Geothermal fluids and their interactions with rocks and materials are in the research focus of our working group. Geothermal fluids are gas-water mixtures from deep geological formations that are typically of high salinity and contain a complex mixture of various organic and inorganic components. Research on those fluids and on processes in geothermal installations is challenging due to this complex fluid composition and the rough conditions of their occurrence (high temperatures, pressures, and salinities).

In the working team, we are interested on the origin and migration pathways of the fluids and examine geochemical processes under those extreme conditions (e.g. within the EU project REFLECT). Furthermore, we develop methods for risk minimization during geothermal plant operation (e.g. in the EU GEOTHERMICA project PERFORM II) as well as –material tests for geothermal applications (corrosion processes tracer, inhibitors).

Besides deep geothermal energy systems, we also look at geochemical processes in the underground occurring during aquifer thermal energy storage (e.g. in the BMWi projects ATES-GeoFern, ATES-IQ and in the EU project Push-it).

As an emerging research field connected to geothermal energy research, we recently started to investigate also the benefits that are provided by the fluids, especially in terms of the extraction of economically valuable components from the brine. In the Horizon Europe project CRM-geothermal we develop innovative extraction technologies for the extraction of Lithium, Strontium and other critical raw materials.

Our  Laboratory for fluid chemistry and fluid physics, and fluid monitoring are equipped with high pressure and temperature resistant equipment (autoclaves, FTIR spectrometer, flow-through devices, and various sensors). We also developed special mobile fluid monitoring devices and maintain a handheld XRF spectrometer to perform in-situ field experiments directly at geothermal sites.

As the carrier of heat, geothermal fluids play a fundamental role in all deep underground processes. As such the themes examined by the working group are cross cutting topics and we collaborate closely with other teams of the Geoenergy Section) as well as with other sections at GFZ that deal with geomicrobiology, organic and inorganic chemistry, and geochemical modeling.