Your analysis is way too conservative. An analysis by Tesla Motors some time ago calculated that if you drive the Roadster an average of 35 miles a day, you nee

Your analysis is way too conservative. An analysis by Tesla Motors some time ago calculated that if you drive the Roadster an average of 35 miles a day, you need about 105ft^2 of solar panels to produce all the electricity for it, assuming 18%-efficient solar panels. [1] The Tesla Roadster has an area, when viewed from the top, of 72ft^2. [2] That means if you were able to cover it with solar panels that were 27% efficient, you could power it just from the power it produced. As far as your last point, I agree: I'd rather put the solar panels on the garage roof, where I can somewhat control how much sunlight it gathers, than on the car. 1. http://www.teslamotors.com/blog/electric-cars-and-photovoltaic-solar-cells http://www.teslamotors.com/blog/electric-cars-and-photovolta... 2. http://www.netcarshow.com/tesla/2008-roadster/ http://www.netcarshow.com/tesla/2008-roadster/