Mannheim, Germany – MVV Energie is constructing what could become the world’s most powerful heat pump system.
The project will draw water from the River Rhine through pipes two metres wide, wide enough for a person to walk upright. Felix Hack, MVV project manager, said the system will take 10,000 litres of river water every second to extract heat before returning it safely.
Two heat pump units, each producing 82.5 megawatts, will supply enough energy to heat roughly 40,000 homes via a district heating network. The system will be installed on the site of a former coal power plant, now shifting to renewable energy sources.
“The Rhine location already has a strong electricity connection and district heating links,” Mr Hack explained. The technology uses large compressors similar to those in the oil and gas industry, enabling city-scale heat production.
Work will begin in 2026, with full operation expected in winter 2028-29. Filters will prevent river fish from being drawn in, and modelling suggests the river’s temperature will barely change.
The €200m (£176m) project reflects rising interest in city-wide decarbonisation. Everllence, a German heat pump manufacturer, is developing even bigger units in Denmark, capable of 176MW and supplying a third of Aalborg’s heat demand.
Large storage tanks will improve flexibility, allowing heat pumps to pause when electricity costs are high. Experts say water-sourced heat pumps are particularly efficient for district heating, while air-sourced systems are viable even in colder climates like Helsinki.
The Mannheim heat pumps highlight a major shift in Europe towards large-scale, low-carbon heating solutions.
Image: MVV-Pressebild / MVV Energie AG, Mannheim
