At nearly every electric vehicle or smart grid conference, someone in the audience asks the question about just how clean electric vehicles are given that they are probably fueled by coal power plants.

There is a short answer and a long answer. The short answer is that if you are just asking about CO2, the electric vehicle, even from the dirtiest of U.S. coal plants, is still cleaner than a traditional internal-combustion vehicle.

However, toss hybrid vehicles, e-bikes, buses, renewable energy and particulates into the picture and it is not as clear-cut. A new study that examined electric vehicles, including e-bikes, in China found that EVs were not necessarily cleaner in terms of particulate emissions and their health effects, but rather the source of pollution was just offset from the urban centers to the areas where the power plants are located.

via Smokestack vs. Tailpipe: How Clean Are Electric Vehicles? : Greentech Media.