RWE Power AG drilled two exploratory wells, EB1 and EB2, near the Weisweiler power plant as part of the Rhenish Lignite Mining Area’s transition to renewable heat sources. The plant currently supplies about 165 MWth of heat to the regional district‑heating network, and its planned phase‑out in 2029 makes geothermal alternatives urgent.

EB1 was completed in October 2023 to a measured depth of 100 m and fitted with a 3‑component seismometer. EB2, finished in February 2024, reaches 506 m and hosts a double‑U heat exchanger and an enhanced geothermal response test to estimate effective thermal conductivity.

Core, cuttings, and geophysical logs from both holes reveal the distribution of Cenozoic and Palaeozoic strata on the Weisweiler Horst of the Lower Rhine Embayment. At about 70 m depth the Palaeozoic deposits of the Inde Syncline in the Rhenohercynian Fold‑and‑Thrust Belt appear, allowing detailed characterization of cyclothem sequences and the petrophysical properties of alternating mudstone, siltstone, sandstone, and coal layers.

Future work includes seismic surveys and deeper boreholes to refine structural models, update stratigraphic boundaries, and assess the depth distribution of Lower Carboniferous coal‑carbonate formations—ultimately supporting the development of medium‑deep (400 m+) and deep (>1,500 m) geothermal reservoirs for Aachen’s district heating network.