The key is where the source of the electricity all-electric cars. If it comes from coal, the electric cars produce 3.6 times more soot and smog deaths than gas, because of the pollution made in generating the electricity, according to the study that is published Monday by the Proceedings of the National Academy of Sciences.
The study examines environmental costs for cars’ entire life cycle, including where power comes from and the environmental effects of building batteries.
“Unfortunately, when a wire is connected to an electric vehicle at one end and a coal-fired power plant at the other end, the environmental consequences are worse than driving a normal gasoline-powered car,” said Ken Caldeira of the Carnegie Institution for Science, who wasn’t part of the study but praised it.
The states with the highest percentage of electricity coming from coal, according to the Department of Energy, are West Virginia, Wyoming, Ohio, North Dakota, and Illinois.