in. While previous literature has focused on the eiciency of PEUs during charging [19, 20], inding similar charging eiciencies as presented in Table 3.1, future research should focus on increasing the eiciency of discharging, and implementing higher eiciencies (e.g., 94.5% discharging eiciency) in practice [21, 22]. One simple solution to reduce overall losses is to increase the EVSE’s current and voltage capacity, as increasing the EVSE’s capacity from 8 amps at 120 volts to 10 amps at 240 volts would reduce within-EV losses from 20% down to only 6% [17]. However, underscoring the cheapness of electricity they found that this sharp decrease in energy losses only resulted in an increase in savings of $60 per year. Likewise, other studies found that higher capacity EVSEs (e.g., Level 2) would also perform more eiciently at higher temperatures than lower capacity EVSEs (e.g., Level 1) [23]. Additionally, upgrading the EVSE would have beneits beyond charging and discharging eiciency, such as quicker charging and higher capacity to bid into ancillary market services (as we briely described in Chapter 2). A second means of reducing energy losses is by designing a control algorithm that optimizes eiciency. Given that losses change depending on factors that can be either known (such as the battery’s SoC) or controlled (the current low), an algorithm can be designed to take this information into account to reduce losses either during charging or while providing V2G services (charging and discharging). For example, by taking into consideration power capacity and battery SoC, one algorithm decreased overall energy losses by 8.5% [17]. On the other hand, while algorithms can be used to resolve several challenges (as we discuss in more detail in Sect. 3.3.1), a recent review has found that there has not been enough focus in the literature in designing algorithms to speciically limit energy losses throughout the charging and discharging process [24]. All in all, control algorithms can be better designed in the future in order to maximize system eiciency, which is more complex than the literature commonly assumes (i.e., eiciency is rarely a constant and highly dependent on variable factors).
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Aggregation and Communication
Aggregation of individual EVs in the V2G system ofers a plethora of advantages that we have described above and in the previous chapters. hrough aggregation, V2G aggregators can implement control and dispatch algorithms that provide the means to optimize a variety of diferent aspects of the V2G system. For example, a variety of papers have investigated how algorithms can optimize grid stability, balance energy among EVs, maximize the economic beneit for EV owners, and minimize battery degradation, among other goals [24]. Despite these beneits, aggregators face two central challenges, the irst with implementing algorithms that can handle the growing complexity of V2G systems, and the second with the communication system. In order to capture the beneits that algorithms could ofer to the V2G system, these barriers need to be irst addressed.
3.3.1 Aggregation and Scaling As we describe in Chapter 1, aggregation is often a necessary aspect of the V2G system to have enough capacity to participate on large electricity grid markets. And while dispatch and control algorithms implemented in aggregation are not only necessary, and have a variety of secondary beneits, they also pose a set of challenges. Because a V2G system may be based on thousands (if not millions) of EVs, there is unpredictability and stochasticity inherent to any dispatch or control algorithm. While a variety of papers have endeavored to investigate the ways these algorithms can improve overall V2G performance, there remains several key issues that warrant further research. In a recent review of the literature Peng et al. ind four key areas that require a better understanding from an algorithm perspective: (1) a better understanding of economic factors (charging and discharging price, battery degradation, etc.), (2) the space and time distribution of EV integration in the grid (including prediction and machine learning), (3) algorithms that take into account factors that minimize energy loss,
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and inally, (4) increasing the practical implementation of the heavilytheoretical focus of the existing literature (especially important as V2G system grows and becomes more integral to electricity grid operation) [24]. While we discuss the economic challenges (especially battery degradation) and energy eiciency above, we will briely discuss the challenge of timing in V2G algorithms. he problem of timing within the EV leet can pose challenges in that the uncertainty of human behavior prevents accurately and easily predicting the capacity for leet lexibility a day in advance, when bids in electricity markets are often required. In order to resolve this uncertainty, algorithms can be designed to assist V2G aggregators to avoid energy imbalances and over-bidding capacity. For example, one study used reinforcement learning of EV behavior to reduce day-ahead prediction error and reduce overall operation costs due to energy imbalances [25]. In sum, implementing algorithms such as this one, in tandem with algorithms that minimize battery degradation, optimize overall economic beneits, and improve energy eiciency, should be put in the primary focus of research, especially as it moves away from theoretical aspects, and more toward practical applications. Beyond these recommendations, V2G can be considered an innovation the falls under the Internet-of-hings (IoT) landscape, of which there is substantially more literature on the barriers that these technologies will generally face. When placed in this context, the IoT literature provides another set of novel barriers to V2G. By far the most common challenge suggested by the IoT literature is the extensive amount of data needed to be collected, managed, and analyzed [26–29]. For example, if a V2G system consisted of 1 million EVs providing frequency regulation, the system will have data collected every few seconds, resulting in billions of data points each hour, or trillions of data points per year! Based on rough estimates of data collection for V2G systems in existence today,1 this amount of data would equate to tens to hundreds of petabytes (roughly a trillion kilobytes) for each million of V2G-capable EVs (keeping in mind that the USA alone has around 270 million vehicles [30]). Simply having enough storage for this data in of itself will 1Based
on the author’s personal experience with the data collection process with Nuvve, a V2G aggregator company (discussed in Chapter 1).
