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4 The Electric Grid An important component of the ecosystem of the plug-in electric vehicle (PEV) is the electric grid, which provides the electricity that powers the vehicle. For the near term, PEVs do not pose unmanageable problems for the distribution, transmission, and generation components of the electric grid. For the longer term, successful integration of the smart grid and the smart electric vehicle could improve the services offered by both. This chapter examines how PEVs affect the electric grid and other issues related to the electric grid that might be barriers to PEV adoption. It discusses possible roles of the federal government in overcoming these barriers. There might be additional grid-integration issues of interest for PEVs (such as the use of PEVs in smart grid applications), but these issues are not addressed in this report because they are beyond the committee’s charge for its interim report and do not necessarily constitute barriers. Grid- integration of PEVs might enable the provision of additional services by utilities, particularly if achieved on a large scale; any issues pertaining to these new potential applications will be addressed fully in the committee’s final report. THE ELECTRIC GRID AND ITS INTERACTION WITH PLUG-IN ELECTRIC VEHICLES PEV recharging causes a new kind of service demand for the electric grid. Specifically, the cost and nature of service vary sharply with the time of day when the service is required and with the power demanded. The electric grid can be thought of as having three components: distribution wires and transformers that serve individual houses, streets, and neighborhoods; transmission infrastructure that moves power from generating units to the local distribution system; and generation units that provide the energy to the grid (Figure 4-1). PEV adoption does not now pose a substantial problem for the distribution, transmission, and generation components of the electric grid. Studies have shown that the existing generation and transmission capacity of the nation could accommodate 5 to 50 million PEVs, depending on which strategies are used to manage the charging demand (Hadley and Tsvetkova, 2008; Kintner-Meyer et al., 2010; MIT, 2010). The energy and total capacity required for charging PEVs under some conditions can be of the same magnitude as the capacity of individual components of the distribution system, but this has not proved to be a major issue (CAIOUs, 2012). Local distribution infrastructure typically is sized to manage the peak electricity demand of a few houses. If PEVs were to be charged at the same time as those houses typically used the most electricity, there would be a potential for overloading elements of the local distribution system and thus a need for local upgrades. However, upgrading local infrastructure is a continuing activity of utilities as load patterns change owing to growth in units of demand or to changes in patterns of demand, such as could occur with increased adoption of PEVs. Given the studies noted above and the practice of continuing infrastructure upgrades, the committee does not consider consumer PEV adoption to present an issue for the electric grid or specifically for the distribution system. The main exception would be adoption concentrated on a single distribution branch circuit—as would occur with a fast-charging station, dense clustering of private PEV- owner charging, or a fleet-charging facility—which could require an upgrade. 49

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FIGURE 4-1 Basic diagram of the electric power delivery system. SOURCE: U.S.-Canada Power System Outage Task Force (2004). However, characteristics of the electric grid could have substantial effects on consumer adoption. These include rate structures, regulation of charging-service providers, levels of participation of utilities in charging-infrastructure investment, allocation of distribution-upgrade costs, and the amount of greenhouse gas (GHG) emissions from using PEVs. Those topics are discussed below. UTILITY POLICIES THAT POTENTIALLY AFFECT ADOPTION OF PLUG-IN ELECTRIC VEHICLES The price and availability of electricity for PEVs will be significantly influenced by decisions made by utilities and utility regulators. The outcomes of these decisions will affect the willingness of individuals and corporations to install PEV chargers and, therefore, can create barriers to PEV deployment or potentially accelerate it (Baumhefner et al., 2012a). This section describes potential barriers related to utility policies and decisions. Rate Structure Utility rates are designed to recover the fixed and variable costs of a utility’s generation of power and operation of the electric grid in a safe and reliable manner. Utility-rate design typically uses three primary constructs to recover the costs of operating the grid: volumetric charges (in kilowatt-hours), demand charges (in kilowatts), and