Four-stage heat pump being built for Hamburg-Wilhelmsburg geothermal heating project, Germany
Diagram of geothermal heat pump operations for Hamburg-Wilhelmsburg project in Germany (source: Geothermie Wilhelmsburg)
Carlo Cariaga
20 Jun 2025
Two four-stage heat pumps are now being manufactured for the geothermal district heating project in Hamburg-Wilhelmsburg, Germany.
The geothermal heating project in Hamburg-Wilhelmsburg is making steady progress, with the latest update now indicating that a customized heat pump system is being manufactured. The two four-stage heat pumps will have a combined output of 8 MW and a COP of up to 4.5 based on Saxony-based manufacturer WESKA Kälteanlagen GmbH.
The geothermal heating project being developed by Hamburg Energie Geothermie GmbH, a subsidiary of Hamburger Energiewerke GmbH, drilled two wells successfully back in 2022. The results of productions tests announced in 2023 were promising, with thermal waters at 48 °C extracted from a depth of more than 1,300 meters. Over the following months, the developer worked intensively on pipeline construction for the heating distribution network.
Using the heat pumps, the temperature of the water will be increased to the 75-85 °C needed by the district heating network. The multi-stage heat pumps operate with a natural refrigerant. Due to their design, they can be controlled very precisely to regulate the output and the required temperature. Thanks to the planned multi-stage heat pump process, the heat energy generated and thus the number of households supplied can be increased from the original 4,700 to over 6,000.
“We want to maximize the use of our geothermal heat. Our engineers and Weska have therefore designed a highly efficient and technologically advanced heat pump system,” explained Thomas-Tim Sävecke, Head of Engineering at Hamburger Energiewerke.
Source: Geothermie Wilhelmsburg
