Switching to Electric Vehicles May Improve Air Quality: Study

Adopting electric vehicles (EVs) could improve overall air quality and lower carbon emissions, according to a study.

Researchers from the Northwestern University in the US quantified the differences in air pollution generated from battery-powered electric vehicles versus internal combustion engines. They found that even when their electricity is generated from combustion sources, electric vehicles have a net positive impact on air quality and climate change.

"In contrast to many of the scary climate change impact stories we read in the news, this work is about solutions," said Daniel Horton, senior author of the study published in the journal Atmospheric Environment.

"We find that EV adoptions reduces net carbon emissions and has the added benefit of reducing air pollutants, thereby improving public health," Horton said in a statement.

To quantify the differences between the two types of vehicles, the researchers used an emissions remapping algorithm and air quality model simulations.

They used these methods to closely examine two pollutants related to automobiles and power emissions: ozone and particulate matter.

Both are main components of smog and can trigger a variety of health problems, such as asthma, emphysema and chronic bronchitis. Ozone levels decreased across the board in simulations of warmer weather months, researchers said.

In the wintertime, however, ozone levels increase slightly but are already much lower compared to summer due to a chemical reaction that occurs differently during times of lesser winter sunlight.

Across scenarios, we found the more cars that transitioned to electric power, the better for summertime ozone levels

Jordan Schnell, postdoctoral research fellow, Northwestern University

"No matter how the power is generated, the more combustion cars you take off the road, the better the ozone quality," Schnell said.

Particulate matter, which is also called "haze," decreased in the wintertime but showed greater variation based on location and how the power was generated. Locations with more coal-fired power in their energy mix, for example, experienced an increase in haze during the summer. Locations with clean energy sources, however, saw drastic reductions in human-caused haze.

"We found that in the Midwest, the increased power demands of EV charging in our current energy mix could cause slight increases in summer particulate matter due to the reliance on coal-fired power generation," Schnell said. "However, if we transition more of the Midwest's power generation to renewables, particulate matter pollution is substantially reduced," he added.