In the period from 07/2021 to 12/2022, the Chair of Technical Thermodynamics at the TU Bergakademie Freiberg and DBI Gas- und Umwelttechnik GmbH are working on the development of energy utilisation concepts for the communes of the former Lugau/Oelsnitz coalfield. They are supported by the four municipalities of Gersdorf, Hohndorf, Lugau, Oelsnitz i.E. and the State Office for the Environment, Agriculture and Geology (LfULG).

Project content

The communities bordering the former Lugau-Oelsnitz coalfields were shaped by active mining for over 100 years. Now the structural change calls for aftercare measures. When the flooding is complete, strategies for dealing with the resulting water will be necessary from around 2032. But this eternal task also offers the potential to make a significant contribution to a renewable energy supply for communes. In order to achieve the targeted climate protection goals of the federal and state governments, the integration of renewable energy sources in the entire energy system must be further promoted. While the share of renewable energies in the power supply has increased significantly in recent years, there is still a need to catch up in the regenerative heating and cooling supply. Particularly in the building sector, which requires about one third of the total energy, great efforts are needed in the area of climate-friendly heating and cooling of buildings to achieve the envisaged climate protection goals.

In addition, subterranean reservoirs created by the flooding of old mines can serve as a source of energy. The mine water can thus be increasingly used as an energy source for regenerative building conditioning in the future. Due to the year-round and weather-independent availability with constant water temperatures, this represents a base load energy source for heating and cooling. This can result in an economic and ecological synergy effect for the municipalities from the tasks of mining aftercare for the renewable energy supply of buildings.

The main activities of the project include:

  • Identify possible extraction points for mine water
  • Calculation of the theoretically usable heat and cold quantities
  • Carrying out above-ground site-specific energy demand analyses
  • Planning of concrete network routes (routing of possible heating and cooling networks)
  • Examination of a possible thermal use of mine water by means of miniaturised heat pump systems
  • Informing the public in workshops and conferences
  • Networking for long-term management and positive shaping of the mining consequences


  • L. Oppelt, T. Grab, T. Wunderlich, T. Storch, T. Fieback: Mine Water Geothermal Energy - Abandoned Mines As A Green Energy Source. (Article/Poster) CLIMA 2022, Rotterdam, 22.05. - 25.05.2022, DOI: 10.34641/clima.2022.55

Involved project partners

TU Bergakademie Freiberg

Within the scope of the main topic to be worked on by the Chair of Technical Thermodynamics, mainly the underground parameters, i.e. the energetic potential of the mine water, are considered. In addition to considering the usable heat and cold flows, an effective heat exchanger design and the possibility of energy storage are also being investigated.

More informations: Chair of Technical Thermodynamics


DBI Gas- und Umwelttechnik GmbH

DBI Gas- und Umwelttechnik GmbH works on the topic of energy distribution and use above ground. The focus here is on above-ground requirements and distribution options.

More informations: DBI GUT


Associated project partners

As part of the project work, there is intensive exchange and cooperation with: