In water electrolysis, water is divided into hydrogen and oxygen with the aid of an electric current. Its focus is usually on the recovery of hydrogen. Hydrogen production as a mean of energy storage promotes the stabilization of electricity generation from renewable energies, especially wind power and photovoltaics, by allowing surpluses of wind and solar power to be temporarily stored chemically. The produced hydrogen can be used for chemical processes, as a fuel or blended into the natural gas grid.