fixed charges. Fixed charges can be used in the rates for all customers and are intended to recover the fixed costs of operating the electric grid, such as the investment needed for transmission and distribution infrastructure. In addition to fixed charges, residential customers most often have volumetric rates, whereas larger commercial and industrial customers are frequently billed on both a demand and a volumetric basis. Volumetric rates can be fixed (a constant price per kilowatt-hour that is independent of when power is consumed) or variable with time (for example, peak and off-peak time-of-use rates). Demand charges are applied most often to large consumers and are meant to recover the cost of physical assets needed to supply and deliver electricity. Demand charges often are based on the instantaneous highest demand (in kilowatts) for the customer site in a rolling 12-month period, but many other structures exist (Box 4-1). However, utilities have different rates, and there is little or no consistency between utilities. 50

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BOX 4-1 Demand Charges The distinction between power (measured in kilowatts) and energy (measured in kilowatt-hours) is central to an understanding of the cost of electricity. The rate of delivery of energy to a customer is measured in kilowatts. Kilowatt-hours are used to indicate the amount of energy delivered over a specified period. Both energy and power demands require distinct capabilities of the electric grid, and the utilities must recover the costs of meeting those needs. Introducing electric vehicles imposes an electric load with special characteristics. Consider, for example, a Chevrolet Volt recharging on a 240-V, 30-A circuit (AC Level 2). The amount of electricity consumed for a 10-kWh recharge would cost around $1.10 at a retail price of $0.11/kWh. But the power load is equivalent to that of a single home in areas like San Ramon, California.1 Because utility circuits and transformers tend to be sized to accommodate only a few homes, a small number of vehicles can change the power loading of a circuit markedly. For DC fast charging, the power load can be even greater, upwards of 50 kW, meaning that although individual vehicles might draw only a small amount of energy for a single charge, there can be short periods of substantial power use for charging-service providers. Upgrades of the local distribution infrastructure might be required if the electric- vehicle charging load occurs at the same time as the maximum electricity demand for a given section of the grid, as would be the case for any other type of electric load. For that reason, utilities have historically provided an incentive to customers to distribute their electricity consumption evenly throughout the day by imposing demand charges that are intended to reward customers with flat, unvarying loads during the day and penalize customers that have “spiky” electricity load consumption during the day. 1 May, E., and S. Johnson, Top Ten EV challenges. Fortnightly Magazine, June, pp. 56- 60, 2011. A rate structure that is attractive to both customers and utilities for PEV charging is one in which the rate is time-varying—time of use or real time—and the vehicle owner is able to schedule charging to take advantage of the generally lower off-peak rates. The EV Project sponsored by the Department of Energy (DOE) has demonstrated that PEV owners respond to time-of-use signals, substantially delaying their charging to times when there is lower demand for electricity (Figure 4-2). Numerous other studies have also shown the ability of time-of-use pricing to reduce residential peak use (Barbose et al., 2004; Faruqui and Sergici, 2009; Allcott, 2011). Well-designed utility policies can play a critical role in minimizing costs and avoiding potential adverse grid effects associated with vehicle charging (Baumhefner et al., 2012a). From the utility and customer perspectives, rates that provide incentives for off-peak charging have the smallest effect on the utility infrastructure and the lowest cost per kilowatt-hour charged to PEV owners. At the other end of the spectrum, utility rates that include demand charges are the least favorable to charging of PEVs, inasmuch as a single high-demand event, such as charging at midday on a hot day when air conditioning is being used, can adversely affect a PEV owner’s rate structure for an entire year. 51

