The subsurface provides a wide range of geothermal applications that can contribute to a sustainable future energy provision, especially in urban environments. All subsurface usages (like direct use of geothermal fluids, shallow and deep geothermal applications, or aquifer thermal energy storage systems) require a profound understanding of the processes which are related to the respective utilization. In our group, we focus on the characterization of thermal properties and processes of the subsurface, including reservoir and non-reservoir rocks. To characterize the respective thermal geosystem thoroughly, an enhanced quantitative understanding and a detailed 3D characterization of the structure, composition, and of the geothermal potential of the Earth’s uppermost crust is needed. The reliable characterization of the thermal geosystem represents a prerequisite for a sustainable geothermal resource management and for its integration into the concert of all technologies shaping the energy system of the future. Our working group explores the Earth’s thermal field and geothermal resources, studies involved processes, quantifies their relevance, and provides knowledge on its behaviour over time and across scales. The group is aimed at identifying priority targets for different geoenergy utilizations. With our work, we contribute to the transformation of the conventional energy system and to the reduction of CO2 emission.

With an applied focus, we elaborate exploration strategies to advance the successful development of geoenergy utilization in urban areas, where conventional surface exploration methods are often not applicable. We develop advanced methodologies for cross-scale characterization and for a better scale-dependent parameterization of the subsurface for risk reduction. A key concept is to combine geological expertise with a multi-methodological approach to establish adequate and reliable conceptual subsurface models. Fields of application include the sustainable provision of geothermal energy or the successful application of (thermal) storage systems.

With a more fundamental perspective, we investigate thermal processes in the crust and analyse the thermal field (including heat flow), and provide boundary conditions for multi-process or integrated geodynamic models. With an integration of multidisciplinary observation data, we improve the understanding of the present thermal state and involved processes in subsurface thermal geosystems: from local to global views, from rock to lithospheric scales and across time domains.

Our Thermal Petrophysics Lab allows to measure thermal rock properties under ambient conditions as well as under elevated (in-situ) pressure and temperature conditions. We also maintain a mobile temperature winch to perform in-situ borehole logging directly at geothermal sites and also mobile devices for the determination of thermal rock properties and rapid first-order rock permeabilities on cores or in outcrops.