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Overcoming Barriers to Electric-Vehicle Deployment: Interim Report (2013)

Chapter: 3 The Charging Infrastructure

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Suggested Citation:"3 The Charging Infrastructure." Transportation Research Board and National Research Council. 2013. Overcoming Barriers to Electric-Vehicle Deployment: Interim Report. Washington, DC: The National Academies Press. doi: 10.17226/18320.
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Suggested Citation:"3 The Charging Infrastructure." Transportation Research Board and National Research Council. 2013. Overcoming Barriers to Electric-Vehicle Deployment: Interim Report. Washington, DC: The National Academies Press. doi: 10.17226/18320.
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Suggested Citation:"3 The Charging Infrastructure." Transportation Research Board and National Research Council. 2013. Overcoming Barriers to Electric-Vehicle Deployment: Interim Report. Washington, DC: The National Academies Press. doi: 10.17226/18320.
×
Page 29
Suggested Citation:"3 The Charging Infrastructure." Transportation Research Board and National Research Council. 2013. Overcoming Barriers to Electric-Vehicle Deployment: Interim Report. Washington, DC: The National Academies Press. doi: 10.17226/18320.
×
Page 30
Suggested Citation:"3 The Charging Infrastructure." Transportation Research Board and National Research Council. 2013. Overcoming Barriers to Electric-Vehicle Deployment: Interim Report. Washington, DC: The National Academies Press. doi: 10.17226/18320.
×
Page 31
Suggested Citation:"3 The Charging Infrastructure." Transportation Research Board and National Research Council. 2013. Overcoming Barriers to Electric-Vehicle Deployment: Interim Report. Washington, DC: The National Academies Press. doi: 10.17226/18320.
×
Page 32
Suggested Citation:"3 The Charging Infrastructure." Transportation Research Board and National Research Council. 2013. Overcoming Barriers to Electric-Vehicle Deployment: Interim Report. Washington, DC: The National Academies Press. doi: 10.17226/18320.
×
Page 33
Suggested Citation:"3 The Charging Infrastructure." Transportation Research Board and National Research Council. 2013. Overcoming Barriers to Electric-Vehicle Deployment: Interim Report. Washington, DC: The National Academies Press. doi: 10.17226/18320.
×
Page 34
Suggested Citation:"3 The Charging Infrastructure." Transportation Research Board and National Research Council. 2013. Overcoming Barriers to Electric-Vehicle Deployment: Interim Report. Washington, DC: The National Academies Press. doi: 10.17226/18320.
×
Page 35
Suggested Citation:"3 The Charging Infrastructure." Transportation Research Board and National Research Council. 2013. Overcoming Barriers to Electric-Vehicle Deployment: Interim Report. Washington, DC: The National Academies Press. doi: 10.17226/18320.
×
Page 36
Suggested Citation:"3 The Charging Infrastructure." Transportation Research Board and National Research Council. 2013. Overcoming Barriers to Electric-Vehicle Deployment: Interim Report. Washington, DC: The National Academies Press. doi: 10.17226/18320.
×
Page 37
Suggested Citation:"3 The Charging Infrastructure." Transportation Research Board and National Research Council. 2013. Overcoming Barriers to Electric-Vehicle Deployment: Interim Report. Washington, DC: The National Academies Press. doi: 10.17226/18320.
×
Page 38
Suggested Citation:"3 The Charging Infrastructure." Transportation Research Board and National Research Council. 2013. Overcoming Barriers to Electric-Vehicle Deployment: Interim Report. Washington, DC: The National Academies Press. doi: 10.17226/18320.
×
Page 39
Suggested Citation:"3 The Charging Infrastructure." Transportation Research Board and National Research Council. 2013. Overcoming Barriers to Electric-Vehicle Deployment: Interim Report. Washington, DC: The National Academies Press. doi: 10.17226/18320.
×
Page 40
Suggested Citation:"3 The Charging Infrastructure." Transportation Research Board and National Research Council. 2013. Overcoming Barriers to Electric-Vehicle Deployment: Interim Report. Washington, DC: The National Academies Press. doi: 10.17226/18320.
×
Page 41
Suggested Citation:"3 The Charging Infrastructure." Transportation Research Board and National Research Council. 2013. Overcoming Barriers to Electric-Vehicle Deployment: Interim Report. Washington, DC: The National Academies Press. doi: 10.17226/18320.
×
Page 42
Suggested Citation:"3 The Charging Infrastructure." Transportation Research Board and National Research Council. 2013. Overcoming Barriers to Electric-Vehicle Deployment: Interim Report. Washington, DC: The National Academies Press. doi: 10.17226/18320.
×
Page 43
Suggested Citation:"3 The Charging Infrastructure." Transportation Research Board and National Research Council. 2013. Overcoming Barriers to Electric-Vehicle Deployment: Interim Report. Washington, DC: The National Academies Press. doi: 10.17226/18320.
×
Page 44
Suggested Citation:"3 The Charging Infrastructure." Transportation Research Board and National Research Council. 2013. Overcoming Barriers to Electric-Vehicle Deployment: Interim Report. Washington, DC: The National Academies Press. doi: 10.17226/18320.
×
Page 45
Suggested Citation:"3 The Charging Infrastructure." Transportation Research Board and National Research Council. 2013. Overcoming Barriers to Electric-Vehicle Deployment: Interim Report. Washington, DC: The National Academies Press. doi: 10.17226/18320.
×
Page 46
Suggested Citation:"3 The Charging Infrastructure." Transportation Research Board and National Research Council. 2013. Overcoming Barriers to Electric-Vehicle Deployment: Interim Report. Washington, DC: The National Academies Press. doi: 10.17226/18320.
×
Page 47
Suggested Citation:"3 The Charging Infrastructure." Transportation Research Board and National Research Council. 2013. Overcoming Barriers to Electric-Vehicle Deployment: Interim Report. Washington, DC: The National Academies Press. doi: 10.17226/18320.
×
Page 48

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3 The Charging Infrastructure One of the critical elements of a plug-in electric vehicle (PEV) is the charging infrastructure. It is a source of confusion for customers (as noted in Chapter 2) and a substantial requirement for enabling the widespread deployment of PEVs. This chapter begins with a basic discussion of charging and then describes possible charging locations and the needs or barriers associated with each. Next, it discusses the charging-infrastructure considerations for fleets and shared vehicles, and it concludes with findings and possible roles for the federal government in overcoming the barriers identified. In trying to answer questions concerning charging-infrastructure needs, the committee assumed that the goal was to maximize the fraction of miles traveled by light-duty vehicles fueled by electricity. The committee recognizes that the goal influences the type, number, and location of charging infrastructure needed and that other potential goals—such as maximizing the number of PEVs on the road or maximizing the number of miles traveled by battery electric vehicles (BEVs)—might lead to different conclusions. It must be remembered that the committee’s stated goal means that it is indifferent to whether miles are traveled by BEVs or plug-in hybrid electric vehicles (PHEVs). The goal of maximizing the fraction of electric miles addresses two objectives of U.S. energy policy noted in Chapter 1: increasing energy security by reducing dependence on petroleum imports and reducing greenhouse gas emissions. The latter objective will be reached fully only when emissions from the sources that generate electricity for distribution over the electric grid are reduced (this issue is discussed further in Chapter 4). CHARGING AND HOW IT WORKS Electricity from a battery powers the electric motor of a PEV in a way that is similar to how gasoline in a tank powers the engine of a conventional vehicle. The range, in miles, of a conventional vehicle depends on how many gallons of liquid fuel the fuel tank can hold and the fuel economy of the vehicle. Similarly, the electric range of a PEV depends on how much electric energy—expressed in kilowatt-hours (kWh)—the battery can hold. Table 3-1 provides some examples of currently available PEVs, their nominal and usable battery capacities, 1 and estimated electric ranges based on the Environmental Protection Agency (EPA) Federal Test Procedure. It is important to note that the actual electric range of a vehicle depends on such factors as the weight and age of the vehicle, how aggressively the vehicle is driven, the ambient temperature, the road grade, and the level of air conditioning and heating used. As noted, the estimated electric ranges provided in Table 3-1 are based on the EPA Federal Test Procedure, but other driving cycles, such as the New European Driving Cycle, produce different results. For example, the 2012 Nissan Leaf has an estimated 1 The usable capacity of a battery is the portion of the total capacity that is accessed by the vehicle during operation. A rechargeable battery, such as those in PEVs, theoretically can be charged to 100 percent of its nominal capacity and discharged to 0 percent. But allowing the battery to charge and discharge fully could seriously reduce its future performance. Thus, a battery could be limited in its charging range, for example, from 80 percent to 30 percent of its capacity. This example represents a 50 percent state-of-charge range, and the usable capacity of the battery would be 50 percent of its nominal capacity (NRC, 2010). 27

