Electric vehicles may be zero-emission at the tailpipe, but the relative filth of the electric production they draw from has a big effect on just how green an electric car can be.
For example, for an electric car in the United States, the equivalent is 55.4 miles per gallon � that is, any gasoline car with that mileage or higher is as good or better than an electric vehicle for greenhouse gas reduction, according to a new study. That's because more than a third of electric generation comes from the most greenhouse-dirty source, coal.
In France, an electric car contributes greenhouse gases equivalent to a gasoline-powered car that gets 524.6 miles per gallon. That's because nuclear power is France's main electric energy source, and nuclear power is relatively clean, at least where greenhouse gases are concerned.
The rankings come from a study by Sustainable Worldwide Transportation at the University of Michigan.
The study didn't look at individual U.S. states.
Countries that rely mainly on hydropower scored best. One is Albania, with a 5,100 mpg equivalent. Sweden, Norway and the Congo also scored well.
The worst performers, because they rely almost exclusively on coal and oil for electricity, include Botswana, Eritrea and Kosovo.
