Energy storage in salt caverns with supercritical CO2

Energy storage is essential for a supply-secure power grid in the further expansion of the renewable energies, in order to integrate the increasing fluctuating power generation with their low guaranteed power into the energy system. A novel storage technology, an innovative, emission-free cavern storage power plant using supercritical CO₂ as the working fluid in a closed loop is presented. Energy storage with sCO₂ in a salt mine is comparable to a pumped storage power plant with the difference that supercritical CO₂ is used instead of water and the storage does not take place at the surface in an upper and lower reservoir, but in a high- and low-pressure cavern underground in rock salt with a small footprint on the surface. Supercritical CO₂ turbines represent a technical innovation in energy conversion. For the long-term goal of achieving climate neutrality, CO₂ sinks are required for the remaining CO₂ sources from industry and other sectors. The construction of sCO₂ energy storage mines in salt through Carbon Capture, Utilization and Storage can contribute to this.