TABLE 3-1 Battery Capacities and All-Electric Ranges for Several Plug-in Electric Vehicles Vehicle Type Battery Capacitya Electric Rangeb 2013 Toyota Plug-in Prius Plug-in hybrid 4.4 kWh nominal 11 miles (blended) electric vehicle (~3.2 kWh usable) 6 miles (battery only) 2013 Ford C-MAX Energi Plug-in hybrid 7.6 kWh nominal 21 miles electric vehicle (~7 kWh usable) 2013 Chevrolet Volt Plug-in hybrid 16.5 kWh nominal 38 miles electric vehicle (~11 kWh usable) 2012 Nissan Leaf Battery electric 24 kWh nominal 73 miles vehicle (~21 kWh usable) 2013 Tesla Model S Battery electric 85 kWh nominal 265 miles vehicle a Nominal battery capacities are reported by manufacturers in product specifications. Usable battery capacities reflect the amount of the nominal capacity that is used during vehicle operation, and the values reported here reflect the actual charge used by the battery to achieve the measured all-electric range. b The electric ranges noted are average values estimated by EPA. Because of the motor size and design architecture of the Toyota plug-in Prius, it requires use of its internal combustion engine to complete the Federal Test Procedure; therefore, its range is given in blended, charge-depleting operation and battery-only operation. All other vehicle ranges are given only for fully electric, charge-depleting operation. SOURCES: Based on data from Duoba (2012), DOE (2012, 2013a), and EPA (2012, 2013). all-electric range of 73 miles on the basis of the EPA Federal Test Procedure, but an estimated all-electric range of 109 miles on the basis of the New European Driving Cycle (Crowe, 2013). Charging a PEV is analogous to filling a conventional vehicle’s fuel tank with gasoline. A gasoline-powered vehicle is attached to a pump that allows the gasoline to flow through a hose into the 28

fuel tank. A typical flow rate of 8 gal/min, for example, means that empty gasoline tanks with capacities of 10 to 20 gal will be filled in a few minutes. Similarly, a PEV is plugged into the electric grid so that electricity can flow through wires and into the battery. An energy flow rate of 6.6 kW, for example, can fill an empty battery with a capacity of 24 kWh in about 4 hours. The peak charging rate for residential charging is limited by the size of the charger in the vehicle that changes the alternating-current (ac) electricity into direct-current (dc) electricity. A fully discharged battery initially charges at the maximum rate that the on-board charger can manage and then charges more slowly as the battery nears capacity. Thus, a vehicle battery does not charge at a constant rate, and that is why it takes about 4 hours to fill a 24-kWh battery at 6.6 kW. For dc fast charging (discussed below), the component that changes ac to dc is outside the car and is governed by control signals from the car. Regulating the charging rate is necessary to ensure safety and to protect battery life. Although increasing the charging rate with high-power chargers shortens the time needed to charge a vehicle’s battery, an important technical issue now being researched is the extent to which faster charging at high power hastens the normal aging of a battery (Francfort, 2013). The electric “pressure” with which an electric circuit in a home or business can force electricity through wires into some device is measured in volts (V). The amount of electricity flowing through various devices, the electric current, is measured in amperes (A). The product of the two is the power flow in watts. Every circuit delivering electricity has a circuit breaker or fuse that keeps the flow of electricity from exceeding the amperes that the circuit can safely provide. For example, a 2013 Nissan Leaf is capable of using a maximum of 30 A of electric current when it is connected to a 240-V electric circuit, so the power flow is 7.2 kW. The car will not accept more current or power even if the circuit is able to provide it. The circuit breaker that monitors the current flow in a dedicated circuit would typically switch off the electricity going to the car if current were flowing at about 40 A because this would indicate a problem with the car. The electric circuit required to do this charging is called 40-A service at 240 V. As recommended by the National Electrical Code (NEC), an apparatus known as the electric vehicle supply equipment (EVSE) is always connected between the charging circuit and the car to protect the people and the car during charging. The purpose of the EVSE is to create two-way communication between vehicle and charger before and during charging to detect any anomalies that might affect safety or the equipment (Rawson and Kateley, 1998). The NEC (2008) defines the EVSE as “the conductors, including the ungrounded, grounded, and equipment grounding conductors and the electric vehicle connectors, attachment plugs, and all other fittings, devices, power outlets or apparatus installed specifically for the purpose of delivering energy from the premises wiring to the electric vehicle” (Section 625.2). Its ground fault interrupters—similar to those used in bathrooms and kitchens—are safety devices that can detect when a small electric current from the circuit has “gone missing” and disconnect the electric circuit and the current flow before anyone is injured. Furthermore, the EVSE is able to communicate with a car to ensure that no current is provided before the car is connected and to ensure that a current larger than the car can handle is not provided. The EVSE for slow charging via 120 V is typically a portable device that can be carried in the car for possible use at remote locations (Figure 3-1a). The EVSE for normal 240-V charging is typically mounted on a garage wall (Figure 3-2a) or on a purpose-built column. Fast chargers that use higher voltages have the EVSE built into the substantial charger that is required. A plug wired to the EVSE connects to a socket on the vehicle. In the United States, there is one standard plug that is used to charge vehicles from the normal 120-V and 240-V circuits found in residences, the J1772 standard set by SAE International (formerly the Society of Automotive Engineers International; SAE, 2012). This interchangeability removes what otherwise could be a substantial barrier to the adoption of PEVs. However, at least two standard plugs are used for the dc fast charging that is becoming available in public locations. Most BEVs on the road that can be connected to a dc fast- charging unit (and the vast majority of chargers that have been installed in the United States, Japan, and Europe) use the CHAdeMO standard. Automobile manufacturers and SAE International have agreed on a new standard that they call the Universal EV Combined Charging System. Furthermore, Tesla vehicles 29

