Motor vehicle electrification has emerged in the past decade as a potentially viable alternative to internal combustion engines. Although only a small proportion of the current motor vehicle fleet is electrified, interest in passenger vehicle electrification has accelerated in several major industrial countries, including the United States, parts of Europe, and China. Despite advances in technology, electric vehicles (EVs) continue to be significantly more expensive than similarly sized vehicles with internal combustion engines. For this reason, governments in many countries have adopted policies to promote development and sales of electric vehicles. This report discusses federal and state government policies in the United States to support electrification of light vehicles and transit buses, as well as proposals to reduce or eliminate such support. More than 92 million light vehiclesâpassenger cars, pickup trucks, and SUVsâwere sold worldwide in 2018. The three largest markets were China (27 million vehicles sold), Europe (20 million), and the United States (17 million). Most of these vehicles are powered by internal combustion engines. The global market for electrified vehicles is small but growing: In 2018, more than 2 million plug-in hybrid and battery electric vehicles were sold worldwide, a 64% increase over 2017. These account for about 2% of all passenger vehicle sales, both worldwide and in the United States. Demand for electric vehicles is expected to continue to grow, as some countries have called for a complete shift away from sales of new fossil-fuel vehicles by 2030. The market for urban transit buses is smaller than the passenger car and SUV markets, but electric vehicles make up a larger part of its footprint. China leads in this category, with 106,000 electric buses put in service in 2017, bringing its total electric bus fleet to 384,000. It has been forecast to remain the largest electric bus market going forward. In the European Union (EU) and the United States, the pace of electrification is slower: More than 200 electric buses were sold in the EU in 2017, bringing the total in service to 1,700; in the United States, approximately 100 electric buses were sold, bringing the total to 300. Two basic types of electric vehicles are now in use: Hybrid electric vehicles (HEVs) have both internal combustion engines and electric motors that store energy in batteries. They do not plug into external sources of electricity, but use regenerative braking and the internal combustion engine to recharge. Plug-in electric vehicles, of which there are two types: plug-in hybrid electric vehicles (PHEVs) use an electric motor and an internal combustion engine for power, and they use electricity from an external source to recharge the batteries. Battery electric vehicles (BEVs) use only batteries to power the motor and use electricity from an external source for recharging. In this report, electric vehicles refer to these two types of plug-in vehicles, unless otherwise noted. Electrification of vehicles has been limited by three factors: (1) the high cost of producing the lithium ion batteries (currently the preferred battery chemistry) that propel them; (2) their limited range; and (3) vehicle charging time and location. Not all motorists have easy access to charging stations at home or at work, and it can take several hours to fully charge the battery that powers the vehicle, depending on the type of charger used. In 2018, more than 361,000 plug-in electric passenger vehicles (including PHEVs and BEVs) were sold in the United States, as well as more than 341,000 hybrid electric vehicles. This was the first year in which total sales of plug-in vehicles exceeded sales of hybrids ( Figure 1 ). Nearly all automakers offer electric vehicles for sale: 42 different models were sold in 2018, with Tesla and Toyota recording the largest number of vehicle sales. Sales of plug-in hybrid and battery electric vehicles in 2018 rose by over 80% from the previous year, bringing the total sales of plug-in vehicles since 2010 to just over 1 million. The plug-in hybrid and battery electric share of the U.S. light vehicle market in 2018 was 2.1%. The price of new electric vehicles is one factor inhibiting faster adoption. For example, the Leaf, a battery electric vehicle produced by Nissan, has a manufacturer's suggested retail price (MSRP) of $29,990, whereas the Nissan Sentra, a conventional vehicle similar in size and specifications to the Leaf, has an MSRP of $17,990. A smaller, less powerful vehicle with an internal combustion engine, the Nissan Versa, has an MSRP of $12,360; no electric counterpart is available in this price range. Electric vehicles are generally more expensive because of the high cost of producing the lithium-ion batteries that power them. The federal government has supported vehicle electrification in several ways. There have been tax incentives for the purchase of vehicles as well as for construction of vehicle infrastructure, such as charging stations. Federal research and development investments have sought to reduce battery costs, increase vehicle range, and decrease charging times. The federal government has also made other investments to build out EV infrastructure. Two types of tax incentives have been used to promote electric vehicles: consumer incentives for the purchase of plug-in electric vehicles and individual and business