Large-scale, high-temperature heat pump trial coming to Berlin

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Vattenfall Wärme Berlin AG and Siemens Energy will demonstrate and trial a new large-scale, high-temperature heat pump in Berlin. In the Qwark³ project (the German acronym represents “coupling of district heating, power, and cooling”), the companies will test the use of the technology for the first time at Berlin’s Potsdamer Platz to generate green district heating using waste heat and electricity from renewables, and feed it into Berlin’s district heating network. The project is funded by the German Ministry of Economic Affairs and Energy as part of its 7th Energy Research Program: The aim of the pilot project is to establish technical viability and economic potential of generating heat using large-scale and high-temperature heat pumps.

Since 1997, the cooling plant on Berlin’s Potsdamer Platz has been supplying locally generated cooling power to some 12,000 offices, 1,000 housing units, and numerous cultural facilities in the vicinity. This has previously generated unused waste heat, which has been dissipated into the surrounding air via cooling towers.

A new high-temperature heat pump is hoped to provide a more environmentally friendly way of linking heating, cooling, and electricity in the future. The new technology turns waste heat into a usable product, improving the energy-efficiency of the cooling power generation process while providing the urban district in Berlin with green heat from renewable electricity. The use of the heat pump will substantially reduce the amount of heat being dissipated into the environment and provide additional heat for the district heating network, amounting to about 55 GWh per year, with an estimated annual saving of about 6,500 metric tons of CO2 emissions and 120,000 m³ of cooling water.


Siemens Energy is delivering this new type of large-scale, high-temperature heat pump to provide thermal capacity of up to 8 MW, which will be capable of flexibly delivering flow temperatures in the district heating network of between 85°C and about 120°C, depending on ambient conditions. This is one way in which technology can make a further contribution toward replacing fossil-based heating in urban district heating networks. In addition to more efficiently linking energy resources at a local level, this project represents the first trial of the large-scale, high-temperature heat pump at a practical scale under real conditions.