AC Level 1 Charging (a) 12 A 120 V ac Leaf 2012 EVSE Leaf 2013 (15 A Volt circuit Prius Plug-in breaker) (b) Miles for an hour of peak charging (c) Time to fully charge 6 25 Miles per hour of charging 5 20 Hours to fully charge 4 15 3 10 2 1.4 kW 1.4 kW 1.3 kW 1.1 kW 1 5 20 hr 20 hr 12 hr 3 hr 0 0 Nissan Leaf Nissan Leaf Chevy Volt Toyota Prius Nissan Leaf Nissan Leaf Chevy Volt Toyota Prius 2012 2013 Plug-In 2012 2013 Plug-In FIGURE 3-1 AC Level 1 charging information. (a) For AC Level 1, a vehicle is plugged into a common 120-V electric socket through a portable safety device labeled EVSE (electric vehicle supply equipment). (b) The mileage range that results from 1 hour of peak charging is about the same for all the example vehicles noted because they are about the same size and weight. (c) Vehicles that have larger batteries to allow them to be electrically powered for longer distances take longer to charge fully. SOURCE: GM- Volt (2013); Toyota (2013). that are now available use a proprietary plug. The lack of component compatibility will effectively reduce the coverage of charging stations by reducing the potential user base or will increase installation costs by requiring charging outlets to be compatible with multiple plug designs. More details on the standards and photographs of the various plugs are provided in Appendix D. CHARGING LEVELS As shown in Appendix D (Figure D-5), SAE International defines four levels of charging: slow charging with 120-V ac circuits that is defined by SAE as AC Level 1 charging, normal charging with 240-V ac circuits that is defined by SAE as AC Level 2 charging, and two levels of dc fast charging (DC Level 1 and DC Level 2), which are distinguished by SAE International by the maximum power draw. For the present report, the committee uses the terms AC Level 1, AC Level 2, and DC fast charging to describe the levels of charging available and does not distinguish between DC Level 1 and DC Level 2. The following sections describe those options in more detail. 30

(a) AC Level 2 Charging 240 V ac 12 A Leaf 2012 (15 A EVSE Volt circuit breaker) Wall mounted 240 V ac 30 A Leaf 2013 (40 A EVSE circuit breaker) (b) (c) Miles for an hour of peak charging Time to fully charge 25 8 7 Miles per hour of charging Miles per hour of charging 20 6 15 5 4 10 3 6.6 kW 3.3 kW 2.2 kW 3.3 kW 2 5 1 7 hr 4 hr 3 hr 1.5 hr 0 0 Nissan Leaf Nissan Leaf Chevy Volt Toyota Prius Nissan Leaf Nissan Leaf Chevy Volt Toyota Prius 2012 2013 Plug-In 2012 2013 Plug-In FIGURE 3-2 AC Level 2 charging information. (a) For AC Level 2 charging, a vehicle is plugged into a 240-V electric circuit like those used by electric dryers, stoves, and large air conditioners through a wall- mounted safety device labeled EVSE (electric vehicle supply equipment). (b) The mileage range that results from 1 hour of peak charging depends on how much current the plug-in electric vehicle can draw. (c) Vehicles that have larger batteries and ranges take longer to charge fully. SOURCES: GM-Volt (2013); Toyota (2013); Voelcker (2013). AC Level 1 Charging Most electric devices in the United States—such as lamps, small air conditioners, and computers—are plugged into 120-V electric circuits. Wall sockets in essentially every room of every building provide access to 120-V electricity. To prevent fires and other damage to the electric circuits, circuit breakers or fuses incorporated into the electric system typically switch off the electricity if the current flowing through the circuit exceeds 15 to 20 A. Because the United States has little charging infrastructure dedicated to PEVs, it is important that owners be able to charge their vehicles by plugging into an ordinary 120-V wall receptacle when no better charging option is available. Accordingly, all PEVs can be charged by plugging into 120-V circuits (see Figure 3-1a) and are designed to draw a current compatible with the circuit rating to avoid having a normal circuit breaker turn off the current. This option is essentially a no-cost solution to charging infrastructure. Each hour of charging provides about 4 to 5 miles, depending on the vehicle (see Figure 3- 1b). Much like an air conditioner plugged into a 120-V circuit, a charging vehicle typically must be the only device drawing current from the circuit to avoid exceeding the maximum current that the circuit can 31

provide. The PEVs shown in Table 3-1 can easily carry the EVSE needed for AC Level 1 charging. However, the components are not mounted directly on the vehicle and are thus susceptible to theft or vandalism. The time required for charging a battery that has fully depleted its usable energy (or charge) by using 120 V can be 10 hours or more for PEVs that have a large electric range (see Figure 3-1c). Thus, AC Level 1 charging is not a practical primary charging method for BEVs that use electricity to travel a substantial number of miles. AC Level 1 charging might be useful in some cases to extend the range by a few miles (see Figure 3-1b). AC Level 2 Charging The manufacturers’ recommended charging for vehicles that have appreciable electric ranges uses 240-V circuits, which can often charge a PEV at least twice as fast as a 120-V circuit. Most residences and businesses have 240-V circuits installed, although the higher-voltage circuits are typically available only at the location of large appliances. Electric clothes dryers, electric stoves and ovens, large microwave ovens, and large window air conditioners typically use 240-V circuits. Where there is access to a 240-V circuit, the infrastructure needed (see Figure 3-2a) is much like that needed for AC Level 1 charging (see Figure 3-1a) except that the EVSE is typically mounted more permanently. The 240-V EVSE is connected to the same standard socket that is used on all vehicles for 120-V charging, the J1772 standard, and this makes it possible for different types of vehicles to share chargers. The number of miles that can be traveled after 1 hour of AC Level 2 charging depends on the vehicle and the electric current (see Figure 3-2b). The important advantage of 240-V charging is that the time required to charge a battery fully is short enough to charge PEVs with substantial electric ranges during the time that a vehicle is parked at a residence or a workplace (see Figure 3-2c). The configuration shown in Figure 3-2 is the one typically recommended for most residences and workplaces. DC Fast Charging Some PEVs can be charged by using high-voltage (for example, 480-V) circuits that allow the battery to charge much more rapidly. Unlike the charging systems discussed above, the conversion of the ac electricity that is available from the U.S. electric grid to the dc electricity needed to charge the battery takes place in the EVSE rather than in the vehicle. The DC fast chargers typically require a connection to high-voltage, three-phase power that is almost never available in residences or workplaces except where industrial equipment is powered with electricity. Thus, access to the high-voltage electricity is one factor to consider when locating DC fast-charging stations. Fast charging typically charges a battery to about 80 percent of its usable capacity (Figure 3-3); charging beyond that point typically cannot be nearly as fast without endangering the battery. In fact, fast charging can shorten the life of a battery because of materials degradation from internal heating. How much the battery life is shortened is being investigated for a Nissan Leaf in a study commissioned by the Department of Energy (DOE; Francfort, 2013). DC fast charging is not available for most PHEVs, such as the Chevy Volt and the Toyota Prius plug-in, because these vehicles can rely on their internal combustion engines for longer trips. It is primarily for BEVs, such as the Nissan Leaf and the Tesla Model S. Most PEV models that can accept DC fast charging use the CHAdeMO plug, as do most of the fast chargers installed in the United States, Japan, and Europe. As noted earlier, SAE International has adopted an alternate DC fast-charging standard (the Universal EV Combined Charging System), and many automakers are planning to deliver vehicles compatible with that standard. Tesla has its own DC fast charger and proprietary plug configuration. 32

