As of 1999, here's the numbers I found. Percentage of US electricity production, by source fuel:

Coal: 54%
Nuclear: 22%
Hydroelectric: 10%
Natural gas: 9%
Oil: 2%
Other: 1%

I've heard that since then, oil is down to 2 or 3% with solar/wind up to about 2%. Still, it's a balancing act. The main problem with purely electric cars is they have no range and no rapid refueling. You can use hydrogen as the storage medium, but you're going to use far more electricity and still have an obscenely expensive vehicle and questionable refueling infrastructure.

I see this country's primary goal as being getting OFF the oil import bottle within 20 years. I don't care if we're still using oil, I just want it to be our OWN by means of either ethanol, biodiesel, or oil from shale.