Cologne sets sights on deep geothermal potential
City view of Cologne (source: flickr/ Aleksandr Zykov, CC BY-SA 2.0)
Alexander Richter
3 Jun 2025
The Geological Survey of NRW to drill in Cologne-Dellbrück by late 2025, assessing geothermal heat potential from 600 to 1,000 meters.
The Geological Survey of North Rhine-Westphalia (GD NRW) will begin a deep geothermal research drilling project in Cologne-Dellbrück at the end of 2025. The project, part of the NRW Geothermal Master Plan, aims to investigate underground rock formations between 600 and 1,000 meters deep for potential district heating applications.
The drilling will take place at the unused Thurner Kamp site, carefully chosen for its favorable geology, existing infrastructure, and minimal impact on surrounding areas. A city council resolution has also designated the site as a compensation area, further supporting its suitability.
Key details of the project:
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The drilling will target “mass limestone” layers known for their karst features, which may allow for water flow and geothermal heat extraction.
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Core samples and detailed temperature data will be collected to assess the geothermal potential.
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The site will be fully restored to its original condition after the project concludes in mid-2026.
Dr. Ulrich Pahlke, Director of GD NRW, emphasized the importance of this exploration, stating, “With the drilling in Dellbrück, we are closing an important gap in geoscientific exploration of the Rhineland.”
Strict safety and environmental standards
All work will adhere to stringent mining, water, and nature conservation regulations. The project will include:
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Technical protective measures for groundwater
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Erection of 20-meter-high drilling rigs and 10-meter-high noise barriers
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A noise traffic light system to ensure compliance with noise limits
The measures are designed to avoid any disruption to local residents.
Part of a statewide geothermal push
This borehole is the only one planned for Cologne under the Geothermal Master Plan, which aims to meet up to 20% of NRW’s heat demand with geothermal energy by 2045. In Krefeld, similar drilling has already demonstrated significant potential for hydrothermal heat extraction, a promising sign for Cologne’s geothermal ambitions.
The public will be kept informed through on-site information, the project website at geowaerme.nrw and social media updates via @geowaermenrw.
About hydrothermal geothermal energy
This type of geothermal energy uses hot deep water brought to the surface to transfer heat to district heating networks. Once the heat is exchanged, the cooled water is returned underground, providing a climate-friendly and stable energy source year-round.
Source: Geologischer Dienst NRW