FIGURE 3-3 DC fast charging a Nissan Leaf. DC fast charging is able to charge a Nissan Leaf battery to 80 percent capacity in less than 30 min. The charge would typically allow a 2013 Leaf to travel about 64 miles. SOURCE: Copyright 2010 by the eVgo Network; licensed under Creative Commons 2.0 (CC-BY- 2.0). Wireless Charging In its final report, the committee will consider the possibility of charging a PEV wirelessly. Instead of sending electricity through a cord plugged into a vehicle, the energy in wireless charging is transferred inductively from a coil attached to an electricity source to a coil attached to the vehicle; both coils are encased and out of sight below the vehicle. Although that technology is not yet widely available to consumers, wireless charging systems are in the early stages of production and availability, and new designs are being investigated (Electric Vehicle News, 2011; Plugless Power, 2013). The reduced efficiency and increased cost of wireless chargers are disadvantages, especially considering that little time is required to plug in a PEV. However, the advantages of increased convenience and reduced susceptibility to vandalism might eventually be more compelling. CHARGING LOCATIONS: NEEDS, BARRIERS, AND OPTIONS This section discusses the similarities and differences between the infrastructure needs of and barriers to residential, workplace, and publicly accessible charging and offers some options for overcoming the barriers. Most electric-charging infrastructure is (and is likely to remain) at residences, where PEVs are available for charging for the longest time. Because PEVs are also parked at workplaces for substantial times on each workday, workplace charging is a promising option where practical ways can be found to provide the needed infrastructure. PEVs typically have much less time available for 33

Publicly accessible Workplace Residential FIGURE 3-4 The charging pyramid represents the relative importance of residential, workplace, and publicly accessible charging. It indicates that most charging will occur at residences, followed by charging at the workplace, and the least possible time for charging in publicly accessible locations. charging while parked in public places, but charging in publicly accessible locations would serve the needs of PEV drivers if a DC fast charger were available, if the vehicle were parked for at least 4 hours, or if only a partial battery charge were needed. Figure 3-4 is a representation that PEV manufacturers and other stakeholders often use to contrast the relative importance of PEV charging at residences (most important), at workplaces (important), and in publicly accessible locations (somewhat important) (Karner, 2012; Kjaer, 2012). Figure 3-5 gives a more detailed breakdown of where vehicles are during the day and shows that vehicles spend most of the day parked at home and a substantial fraction of time during the week parked at work. Residential Charging Most charging of PEVs takes place at residences because a vehicle is typically parked at a residence for the longest portion of the day, typically more than 12 hours/day (see Figure 3-5). According to the 2011 American Housing Survey, about 63 percent of housing units (both single-family and multifamily units) in the United States have access to a carport or garage, and most of those units are occupied by the owners (U.S. Census Bureau, 2012). 1 In those cases, the charging infrastructure would be controlled by the property owners. AC Level 1 charging should suffice for vehicles that have small batteries and electric ranges, such as the Toyota plug-in Prius, or for vehicles that are driven primarily short distances. No infrastructure beyond a dedicated 120-V circuit capable of delivering 15 to 20 A would be needed. Because most garages or carports have external outlets that could be used, there would be no need to install additional infrastructure. However, multiple PEVs at the same residence might require additional infrastructure if there is only a single-car garage or carport or a single outlet. Furthermore, if PEV owners want to take advantage of special rates for PEV charging and to track their use better, they might need a separate circuit, even for AC Level 1 charging. 1 Among the 37 percent of housing units that lack access to a garage or carport, 83 percent have a driveway or off-street parking available (U.S. Census Bureau, 2012). Such off-street parking may offer access to a dedicated 120-V circuit. 34

FIGURE 3-5 Distribution of vehicle locations throughout the week on the basis of data from the 2001 National Household Travel Survey. SOURCE: Tate and Savagian (2009). Copyright 2009 by SAE International. Reprinted by permission. The recommended charging method for vehicles that have a longer electric range, such as the Nissan Leaf, is AC Level 2 charging. It usually can be completed easily during the time spent at the residence and can even be rapid enough to take advantage of lower late-night electricity rates where these are available. Dedicated 20-A service is required for some vehicles, such as the Chevy Volt and the 2012 Nissan Leaf, which require up to 15 A to charge. Dedicated 40-A service is required for the faster- charging vehicles, such as the 2013 Nissan Leaf, which can accept up to 30 A. Most single-family residences have 240-V electric circuits that can deliver up to 100 A. For those residences, a circuit that can deliver 15 or 30 A to a charging vehicle should be available unless many large electric appliances are being used. In its final report, the committee will consider the additional requirements for charging vehicles that have larger-capacity batteries. Recent analysis provides further insights into the potential for residential charging. On the basis of a Web-based survey, Axsen and Kurani (2012) estimated that about half the new-car-buying U.S. households have residential access to a 120-V electric outlet within 25 ft for at least one vehicle. They also estimated that about one-third of new-car-buying households in San Diego County have access to a 240-V outlet capable of providing AC Level 2 charging. Traut et al. (2013) estimated that although 80 percent of households have some off-street parking, only about half the vehicles have access to a dedicated parking spot at an owned home where a charger could be installed. One potential barrier to residential charging is the cost of an AC Level 2 charger 1 and its installation, which typically adds an average of $1,375 (range, $1,100 to $1,800) to the initial cost of a vehicle that is already more expensive than a comparable conventional vehicle (Francfort, 2012). As noted by Francfort, the costs vary by geography; for example, locations in California have higher than 1 Strictly speaking, the location of the charger for AC Level 2 is on the vehicle itself and not mounted on the unit. Thus, the correct term would be AC Level 2 EVSE. However, AC Level 2 charger is commonly used. 35

average costs. Other factors that affect installation costs include the amount of carpentry and concrete required and the age of the house stock. For example, if a residence has only 60-A service or only 120-V circuits, which might be the case in older homes, the cost of upgrading the service can make installing AC Level 2 charging much more expensive. Francfort also noted that permit fees, typically about $50, can cost as much as $500 and thus become an important part of the installation costs. A recent report by the California Plug-in Electric Vehicle Collaborative (2012) identified a need to streamline the permitting system for installing residential chargers. Some federal and utility programs have subsidized the installation of chargers or provided them free. The installation costs currently can be partially deducted from federal income taxes. Although vehicle dealers provide guidance and potential discounts on vehicle chargers, the cost of the chargers cannot be financed as part of the vehicle. One substantial barrier to residential charging is the need to provide charging infrastructure for residences that have access only to street parking or shared parking lots where installation of such infrastructure is beyond the control of drivers. Retrofitting existing facilities is one option for multifamily units that have dedicated parking. However, a much less expensive option is at least to prepare for the possibility of installing chargers during initial construction. Workplace and publicly accessible charging opportunities might be a substantial help to some PEV owners who lack access to charging infrastructure at their residences. Another option is to restrict parking spaces for PEVs to those with special permits and to recover charging-installation costs through the sale of permits for the spaces. Having dedicated parking spots for PEV charging, however, might be problematic in highly urbanized locations that already have too little parking available. Workplace Charging Workplace charging provides a substantial opportunity to encourage the adoption of PEVs and increase the fraction of miles that are fueled by electricity. First, BEV drivers could potentially double their average range as long as their vehicles could be fully charged both at work and at home, and PHEV drivers could potentially double their all-electric miles. Second, workplace charging would allow commuters who lack access to residential charging the opportunity to commute with a PEV. Third, charging could help to increase electric-vehicle miles traveled by making it possible to reach destinations that currently exceed a vehicle’s range before returning to a residence. Figure 3-5 shows that a typical vehicle during a typical work week (Monday-Friday) is parked for about 8 hours at a workplace; this is consistent with the Bureau of Labor Statistics work-week estimate of the average adult spending 8.6 hours/day at work and in work-related activities (BLS, 2012). AC Level 2 is the best choice for most currently available PEVs that have a large electric range, although it might be prudent to design workplace charging infrastructure to accommodate possible increases in battery capacity. 1 AC Level 1 charging could be sufficient for the substantial fraction of workers who have short commuting distances if ways could be devised to prevent the theft of EVSE devices, which for current vehicles simply lie exposed on the pavement during charging. The U.S. Bureau of Transportation Statistics estimates that 68 percent of commuters travel 15 miles or less in one direction, and the National Household Travel Survey estimates that 70 percent of trips made to earn a living are less than 15 miles (BTS, 2003; FHWA, 2011). As indicated in Figure 3-1b, AC Level 1 charging would meet the needs of drivers who require only enough charge to make it back to their residences. The circuitry and charging infrastructure is much the same as for a residence except that the installation would be at a company parking lot or garage. There are several barriers to workplace charging. A fundamental challenge is to determine how many PEVs will be present on what time scale, what level of charging would be sufficient for their needs, and how to ensure access to chargers as the number of PEVs increases. A worker who relies on workplace 1 The committee notes that it remains to be seen whether faster charging options at workplaces are needed or could be feasible without a large increase in cost. 36