incentives to install electric-vehicle charging stations to expand the charging network. The credit for plug-in electric vehicles (Internal Revenue Code [IRC] Â§30D) is the primary federal tax incentive for electric vehicles. The credit ranges from $2,500 to $7,500 per vehicle, depending on the vehicle's battery capacity. The tax credit is not a function of the vehicle's price. Therefore, the subsidy amount is larger (as a percentage of a vehicle's price) for less-expensive vehicles. Generally, taxpayers claim tax credits for vehicle purchases. If the purchaser or lessee is a tax-exempt organization, the seller of the vehicle may be able to claim the credit. The plug-in electric vehicle credit begins phasing out after a vehicle manufacturer has sold 200,000 qualifying vehicles for use in the United States. General Motors (GM) and Tesla have reached the 200,000-vehicle limit, and tax credits for their vehicles have begun to phase down. Empirical studies have found that tax incentives lead to increased EV purchases. However, particularly for higher-income taxpayers, the tax credit may be claimed for purchases that would have occurred absent a federal tax incentive. Some studies have also found that incentives given closer to the point of sale, such as a rebate given at the time of purchase, are more effective in stimulating vehicle sales than tax credits. The Joint Committee on Taxation (JCT) projects that the plug-in electric vehicle credit will reduce federal tax revenues by $7.5 billion between FY2018 and FY2022. Any extensions to or expansions of the credit could increase this amount. About half of the forgone revenue is from credits claimed on corporate tax returns. Additionally, the tax credits tend to be claimed by higher-income taxpayers. For 2016, 78% of the claimants filed returns with adjusted gross income (AGI) of $100,000 or more, and such returns accounted for 83% of the amount claimed. (By comparison, of all returns filed, about 17% have AGI above $100,000.) Legislation has been introduced in the 116 th Congress that would modify the plug-in electric vehicle tax credit. Some bills propose expanding the credit. For example, the Driving America Forward Act ( S. 1094 / H.R. 2256 ) would increase the per-manufacturer cap to 600,000 vehicles and modify the credit during the phase-out period. The Electric Credit Access Ready at Sale (Electric CARS) Act of 2019 ( S. 993 / H.R. 2042 ) would extend the credit through December 31, 2029, and would also allow the credit to be transferred to the financing entity. Other proposals would eliminate the credit. The Fairness for Every Driver Act ( S. 343 / H.R. 1027 ) would eliminate the credit and impose federal highway user fees on alternative fuel vehicles. The primary federal tax incentive for EV infrastructure has been the tax credit for alternative fuel vehicle refueling property (IRC Â§30C), which expired in 2017. The credit was generally 30% of the cost of qualified property, with the credit limited to $30,000 for businesses at each separate location and $1,000 for property installed at a taxpayer's primary residence. For property sold to a tax-exempt entity, such as a school or a hospital, the seller of the property may have been able to claim the credit. Qualifying property included electric charging infrastructure as well as other forms of clean-fuel refueling property. The credit for alternative fuel vehicle refueling property has been a temporary tax credit since first enacted in 2005. The credit has been extended six times, often retroactively. The credit most recently expired at the end of 2017, but could be extended again. The uncertainty surrounding temporary tax incentives that are often retroactively reinstated diminishes their effectiveness as an investment incentive. The Electric CARS Act of 2019 ( S. 993 / H.R. 2042 ) would extend the credit through 2029. Data are not available on how much of the revenue loss associated with this provision is for EV infrastructure. The most recent one-year extension of this incentive, for all types of alternative fuel refueling property, was estimated to reduce federal tax revenues by $67 million over the 10-year budget window. Making the credit permanent for all types of qualifying property would reduce federal revenue by an estimated $332 million between FY2018 and FY2027. The tax credits for EV charging infrastructure that expired at the end of 2017, if extended, could support additional investment in Level 2 charging infrastructure. Expanded access to Level 2 charging at homes and workplaces could be a cost-effective solution to building out EV infrastructure in the near term. However, if electric vehicles are to be widely used for long-distance trips, a network of direct-current fast charger (DCFC) infrastructure (Level 3) is likely necessary. The tax credit is relatively small compared to the cost of a DCFC charging station. The high cost of this infrastructure, even if tax credits are extended, may continue to pose a barrier, especially if utilization rates are low. Given the differences in the costs and benefits associated with Level 2 and DCFC chargers, tax incentives could be provided that reflect some of these differences. There are few DCFC public chargers, yet having access to such infrastructure may have strong network benefits. Broadly, access to charging infrastructure has been shown in some studies to be a driver of demand for EVs. If