Check out this vehicle. It is all electric and doubles as a solar panel to power the energy grid when idle. It is basically an electric car covered in solar panels and requires a roadway energy exchanger in order to power the grid. At maximum capacity the solar cells return excess energy back to the grid. The car would have an annual driving capacity of 9,000 miles in mild locations like the US east coast, but 16,000+ in sunnier locales like California. Unfortunately there are two big problems. The solar cells cost $10,000/sq. meter and in cities skyscrapers largely shadow the cells.
[Source: Eco Cars | Jukka Rautianinen via gas 2.0]
