I develop thermo-hydraulic models to increase the operational safety and economic efficiency of mine heat storage systems. These models are used, for example, in field tests at the Fraunhofer IEG where a small mine is being developed as part of the WINZER project. The aim here is to model the geomechanical effects that arise when the small mine is used as a seasonal heat storage facility and thus as a reaction to the cyclical thermal load on the subsurface. As a result, statements can be made about the efficiency of heat storage and possible risks can be identified and future locations evaluated.