When you're driving on an energy source as diffuse as sunshine, every bit has to count. Take the compulsory 10 minute pit stops that occur every few hundred kilometres along the route. The panel's still making power, even though it's not being used to drive the car. So teams channel the sunpower into recharging their batteries. In 10 minutes they'll store away enough electricity to drive their car 12 kilometres later if it's cloudy.
Solar panels convert sunlight directly into electricity.
When a photon of light is absorbed it creates a voltage between the upper and lower surface of the cell. The more photons absorbed, the higher the voltage. Solar cell industries are taking off in Germany, Japan and the USA, but for the moment the most efficient cells in the world are made by Professor Martin Green. Physically they look very similar, they are made using very similar processes but you end up with about thirty, thirty to forty percent more power out of a given area when they are out in sunlight. What's different about the Green solar cells is that their surface is covered with microscopic pyramids.