World’s largest heat pump under development in Germany
Pictured from left to right: Thomas Büchner, Managing Director of STRABAG Umwelttechnik GmbH; Dr. Gabriël Clemens, CEO of MVV; Christian Sadleder, Member of the Executive Board of STRABAG AG Austria, Head of Energy Infrastructure; Thomas Hörtinger, CTO of GKM; Dr. Hansjörg Roll, CTO of MVV.
Image: Strabag
German utility MVV Energie AG and Strabag Umwelttechnik GmbH are planning to build a 162 MW industrial heat pump at the Grosskraftwerk Mannheim facility, a 2.1 GW coal power plant located in Mannheim, in the German southern state of Baden-Württemberg.
Once completed, the heat pump will be the largest system of its kind in the world.
The €200 million ($231.4 million) project is being funded by Germany's federal funding scheme for efficient heating networks (BEW).
“The large-scale heat pump will comprise two individual modules, each with an output of 82.5 MW,” Strabag said in a statement. “They will use Rhine water as a heat source, generating district heat with temperatures of up to 130 C by means of the natural refrigerant isobutane. Construction work is scheduled to begin in mid-2026.”
The system is expected to begin commercial operations in winter 2028.
MVV Energie AG has already built a 20 MW river-source heat pump at the same site in 2023.
MVV Energie said that the water of the Rhine River in Mannheim is up to 25 C in summer and only around 5 C in the winter. This thermal energy is sufficient to evaporate the refrigerant in the heat pump and reduce the temperature of the Rhine River water by around 2 C to 5 C.
The refrigerant vapor is then compressed using an electrically powered compressor to increase the pressure and temperature. The heat generated by the refrigerant vapor is transferred to the district heating water through condensation in a heat exchanger, producing hot water at temperatures ranging from 83 C to 99 C.
The refrigerant liquefies and expands again in the heat exchanger. It then cools down and absorbs thermal energy from the river water at a low temperature to restart a new cycle.