Why Electric Vehicles

Electric vehicle technologies offer significant efficiency and lower greenhouse gas (GHG) emissions compared to diesel. Switching to electrification from diesel would reduce GHG emissions around 37 percent in regions of the United States where renewables generate a larger share of electricity. A fully renewable electricity portfolio would result in near-zero GHG and other emissions from commercial transport.

However, significant technological and commercial barriers to widespread adoption in trucking, such as battery size and weight, must be overcome for many solutions to scale. Given these limitations, hybrid electric and electrification of non-engine components may be the most practical applications for medium- and heavy-duty vehicles.

Market Oulook

Electric vehicles comprise only 1 percent of U.S. vehicle sales, and most of this is in the light-duty market. A supportive policy environment is needed to increase sales, which, by one estimate, are projected to be less than 1 percent in 2035, even when combined with hydrogen vehicle sales.^{1 2} The strongest potential for growth exists in class 2b and 3 vans and trucks, electrification of vehicle subsystems, and specialized applications.³

Average U.S. retail prices for electricity for recharging on an energy-cost basis were 63.8 percent lower than diesel in the five years since 2010.⁴ The price difference compared to diesel grew by 14.8 percent for electricity compared to averages for the previous 10 years.⁵ These figures reflect electricity’s high efficiency on a work-power basis.

Vehicle Applications

There are multiple electric vehicle options, but most are not commercially viable for most MDV and HDV applications. Continued growth will depend heavily on reducing upfront costs and improving vehicle range. ⁶

All-Electric

All-electric vehicles, known as battery-electric vehicles (BEV), use an electric motor powered by large batteries.⁷ BEVs are useful for trucks that travel shorter distances and have well-defined routes that can allow for timely, planned charging without interrupting business operations.⁸ Current battery technologies for trucks support a range of up to 100 miles per charge, with larger electric trucks supporting a much shorter range.⁹ Additional tradeoffs include battery weight, power while operating on inclines, availability of charging infrastructure, cost, and charging downtime.¹⁰

Hybrid-Electric

Hybrid-electric vehicles (HEV) use batteries and electric motors as well as an internal combustion engine (ICE) to operate. HEVs have the potential to provide a 20-35 percent improvement in fuel economy over conventional trucks. They address many of the tradeoffs of all-electric vehicles, but range is limited and vehicle costs remain high.¹¹

Plug-in Hybrid-Electric

Plug-in hybrid-electric vehicles (PHEV) function as HEVs relying on electronic components as well as an ICE to power the vehicle and using “regenerative braking” that captures some energy during breaking to extend vehicle range. PHEVs can have an all-electric range of roughly 40 miles and have larger battery packs than regular HEVs.¹²

Electrification of Non-Engine Components

Idling technologies require roughly 1,400 gallons of diesel per vehicle, per year. Electrification can power vehicle subsystems such as heating, air conditioning, refrigeration units, and electricity for personal devices such as televisions and refrigerators.^{13 14}

Key Issues

Key Feedstock and Process Choices

The majority of electricity is produced in the United States with coal, natural gas, and nuclear, followed by hydropower and renewable sources such as solar and wind. The feedstock used varies significantly by region and state. Monthly figures by region can found at www.eia.gov/electricity/monthly/update.

Key Sustainability Opportunities and Impacts

Opportunity: Climate Change

Electric vehicle efficiency is up to three times higher than ICE efficiency. Efficiency alone confers a significant carbon emissions reduction from diesel combustion, but regions powered by a high percentage of nuclear, hydropower, and renewable energy reduce emissions even further.¹⁵ Use of high- or low-carbon electricity generation as a percentage of total regional mix can vary by as much as 61 percent in the United States, but some studies show even regions with high coal use show emissions reduction benefits.^{16 17}

Opportunity: Air Pollution (Tailpipe)

Tailpipe emissions that lead to air pollution will depend on the type of vehicle electrification—use of the ICE is the main driver of emissions. Trucks with electrification used exclusively for supporting systems will reduce air emissions only somewhat without emissions controls. HEVs do have some tailpipe emissions, but the electric components in HEVs allow for extended ranges and increased vehicle efficiencies that reduce fuel consumption significantly.¹⁸ BEVs have zero tailpipe emissions.