Congress wanted to encourage greater EV use, tax credits could be designed to provide a larger incentive for investments in public DCFC infrastructure, relative to Level 2 charging stations. Storage incentives are another policy option that could support investment in EV infrastructure. On-site battery storage systems can be installed to allow solar power to be used for EVs. Tax incentives for batteries that facilitate EV use could encourage more of this activity. The Energy Storage Tax Incentive and Deployment Act of 2019 ( S. 1142 / H.R. 2096 ) would provide an investment credit for business or home use of energy storage. Tax-preferred bond financing options could also be used to support EV infrastructure investment. State and local financing for infrastructure solely or partially dedicated to EV charging projects may use tax-exempt bonds so long as the project is classified as serving a "public purpose" as defined in the federal code (IRC Â§141). A federal infrastructure bank or "green bank" might also be used to support EV infrastructure investment. One option to capitalize this type of bank would be to issue tax-favored bonds. Since 1956, federal surface transportation programs have been funded largely by taxes on motor fuels that flow into the highway account of the Highway Trust Fund (HTF). A steady increase in the revenues flowing into the HTF due to increased motor vehicle use and occasional increases in fuel tax rates accommodated growth in surface transportation spending over several decades. In 2001, though, trust fund revenues stopped growing faster than spending. In 2008, Congress began providing Treasury general fund transfers to keep the highway account solvent. Electric vehicles do not burn motor fuels, and hence users do not pay motor fuels taxes. Several states have imposed some form of tax or fee on electric vehicles that is dedicated to transportation, such that EV drivers also contribute to paying for highway infrastructure. Legislation has been introduced in the 116 th Congressâthe Fairness for Every Driver Act ( S. 343 / H.R. 1027 )âthat would, in addition to repealing the existing tax credit for plug-in electric vehicles, impose an annual fee on alternative-technology vehicles that draw power from a source not subject to fuel excise taxes. This fee would be designed to compensate for plug-in electric vehicles not paying the gas tax (or other fuel excise tax). Imposing a fee on electric vehicles or other alternative vehicles would increase their cost of ownership, although as a share of the vehicle's total cost, the amount would likely be small. Exempting electric vehicles from taxes or fees imposed on other types of vehicles is one option for encouraging the purchase of electric vehicles. Investment in transportation electrification R&D is one approach to reducing the overall cost of electric vehicle technologies. The Obama Administration made vehicle electrification a national goalâincluding increased spending on battery R&D, stimulus funding for construction of battery manufacturing plants in the United States, and development of DOE electric vehicle research and demonstration programs such as the "EV Everywhere Grand Challenge." The Trump Administration requested reductions in funding levels for vehicle technologies R&D for FY2018 and FY2019, but Congress instead increased the program's funding levels for those years. Federal R&D funding for electric vehicles and electric vehicle charging infrastructure is primarily administered through the DOE's Office of Energy Efficiency and Renewable Energy (EERE). Within EERE, the Office of Transportation oversees the sustainable transportation R&D portfolio, which includes R&D programs in vehicle technologies, bioenergy technologies, and hydrogen and fuel cell technologies. Activities related to electric vehicles and charging infrastructure are within the Vehicle Technologies Office. In the 116 th Congress, some legislative proposals would support R&D programs. The Vehicle Innovation Act of 2019 ( S. 1085 / H.R. 2170 ) would authorize R&D programs and other activities to develop innovative vehicle technologies (including electric vehicles and charging infrastructure). Congress provides funding for electric vehicle technologies R&D through annual appropriations to EERE in the Energy and Water Development appropriations bill. The Trump Administration's budget request for EERE was $343 million for FY2020, $2,036 million (86%) less than the FY2019 enacted level of $2,379 million ( Table 1 ). The budget request, which "focuses DOE resources toward early-stage R&D and reflects an increased reliance on the private sector to fund later-stage research, development, and commercialization of energy technologies," would provide $73.4 million to vehicle technologies for FY2020, $279.6 million (79%) less than the $344 million that was directed to vehicle technologies within the Joint Explanatory Statement of the FY2019 appropriations conferees. The FY2019 joint explanatory statement included support for various vehicle technologies to advance transportation electrification research: $163.2 million for the battery and electrification technologies subprogram ($38.1 million for electric drive research and developmentâincluding $7 million to enable extreme fast charging and advanced battery analytics); $10 million for continued funding of Section 131 of the 2007 Energy Independence and Security