Because of its elevated temperatures in the deep subsurface, the Upper Rhine Graben is especially well suited for geothermal energy exploitation. The deeper the well, the hotter the rock strata become. In middle European countries, the geothermal gradient is generally about 3°C/100m depth, while in the Upper Rhine Graben a geothermal gradient of up to 4.5°C/100m depth can be found. In some parts of the graben, e.g. Landau or Soultz-sous-Fôrets, geothermal gradients up to 15°C/100m depth occur. In these areas, power plants exist, which make use of geothermal energy.