Thermal energy, trapped thousands of kilometres below ground, could be an abundant and naturally renewable energy source for Germany. To exploit its potential, the Fraunhofer Society and RWE power have joined forces to build a world-class new research site: The Fraunhofer Institute for Energy Infrastructures and Geothermal Energy (IEG) at the Weisweiler power plant in North Rhine-Westphalia.

“Geothermal energy and modern heating networks can provide a climate-neutral source of energy in the long term, based on regional know-how and thus bridging the gap between coal mining and heat mining,” says Dr Rolf Bracke, outlining the project’s scope in a press release by the new institute. “The real laboratory in Weisweiler serves at the same time geologically and energy-economically as a pilot location for the entire northwest European area."

The Rhenish mining area is an ideal location for geothermal exploration due to its proximity to the Aachen thermal springs. It sits above 350 million-year-old limestones that contain rock strata with large quantities of hot thermal water.

All aspects of geothermal plant technology will be explored at the site, from the development of high-temperature borehole pumps through to operating strategies for integrating geothermal into district heating and cooling. After the centre is built, the next step will be to sink a borehole up to 1,500 metres deep in 2022 – an activity which is supported by the EU’s Deep Geothermal Energy initiative. Beyond that, a deeper sinkhole up to 4,000 metres deep will be made, which scientists hope will produce warm thermal water.

At the unveiling of the project, which is supported by The Federal Ministry of Education and Research, Parliamentary State Secretary Thomas Rachel commented: "The newly-founded Fraunhofer IEG combines two very central key tasks of our time: Climate protection and successful structural change.”