Act ( P.L. 110-140 ) for transportation electrification; and $37.8 million for the Clean Cities program, which provides competitive grants to support alternative fuel, infrastructure, and vehicle deployment activities. According to the FY2020 DOE budget request, the vehicle technologies program has set goals that "are necessary for new technology options to be more efficient and at least as affordable compared to [the] baseline while also accounting for consumer pay- back period expectations." To advance vehicle electrification, DOE established the following research priorities: identify new battery chemistry and cell technologies with the potential to reduce the cost of electric vehicle batteries by more than half, to less than $100 per kilowatt hour (kWh) (with an ultimate goal of $80/kWh); increase vehicle range to 300 miles; and decrease charge time to 15 minutes or less by 2028. The request for FY2020 would reduce funding and prioritize "early-stage activities," including the development of critical materials-free battery technologies. The request would eliminate funding for battery safety testing, battery thermal performance testing, and Clean Cities coalition support, training and technical assistance, and partnership activities. The DOE Clean Cities program supports local actions to reduce petroleum use in transportation. The program funds transportation projects nationwide through a competitive application process, and leverages these funds with additional public- and private-sector matching funds and in-kind contributions. While the program supports a variety of alternative fuels and vehicles in an effort to reduce petroleum use, funding opportunities by Clean Cities that directly support EVs include the EV Everywhere PlugâIn Electric Vehicle Local Showcases. EV Everywhere PlugâIn Electric Vehicle Local Showcases were selected in 2016 and are in progress. The three projects were selected to promote and demonstrate plug-in electric vehicle (PEV) use by "establishing local showcases that provide a hands-on consumer experience and in-depth education in a conveniently located, brand-neutral setting." The awardees plan to establish showcases in at least 14 states, including states in the Upper Midwest, California, the Pacific Northwest, and New England. In the FY2019 joint explanatory statement, Congress directed DOE "to continue to support the Clean Cities program, including competitive grants to support alternative fuel, infrastructure, and vehicle deployment activities." In the FY2020 budget request, the Trump Administration proposed eliminating funding for the Clean Cities program. In the 116 th Congress, two bills that pertain to electric vehicles would establish competitive grant programs within the Department of Transportation for electric vehicle charging infrastructure ( H.R. 2616 and S. 674 ). Purchases of electric vehicles in the near future will depend to some extent on the steps state and local governments and private entities take to build a reliable network of charging stations. Section 1413 of the Fixing America's Surface Transportation Act (FAST Act; P.L. 114-94 ) seeks to address that goal; it requires the Department of Transportation (DOT) to designate by 2020 national alternative fuel corridors (AFCs) to promote vehicle use of electricity, hydrogen, propane, and natural gas. The Federal Highway Administration (FHWA) has been working with other federal, state, and local officials and industry groups to plan AFC designations on interstate corridors ( Figure 2 ). FHWA has assigned designations to highways as either "corridor ready"âthey have enough fueling stations to serve a corridorâor "corridor pending," where alternative fueling is insufficient. In the case of electric vehicles, a corridor-ready designation would apply if there were EV charging stations at 50-mile intervals, with a goal of establishing Level 3 DC Fast Charge infrastructure. Under this program, FHWA has developed standardized AFC signage and other forms of public education, and encouraged regional cooperation in planning new fueling networks. FHWA has undertaken three rounds of AFC nominations, the latest announced in April 2019. FHWA has identified building out alternative corridors on the most traveled Interstates, such as I-95 and I-80, as priorities for third-round funding. An additional goal is to secure nominations for areas targeted for EV investments by Electrify America in its Zero Emission Vehicle (ZEV) investment plan. Signage and installation of alternative fueling infrastructure along these corridors have been determined to be eligible expenses under FHWA's Congestion Mitigation and Air Quality Improvement (CMAQ) Program. In addition, the Department of Energy's Clean Cities program provides funding for fueling infrastructure, and some states have similar programs. Until recently, the operation of battery electric buses in U.S. cities was seen as a long-term prospect because of their relatively high cost, range limits, and recharging infrastructure needs. But with technological improvements, public transportation agencies have begun to show interest in electric buses to replace vehicles powered by diesel and other fossil fuels. This interest is especially strong in metropolitan areas with air quality problems. The Federal Transit Administration (FTA) provides substantial support to transit agencies to purchase buses. Federal funds can be