MVV Sets New Standards and Begins Construction of the World’s Largest River Heat Pump in Mannheim - 165 MW for Climate-Friendly District Heating

Mannheim (Germany) - MVV Energie AG is continuing to drive the heating transition in the Rhine-Neckar region in southwestern Germany. After the energy company launched a tender for a new large-scale heat pump in spring 2025, the contract for the record-breaking facility has now been awarded. MVV has already been successfully operating its first 20 MW river heat pump at the site since 2023. The new plant will be more than eight times larger.

MVV is building a record-setting river heat pump in Mannheim that, contrary to the plans announced in March 2025, will not have a thermal output of 150 MW but an impressive 165 MW. MVV has awarded the construction contract to STRABAG, a major construction group. The heat pump uses water from the Rhine River as its heat source, operates with the natural refrigerant isobutane, and is scheduled to go into operation in winter 2028.

River Heat Pump as a Central Pillar of the Heating Transition

MVV Energie AG has commissioned STRABAG Umwelttechnik GmbH to build the second river heat pump on the premises of the Grosskraftwerk Mannheim (GKM). The facility is part of a large-scale project with an investment volume of up to 200 million euros. The project was put out to tender across the EU and is receiving funding from the German Federal Support Program for Efficient District Heating Networks (BEW). With a thermal capacity of up to 165 megawatts, it is currently expected to be the largest river heat pump in the world.

“With the new river heat pump, we are investing in the energy future of Mannheim and the Rhine-Neckar metropolitan region. It represents another milestone toward achieving the complete decarbonization of district heating by 2030,” says Dr. Gabriël Clemens, CEO of MVV. The large-scale heat pump consists of two modules, each rated at 82.5 MW. Using the natural refrigerant isobutane, they will generate district heating at temperatures of up to 130 °C (266 °F).

Construction is scheduled to begin in mid-2026, with commissioning planned for winter 2028. In addition, MVV plans to build a hydrogen-ready district heating reheater, which will raise the temperature of the district heating water during the heating season. Both facilities will be operated by GKM, as is already the case with the first river heat pump. Construction work on both projects is expected to begin next year.

“Thanks to the energy generated from thermal waste treatment, the biomass cogeneration plant, and the first river heat pump, we can already cover almost 50 percent of our district heating demand from green sources,” explains Dr. Hansjörg Roll, Chief Technology Officer at MVV.

Partners and Technology for Efficiency and Sustainability

STRABAG brings its comprehensive design and construction expertise to the project. The innovative technology is based on the HEAT PUMP ALLIANCE®, a strategic partnership between STRABAG and Atlas Copco Energas for industrial and high-performance heat pumps. At the heart of the system are proven turbocompressors from Atlas Copco, which are used in more than 7,000 installations worldwide.

“The contract in Mannheim strengthens our role as a partner for sustainable, climate-neutral water and energy infrastructure. The combination of technical expertise and innovative sustainability makes STRABAG a reliable partner for the energy transition,” says Stefan Kratochwill, CEO of STRABAG SE.

MVV is leveraging the existing infrastructure of GKM to efficiently advance the transformation toward a climate-friendly energy supply. The company is also planning an additional river heat pump and the use of regional geothermal resources to achieve full decarbonization of district heating by 2030.

With more than 6,600 employees and annual revenues of around €7.2 billion, MVV is one of Germany’s leading energy companies.

Source: IWR Online, 30 Oct 2025