All-electric vehicles (EVs) run on electricity only. They are propelled by one or more electric motors powered by rechargeable battery packs.
EVs have several advantages over vehicles with internal combustion engines, such as energy efficient, environmentally friendly, performance benefits and reducing energy dependence
People who own all-electric cars where coal generates the power may think they are helping the environment. But a new study finds their vehicles actually make the air dirtier, worsening global warming.
"A lot of the technologies that we think of as being clean are not better than gasoline," said study co-author Julian Marshall, an engineering professor at the University of Minnesota.
The point is where the source of the electricity all-electric cars. When 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. The study also found that EVs are significantly worse at heat-trapping carbon dioxide that worsens global warming.
"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 study finds all-electric vehicles cause 86 percent more deaths from air pollution than do cars powered by regular gasoline. Coal produces 39 percent of the country's electricity, according to the Department of Energy.
But if the power supply comes from natural gas, the all-electric car produces half as many air pollution health problems as gas-powered cars do. And if the power comes from wind, water or wave energy, it produces about one-quarter of the air pollution deaths.
"If we're using ethanol for environmental benefits, for air quality and climate change, we're going down the wrong path," said study co-author Jason Hill, another University of Minnesota engineering professor.