spent on most types of bus technology; the choice of technology is up to the transit agency concerned. Transit buses typically operate over short distances with fixed routes and frequent stops. In 1996, 95% of the buses in service were powered by diesel fuel ( Figure 3 ). More recently, transit agencies have integrated buses fueled by compressed natural gas (CNG), liquefied natural gas (LNG), and biodiesel into their fleets. Since the end of the last recession, the share of lower-emission hybrid busesâincluding diesel buses with electric motorsâhas also increased, rising from just under 5% of buses in use in 2009 to nearly 15% in 2016. Diesel-electric buses are powered by both an electric motor and a smaller-than-normal internal combustion engine; regenerative braking systems store energy from use of the bus's mechanical systems, giving the bus greater range. The purchase price of hybrids is less expensive than a fully electric bus, and hybrids reduce emissions compared to conventional diesel buses. There were 300 battery electric buses in operation domestically at the end of 2017, less than 0.5% of the 65,000 buses in public transit agencies' fleets. However, the two biggest transit bus systems in the United States, Los Angeles Metro and New York City Transit, have announced plans to move to zero-emission bus fleets, most likely using battery electric buses, by 2030 and 2040, respectively. Electric buses are typically expensive to purchase, costing as much as $300,000 more than conventional diesel buses, and require additional investment to build recharging infrastructure. On the other hand, electric buses are quieter than internal combustion engine vehicles, may have lower operating costs due to the absence of engines and transmissions requiring maintenance, and have low or zero direct emissions. The range an electric bus can travel on one charge has in the past been a limiting factor, but newer models can travel more than 200 miles, still short of the 600-mile or more range that conventional and other alternative fuel buses can travel. A study by Carnegie Mellon University found that when social costs, such as the health effects of diesel emissions, are taken into account, battery electric buses have lower total annualized costs than conventional diesel buses over the typical 12-year life cycle of a transit bus. Electric buses are generally eligible for FTA funding under several programs, including the Bus and Bus Facilities Program. One discretionary component of the FTA bus program is the Low or No Emission Vehicle (Low-No) program, which provides funding to state and local authorities for the purchase or lease of zero-emission and low-emission transit buses as well as acquisition, construction, and leasing of required supporting facilities. Electric buses are purchased through the Low-No bus program; mandatory spending of $55 million per year through FY2020 was authorized in the FAST Act. An additional $29.5 million was appropriated for FY2018. School buses generally have diesel engines, and they are primarily funded locally. FTA does not fund school buses, but the Environmental Protection Agency (EPA) administers the School Bus Rebate Program, which assists school districts in reducing diesel emissions. In 2017, nearly $9 million was provided to replace diesel buses with diesel-electric hybrids. In the 116 th Congress, some legislative proposals would support vehicle fleet electrification, including transit buses. The Green Bus Act of 2019 ( H.R. 2164 ) would require that any bus purchased or leased with funds provided by the Federal Transit Administration for public transportation purposes be a zero-emission bus. The Federal Leadership in Energy Efficient Transportation (FLEET) Act ( H.R. 2337 ) would authorize the U.S. Postal Service to enter into energy savings performance contracts to purchase or lease low-emission and fuel-efficient vehicles (including electric vehicles) and to construct or maintain infrastructure, including electric vehicle charging stations, among other provisions. Â  The following policies were generally established for purposes not directly related to vehicle electrification, but they have dimensions that may support that goal. In 2016, Volkswagen Group reached a number of legal settlements concerning violations of the Clean Air Act. As part of its settlement terms, Volkswagen pledged to invest $2 billion over a 10-year period in zero-emissions vehicle infrastructure and education in select U.S. cities through its Electrify America initiative. Of that amount, $800 million is to be spent in California. As an additional condition, Volkswagen was also required to fund a $2.7 billion national Environmental Mitigation Trust, funds from which are available to states and other beneficiaries for mitigating the negative impacts of the excess diesel emissions that were released by Volkswagen's noncompliant vehicles. States could choose to spend some of this special funding on bus electrification, including school buses. The first motor vehicle fuel economy standards were enacted in 1975 in response to the oil embargo of 1973-1974 (Energy Policy and Conservation Act of 1975; P.L. 94-163 , as amended). The National Highway Traffic Safety Administration (NHTSA) sets and enforces the Corporate Average Fuel Economy (CAFE) standards for passenger cars and light trucks, which were most recently legislatively set in the Energy