The Mannheim-based energy company MVV has started construction of an innovative heat pump on the premises of an existing coal power station. It is one of five large heat pumps being built in Germany with different heat sources as part of the Federal Ministry for Economic Affairs and Climate Action’s “Large heat pumps in district heating networks” program.
The system, which is being supplied by Siemens Energy, works like an inverted refrigerator. Just as a refrigerator extracts heat from its interior and releases it outside, the river heat pump will extract heat from the river water and feed this into the existing district heating network.
The system has a thermal output of up to 20 megawatts and an electrical output of around seven megawatts, which will make it one of the largest heat pumps in Europe once it is completed in 2023.
It will provide enough energy to heat a further 3,500 households and save around 10,000 tons of CO2 emission per year in the process. The water of the Rhine can reach 25°C (77°F) in summer and rarely drops below 5°C (41°F) in winter. This makes it a perfect heat source for the heat pump, which will deliver the thermal energy from the river water at higher temperatures suitable for the heating network.
The plant will take advantage of existing infrastructure at the power station such as efficient water in- and outlets, a large-scale district heating storage facility as well as the connection to the district heating network.
The technical potential of the project is enormous: MVV says it conservatively estimates that 500 megawatts could be drawn from the rivers Rhine and Neckar in Mannheim alone. That corresponds to the maximum heat output of one of the blocks at the existing coal power station and enough to heat around 50,000 households.