If all-electric car gets its power from coal, new study says it is dirtier than gasoline

WASHINGTON – People buying all-electric cars where coal supplies the power may think they are helping the environment. But a new study says those plug-in vehicles can be making the air dirtier and worsening global warming.

Ethanol isn’t so green, either.

Study co-author Julian Marshall, an engineering professor at the University of Minnesota, said it is hard to beat gasoline for public and environmental health. The key is where the electricity comes from. If it comes from coal, the electric cars produce 3.6 times more soot and smog deaths than gas.

Hybrids and diesels are cleaner than gas. All-electric cars where the power comes from natural gas, solar, or wind are the cleanest of all.

The study was published Monday by the Proceedings of the National Academy of Sciences.