German energy provider to build 4 MW air-source heat pump

Hamburger Energiewerke is planning to deploy a 4 MW air-source heat pump that will connect to the local heating network. The system can reportedly generate up to 3.2 kWh of heat from 1 kWh of electricity.

German energy provider Hamburger Energiewerke plans to build a large-scale heat pump system at its Bergedorf-West heating plant site in Hamburg.

The air-source heat pump will have a thermal output of 4 MW and will connect to the local heating network.

The system will be installed in a new building next to the current heating plant, with air coolers placed on the roofs of newly built garages to save space.

The pump extracts heat from ambient air using the coolers, even at low temperatures. A fan draws in air and directs it to an evaporator, where a liquid refrigerant circulates. The refrigerant absorbs heat and turns into a gas.

The gas is then compressed by an electricity-driven compressor, increasing its temperature. The heated refrigerant transfers the heat to a condenser and the heating circuit. It then cools, becomes liquid again, and passes through an expansion valve, restarting the cycle.

According to the company, the heat pump can generate up to 3.2 kWh of heat from 1 kWh of electricity. During peak consumption on especially cold days, or when the heat pump is offline, gas boilers will supplement the heat supply.

Construction is expected to begin in fall 2025.

“A comprehensive soundproofing concept will reduce noise emissions compared to the previous heating plant operation,” the company said, without providing further details. “Bergedorf-West is a good example of how we can also make existing decentralized networks climate-friendly — with large-scale heat pumps as the key to the heat transition.”