Power utilities increasingly recognize heat pumps as a critical technology in removing heat from coal. They are deploying multi-megawatt systems across Europe to simultaneously serve multiple users and provide new ways to reduce carbon emissions from buildings.
German energy company RheinEnergie has announced plans for a large heat pump that will use the energy of the Rhine River to generate 150 MW of heat. The heat is available for use by the district heating network in the center of Cologne as “green heat”.
The system is capable of heating approximately 30,000 apartments and is ready to increase RheinEnergie’s current district heating network capacity by 15%. Construction is scheduled to begin early next year and commissioning is planned for early 2027. Another 50 MW heat pump will be installed in the Merkenich area in northern Cologne.
Meanwhile, in the UK, Gateshead Energy Company has delivered “the largest mine water heating network in the UK and one of the largest in Europe”. The system uses warm water from an extensive network of old coal mining infrastructure 150 meters below the city of Gateshead to supply heat and hot water to a range of building types including homes, businesses and community buildings.
The 6 MW water heat pump captures the heat and distributes it through the existing district heating network over a length of five kilometers. 15 C mine water is taken from boreholes and passed through a heat exchanger, which transfers the heat via a heat pump to an underground pipe network that delivers 80 C warm water to homes and buildings.
The mine water does not flow through the network that heats the buildings, but returns back to the ground after the natural heat has been recovered. The delivery of the system took about three years and was put into use at the end of March.
The Danish energy company DIN Forsyning says it is ready to deliver emission-free district heating to the Danish port city of Esbjerg using two large heat pumps. MAN Energy Solutions supplied two 50 MW pumps. They get their power from nearby wind farms and use the Wadden Sea as a heat source.
Heat pumps that replace coal heat produce heat for 25,000 households and produce 350,000 MWh of heat per year. The heat pump can reach a maximum temperature of 150 C and deliver 90 C water to the city’s district heating network. The systems are supposed to be put into use in the fall.
The introduction of heat pumps in district heating systems is a relatively unexplored application. However, it offers huge opportunities for large-scale removal from thermal coal.
Especially in Germany, large heat pumps could produce around 70% of district heating by 2045, according to a study commissioned by the think tank Agora Energiewende and conducted by Fraunhofer IEG. This would mean that the country would have to add up to 4 GW of large heat pumps per year. Currently, Germany has only 60 MW of installed capacity, with another 600 MW under development, according to Fraunhofer IEG.