charging of his or her BEV might not be able to return home if no charger is available. Furthermore, the cost of installing chargers in existing parking lots and garages is substantial for AC Level 1 and AC Level 2 chargers. In addition to construction costs, there might also be costs associated with electricity service upgrades for the AC Level 2 chargers. However, a financial incentive, such as an accelerated depreciation schedule, might make businesses more willing to offer workplace charging. Another potential barrier is that electricity provided to employees must be paid for by the employees or taxed. The requirement to assess the value of the charging or report the imputed income could be an impediment to workplace charging. Yet another barrier is that utilities assess companies a surcharge for exceeding a threshold level of power. Demand charges can be substantial, depending on the total electricity used by a business. (Demand charges are discussed in more detail in Chapter 4.) A final possible barrier is that new BEVs will have larger batteries and thus could require more charging infrastructure than AC Level 2 chargers for full charging, although a full charge might not be required. Vehicles with 85-kWh batteries are available but only for expensive vehicles that will not be widely adopted in the short term. Furthermore, obtaining a full charge at a workplace might not be so critical for those vehicles. Workplace charging is available at some companies, such as Google and Microsoft, which offer it as a way of attracting employees. Employers are adopting various models for providing workplace- charging infrastructure, including having employees pay for the cost of the infrastructure through a daily charge or offering it at no charge as an employee benefit. Alternative models for workplace charging clearly are needed, as is a better understanding of current and future charging demands and the most economical ways to meet employees’ charging needs. Publicly Accessible Charging Federal and state efforts concerning vehicle charging have focused on the development of a charging infrastructure that is accessible to the public (Durst, 2012; Karner, 2012). This section describes the basic characteristics of publicly accessible charging and business models for developing such an infrastructure. Basic Characteristics Although most PEV owners rely primarily on residential charging (Francfort, 2012), the availability of charging in public places can enable drivers to extend the daily range of their vehicles beyond the mileage that can be driven on a single charge. Public charging can include AC Level 1, AC Level 2, and DC fast charging. The vast majority of public chargers are AC Level 2 chargers. DC fast chargers have been deployed in a few regions in the United States (Blink, 2012; DOE, 2013b). DOE estimates that more than 6,500 AC Level 2 and 155 DC fast-charging stations are available to the public in the United States; some stations require users to be members of a subscription-based plan (DOE, 2013b). The bulk of the installed DC fast chargers are along two corridors: along the Interstate-5 corridor in Washington and Oregon and in the “Tennessee Triangle” that connects Nashville, Chattanooga, and Knoxville. Other networks of DC fast chargers are deployed in southern California, Dallas-Fort Worth, Houston, San Francisco, Phoenix, and Chicago. As shown in Figure 3-2b, AC Level 2 charging can add about 10 to 20 miles of range to a vehicle for each hour of charging, depending on the model and driving conditions. That option might be attractive for those whose batteries are not fully discharged or for those who plan a longer stay at some location, such as a restaurant or a theater. AC Level 1 charging might be an economical charging option for locations where drivers are parked for an extended period, such as an airport or train station. However, the public infrastructure for long-distance travel for BEVs will require DC fast charging, which allows drivers to charge to 80 percent of battery capacity in 30 min. Long-distance trips that are fueled only with electricity could be challenging or inconvenient for drivers who do not have time for at least one recharge 37

of 20 to 30 min. 1 DC fast charging might be attractive for city driving that involves short parking times and long periods of driving. Furthermore, the availability of DC fast chargers could make it easier for BEV owners to use their vehicles more fully for intermediate-distance trips, such as weekend and evening noncommute trips. In addition to providing relatively fast refueling, publicly accessible charging must be placed at convenient locations. The availability of publicly accessible charging (and consumer awareness of its availability) is critical for providing a safety net and mitigating concerns regarding vehicle range. Whether the public-charging infrastructure is effective in relieving range concerns and enhancing the attractiveness of BEVs will depend on the extent to which the charging infrastructure is dispersed around an area. For example, Nicholas et al. (2013) provides a model for locating DC fast-charging stations in California to supplement AC Level 1 and AC Level 2 charging to cover vehicle trips that are now driven by conventional vehicles. However, the committee notes that siting also depends on finding a willing location that has sufficient access to electric service and the ability to cover any demand-charge costs that might be incurred. Although data have been collected on charging behavior and on possible locations for publicly accessible charging stations (see, for example, Nicholas et al., 2011 and Francfort, 2012), more information on charging behavior will help planners and companies to decide where to locate charging stations, especially when they are trying to design charging corridors. A key consideration in the deployment of public-charging infrastructure is cost. Although AC Level 1 and AC Level 2 chargers could be made available relatively inexpensively in many public places, DC fast chargers are expensive to install. The capital cost of a fast-charging station depends on the characteristics of the installation site. Important factors include whether the property must be purchased, leased, or rented; what distance must be spanned to connect to high-power supply lines; whether upgrades are required because of insufficient transformer or electric-panel capacity; how much trenching and conduit are needed to reach the charging station; and how much repaving or restriping of the parking area is required to accommodate the charging station. As a point of reference, Table 3-2 shows the average costs of installing charging stations in Washington state with DC fast chargers and AC Level 2 chargers as part of the publicly funded West Coast Electric Highway project. The committee recognizes that some costs might have changed since the project was completed. The basic equipment costs for a DC fast charger is about $10,000 to $15,000, but the figure quoted in Table 3-2 ($58,000) reflects the auxiliary services and features for a publicly accessible unit, including warrantee, maintenance, customer authentication, and networking and point-of-sale capabilities to collect payment from customers. Installation costs can also vary because of other enhanced safety and security measures that are often required by local permitting authorities, such as lighting and revenue-grade meters. Those options can add roughly $90,000 to the cost of the fast-charging equipment itself. Additional costs might also be incurred if multiple plugs are required for compatibility. Although a DC fast-charging station is not directly comparable with a gas station, it is interesting to note that the average cost of installing a new gas station has been estimated at about $2,000,000 in urban areas and $1,700,000 in rural areas (PB, 2009). 2 1 Owners of the Tesla Model S, which has a substantially greater range, could overlap the requirement for a 30- min charge with their desires for food, rest, and other services. That is, a 30-min charge might not be considered inconvenient if the vehicle range is substantial. 2 The committee makes this comparison merely to indicate that the scale of installing a DC fast-charging station is much smaller than the scale of installing a new gas station. It recognizes that gas stations typically have many pumps and dispensers and that refills are much faster. Public charging sites, whether they are DC fast-charging stations or AC Level 1 or 2 chargers, will need to install multiple chargers if the demand for services is sufficient to cause long wait times. Long wait times for public chargers could deter PEV drivers if they expect to depend on such facilities. 38