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prove challenging, not to mention optimizing management practices of the data, and the capacity to analyze the plethora of data in a reasonable matter. A second related set of challenges in this context is security and privacy, as they relate to data collection [27–29]. he main concern is that by providing data to a V2G aggregator that, if a third party was given access or hacked into the data management system, then one can determine an individual’s mobility patterns (as one can tell where one is, based on when and for how long their EV is plugged in). Considering the potential sensitivity of consumers, this is further complicated by the sheer amount of data being collected during V2G, and even more so if combined with other IoT technologies like smart homes or mobile phones [28, 29]. As such, another challenge will be regulating data collection, preventing access to data by third parties, and establishing legally and socially acceptable standards. In this thread, another related challenge commonly discussed in the IoT literature is a variety of legal and social challenges, which is certainly also true for V2G systems, as we discuss further in Chapters 5 and 6, respectively. On the other hand, some of the challenges proposed in the IoT literature may not be as applicable to V2G. For example, when combining a variety of diferent technologies, the heterogeneity of these technologies (i.e., communication, hardware capabilities) may pose a challenge in aggregation [26]. But, unless V2G is placed in the context of disparate other technologies (e.g., cell phones or LED lighting), then this challenge is unlikely to be pressing for V2G systems. Similarly, another study found that this heterogeneity combined with fast-changing innovation cycles could make the operation of an IoT system highly unstable and diicult to manage [27], but a V2G system in isolation is unlikely to face such challenges. Most importantly, it is worth noting that the two central challenges from an IoT perspective, the amount of data and the access to that data, along with several other minor ones such as capacity reliability, energy management and others [26, 28], become more diicult as aggregation continues to scale upward. As we discuss in Chapter 2, many of the societal beneits of V2G, namely renewable energy integration, are captured when large capacities are aggregated. hus, the largest beneits
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of V2G also come with the largest IoT-related challenges. Data collection, privacy, and security are only minor concerns in the current V2G systems that exist within private leets of tens of EVs, but if V2G is to become a dominant technology in the transportation and electricity sectors, then aggregation needs to be developed in such a way that large amounts of data can be stored securely and managed with a consumer’s privacy in mind. Because V2G remains a niche technology, the challenges of big data in V2G systems [31], as well as their potential solutions, remain to be seen.
3.3.2 Communication Standards In addition to the challenges in aggregation, algorithms and scaling of a V2G system, a related challenge is the communication standard that is used in the V2G system to transmit messages to and from the EVs and the EVSEs. his challenge of communication between the EV and the EVSE (as well as the backend of the system thereafter) also provides some opportunities, as a properly designed communication standard can resolve some of the challenges discussed in the above section, e.g., properly designed communication standards can ensure privacy and security of data transfer between an individual’s EV and the aggregator. Currently, there is a myriad of diferent communication protocols proposed by various groups to standardize the means of communicating between EVSEs and an EV, including the International Organization for Standardization (ISO) 15118, the Society of Automotive Engineers (SAE) J2847, and a de facto standard, CHAdeMO [32]. In addition to these, there are also a variety of periphery standards, such as communication between the aggregator and the EVSE, namely ISO 61850 and Open Charge Point Protocol (OCPP). However, here we will focus on the communication between EVSEs and EVs and the diference in implementation between SAE J2847, ISO 15118, and CHAdeMO. he main diferences and similarities are shown in Table 3.2. First, ISO 15118 is a partly published standard, which is still under development, and has the aim to be implemented globally, though initially it is most prominently used and accepted in Western Europe.
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Table 3.2 Differences between the three V2G standards Standard
Means of communication
Currents
ISO 15118
Power line AC or DC communication
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SAE J2847
Power line AC or DC communication