The CEEGS (CO2 based electrothermal energy and geological storage system) project is a 3 years Horizon funded initiative coordinated by the University of Seville 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 TRL 2 to TRL 4 by addressing gaps in the interface between surface transcritical cycle and the subsurface CO2 storage.

CEEGS follows a 3-phase approach: i) From theoretical principles to models, simulations and processes in which advanced numerical simulations integrate reservoir behaviour, wellbore design and surface plant design; ii) From models and simulations to systems/experimental verification addressing CEEGS integration and efficiency in energy systems, with digital functional and laboratory models developed and components validated with results from the CO2 pilot-scale projects and; iii) Social, economic and sustainability assessments where social acceptance studies, LCA and TEA tools evaluate impacts and concept deployment with renewables, hard-to-decarbonise industries, district heating and cooling, or in grid balance.
The consortium integrates partners from 5 EU countries, with multidisciplinary skills on energy systems, energy storage, geology, geothermal systems and CO2 geological storage.