TABLE 3-2 Average Costs of Installing Publicly Accessible DC Fast-Charging Stations for the West Coast Electric Highway Projecta Component Cost DC fast-charging equipment $58,000 • 50-kW DC public fast-charging station (480-V ac input) per unit • 3-year warranty and point-of-sale capabilitiesb • Payment of all electricity dispensed (including utility demand charges) • Overhead lighting and required safety equipment Level 2 charger collocated next to DC fast-charging station $2,500 • 240-V/30-A AC Level 2 public charger per unit • Same terms and conditions as listed above Equipment installation (labor and electric-panel upgrade) $26,000 • Separate power drop or meter for the charging station per location • Electric-panel upgrade (if required) • Construction and environmental and electricity permits • Trenching, backfill, and site restoration • Installation of conduit and power lines to charging station • Installation of concrete pad and electric stub-out • Installation of curb or wheel stop and overhead lighting • Installation and testing of equipment Utility interconnection $12,500 to $25,000 • Costs are highly variable and depend on cost-recovery policies of the electric- per location power provider and condition of existing power-distribution componentsc • Generally includes utility costs for preliminary engineering and design, transformer upgrades, and labor for connection to the grid Host-site identification, analysis, and screening $5,000 • Identification of potential sites per location • Consultation with electric-power providers Negotiation, legal review, and execution of lease $6,000 • Making contact with several property owners per location • Exchanging and negotiating lease documents • Executing and recording documents TOTAL FOR DC FAST CHARGER AND 3-YEAR SERVICE $109,500 to $122,000 a Land costs are not included here. b Point-of-sale capabilities might include radiofrequency identification authentication and networking to back- office functions (such as account management and customer billing), equipment status signals, and credit-card transactions. c Additional costs could be incurred if addition of multiple chargers increases demand charges or requires additional electricity-service upgrades. SOURCE: WSDOT (2012). 39

Models for Deployment of Publicly Accessible Charging There are a variety of business models for deploying publicly accessible charging. As part of their early efforts to promote the deployment of PEVs, federal and state policy-makers sought to establish a “beachhead” of charging stations that would precede introduction of PEVs into the market in 2010 and beyond. Substantial federal funds were allocated via grants for charging infrastructure. In many cases, 100 percent of funding was provided without requirements to demonstrate a viable business model to support current operations or to expand the network of charging stations, and some question whether current approaches are cost-effective in achieving the desired goals (Peterson and Michalek, 2013). The motivation for public funding of infrastructure was to catalyze the deployment of PEVs and charging infrastructure. It was believed that the availability of publicly accessible charging infrastructure would convince people to buy PEVs and that having more PEVs on the road would motivate private entrepreneurs to provide publicly accessible charging. Because of the mutual dependence of PEV sales and public infrastructure deployment, the societal benefits of widescale adoption of PEVs might not be realized without adequate deployment of publicly accessible charging. Continued public-private partnerships or other forms of government support might be required, especially if the objective is to provide DC fast-charging infrastructure necessary to support long-distance travel. In considering whether and how much to subsidize private investments in public charging stations or to enter public-private partnerships to build such stations, it is important to recognize that investments in publicly accessible charging infrastructure can indirectly promote PEV purchases through several channels. First, public awareness of and education about PEVs can be enhanced when governments decide to place publicly accessible chargers, including DC fast-charging stations, in highly visible areas. For example, Electric Avenue in Portland, Oregon, which has six types of chargers for use, is near a major university and transit facility and provides a venue for product demonstrations and briefings (Durst, 2012). Second, some evidence indicates that the mere placement of a DC fast-charging station mitigates BEV drivers’ concerns about range issues (that is, running out of electricity), even if the drivers choose not to use the station. A study by the Tokyo Electric Power Company (TEPCO) demonstrated that an additional fast charger caused employees using BEVs to deplete batteries more than when only a single charger was available (Anegawa, 2008). An important issue is how best to structure public initiatives that draw in private funding and maximize the “bang for government bucks.” In seeking private contributions to the funding of publicly accessible charging stations, government agencies must be careful that their policies do not unduly intrude in the business space of infrastructure providers. Although early investors benefited heavily from government support, private investors now express concerns, for example, that federal or state governments might undermine their business potential by offering free charging or that government regulations may require them to install expensive data-collection devices at their charging stations. They also express concern that compliance with and lack of guidance on compliance with federal regulations, such as the Americans with Disabilities Act, could affect their businesses. Partly in response to government incentives, several private companies have stepped in to fill the nascent needs for public charging. They are experimenting with different business and pricing models for profitability in recovering their capital costs and the costs of electricity. For example, ChargePoint is pricing on a per-charge basis, and ECOtality and eVgo/NRG are pricing on a monthly subscription basis (Krauthamer, 2012; Lowenthal, 2012). Other business models rely on advertising revenue in which a third party—such as a car manufacturer, a retailer, or a local business—pays the charging provider for the space to place an advertisement on the charging station, much as an advertiser pays for a billboard. Other business models for deploying charging infrastructure include the Tesla model, in which the vehicle manufacturer deploys the charging infrastructure, and the BetterPlace model, in which a depleted battery is swapped for a fully charged one and the driver pays a subscription fee that covers all electricity at all stations and the amortized (or leased) cost of the battery (Wolf, 2012). 1 Nissan has recently announced 1 BetterPlace has recently announced that it is withdrawing from the North American and Australian markets. 40

plans to deploy a DC fast-charging station in an approach similar to Tesla’s. Other business models include having utilities provide the charging infrastructure (see Chapter 4 for further discussion) and having business owners provide the charging infrastructure as an enticement to get customers into their establishments. A major barrier to the deployment of publicly accessible charging infrastructure by private investors is the difficulty of achieving a favorable rate of return on investment from PEV charging alone. The problem is especially relevant for higher-cost DC fast-charging stations for which the committee is unaware of any case in which private firms have recovered the installation costs and received sufficient returns. Again, for comparative purposes, gas-station owners are able to recover their larger capital costs for two reasons: (1) although competition compresses margins on gasoline sales, station owners have a much larger volume of purchasers, and this helps them to achieve at least small profits on that product; and (2) gas stations derive additional profits from the sale of convenience food and goods—about two- thirds of the gross profit of a gas station is derived from food and goods, even though fuel sales account for three times the revenue from in-store sales (PB, 2009). In contrast, the revenue streams from dispensing electricity at stand-alone fast-charging stations are now low and unpredictable for the future, and this calls into question their ability to achieve commercial viability. Publicly accessible charging also competes with drivers’ home charging systems. At some price point, it might not be economical to charge a vehicle at a public station. Given the relatively long time required to charge a PEV compared with fueling a conventional vehicle, publicly accessible charging is most likely to be used if it is available where drivers leave their cars parked. Charging providers have strong motivation to locate public charging where people spend time, such as malls, retailers, libraries, and airports. Some retailers view the stations as a way to draw customers and have been willing to cover the bulk of the costs. For example, one charging provider was contracted to install charging units at some Target stores, and Target bears the installation and maintenance costs. A store offers free charging to its customers to encourage them to spend more time shopping while they wait for their cars to charge. Target has estimated that the incremental revenue generated from the additional time in the store makes the investment profitable. In that business model, the charging infrastructure might require only AC Level 2 chargers that provide electricity for an additional 10 to 20 miles. Finally, the public rationale and the private-business case for installing charging stations to enable travel between metropolitan areas are weaker than those for charging stations within metropolitan areas. In general, only 24 percent of total vehicle miles traveled in 2009 were on interstate highways (NHTSA, 2010). Governments can play an important role in assessing the case for electrification of transportation corridors between adjacent metropolitan areas (for example, along the Boston-Washington corridor or in southern Florida), and they would probably need to provide subsidies or enter public-private partnerships if such projects are undertaken. Such assessments could be informed by data on BEV traffic along the Washington and Oregon segments of Interstate 5. On the average, the DC fast chargers along the Washington corridor have been used less than twice a day in recent months, although the TEPCO study indicates that the safety net provided by the presence of chargers may have an important effect on BEV use between adjacent metropolitan areas (Anegawa, 2008). FLEETS A special case of charging-infrastructure needs involves the vehicle fleets owned and operated by corporations or federal, state, and local governments. There are several advantages of PEV adoption by fleets, including the emphasis on total cost of ownership rather than initial costs, route predictability, use of central parking facilities, and corporate sustainability (Electrification Coalition, 2010). The charging- infrastructure needs for fleets depend on their uses; some fleets rely on residential charging, and others rely on central parking facilities similar to sites of workplace charging. Where fleet vehicles sit idle overnight or for long periods during the day, AC Level 2 charging may provide a good solution for 41

