There’s been an implicit assumption that because electric cars don’t burn fossil fuels, they’re cleaner for the environment and safer for people, but that doesn’t take into account how the electricity they use is generated. In China, that would be from — you guessed it — fossil fuels. About 85% of the country’s electricity is powered by fossil fuels, of which 95% is coal. The emissions from these power plants have to be counted when considering how clean electric cars are, the researchers note.
Electric cars dirty emissions are released at the electricity-generating power plant, while the vehicle is used elsewhere. It’s this disconnect that has given electric vehicles an apparently cleaner bill for health, but Cherry says that once you factor in how many people within the range of electricity generating power plants are affected by emissions, the story gets a little dirtier.
On average, the fine particulate emissions per passenger-km are 3.6 times greater for electric cars than for gasoline cars. That’s better than for diesel cars but on par with diesel buses, which can spread their environmental impact across the number of passengers they carry. “If we compare gasoline car emissions to electric car emissions, the electric cars look very, very bad,” says Cherry. “So the point is that you have to consider the emissions exposure when the exposure source is far apart — the electrical power plant as opposed to the tailpipe of a car.”
Edited by Rogerdodger, 14 February 2012 - 01:35 PM.