Independence and Security Act of 2007 ( P.L. 110-140 ) at 35 miles per gallon (mpg) by 2020. Because EPA has authority to regulate greenhouse gas (GHG) emissions, it joined with NHTSA during the Obama Administration to promulgate new, stricter combined CAFE/GHG standards for motor vehicles. These new standards established targets for reduced GHG emissions and rising CAFE fuel economy of nearly 50 mpg by model year (MY) 2025. Electrification was seen as one means of reaching the new CAFE/GHG targets. The Trump Administration has proposed to leave the current CAFE/GHG standards in place through model year 2026, based on its analysis that economic and technological factors have changed since the standards were put in place in 2010. EPA asserted in April 2018 that the goals established for MY2026 could be achieved only with more extensive vehicle electrification than now anticipated, and rejected previous EPA determinations that EV sales in future years would grow rapidly enough to enable automakers to comply with the MY2022-MY2025 standards: "Based on consideration of the information provided, the Administrator believes that it would not be practicable to meet the MY 2022â2025 emission standards without significant electrification and other advanced vehicle technologies that lack a requisite level of consumer acceptance." Fully autonomous passenger vehicles hold the potential for safer transportation and new mobility for the elderly, the disabled, and those who cannot afford to purchase a car. The projected timeline for emergence of fully autonomous vehicles varies from several years to several decades. It is often assumed that autonomous vehiclesâincluding those providing ride-sharing servicesâwill employ electric motors instead of internal combustion engines, but that assumption is based on the types of federal and state policies that are put in place. In the absence of policies favoring EVs, future autonomous vehicles could be powered by fossil fuels. There are several reasons why electrification may not be the ultimate choice for autonomous vehicles. Analyses by Ford and Volvo have for the following reasons led them to retain internal combustion engines for their ride-sharing ventures for the present: Expense and I nconvenience . Electric vehicles remain expensive compared to conventional vehicles, and many models have short driving ranges and long refueling times. Shared vehicles, which may be on the road for many hours a day, magnify these shortcomings. Battery L ife . Frequent use of battery fast charging is known to lead to faster degradation of the battery. Energy- I ntensity . Autonomous vehicles rely on energy-intensive technologies. It has been estimated that operation of an autonomous driving system for two hours in an electric vehicle could use as much as 10% of its stored energy before the vehicle moves, requiring even more frequent recharging. These drawbacks are countered by the following factors that could make electrification of autonomous vehicles the more attractive power source: Compatibility . The extensive use of computers and sensors in autonomous vehicles may be easier to embed in electric vehicles, which have fewer mechanicalâand more electronicâparts than a conventional vehicle. Operability . Electricity is generally less expensive than gasoline or diesel, and maintenance costs for electric vehicles, with many fewer parts, may be considerably lower. Emissions . The power demands of autonomous vehicle equipment and computers will reduce the fuel economy of gasoline and diesel vehicles and increase emissions. It has been estimated that increased power requirements will increase emissions from combustion vehicles by over 60 grams of CO 2 equivalent per mile, equal to reducing fuel economy of a 35 mpg vehicle to 29 mpg. Switching to electricity would diminish the direct emissions. Acceptance of electric vehicles and related infrastructure is affected by legislation, regulations, and policies adopted by state agencies and electric utilities. Incentives vary widely from state to state. The National Conference of State Legislatures tracks vehicle and charger incentives on a state-by-state basis. Forty-five states and the District of Columbia currently offer incentives for certain hybrid or electric vehicles, or both. Those incentives include permitting solo drivers of electric and hybrid vehicles to use high-occupancy (carpool) lanes, income tax credits and rebates for the purchase of an electric vehicle, reduced registration fees, parking fee exemptions, excise tax and emission test waivers, and income tax credits for installation of a home or business charger. These incentives have been found to vary in their effectiveness. Several analyses have shown that tax incentives for electric vehicles and infrastructure are the "dominant factors in driving PEV adoption." Rebatesâwhich happen at the point of sale or within a short time after a vehicle purchaseâhave been identified as the most effective incentive because their value is clear to buyers at the time of a vehicle transaction. The California Air Resources Board (CARB) adopted low-emission vehicle regulations in 1990, requiring automakers to sell light vehicles in that state that meet progressively cleaner emissions standards. As part of these emission regulations, CARB also established the Zero-Emission Vehicle (ZEV) program, which requires automakers to offer for sale the