Audi is building a plant that will use solar and wind power to make methane from water and carbon dioxide. The plant, which will use technology developed by Stuttgart, Germany-based SolarFuel, is scheduled to start operation later this year. It will produce enough methane to power 1,500 of Audi’s new natural-gas vehicles, which also go on sale this year.

SolarFuel’s process uses excess renewable energy generated as a result of Germany’s push to reduce greenhouse-gas emissions. There’s now so much renewable energy in Germany that supply sometimes exceeds demand—such as when the wind is blowing late at night.