Fraunhofer Research Institution for Energy Infrastructures and Geothermal Systems IEGThe utilisation of renewable energy potentials, in particular the provision of geothermal energy, requires the installation of underground and aboveground components. The focus of our laboratory lies on aspects of providing suitable temperature levels, necessary plant components and integration of renewable heat into district heating grids. Sector coupling strategies as well as optimized control schemes can greatly improve the overal lsystem efficiency. As central components of the Fraunhofer IEG infrastructure test rigs to characterize heat pumps as well as their integration in local heating grids will serve to qualify necessary components for the energy transition. Energy systems with multiple prosumers such as high-temperature heat pumps, concentrated solar power systems or two-phase salt storage systems will be tested individually or in combination. In addition, the laboratory is equipped with a geothermal test facility whose instrumented boreholes serve to supply energy to the Fraunhofer IEG campus in Bochum and at the same time enable heat extraction and recovery tests under load conditions with passive and active cooling. Thermal activation of the concrete, panel radiators and static radiators are used to efficiently investigate the individual heating and cooling requirements of buildings. In addition, air conditioning and fresh air supply systems can be added for complex building simulations. The system is controlled via building management software, which is also used to monitor and optimise the system. The "GeoStar" geothermal probe field, drilled in a star-shaped deflected pattern, serves as the geothermal system. At the neighbouring Bochum University of Applied Sciences, the "GeoStar2" geothermal probe field with 12x150m was installed to supply heating and cooling to the new auditorium building, and further measurement data is recorded via monitoring.