refueling. For many fleets, however, the need to charge a number of vehicles in the same fixed period or the business case for turning around vehicles quickly is likely to necessitate DC fast charging. Special challenges can arise when large numbers of vehicles parked near each other must be charged at the same time given the load that this can place on the electricity-distribution system and possible demand charges (see Chapter 4 for further discussion). Several companies have made PEVs a component of their vehicle fleets. For example, General Electric announced in 2010 that it would purchase as many as 25,000 PEVs of which 12,000 were to be Chevrolet Volts, although recently the company has indicated that it would not purchase as many PEVs and would include other alternative-fuel vehicles (Catts, 2013). The company envisions that most charging of PEVs would occur at the residences of those using them. Federal, state, and local governments can contribute to the deployment of PEVs by electrifying their own fleets. Such an initiative would increase PEV sales and increase the visibility of such vehicles. If electrifying their fleets reduces the operating costs of refueling and increases the capital costs of vehicles, it might require overcoming bureaucratic constraints on shifting funds between operating budgets and capital budgets. Some government agencies have a disincentive to include PEVs in their fleets in that the electricity charges are not allowed in their operating budgets although fuel charges are. In addition, the federal government could provide charging at its own facilities and encourage workers to buy PEVs, it could collect information and serve as a centralized source for consumer information, and it could play an important role in shaping standards if the General Services Administration became involved in a major effort to procure charging systems. Those possible roles will be considered more fully in the committee’s final report. Another type of fleet to consider is a rental-car fleet. Hertz offers several options for PEV rentals, including making the vehicles part of its typical rental-car fleet or offering more specialized programs, such as EV-On-Demand or car-sharing services (Hidary, 2012). As noted above, residential charging is potentially problematic for the roughly 37 percent of U.S. households that do not have garages or carports (U.S. Census Bureau, 2012). Use of PEVs by those households could be encouraged through the deployment of PEVs in rental-car fleets and initiatives to make PEVs available in convenient locations for car-sharing, as discussed below. For rental-car fleets, the businesses would need to consider such issues as reprogramming of websites to have a PEV option, reprogramming of capacity planning to have downtime for PEV charging, and pricing of vehicles to facilitate PEV experimentation. The role of the government in facilitating deployment of charging infrastructure for fleets could include educational initiatives targeted at fleet operators and some combination of tax and depreciation incentives. As noted, the federal government also could spur sales and visibility of PEVs by converting some of its fleet to such vehicles and by providing charging at its own facilities, thus encouraging the deployment of PEVs and standardization of infrastructure though its procurement process. SHARED-USE VEHICLES Another special case of charging-infrastructure needs involves shared-use vehicles. In recent years, urban congestion, high gasoline prices, and information technologies have combined to encourage the emergence of shared-use vehicles. A handful of companies have entered the business of making vehicles available for sharing, and a couple offer programs based on electric vehicles. Car2Go (a Daimler subsidiary) offers rentals of electric Smart cars in several U.S., European, and Canadian cities. BMW’s Drive-Now program also offers electric-car sharing in several U.S. and European cities. And in parallel with initiatives to integrate PEVs into their fleets, Hertz is developing a new business model, Mobility as a Service, which could lead it to offer a subscription-based service in which customers have access to vehicles of choice, including PEVs, at any time for a monthly fee (Hidary, 2012). The trend toward shared-use vehicles—and perhaps also shared ownership of vehicles—might facilitate the use of PEVs. Shared-use options might prove to be particularly attractive to U.S. households that want to drive PEVs but do not have garages or carports where they can conveniently charge their cars 42

overnight and to younger people, partly because they tend to be more affected by income constraints, urban congestion, and lack of residential charging facilities. Young people also tend to be more adept at (and comfortable with) using the information technologies that are relied on in managing the vehicle- sharing process. The potential for shared-use vehicles to increase the number of electric miles traveled and the potential role of the federal government in encouraging shared use of PEVs—other than to monitor and be ready to modify policy as trends emerge—are not entirely clear. FINDINGS AND POSSIBLE GOVERNMENT ROLES IN THE CHARGING INFRASTRUCTURE A fundamental impediment to developing and assessing policies to overcome barriers to the deployment of PEV charging infrastructure is an understanding of the charging needs of PHEV and BEV drivers and how their needs might change, depending on the types of PEVs on the road and travel patterns, for example. The federal government—through its continuing efforts to collect, analyze, and disseminate data on vehicle charging, PEV sales, and policy effectiveness—could help to address the data gaps. Its analysis could include research to understand the effects of installing charging infrastructure on economic and related activity. The committee’s final report will investigate further the extent to which AC Level 1, AC Level 2, and DC fast charging meet residential, workplace, and publicly accessible charging needs. Residential Charging There are no serious technical barriers to the installation of residential charging infrastructure at most residences that have access to garages or carports. Charging at such residences, although installation and permitting of an AC Level 2 charger are expensive (about $1,100 to $1,800; Francfort, 2012), meets the needs of overnight charging of all foreseeable PHEVs and of BEVs that have a range of about 100 miles. AC Level 1 charging appears to be adequate for overnight charging of many PHEVs and of BEVs that are not driven extensively, and it will not require any modifications of many existing residences. The main barrier to the widespread adoption of residential charging of PEVs for such housing units seems to be the cost and effort of installing the outlet and, more fundamentally, the cost of the vehicle itself. An important barrier to PEV adoption is the lack of access to residential charging infrastructure, which can be the case for people who lack garages or carports, especially in multifamily dwellings or high-density locations. Retrofitting buildings that were not constructed with PEV charging as a possibility can be expensive. Possible roles for the federal government in reducing the barriers to residential charging of PEVs are as follows: • Continuing tax incentives and subsidies for installation of residential charging units, including those for multifamily units; • Encouraging state and local governments to streamline the permitting for residential charging and to adopt building codes that mandate that new construction be PEV-charging-enabled; • Helping to enable housing units that lack access to garages or carports to have better access to charging by encouraging or subsidizing local governments to have dedicated parking spots or by providing other incentives to install chargers; and • Continuing efforts to understand charging needs and future requirements through collection and analysis of charging and PHEV and BEV sales data by the federal government and through support and collaboration with researchers who are collecting and analyzing such information. Although all the above options would encourage residential charging, the committee recognizes that any continuing federal subsidies and incentives come at a monetary cost. Tax incentives add 43