Impact: Air Pollution (Feedstock)

According to the EPA, fossil fuel-fired power plants are responsible for 70 percent of SOx emissions and 13 percent of NOx emissions from the combustion of fossil fuels in the United States¹⁹ Yet, actual rates of non-GHG emissions are regional. Coal is the biggest source of emissions from electricity that contribute to air pollution, and electricity in the Northeastern United States uses the least amount of coal, whereas the Central United States generates 65 percent of its electricity from coal.²⁰

Impact: Hazardous Substances

Electric vehicle technologies generate hazardous substances through the lifecycle of production, use, and disposal.²¹ Electric vehicle production is tied to toxic impacts on environmental and human health, along with metal depletion.²² Batteries used in electric vehicles rely on lithium-ions, which are flammable and highly reactive and include materials that are known carcinogens; disposal can generate waste and leaching of these materials.^{23 24}

Impact: Water Availability and Aquatic Ecosystems

Thermoelectric facilities, which are responsible for 44 percent of water withdrawals in the United States (more than 80 percent of U.S. electricity is generated this way), return most of their water to their source, though water withdrawals for thermoelectric power generation is poorly documented. Altering the water quality and quantity in this way can negatively impact local ecosystems when the temperature, chemical makeup, and/or pH is different from the receiving body—even if the water released meets regulatory requirements.

Key Uncertainties and Unresolved Issues

Uncertainty: Resource and Water Availability (Renewables)

Research is needed to improve the understanding of the potential sustainability challenges that may come with renewables at a large scale, especially around mining, manufacturing, and production of wind and solar power.²⁵ Water is required for cooling in concentrated solar power facilities, many of which are built in water-stressed regions like the Southwest United States.

Uncertainty: Battery Recycling and Reuse

It is important to improve the shared understanding of potential unintended consequences of battery life-cycle impacts of large-scale electric vehicle production.²⁶ Specifically, there is need for better understanding of second-life battery use and battery recycling and to what extent these opportunities reduce the cost of battery ownership as well as environmental and climate-specific impacts.²⁷

Uncertainty: Grid Integration and Reliability

Bringing more renewable energy onto the grid comes with challenges, such as low-capacity factors and resource intermittency (i.e., solar and wind energy are only available when the sun is shining and the wind is blowing). Intermittency solutions such as increased demand response, increased use of smart grid technologies, and affordable energy storage options are needed for effective wind and solar grid integration.²⁸

Sustainability Potential

Best Case

Electrification powered by renewable sources coupled with mitigating processes and technologies to minimize supply chain GHG emissions would be a near-zero emissions fuel source.²⁹ Such an approach would also eliminate tailpipe and feedstock emissions that cause air pollution. Batteries designed for end-of-life recycling or reuse, with an effective reverse logistics system for collection, would drastically reduce hazardous substance contamination from batteries. Energy generation from wind and solar photovoltaic in water-stressed regions, combined with water recycling, would reduce impacts to water availability.

Best Practices

Purchase Renewable Electricity

Renewable electricity from solar and wind is scaling rapidly across the United States Many utility-scale projects are competitive with fossil sources today, and in 2014 non-hydropower renewable energy produced 8 percent of electricity in the United States³⁰ Companies have many options for increasing the mix of renewables in their power sources: creating distributed generation projects onsite, building and investing in offsite projects through power purchase agreements, and buying “green-tariff” products from existing centralized utilities.

Install Renewable Electricity

Installing on-site renewable electricity or investing in ownership of nearby projects is a viable option to power distribution centers and other facilities. Some projects are cost-competitive with utility purchases, or show returns within two-to-five years and most offer predictability and savings in electricity prices. Coupled with charging infrastructure, these projects offer low-carbon power for the facilities and vehicles themselves.

Use Electrification to Optimize Vehicle Efficiency

Auxiliary power units (APU) traditionally use diesel. By switching to electric power, these APUs can help eliminate 11 million tons of carbon dioxide emissions in the United States each year and are particularly useful for long-haul trucks where drivers rely heavily on comfort systems to support long drives.³¹

Invest in Second-Life Battery Opportunities

Although additional research is needed to better predict the likely future markets for second-life batteries, fleet operators should participate in opportunities to reuse, repurpose, and recycle batteries at the end of their first life and source from OEMs that have battery recycling programs in place.³².

Use Electric Vehicles for Battery Storage

Increasingly, EVs are being used to help with renewable integration by providing battery storage for homes and business relying on renewables for electricity generation.³³ For example, the National Renewable Energy Lab (NREL) is working with the U.S. Department of Defense and the U.S. Army Corps of Engineers to develop a system that integrates solar energy and EVs into a microgrid system at a large Army facility in Colorado.³⁴

Encourage Electric Vehicle Uptake

In the short term, advancing electric vehicle uptake will require large private and public investment. Companies can encourage this by seeking public support, encouraging innovative financing opportunities to reduce upfront costs, and exploring group purchasing opportunities to further drive down costs.

Invest in Technology Research

For electric vehicle technologies to grow in the medium- and heavy-duty sectors, major technological advances are needed to increase range and power. OEMs should invest in research needed to make critical technology advancements in these areas, and fleet owners can pilot new vehicle technologies.