In this paper, four mining levels in a closed coal mine in the Asturian Central Coal Basin (NW Spain) have been selected as a case study to investigate the technical feasibility of underground compressed air energy storage systems. First, in order to determine the suitable level and type of concrete lining, a numerical model has been established to analyze the geomechanical performance considering air pressures of 6, 10, 20 and 25 MPa and three different embodiments of concrete lining. Then, another numerical model is used to study the coupled thermo-mechanical performance at level 3, consider...