Though hydroelectricity and nuclear power is slowly becoming a major part of worldwide energy generation, fossil fuels, especially coal, is still the majorly used (about 68% in the USA) fuel in electricity generation. Unless you live in Norway, which gets a spectacular 98% of its total electricity from hydro power, recharging a battery-powered car uses electricity that's probably been generated in plants that are just as dependent on fossil fuels as the W16 engine of a Bugatti Veyron.