CEEGS is a 3-year long Horizon Europe funded project, that will develop a cross-sectoral technology for the energy transition, combining a renewable energy storage system based on the transcritical CO₂ cycle, CO₂ storage in geological formations and geothermal heat extraction. The main objective of the project is to provide scientific proof of the techno-economic feasibility of the technology, raising the current low Technology Readiness Level (TRL) from 2 to 4 by addressing gaps in the interface between surface trans-critical cycle and the subsurface CO₂ storage.