The Motley Fool writer figured out his monthly electric bill ($101) and his monthly gas bill ($180) and then used "conservative Tesla Motors numbers for power for their vehicle" to find out how much energy it'd take to drive an average of 1,500 miles a month. The next step was to figure out how many solar panels it'd take to generate all that energy. After some tax breaks (he thinks there are more, but he can't figure them out) the solar power system he needs on his roof to power the car and his house would cost him $37,820. Taking out a $37,800 home equity loan at the current rate of 6.5 percent would cost him $239 a month. After doing all this math, he's entirely optimistic on solar-powered EV. I'll let him take us out: "Therefore, with rebates, such a solar system would actually save me $40/month in total fuel/energy costs. And I use NO OIL! I produce NO HYDROCARBON emissions."
[Source: The Motley Fool]