One way to store wind and solar renewable energy, which is by nature intermittent, is to transform it into gas in the “Power to Gas” method. A first P2G demonstrator began operating in Nantes in February 2018. The demonstrator, which is currently supplied by photovoltaic panels and will soon add a wind turbine, consists of a 12-kilowatt electrolyser that produces hydrogen. Hydrogen is then mixed with CO2 in a methanation reactor to generate synthetic methane. So far, the technology has not proven economically profitable, but Ademe, the French Environment & Energy Management Agency, believes that it could be rolled out 10 or 15 years from now.