The report finds that greenhouse gas emissions from light-duty vehicles could drop as much as 64% below today’s levels. Widespread use of electric vehicles (EVs)—including lawn and garden equipment and heavy industrial equipment such as forklifts—could improve air quality, particularly in densely populated urban areas.

Use of electric vehicles would achieve greater reductions in GHG emissions, corresponding to the rate that the electric grid becomes cleaner, through greater reliance on renewables and low- and non-emitting generation.

This research points to the importance of two fundamental and parallel trends in energy and the environment. First is the continuing decarbonization of the electricity sector and second is the electrification of energy use in transportation and industry. We expect to see continued interest and work in measuring and understanding these trends more fully in the years and decades ahead.

—Mike Howard, EPRI president and CEO

The study analyzes two potential scenarios of the future electric sector, the “Base GHG” and “Lower GHG” scenarios. Both project grid emissions decreasing over time, in part because of existing and potential regulations and plausible economic conditions. In the Lower GHG Scenario, further reductions in carbon emissions result from adoption of policies that apply an increasing price on carbon emissions, resulting in faster deployment of low-emission generation technologies.

• In the Base GHG scenario, the study estimates that, by 2050, the electricity sector could reduce annual GHG emissions by 1030 million metric tons relative to 2015 levels, a 45% reduction.

• In the Lower GHG scenario, the study estimates that, by 2050, the electricity sector could reduce annual GHG emissions by 1700 million metric tons relative to 2015 levels, a 77% reduction.

The analysis modeled electric sector and transportation sector emissions with and without widespread vehicle electrification to determine the effect of electrification of light-duty vehicles, medium-duty vehicles and certain non-road equipment. For wide-spread adoption, the analysis assumes that the electric vehicle market share grows from approximately 1% today to a substantial share of total sales, such that by 2050 electricity is powering 53% of personal vehicle miles traveled.

As transportation is electrified, a comprehensive grid model uses the incremental load growth to estimate power sector emissions. The analysis compares resulting grid emissions with emissions from conventional petroleum fuels, using a full-fuel-cycle method that accounts for the production, delivery and use of fuels in the transportation and electricity sectors.

Without electrification, the results point to a 24% reduction in GHG emissions relative to 2015 levels, based on current policies that require greater efficiency for new vehicles, along with additional, assumed improvements. The results indicate that electrification could displace emissions from conventional petroleum-fueled vehicles for each scenario as follows:

• In the Base GHG scenario, emissions were reduced by 430 million metric tons annually in 2050—equivalent to removing 80 million passenger cars from the road.

• In the Lower GHG scenario, emissions were reduced by 550 million metric tons annually in 2050—equivalent to removing 100 million passenger cars.

When combining reductions from vehicle electrification, a cleaner electric sector, and existing programs that improve conventional vehicle efficiency, the modeled electricity and transportation sectors together achieve a 48% reduction in GHG emissions between 2015 and 2050 in the Base GHG scenario, and a 70% reduction in the Lower GHG scenario.

In the Lower GHG scenario, in 2050, total emissions for the electricity and transportation sectors could be reduced by 2610 million metric tons relative to 2015 levels.

While electric vehicles are cleaner than petroleum-fueled vehicles today, the greenhouse gas reductions can be maximized by charging vehicles from a cleaner grid. With a 62% share of light- and medium-duty vehicles in 2050 electric vehicles would consume 13% of grid-supplied electricity.

Transportation electrification can lead to modest, but widespread air quality benefits. The electrification case assumes that the overall fraction of vehicle miles traveled by the US vehicle fleet using electricity stored in batteries is 17% for light-duty vehicles and 8% for medium-duty vehicles. For non-road equipment, the fraction in 2030 varies for electrified equipment types depending upon their characteristic applications and uses. Emissions from transportation and power sectors were calculated and subsequent effects on air quality were modeled in the continental United States, using a comprehensive three-dimensional atmospheric model.

Considering the electric power sector and transportation sectors together, net emissions of pollutants leading to atmospheric ozone and fine particulate matter (PM_2.5) decrease in the electrification scenario. Modeling simulations indicate that even considering recent Tier 3 vehicle emission standards, electrifying on-road vehicles can result in modest, yet widespread reductions in ozone and PM_2.5 levels throughout the United States.

Electrifying non-road equipment provides significant air quality benefits, in some cases greater than those of on-road electrification, particularly in urban areas. The electrification scenario also showed reductions in the deposition of acids and nutrients that can damage ecosystems.

Today’s study gives us a clear vision of how expanding transportation electrification is a key strategy to achieving critical greenhouse gas and air quality goals. This underscores the important role utilities can play nationally in accelerating the market through efforts such as investing in infrastructure to support public and workplace charging stations and incorporating EVs into our own fleets.

—Ted Craver, chairman, president and CEO of Edison International

Utilities supporting this research include American Electric Power; British Columbia Hydro and Power Authority (BC Hydro); Duke Energy Corporation; FirstEnergy Corporation; LG&E and KU; New York Power Authority; Oglethorpe Power Corporation; Oncor Electric Company; Southern California Edison; Southern Company; Seattle City Light; and the Tennessee Valley Authority (TVA).

Resources

• Environmental Assessment of a Full Electric Transportation Portfolio