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FIGURE 4-2 Aggregate electricity demand from plug-in electric vehicles in (a) San Francisco, California, and (b) Nashville, Tennessee. Note that in San Francisco the bulk of the demand is shifted until after midnight, when an off-peak rate is in effect, indicating that a substantial number of consumers are postponing charging events until midnight. SOURCE: ECOtality (2012). A recent dialog group convened by the Center for Climate and Energy Solutions (C2ES), which included charger-service providers, utility regulators, and utilities, recommended that public utility commissions not treat PEV charging any differently from comparable loads (such as hot tubs and central air conditioning) when deciding whether demand charges should apply. In general, that would mean that PEV-specific demand charges should not apply to residential customers but might apply to commercial or industrial charging (C2ES, 2012). In a recent decision, the California Public Utilities Commission (CPUC) also chose not to adopt PEV-specific demand charges for residential PEV loads, citing similar reasoning (CPUC, 2011). Utility Rates and Possible Roles of the Federal Government Because decisions regarding retail rates are in the jurisdiction of state regulators and many states have not started proceedings regarding the treatment of PEV loads, there is a lack of a uniform national policy regarding the best rate structure that equitably recovers the costs associated with PEV loads (C2ES, 2012). To reduce barriers to PEV infrastructure and attempt to ensure equitable cost-recovery treatment, federal agencies could coordinate with state regulators, the National Association of Regulatory Utility Commissioners (NARUC), and other stakeholders to develop national rate-structure guidelines for PEV loads that allow reasonable recovery of costs of providing service to PEVs while not hindering PEV adoption or installation of PEV infrastructure. In addition, the Federal Energy Regulatory Commission and DOE could convene discussions with NARUC and other stakeholders and analyze the benefit of time-varying rates for PEV owners and utilities. The results of such analysis should be made readily available to PEV owners or potential buyers to complement any other information that the utility provides on PEVs. Carefully managed charging is likely to be crucial for minimizing the effect of widespread PEV adoption, so it is important to give PEV owners extensive information on optimal pricing scenarios. Treatment of Charging-Service Providers and The Role of Utilities in the Charging-Service Market The treatment of charging-service providers as utilities is a potential barrier. State public utility codes often define electric utility in broad terms. There is uncertainty as to whether PEV charging-service providers will be treated as utilities, that is, as retail sellers of electricity that are subject to state regulation or simply as commercial customers that sell a service that uses electricity as a factor of production. That uncertainty could act as a barrier to PEV-infrastructure deployment because regulating PEV charging- service providers as utilities could result in higher costs and decrease business-model flexibility at this 52

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formative stage in the market (C2ES, 2012). NARUC (2011) and the CPUC (CA AB631 [2011]) have decided that PEV charging-service providers are not utilities, although they resell electricity. Those decisions were made to encourage business-model flexibility and to preserve PEV-owner safety through explicit acknowledgment that the utility commission can still exercise other powers to ensure the environmental performance and integrity of the electric grid (CA AB631 [2011]). Whether utilities should be allowed to compete with third-party providers to provide residential or commercial charging is another important issue. Proponents of restricting utilities’ access to the market argue that utilities have some important advantages over third-party companies. For example, utilities determine where the electricity infrastructure is located, can reduce their risks by recovering their costs from their investments, and are assured revenues from other electricity sales (C2ES, 2012). 1 However, utility investment can be viewed as a positive in that it is an existing sustainable path to deploy publicly accessible charging infrastructure. 2 Many third-party providers, however, argue that they could offer cheaper and more efficient service and emphasize that a competitive marketplace will promote innovation and high-quality service (C2ES, 2012). There is no consensus as to what the role of utilities should be in providing charging infrastructure. CLEAN ENERGY, THE ELECTRIC GRID, AND POSSIBLE ROLES OF THE FEDERAL GOVERNMENT Early adopters of new technology are more likely to purchase PEVs if the electricity that powers them is considered “clean,” as many PEV early adopters are buying PEVs for environmental concerns (Accenture, 2011; Turrentine et al., 2011; Kurani et al., 2012). Emissions from the additional electricity mix needed to charge PEVs vary temporally and regionally; thus, different times and regions have different generation mixes (Kintner-Meyer et al., 2010), and this makes managed charging of vehicles crucial for minimizing their emissions (Peterson et al., 2011). Generally, the amount of GHG emissions generated in producing the additional electricity required to charge a PEV fleet is less than that generated by conventional vehicles, and criteria pollutants also will tend to be reduced in most areas (EPRI/NRDC, 2007; Kammen et al., 2009; Elgowainy et al., 2010). 