complexities to the tax code. Federal research efforts, including the support of external researchers, also come at a cost, albeit a smaller one. And the committee recognizes that many of these efforts will require initiatives not from the federal government but from state and local governments. In those cases, the federal government’s role would be to analyze data and policies and to disseminate information to the public, businesses, state and local officials, and other stakeholders. The federal government could also use its convening function to facilitate interaction and coordination among stakeholders. Workplace Charging Increasing the availability of workplace-charging infrastructure potentially offers an important opportunity to encourage the adoption of PEVs. At workplaces, vehicles are typically parked for 8 hours or longer each day during the workweek. Over such a time, AC Level 2 chargers could provide a substantial amount of vehicle range, and AC Level 1 chargers might be sufficient for many PHEVs and for BEVs that are used for short commutes. Workplace charging also might be a charging solution for PEV owners who do not have access to charging at their residences. Possible roles for the federal government are as follows: • Providing a financial incentive, such as an accelerated depreciation schedule, to give businesses an incentive to offer workplace charging; • Exempting electricity provided by workplace charging infrastructure from being treated as a taxable benefit; • Working with utilities and their regulators to minimize demand charges that might be incurred because of workplace charging of PEVs; and • Continuing efforts to understand workplace charging needs and future requirements and disseminating information on examples of installations to illustrate costs, installation requirements, and possible methods to recoup installation costs or deal with tax implications. All the above options would encourage further deployment of workplace charging. The committee recognizes that there are disadvantages, including the monetary costs that come with providing subsidies or supporting analysis; increased complexity in the tax code due to accelerated depreciation schedules for workplace-charging infrastructure; and the fact that utilities and state regulators must work together to determine how demand charges will be assessed. Similarly, the decision on whether to pass the costs of workplace charging on to employees or to internalize the costs lies with employers. As with residential charging, the federal government’s roles in policies that lie outside its direct domain would be to analyze data and policies; disseminate information to the public, businesses, state and local officials, and other stakeholders; and facilitate coordination among them. Publicly Accessible Charging Concerns about the availability of publicly accessible charging may restrict widespread adoption of PEVs. Adequate deployment of public-charging infrastructure in the near term might require public- private partnerships or other forms of government support. In the middle to long term, a sustainable business model is needed. Although publicly accessible charging provides opportunities for briefer charging than residential and workplace charging, it offers several important benefits, including extending the electric range of all PEVs, relieving range concerns of BEV owners, and providing increased visibility for both PHEVs and BEVs. 44

Possible roles for the federal government include the following: • Providing continued incentives to support the deployment of publicly accessible charging, especially demonstration projects that propose credible and creative business models that could eventually be sustained when subsidies are no longer available; • Providing increased clarity and simplicity regarding regulatory compliance, such as compliance with the Americans with Disabilities Act; • Incentivizing landowners, retailers, and public agencies to offer host sites for the installation of public charging stations in key highway corridors; and • Continuing efforts to understand public-charging needs, future requirements, and the extent to which publicly accessible charging encourages PEV adoption and increases the number of electric miles driven. The committee recognizes the disadvantages of continuing to have federal and other subsidies involved in the deployment of publicly accessible charging infrastructure, including the monetary cost and the potential to exclude or discourage private investors. It also recognizes that there is little understanding of the extent to which incentives to deploy publicly accessible charging encourage PEV adoption or increase the number of electric miles driven. Fleets Fleets of PEVs have the potential to increase consumer awareness and adoption of such vehicles if cost-effective ways to charge large numbers of vehicles at the same time and close to each other can be found. PEV fleets increase the sales of such vehicles by automobile manufacturers and thus can help to reduce the costs through increased sales volume. The role of federal, state, and local governments could include providing incentives to encourage the adoption of electric fleets and the installation of the required charging infrastructure. Governments could also increase sales by purchasing such vehicles as part of their fleets and by modifying accounting rules to allow electricity costs for PEVs to be treated in a manner similar to how gasoline costs are treated for conventional vehicles. The federal government could play a specific role by providing charging at its own facilities and thus encouraging the deployment of PEVs and standardization of infrastructure though its procurement process. The added initial purchase costs and costs for needed charging infrastructure are disadvantages of increasing the use of PEVs in the federal government’s vehicle fleet. Standardization of the Charging Infrastructure The committee recognizes the importance of standardization of many facets of the infrastructure and concludes that multiple plugs for DC fast chargers and the lack of standardization of payment methods for different charging networks are particularly problematic. It recognizes that the federal government typically looks to professional societies or standard-setting organizations to develop common technology standards. However, an appropriate role for the federal government would be to play a convening role to encourage standardization of charging plugs and payment methods. A disadvantage of such standardization is that it might have the potential to restrain innovation, although increasing the interoperability of charging networks and plugs increases the coverage for the whole charging infrastructure. 45

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The electric vehicle offers many promises—increasing U.S. energy security by reducing petroleum dependence, contributing to climate-change initiatives by decreasing greenhouse gas (GHG) emissions, stimulating long-term economic growth through the development of new technologies and industries, and improving public health by improving local air quality. There are, however, substantial technical, social, and economic barriers to widespread adoption of electric vehicles, including vehicle cost, small driving range, long charging times, and the need for a charging infrastructure. In addition, people are unfamiliar with electric vehicles, are uncertain about their costs and benefits, and have diverse needs that current electric vehicles might not meet. Although a person might derive some personal benefits from ownership, the costs of achieving the social benefits, such as reduced GHG emissions, are borne largely by the people who purchase the vehicles. Given the recognized barriers to electric-vehicle adoption, Congress asked the Department of Energy (DOE) to commission a study by the National Academies to address market barriers that are slowing the purchase of electric vehicles and hindering the deployment of supporting infrastructure. As a result of the request, the National Research Council (NRC)—a part of the National Academies—appointed the Committee on Overcoming Barriers to Electric-Vehicle Deployment.

This committee documented their findings in two reports—a short interim report focused on near-term options, and a final comprehensive report. Overcoming Barriers to Electric-Vehicle Deployment fulfills the request for the short interim report that addresses specifically the following issues: infrastructure needs for electric vehicles, barriers to deploying the infrastructure, and possible roles of the federal government in overcoming the barriers. This report also includes an initial discussion of the pros and cons of the possible roles. This interim report does not address the committee's full statement of task and does not offer any recommendations because the committee is still in its early stages of data-gathering. The committee will continue to gather and review information and conduct analyses through late spring 2014 and will issue its final report in late summer 2014.

Overcoming Barriers to Electric-Vehicle Deployment focuses on the light-duty vehicle sector in the United States and restricts its discussion of electric vehicles to plug-in electric vehicles (PEVs), which include battery electric vehicles (BEVs) and plug-in hybrid electric vehicles (PHEVs). The common feature of these vehicles is that their batteries are charged by being plugged into the electric grid. BEVs differ from PHEVs because they operate solely on electricity stored in a battery (that is, there is no other power source); PHEVs have internal combustion engines that can supplement the electric power train. Although this report considers PEVs generally, the committee recognizes that there are fundamental differences between PHEVs and BEVs.

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