iCHP Plant Generates Heat for Gießen Using River Water

Source: E&M Powernews

July 3, 2026

A trio is now harnessing heat from the Lahn River. The three-part iCHP plant “PowerLahn” operated by Stadtwerke Gießen has officially gone into operation.

A flagship project of the heat transition is now up and running. With the official launch of “PowerLahn” on July 2, Stadtwerke Gießen in Hesse has set new standards. The combination of three heat pumps that extract energy from the river water, two combined heat and power (CHP) units, and a direct electric heating system (P2H module) is the first of its kind in the state.

Many prominent figures from politics and the energy sector attended the opening ceremony. The local utility spent approximately 30 million euros on the innovative combined heat and power (iCHP) plant (as we reported).

The three large heat pumps produce about 29 million kWh of sustainable heat per year, which, according to the utility, is enough to supply 3,900 households. In addition, there are about 50 million kWh of heat (enough for 6,800 apartments) from the two CHP units at the nearby energy center, which, however, will continue to run on natural gas for the foreseeable future. As soon as sufficient quantities are available, the facility will use biomethane or hydrogen, making “PowerLahn” completely climate-neutral, according to Matthias Funk, CEO of Giessen’s municipal utility, in a press release.

The CHP plants also supply up to 47 million kWh of electricity, which is enough to power 21,000 households. Overall, greenhouse gas emissions will decrease by approximately 10,500 metric tons per year. This calculation is based on the plant replacing two decommissioned gas turbines and several gas boilers.

Matthias Funk once again highlighted the power-to-heat (P2H) module. Electric heat generation is used whenever there is an abundance of renewable electricity available—that is, when there is plenty of wind or sunshine. With this module, Frank explained, “we relieve the strain on the power grid and ensure that solar and wind power plants have to disconnect from the grid less frequently.”

Author: Volker Stephan