3 It should also be noted that the manufacture and production of PEVs might result in emissions beyond those from conventional vehicles (Samaras and Meisterling, 2008; NRC, 2010; Michalek et al., 2011); however, those emissions are considered less of a barrier to deployment than the well-to-wheels emissions, and that topic is left for further discussion in the committee’s final report. There are various methods for owners to obtain clean electricity directly, including installing photovoltaic panels or purchasing renewable energy from their electricity provider (Baumhefner et al., 2012b). For customers that do not have access to clean electricity, the general environmental benefit of using electricity to charge PEVs might be a concern. One solution is for PEV drivers to purchase renewable-energy credits (RECs), and at least one company is offering to purchase RECs on behalf of its battery electric vehicle customers (Baumhefner et al., 2012b). Another way to ensure greater GHG benefits of charging PEVs is to make the overall generation mix cleaner. Many states have adopted renewable-portfolio standards to decrease GHG emissions from 1 A recent dialogue group convened by C2ES, which included PEV charging-service providers, utility regulators, and utilities, recommended the following: “Utilities wishing to act as a PEV service provider should do so through unregulated affiliates as the use of ratepayer dollars could provide utilities with an unfair competitive advantage. Further, utilities should be allowed to own and operate EVSE for internal use, for demonstration purposes, and in areas that the private market would not support otherwise” (C2ES 2012, pp. 16-17). 2 NARUC recommends not limiting utility access: “NARUC supports a competitive . . . marketplace, where utility companies, businesses, governments, and third-party service providers are able to participate in the owning, leasing, operating, or maintenance of charging or fueling equipment”(NARUC, 2011). 3 To the extent that the electricity is generated by coal-fired generation plants, there are potentially slight increases in mercury and airborne particulates. 53

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the electric grid. Such efforts will continue to reduce emissions from the grid over the long term and increase the opportunity for GHG reductions from PEVs. The federal government has many options for continuing to encourage the adoption of renewable-energy sources and the conversion from coal plants to power-generation sources that have lower life-cycle emissions. Options include federal tax credits for installing renewable-power sources, preferential treatment in wholesale electricity markets, a national price for GHG emissions, a federal standard for carbon emissions from power plants, and a nationwide renewable portfolio standard. The federal government has previously used tax credits and preferential treatment to encourage renewable-resource installations and could also do so by procuring green power for federal facilities. Finally, the federal government could create or encourage marketing campaigns to ensure that potential PEV customers are aware of the GHG benefit of converting to PEVs. LOCAL ELECTRICAL CODE REQUIREMENTS Virtually all states and localities have adopted the National Electrical Code (NEC), which is developed by the National Fire Protection Association (NFPA). The NEC is approved as an U.S. national standard by the American National Standards Institute (ANSI) as ANSI/NFPA 70. Specific elements of the code are tightened in some regions. The NEC 625.13 Electric Vehicle Supply Equipment Connection covers the requirements for connection at residential level 1 or 2. AC Level 2 charging requires installation of a 240-V supply. Installation of a new 240-V circuit is subject, in all identified local building codes, to the NEC. Which permit is required is a function of whether the installation is associated with new construction or an existing residence. If it is new construction, the cost of the 240-V circuit is incorporated into the cost of the construction permit and is inspected as part of that process. For an existing residence, a permit is generally required at a cost of about $50 for the permit and inspection, although some regions have seen permit fees as high as $500 and as low as $7.50 (Francfort, 2012). Data from the EV Project indicate that the total cost of installing an AC Level 2 charger ranges from $1,100 to $1,800 (Francfort, 2012). Given the cost of installation, any costs associated with permitting or inspection are minor and, therefore, do not constitute a barrier to adoption today, nor are they expected to constitute a barrier in the future. FINDINGS ON THE ELECTRIC GRID • The existing electric infrastructure does not present a