Integrated Underground Gas Storage of CO2 and CH4 to Decarbonise the “Power-to-gas-to-gas-to-power” Technology

Excess energy produced from renewables can be stored and reused via the “power-to-gas-to-power” (PGP) technology. We present an innovative idea which represents a decarbonised extension of PGP based on a closed carbon cycle. Our show case for the cities Potsdam and Brandenburg/Havel (Germany) outlines an overall efficiency for the entire process chain of 28% with total costs of electricity of 20 eurocents/kWh. If existing locations in Europe, where natural gas storage in porous formations is performed, were to be extended by CO2 storage sites, a significant quantity of wind and solar energy could be stored economically as methane.