Solar or Wind
You have a car that runs on those? That you only charge during the wind or bright sunshine?
Actually, except for a few off grid hippies and survivalists, most solar or wind energy is fed into the major electric grids where it is balanced with feedstocks of coal and natural gas, and other renewables. An electric car owner can have an electric outlet in his garage or yard to plug in his electric car. Also, charging stations are beginning to appear at commercial locations. Renewables are a useful addition to power needs. Some day when oil supplies are low people will be screaming because all the useful plastics and other things produced from petroleum are in short supply and very costly.