Haldengeothermie - Chancen und Risiken bei der thermischen Nutzung von Haldenschwelbränden

Mining spoil heaps are common in coal-mining areas. A little-known fact that has not yet attracted much public attention is the phenomenon of smouldering inside heaps. The energetic utilization of smouldering waste heaps is being investigated as part of a joint research project funded by the BMBF. Three borehole heat exchangers were installed in a spoil heap in the western Ruhr. It can be shown that the flow temperatures and thus the achievable heat extraction rate are much higher than in conventional geothermal systems. In order to determine the thermal and physical properties of the mining materials, several field and laboratory tests were performed. The variation of the properties of the inhomogeneous material is much less than expected. When working on old mining waste heaps, many challenges have to be faced but the high energetic potential justifies the efforts.