Carnegie Mellon University

Nicholas Muller

July 01, 2018

Electric Vehicles Cause Greater Air Pollution Through Power Plant Emissions

The U.S. government currently offers subsidies to individuals for the purchase of electric vehicles, in an effort to reduce emissions caused by traditional gasoline vehicles. However, ongoing research by Nicholas Muller, Lester and Judith Lave Associate Professor of Economics, Engineering and Public Policy, demonstrates that the environmental benefits of electric vehicles often are outweighed by the damages caused by the increased emissions from power plants.

In one study, Muller and colleagues found that an electric vehicle can cause up to $5,000 more damage than an equivalent gasoline vehicle when driven in the Midwest, where coal-fired power plants are common. Conversely, in California, where the power grid is much cleaner, electric vehicles yield nearly $5,000 in environmental benefits.

In another study, Muller and co-authors analyzed the environmental impact from all U.S. electric vehicles in 2014. They found that while urban counties saw $2.9 million less in air pollution damages from electric vehicles, rural counties had almost $3 million more. This is in part because an overwhelming majority — 98 percent — of electric vehicles are registered in urban counties.

“The benefits of charging, in terms of air quality, accrue where air quality would have been most adversely affected by the gas engine car — and that’s going to be in cities,” Muller said. “Our power plants tend to be in rural locations. As a result, when you charge that car, emissions disproportionately affect lower-income folks.”

In a study focusing on the distribution of air pollution damages titled “The Distribution of Income is Worse Than You Think,” Muller and co-authors Peter Hans Matthews of Middlebury College and Virginia Wiltshire-Gordon from ECONorthwest found that the damages act as a regressive tax: Households in the bottom 20 percent of income levels saw their market share of income decreased by exposure to pollutants, while households in the top 20 percent saw an increase.

Muller noted one positive trend appearing in his research: “As we transition to a grid more dominated by natural gas at the expense of coal, electric vehicles are going to look increasingly advantageous.”

Read more in the summer 2018 Tepper Magazine