Rivers and lakes offer great potential for climate-friendly heat in Bavaria

16.03.2026

Source: Bavarian State Office for the Environment (LfU)

The Bavarian State Office for the Environment has investigated the thermal potential of Bavarian water bodies for heat supply. The study shows that rivers and lakes could play an important role in the regional heat transition in the future.

According to the study, around 30% of Bavarian municipalities (667 out of 2,056) have usable potential for river thermal energy. Projects along larger rivers such as the Danube, Inn, Isar, Salzach, Main or Lech are particularly promising. The total potential of river heat is estimated at 10 to 27 terawatt hours. This could supply between 220,000 and 610,000 residential buildings with heat.

31 Bavarian lakes also offer suitable conditions for hydrothermal projects. This opens up the possibility for 69 municipalities to include lake thermal energy in their municipal heat planning.

The state office provides water thermal maps and calculation tools for river and lake thermal energy. They provide initial indications of possible locations and heat potential, but are no substitute for a detailed analysis of local conditions.

The study also shows that water thermal energy usually has to be combined with supplementary heating systems, as water temperatures are sometimes too low in winter. Overall, the authors nevertheless see great potential to make greater use of rivers and lakes as a renewable heat source.

You can find the study and further information here: Potentials