MVV, Germany: Thousands of homes heated by river heat pump

Together with MVV we have built a large-scale heat pump plant in Mannheim. It uses river water as a heat source, helping to reduce the use of coal at the GKM plant. The new heat pump is the first step towards the goal of green district heating. MVV and the City of Mannheim is targeting to become CO₂ neutral in the district heating production by 2030.

At the Mannheim site, the heat pump uses 7 MWe of electrical power from renewable sources to produce 20 MWt of thermal energy which is used to reheat the district heating return flow up to 99 °C.  From 2023 onwards, the facility is expected to supply heating for 3,500 households and save some 10,000 tonnes of carbon emissions per year.

Heat pumps move thermal energy in the opposite direction of spontaneous heat transfer, by absorbing heat from a colder space and releasing it to a warmer one.

Heat pumps work like an inverted refrigerator, i.e. the river heat pump extracts a small part of the heat from the outside (here: Rhine water) and releases it again as heating energy for district heating. The Rhine water gets up to 25°C warm in summer and rarely below 5°C in winter. This makes it perfectly suited as a powerful heat source.

The heart of the heat pump plant is the compressor with gear, electrical motor, heat exchangers, and control system. The reliable heat pump is manufactured in our factory in Finspong, Sweden, and Siemens Energy is responsible for the full installation and commissioning. The technology has been proven for many years.