© LIAG

Researchers develop an interactive geothermal energy map for Germany

Heating with geothermal energy is considered a particularly environmentally friendly form of heat supply. An interactive map of Germany developed as part of the WärmeGut research project now shows at a glance where geothermal probes are possible in Germany.

With just a few clicks, the online tool GeotIS (Geothermal Information System) shows whether a location is suitable for geothermal probes: green indicates unrestricted, yellow indicates restricted, and red indicates unsuitable. “In principle, however, these regions are also suitable for ground-coupled heating systems”, emphasises Prof. Dr Inga Moeck from the LIAG Institute, pointing out that several shorter probes could also be used, for example.

The State Geological Surveys of all 16 German Länder have combined their data, partly from analogue and partly from digital sources, in order to create a uniform, interactive map. It facilitates both the expansion of ground-coupled heating systems and geothermal research.

^{Geothermal probes are the most commonly used system}

The nationwide map currently refers to geothermal probes. They are the most commonly used system for ground-coupled heating systems. Approximately 100-meter-long pipes are inserted into a vertical borehole and filled with a heat transfer fluid. The borehole is filled around the pipes with particularly heat-conductive cement. These probes are combined with a heat pump to generate the required heating temperature. There are also two other variants of ground-coupled heating systems that are also combined with a heat pump: Geothermal collectors are located horizontally in the ground at a depth of approximately two to five meters. They therefore require more space than the probes. Finally, geothermal wells require groundwater aquifers at a depth of approximately 15 meters.

^{Using geothermal potential for the municipal heat transition}

Researchers are already working on additional maps that can visualise the regional conditions for geothermal collectors and geothermal wells. The various maps will be used in the future to support municipal heat planning. Interactive potential maps can then be used to calculate the usable heat energy for each location. “Municipalities can see what percentage of their respective heat demand geothermal energy can cover,” explains Inga Moeck.

^{Research project supports goals for geothermal expansion}

WärmeGut is therefore a key research project within the framework of the Key points for a geothermal energy campaign (in German only) of the Federal Ministry for Economic Affairs and Energy (BMWE). It describes measures aimed at tapping the potential of geothermal energy for a climate-neutral heat supply in Germany. While the completed interactive map on GeotIS simplifies access to information about geothermal probes, the German government approved the draft of the Geothermal Energy Acceleration Act in the cabinet on 6 August 2025. Removing barriers is intended to help accelerate the development of geothermal energy. It may also make it easier for households to obtain approval for their own heat pumps.