The project "CO2-based electrothermal energy and geological storage system - CEEGS" investigates a new concept for the integration of CO2 cycles with underground energy storage and geothermal heat generation. In "CEEGS" CO2 is used as the working medium, which, due to developing density difference, creates an overpressure between the injection and production wells. This leads to the thermosiphon effect, which can reduce the need for circulating pumps and energy in this system. For the CEEGS system, excess energy from wind or solar sources is to be used and part of the injected CO2 is to be permanently stored underground. In the project, the technical feasibility of this CO2-based cycle is to be worked out using a model-based approach.

In the "CEEGS" project, optimal CO2 storage locations will be identified and the dynamic behavior of the reservoir will be combined with the competences of the project partners in the areas of geothermal components and technologies, modeling of injection/production cycles of storage and economical calculations.