The High Temperature-Mine Thermal Energy Storage (HT-MTES) project in Bochum, Germany

The aim of the German HEATSTORE sub-project has been the development of a mine thermal energy storage (MTES) pilot plant for the energetic reuse of an abandoned small colliery below the premises of the Fraunhofer IEG in Bochum, Germany. In the summer 2020 three wells have been drilled into existing open mine voids from the IEG drilling site. During the winter of 2020/2021, a first MTES test operation has been carried out. The underground temperature has been recorded before, throughout and after a test operation by Distributed Temperature Sensing (DTS) as well as groundwater temperature and pressure loggers, which had been installed into the MTES wells. In spring 2021, a local district heat network (DHN) has been built up at the case study site. In summer 2021, a Concentrated Solar Power plant (CSP) as the future renewable heat source has been successfully erected at the demo site and was connected to the MTES via a common heat exchanger.