barrier to the expansion of PEV technology in the United States given the projected growth of PEV use in the next decade. With the exception of a scenario in which a concentration of PEVs appears in an overburdened branch of the distribution system, no major physical barriers have been identified. As PEVs become a more significant share of total electricity consumption, the committee foresees no issues at the distribution level that cannot be handled through the normal processes of infrastructure expansion and upgrades in the electric- utility industry. • The current time-based (time-of-use or real-time pricing) rate structures available to most commercial and industrial customers and some residential customers are an incentive to PEV owners and utilities in that they encourage charging at times when there is lower-cost generating capacity available and thereby reduce cost effects on the grid. • Regulating third-party entities (nonowner, nonutility charging-service providers) as utilities could increase operating costs and decrease business-model flexibility. • The role and scope allowed to utilities (compared with third-party entities) in providing charging equipment are unclear. 54

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• The lack of access to or price premium for clean electricity could be a barrier to PEV adoption. However, there generally is a net benefit of using PEVs rather than conventional vehicles, even with the existing generation mix. The benefit can be increased by a continued transition to generation sources that have lower life-cycle emissions. • Local building codes based on the national building code are not seen to be a barrier to the development of the PEV market. REFERENCES Accenture. 2011. Plug-in Electric Vehicles—Changing Perceptions, Hedging Bets. Accenture End- Consumer Survey on the Electrification of Private Transport. ACC11-0320/7-1792. Available at http://www.accenture.com/Microsites/accenturesmartsolutions-electricvehicles/Documents/ Accenture_Plug-in_Electric_Vehicle_Consumer_Perceptions_FINAL.PDF, accessed April 23, 2013. Allcott, H. 2011. Rethinking real-time electricity pricing. Resour. Energ. Econ. 33(4):820-842. Barbose, G., C. Goldman, and B. Neenan. 2004. A Survey of Utility Experience with Real Time Pricing. LBNL-54238. Lawrence Berkeley National Laboratory, Berkeley, Calif. Available at http://eetd.lbl.gov/ea/emp/reports/54238.pdf, accessed April 23, 2013. Baumhefner, M, S. Mui, and R. Hwang. 2012a. Importance of model utility policy for vehicle electrification. Electr. J. 25(5):16-25. Baumhefner, M., E. Pike, and A. Klugescheid. 2012b. Plugging Vehicles into Clean Energy. Natural Resources Defense Council, Energy Solutions and BMW Group, October. Available at http://switchboard.nrdc.org/blogs/mbaumhefner/Plugging%20Vehicles%20into%20Clean%20En ergy_November_2012.pdf, accessed April 23, 2013. C2ES (Center for Climate and Energy Solutions). 2012. An Action Plan to Integrate Plug-in Electric Vehicles with the U.S. Electrical Grid. A report of the PEV Dialogue Group convened by the Center for Climate and Energy Solutions. March. Available at http://www.c2es.org/docUploads/ PEV-action-plan.pdf, accessed April 23, 2013. CAIOUs (California Investor Owned Utilities). 2012. Joint IOU Electric Vehicle Load Research Final Report. Pacific Gas and Electric Company, Southern California Edison Company, and San Diego Gas and Electric Company. December 28. CPUC (California Public Utilities Commission). 2011. Phase 2 Decision Establishing Policies to Overcome Barriers to Electric Vehicle Deployment and Complying with Public Utilities Code Section 740.2. Decision 11-07-029. July 14. Available at http://docs.cpuc.ca.gov/PublishedDocs/ published/final_decision/139969.htm, accessed April 23, 2013. ECOtality. 2012. The EV Project: Q3 2012 Report. INL/MIS-10-19479. Idaho National Laboratory, Idaho Falls. October 25. Available at http://www.theevproject.com/downloads/documents/ Q3%202012%20EVP%20Report.pdf, accessed April 23, 2013. Elgowainy, A., J. Han, L. Poch, M. Wang, A. Vyas, M. Mahalik, and A. Rousseau. 2010. Well-to-Wheel Analysis of Energy Use and Greenhouse Gas Emissions of Plug-in Hybrid Electric Vehicles. ANL/ESD/10-01. Argonne National Laboratory. June. Available at http://www.afdc.energy.gov/ pdfs/argonne_phev_evaluation_report.pdf, accessed April 18, 2013. EPRI/NRDC (Electric Power Research Institute and Natural Resources Defense Council). 2007. Environmental Assessment of Plug-in Hybrid Electric Vehicles, Volume 1: National Greenhouse Gas Emissions, Final Report. Electric Power Research Institute, Palo Alto, Calif. July. Available at http://www.electricdrive.org/index.php?ht=a/GetDocumentAction/id/27936, accessed April 18, 2013. Faruqui, A., and S. Sergici. 2009. Household Response to Dynamic Pricing of Electricity—A Survey of the Experimental Evidence. Harvard Electricity Policy Group Research Paper. January 10. 55

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