Jena, May 14, 2026. The city of Jena is advancing its municipal heat planning and plans to use treated wastewater as a future-oriented heating source. Up to 12,000 households are to be supplied in a climate-friendly manner in the future.
- Project: Heat generation from treated wastewater for up to 12,000 households
- Central location: Kläranlage Jena-Zwätzen
- Timeline: Implementation planned from 2030 at the earliest
- Additional option: The Saale is being examined in parallel as a potential heat source
- Overarching goal: Transition to renewable energies for heating by 2045
Heat Pumps to Extract Energy from Wastewater
Thuringian municipalities face the enormous legal and ecological challenge of completely switching heating requirements to renewable energies by 2045. In Jena, the focus is on a resource that has often remained unused: wastewater. Specifically, this concerns the treatment plant in the northern district of Zwätzen. There, residual heat is to be extracted from the already treated wastewater using powerful heat pumps before the water flows back into the natural cycle. The energy obtained in this way could then be fed directly into the local heating network to supply tens of thousands of citizens.
Implementation from 2030 and Alternative Concepts
Despite the promising potential, the residents of the “Lichtstadt” will have to be patient. According to current plans, the technical and infrastructural implementation of this ambitious project is scheduled for 2030 at the earliest. In addition to wastewater, planners are currently investigating other water-based energy sources. In particular, the water of the Saale is a focus of the assessments. Flowing waters can be used thermally, similar to wastewater, to generate sustainable heating energy and significantly reduce dependence on fossil fuels.
Background on Heat Planning and the Kläranlage Zwätzen
Municipal heat planning is a central component of the local energy transition. Jena, as a growing university city with an extensive district heating network traditionally supported by power plants in the south and center of the city, must develop new climate-neutral feed-in points. The Kläranlage in Jena-Zwätzen is strategically and technically ideally located. It processes enormous amounts of wastewater daily, which maintains a relatively constant residual temperature even after the treatment process. These are perfect conditions for the efficient operation of large-scale industrial heat pumps, which effectively utilize even small temperature differences. The possible use of the Saale also links back to historical practices: rivers were already important local energy suppliers in Jena during the Middle Ages through water mills.
Source:
Abwasser als Energiequelle: Jena sucht neue Wege beim Heizen
Transparency Note: This article was automatically created, editorially reviewed, and expanded with AI support.