"This is one of my favorite charts: A comparison of the distance a car can drive based on either of the following forms of energy, each produced on 100m x 100m of land (2.5 acres). How come that biofuel does not really cut it? Electric cars are about four times more energy efficient than fuel based cars, no matter whether they are based on biofuel or other fuel. This is because any fuel engine mostly creates heat and thus wastes the majority of the available energy units. Combine this with plants not being very efficient solar energy harvesters relative to semiconductor based solar electricity, and the result is this huge difference."
"I for one have vowed that the Prius I bought six years ago will have been the last fuel powered car I’d buy in my life. Presently, it is baking in the sun all day while I’m at work. My future all-electric car would charge up while idling under a solar carport." Source: Nanosolar Blog