[mikeash]

The amount of electricity generated by coal is down significantly in the US. In 1997 it was almost 53%. Today it's around 33%. So that change is happening.

Based on my local grid, my car runs on roughly one third coal, one third natural gas, and one third nuclear. This seems pretty good, especially as it seems like the coal part will continue to decrease throughout the lifetime of the car.

Of course, with SolarCity joining Tesla, soon you'll be able to get both the car and the energy to run that car from the same company. Assuming your living situation allows for solar power, anyway.