Geothermal potential of the Buntsandstein and Keuper aquifers in NE Bavaria with a focus on deep thermal aquifer storage

Abstract

Intermediate and deep geothermal resources of Germany are limited to medium and low enthalpy resources. These resources are predominantly used for balneological applications, space and district heating and for power production at nine separate sites. This study focuses on confined aquifers in northeast Bavaria, which can be used for balneology as well as energy storage. Data from pumping tests and production data were interpreted to map the hydraulic conductivity of the main Keuper and Buntsandstein aquifers with a large spatial distribution for geothermal applications deeper than 100 m. Furthermore, temperature estimates as well as the depth of the two aquifers (Keuper 100 to 650 m, Buntsandstein 100 to 1400 m) are incorporated. The results will be visualized in the form of spatial distribution maps of the hydraulic conductivity and temperature, and will be integrated into the geothermal information system GeotIS (https://www.geotis.de). Altogether, about 80% of all 243 sampling sites show hydraulic conductivity values sufficient for geothermal energy utilization. For the Keuper aquifer, even 90% of all 155 sampling sites show transmissivities sufficient for geothermal energy utilization. However, these maps do not replace a feasibility study for specific geothermal projects because detailed geological site assessment is essential when planning a subsurface geothermal system.