Free clean electricity for electric cars
Wind energy and electric cars are a good match. Article below is about a Texas utility that actually offers FREE electricity overnight for charging electric cars, as a way to keep overnight wind energy from going to waste:
http://cleantechnica.com/2012/05/18/txu-is-first-to-offer-free-night-t ime-electricity-rate-plan/
At zero cents per kilowatt-hour, the energy cost of driving on electricity becomes cost-equivalent to infinity miles-per-gallon. Or we could just call it 1,000,000 mpg.
Of course, this won't remain free. But it will always be far cheaper than gasoline.