Even in the cold winter months, municipal wastewater has a relatively high temperature compared to the outside air and is therefore a valuable source of heat, especially during the heating period. As part of municipal heat planning, which will be mandatory for larger municipalities in Hesse from 2024, wastewater heat should therefore be given special consideration.

Against this background, the Urban Water Management department developed standardized annual curves of the wastewater heat potential in the KlärWP.Hessen project with a focus on wastewater treatment plants of size classes 4 and 5. The results show that despite the falling wastewater temperatures in winter, increased extraneous water shares can compensate for the effect on the wastewater heat potential.

The follow-up project WQ.Hessenwhich is dedicated in particular to smaller wastewater treatment plants of size classes 2 and 3. In addition, the influence of extraneous water on the wastewater heat potential is being investigated in more detail.

The project will provide in-depth findings on seasonal fluctuations in the heat supply potential, which can be intersected with the annual profile of heat demand. These studies help to identify suitable areas for the construction of new heating networks and thus facilitate the planning effort for municipalities.