First exploratory well for deep geothermal energy at Weisweiler site

The drill bit is slowly but surely working its way underground: The borehole currently being drilled by a team from RWE Power in cooperation with Fraunhofer IEG in front of the Weisweiler power plant will reach around 100 meters deep. It serves to explore the subsurface and prepares the search for heat from great depths, i.e. geothermal energy. The borehole is part of the international Interreg research project DGE-ROLLOUT.

The 100-meter-deep exploratory borehole will first be technically evaluated and then developed into a seismological observatory by Fraunhofer IEG. The borehole will thus become part of a network of monitoring stations for the deep underground in the Weisweiler area. At the beginning of next year, a second exploratory borehole is to be drilled next door, to a depth of around 500 meters. There, Fraunhofer will install a geothermal probe to supply the observatory.

 "Hot water from the depths is used to supply heat in many European cities and can also become an alternative, climate-friendly heat source in NRW. Aachen has benefited from this indigenous energy source for heating buildings since Roman times. We want to demonstrate the modern contribution of geothermal energy to municipal heat planning with this project and collect the data we need on the way to the heat turnaround in the southern Rhineland," says Prof. Rolf Bracke, head of Fraunhofer IEG.

If the thermal water is hot enough, it can replace fossil fuels such as natural gas and lignite in the district heating supply, for example. Successful examples are provided by plants in Munich, Paris, and the Netherlands. In combination with large heat pumps, geothermal energy can also supply many processes in industry with sustainable heat.

RWE Power Executive Board member Dr. Lars Kulik: "District heating from thermal water - that would be a technologically new component of the energy turnaround for our region. A district heating pipeline runs from the Weisweiler site to Aachen. If renewably generated district heat were to flow through it one day, it would be another tangible contribution by RWE to regional structural change, just like our wind power and solar projects here in the coalfield."

There are still many steps to be taken on the way to heat supply with deep geothermal energy. It is often a matter of obtaining very local, meaningful data as a basis for subsequent decisions. The wells in Weisweiler are intended to provide new data and insights into the sequence of the earth's layers in the region. On the basis of the two boreholes, a deep exploratory borehole could later be drilled under the direction of Fraunhofer IEG to explore thermal water. Current studies by Fraunhofer IEG show that deep geothermal energy could cover at least a quarter of Germany's current heating requirements. The geothermal potential of NRW is particularly large. Geological explorations such as drilling and seismic measurements are absolutely essential for development.