RheinEnergie has commissioned MAN Energy Solutions to build Europe’s largest fluvial heat-pump system at the Cologne-Niehl power plant. The 150 MW facility will harness thermal energy from the Rhine River to provide climate-neutral district heating for around 50,000 households in Cologne. RheinEnergie is investing approximately €280 million in the project, which is expected to reduce CO₂ emissions by 100,000 tons annually and begin operations in 2027.
The heat pump will extract thermal energy from river water using a thermodynamic cycle with a natural refrigerant. It will heat the district network water to up to 110°C in a closed-loop system, powered by electricity. This replaces fossil fuels and marks a significant step toward decarbonizing Cologne’s heating supply.
Andreas Feicht, CEO of RheinEnergie, emphasized the project's strategic importance, stating: “The large-scale heat pump in Cologne-Niehl is a cornerstone of our long-term strategy to decarbonize the heating sector. We are pleased to have found, in MAN Energy Solutions, a partner capable of delivering the project entirely from a single source.”
Dr. Uwe Lauber, CEO of MAN Energy Solutions, highlighted the pioneering role of the initiative: “Cologne is taking a leading role in showcasing how climate-neutral heat supply can succeed at a large scale. Together with RheinEnergie, we are driving the heating transition forward and inspiring other large cities to adopt similar, climate-neutral solutions.”
How the Technology Works
The system will operate by transferring thermal energy from the Rhine River to the district heating network. In the evaporator, the liquid refrigerant absorbs heat from the river water, evaporates, and is then compressed to raise its temperature. This heat is transferred to the district heating water through a heat exchanger, reaching temperatures of up to 110°C, after which the refrigerant condenses and the cycle restarts.
MAN Energy Solutions’ Scope
MAN Energy Solutions will deliver the entire heat-pump system, including three 50 MW heat-pump units, the district-heating pump station, and river-water and district-heating pipelines. The project also includes compressors, condensers, heat exchangers, control systems, and electrical infrastructure. As EPC contractor, MAN Energy Solutions will provide a turnkey solution.
Alexander Stöckler, Head of Sales, Tendering & Project Management, Power Segment at MAN Energy Solutions, said: “We are creating a blueprint that can also be transferred to other large-scale heat-pump projects in Germany, Europe, and worldwide.”
Three integrally-geared compressors, the core of the system, will be produced and tested at MAN Energy Solutions facilities in Berlin and Oberhausen. Each unit offers a compact design with high power density, delivering 50 MW heating capacity. Electrically-driven compressors also provide grid power-balancing, supporting renewable energy integration.
MAN PrimeServ will oversee long-term system monitoring, data analytics, and diagnostics through a service agreement, ensuring system reliability and performance.