How does Power-to-Gas work?
In the power-to-gas (PtG) plant, excess electricity is converted into gas, i.e. hydrogen or methane.
In a first step, water is electrolysed. In the so-called water electrolysis, two water molecules are split into two hydrogen molecules and one oxygen molecule using electricity.
Oxygen is generally not used further and is released into the atmosphere. The hydrogen is fed into a second reactor. In the methanisation reactor, carbon dioxide (CO2) is added to the hydrogen gas just obtained. This produces methane gas (CH4).
PtG only contribute to climate protection if they are produced with energy from green electricity plants and the CO2 is fished out of the environment. High-dose CO2 is found in industrial waste gases, for example from waste incineration plants, cement factories, biogas plants or coal-fired power stations. Most CO2 is extracted from the depths of the oceans.