lowest-emission vehicles available, with a focus on battery electric, plug-in hybrid electric, and hydrogen fuel cell vehicles. The number of ZEVs each automaker is required to sell is based upon its total light-vehicle sales in California. CARB has set ZEV sales percentages through a vehicle credit system, increasing annually to 2025. Nine other states have adopted the California ZEV regulations. The states affected by the regulations represent over one-third of all U.S. new light vehicle sales. Electric utilities, which are regulated by the state in which they are located, are in a unique position as the primary providers of electricity to aid in integrating EVs into the grid. Utilities can provide incentives to consumers to charge EVs during off-peak hours when there is excess generation. Utilities may also be in the position to install public electric charging infrastructure, assuming that there are no limits on their owning these assets. Many of the barriers utilities face with respect to electrification infrastructure are regulatory, and the role of tax policy in addressing such barriers may be limited. Sluggish growth in energy demand has posed a challenge for the electric utility sector. The industry has recognized EVs as an opportunity for growth. For this reason, electric utilities may have their own market-based incentives (absent federal intervention) to invest in EV infrastructure and take measures to support consumer EV adoption. Further, electric utilities may support extending current-law vehicle and infrastructure tax credits. At the same time, preparing the grid for a surge in electric car ownership could require substantial capital investments, if peak demand is increased. A number of challenges are associated with providing tax incentives to utilities that provide EV infrastructure. While 65% of electricity customers across the United States are customers of investor-owned utilities, most other users purchase electricity from cooperatives or municipal power providers. There are limited options for providing a direct federal tax benefit to cooperative or municipal utilities that do not pay federal income taxes. Further, in many states customers may purchase electricity from competing suppliers and pay the local electric utility for delivering it. A tax incentive to provide EV infrastructure might be made available only to utilities, to other electricity suppliers, or to both. Applicability of such an incentive would vary according to state policies or the type of utility. State regulatory commissions typically establish prices or rates that allow utilities to earn a rate of return that the regulator determines to be reasonable. This rate of return is fixed, such that additional tax incentives do not necessarily increase the return that a utility can realize. Federal taxes are an operating expense. In some states, tax incentives that reduce utilities' operating expenses result in lower rates for electricity customers (not higher returns for utilities). Hence, federal tax incentives may provide a limited near-term incentive for utilities to increase capital spending on EV infrastructure. In the United States, the sale of electricity is governed by many different federal, state, and local regulations. When it comes to the sale of electricity for the purpose of charging EVs, the states generally have regulatory jurisdiction over retail electricity transactions, though federal and municipal authorities may also play a role. State approaches to regulation vary considerably. Rules and regulations governing the retail sale of electricity generally originate with a state public utility commission. An electric utility is defined in federal law as any person, state, or federal agency "which sells electric energy." This definition could potentially be interpreted to mean that electric vehicle charging station operators are electric utilities by virtue of the fact that they sell electricity, and are therefore subject to all laws, requirements, and regulations pertaining to electric utilities. Should charging station operators be subject to regulation as electric utilities, or is regulatory reform necessary to accommodate this new class of electricity transactions? Faced with the question of whether or how to regulate the operators, states have taken a variety of approaches: Some states have issued new guidelines or regulations that define the requirements for regulated utilities to operate charging stations. For example, some states (e.g., Oregon) allow existing regulated utilities to invest in and operate EV charging stations as separate, nonregulated ventures. Others (e.g., Texas) have effectively limited the operation of charging stations to electric distribution utilities by requiring operators to meet high technical and financial standards. Still others (e.g., Kansas) have prevented electric utilities from owning and operating charging stations altogether. Other states (e.g., New York) have exempted charging station operators from public utility regulations. This leaves questions as to which regulatory agency, if any, is responsible for regulating the charging station operators, as well as whether additional regulation is needed in order to ensure fair market practices. Finally, some states have refrained from taking action altogether. Without regulatory changes, private charging station operators in these states may be subject to regulation