If you've ever wondered how important adoption of electric vehicles (EVs) is for the environment, a new study shows that switching would improve overall air quality and reduce carbon emissions.
The Northwestern University study quantified the differences between air pollution generated by battery electric vehicles and internal combustion engines. The researchers found that even when their electricity is produced from combustion sources, electric vehicles have a net positive impact on air quality and climate change.
"Unlike many scary stories we read in the news about the effects of climate change, this work is about solutions," said Daniel Horton, lead author of the study. "We know that climate change is happening, so what can we do about it? A technologically available solution is to electrify our transportation system. We find that adoptions of electric vehicles reduce net carbon emissions and have the added benefit of reducing air pollutants, thereby improving public health. "
The research was published on Friday, April 5th in the journal Atmospheric Environment. Horton is an Assistant Professor of Earth and Planetary Science at Northwestern Weinberg College of Arts and Sciences. Jordan Schnell, a postdoctoral fellow at the Ubben Climate and Carbon Science Program at the Northwestern Institute for Sustainability and Energy, was the first author of the paper.
To quantify the differences between the two types of vehicles, the researchers used an emissions remapping algorithm and simulations of air quality models. They used these methods to closely examine two pollutants related to automobiles and power emissions: ozone and particulates. Both are major components of smog and can trigger various health problems, such as asthma, emphysema and chronic bronchitis.
To fully take into account the complexity of the changes in the chemistry of atmospheric pollution, the researchers took into account several variables:
- Adoption rate of potential electric vehicles
- Electricity Generation for Electric Vehicles, Including Our Current Combustion Blend, Our Combustion Only Sources and Our Enhanced Emissions Free Renewable Energy
- Geographical Locations
- Seasons and times of the day
Ozone levels decreased in all areas during hot month simulations. In winter, however, ozone levels increase slightly but are already much lower than in the summer due to a chemical reaction that occurs differently during periods of less sunlight.
"In all scenarios, we found that the more cars that went to electricity, the better the summer ozone levels," Schnell said. "No matter how the energy is generated, the more you remove from combustion cars, the better the quality of the ozone layer."
Particles, also called "haze", decreased in the winter but showed greater variation depending on the location and how the energy was generated. Sites where the energy mix of their energy park is larger, for example, have experienced an increase in haze during the summer. Sites with clean energy sources have, however, experienced a drastic reduction in man-made fog.
"We found that in the Midwest, the increasing energy demands of EV charging in our current energy mix could result in a slight increase in particulate matter in the summer due to the dependence on the production of electricity." 39, coal-fired electricity, "said Schnell. "However, if we further convert Midwest power generation into renewable energy, particle pollution is significantly reduced. In the Pacific Northwest or the Northeast Pacific, where there is already more clean energy available, the adoption of EV, even with the current energy mix, will allow for reduce pollution by particles. "
The research was funded by the Ubben Program for Carbon and Climate Science and the National Science Foundation (Grant Number CBET-1848683).