Germany is taking another major step toward carbon-neutral heating as Mannheim-based energy company MVV Energie AG (MVV) commissions STRABAG Umwelttechnik GmbH to construct the world’s largest river-source heat pump at the Grosskraftwerk Mannheim (GKM) power plant site.
The project, representing a total investment of around €200 million, is supported by the German Federal Funding Scheme for Efficient Heating Networks (BEW) and follows an EU-wide tendering process. The installation will have a thermal output of up to 165 megawatts (MW) — making it the largest heat pump of its kind globally.
“With this new river-source heat pump, we are investing in the energy future of Mannheim and the Rhine-Neckar metropolitan region,” said Dr. Gabriël Clemens, CEO of MVV. “It marks another milestone on our path to achieving full decarbonisation of district heating by 2030.”
The large-scale heat pump will consist of two 82.5 MW modules using Rhine River water as a renewable heat source. By employing isobutane as a natural refrigerant, the system will generate district heat at temperatures up to 130°C. Construction is scheduled to begin in mid-2026, with completion expected by winter 2028.
Once operational, the new plant will supply climate-friendly heating for up to 40,000 households, bringing MVV closer to its goal of 100% renewable district heating.
“Thanks to our energy-from-waste, biomass CHP, and the first river-source heat pump, we already cover nearly 50% of district heating from renewables,” said Dr. Hansjörg Roll, CTO of MVV. “This second unit, together with future geothermal potential, will enable complete decarbonisation.”
The project strengthens STRABAG SE’s role as a leading partner in Europe’s energy transition.
“We are proud to work with MVV to make an active contribution to decarbonising urban energy supply,” said Stefan Kratochwill, CEO of STRABAG SE. “Our HEAT PUMP ALLIANCE® with Atlas Copco Energas brings advanced industrial heat pump technology that ensures efficiency and reliability.”
The Mannheim system will use Atlas Copco’s turbo compressors, proven in over 7,000 applications worldwide, and will be built leveraging STRABAG’s comprehensive design-and-build expertise.
GKM CTO Thomas Hörtinger added, “Building this second heat pump reinforces Mannheim’s role as an energy hub. It’s a model for sustainable joint planning, combining existing infrastructure with new energy technologies.”
MVV is also planning a hydrogen-ready post-heater at the same site to support network heating during peak demand. Both systems will be operated by GKM, continuing its role in the region’s sustainable energy transformation.