as a utility by the state's public commission. Lack of clarity about how operators will be regulated is seen by some as an impediment to the spread of the technology in these states. In some cases, EV service providers have avoided regulation as a utility by providing charging services for free, or by charging customers by the minute rather than by the amount of electricity used. Whether public utilities or private companies may operate electric vehicle charging stations and whether station operators are subject to regulation as a utility may affect deployment of EV charging infrastructure. State jurisdiction over retail electricity transactions may limit the potential role of the federal government in regulating the provision of EV charging services. An additional consideration is the potential for electric vehicle batteries to be used for storage, referred to as vehicle-to-grid (V2G) storage. V2G storage would allow idle vehicle batteries to be used for grid services, such as demand response. The batteries could reduce vehicle owners' electricity demand during peak periods or provide electricity to the grid during peak periods in response to time-based rates or other financial incentives. In the United States, utilities are beginning to test V2G performance in demonstration projects. In addition to technology, other identified challenges include regulation, market, and end-user acceptance.

Summary: Most of the 270 million cars, trucks, and buses on U.S. highways are powered by internal combustion engines using gasoline or diesel fuel. However, improvements in technology have led to the emergence of vehicle electrification as a potentially viable alternative to internal combustion engines. Several bills pending in the 116 th Congress address issues and incentives related to electric vehicles and charging infrastructure. Experience with fully electric vehicles is relatively recent: While a few experimental vehicles were marketed in the United States in the 1990s, the first contemporary all-electric passenger vehicles were introduced in 2010. Since then, newer models have increased the range an electric vehicle can travel on a single charge, and charging stations have become more readily available. These developments have been spurred by a range of government incentives, both in the United States and abroad. Transit buses are the fastest-growing segment of vehicle electrification in China, while in the United States and the European Union, the pace of bus electrification is slower. In the United States, federal incentives for electric passenger vehicle purchases have remained largely unchanged for more than a decade and are based primarily on tax credits for electric vehicle purchases and recharging infrastructure investments, and spending on battery chemistry research to develop less-expensive technologies: The plug-in electric tax credit permits a taxpayer to take a credit of up to $7,500 for each vehicle that can be recharged from the electricity grid; it phases out after a manufacturer has sold 200,000 eligible vehicles, a threshold that has been met by Tesla and General Motors. A tax credit for installation of alternative fuel vehicle refueling property expired in 2017; it had allowed a tax credit of $1,000 for equipment installed at a residence and up to $30,000 for business installations. I nvestment in transportation electrification research and development (R&D) , which has led to the gradual reduction in the cost of producing lithium-ion batteries, is administered by the U.S. Department of Energy (DOE) in cooperation with private industry. Although the Trump Administration has recommended large reductions in these programs, Congress has maintained annual funding for sustainable transportation of nearly $700 million in the past two fiscal years. Other programs that directly influence the level of vehicle electrification include the DOE Clean Cities Program, which supports local efforts to reduce fossil fuel-powered transportation, and the Department of Transportation's Alternative Fuel Corridors, which are designated Interstate Highway corridors with a sufficient number of alternative fueling stations, including electric vehicle chargers, to allow alternative fuel vehicles to travel long distances. The federal government also funds municipal transit bus electrification through Federal Transit Administration grants, which may be used for the purchase of all-electric buses. The pace of electrification also may be affected by proposals for less stringent federal standards for Corporate Average Fuel Economy (CAFE) and greenhouse gas emissions from vehicles. Beyond these federal programs, states and electric utilities provide a range of incentives for electrification. The National Conference of State Legislatures reports that 45 states and the District of Columbia offer incentives such as income tax credits for electric vehicle and charger purchases, reduced registration fees, and permitting solo drivers of electric vehicles to use carpool lanes. The California Zero Emission Vehicle program is spurring sales of electric vehicles in 10 states. Utilities can provide incentives to charge during off-peak hours, install public electric charging infrastructure, and utilize vehicle-to-grid (V2G) storage. V2G storage would allow idle vehicle batteries to supply electricity to the grid rather than drawing power from it during peak demand periods.