Heat pumps

Heat pumps enable geothermal to scale in Aarhus district heating

1. October 2024
Heat pumps enable geothermal to scale in Aarhus district heating

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Aalborg CSP is supplying a large-scale heat pump station for what is set to become the EU’s largest geothermal district heating project — highlighting the role of heat pumps in making geothermal viable at scale.

OUR IMPACT

We have been selected by geothermal developer Innargi to deliver an integrated heat pump station for a major district heating project in Aarhus, Denmark. The system will upgrade geothermal heat from underground water and feed it into the city’s network.

The installation combines a 10 MW electric heat pump within a total system capacity of approximately 18 MW. It is designed to handle fluctuating geothermal flow conditions while delivering supply temperatures of up to 95°C — suitable for direct use in district heating.

The project forms part of a larger geothermal rollout in Aarhus, developed by Innargi and utility company Kredsløb. Once completed, the system will include multiple well sites with a total capacity of around 110 MW, covering up to 20% of the city’s district heating demand — equivalent to roughly 36,000 households.

Within this setup, the heat pump station plays a central role. Geothermal sources typically deliver heat at temperatures below network requirements. The heat pump lifts this energy to usable levels, turning a stable but low-temperature resource into dispatchable district heating.

The solution is based on a modular design using natural refrigerants and is engineered for integration into a complex, multi-site system. In parallel, the project includes the development of a standardized plant design that can be replicated across future geothermal installations in Aarhus.

Construction of the first plant in Skejby is underway, with initial heat delivery expected in 2025. The full geothermal system is planned for completion by 2029.

WHY IT MATTERS

Geothermal energy is stable — but not directly usable at scale without temperature lift.
This project shows how large heat pumps turn geothermal into a reliable base-load source for district heating.

 

This article was originally published under Aalborg CSP and has been editorially adapted for aalborg hc systems.

WHAT WE DID

Proven at scale,
delivered worldwide

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ANY QUESTIONS?

FAQ

What does aalborg hc systems deliver?

aalborg hc systems designs and delivers integrated heating and cooling systems in new and existing networks.

This includes:

  • large-scale heat pumps
  • thermal energy storage (TES and PTES)
  • integration of multiple heat sources

The focus is on complete system solutions, not standalone technologies.

Can you integrate into existing district heating plants?

Yes. Most projects involve integration into existing infrastructure. aalborg hc systems connects new technologies to:

  • existing networks
  • boilers and CHP units
  • available heat sources

The result is a coordinated system upgrade, not a replacement of existing assets.

Do you act as EPC contractor?

Yes. aalborg hc systems delivers projects on an EPC basis.

This covers:

  • engineering and system design
  • procurement and supplier coordination
  • construction and commissioning

The responsibility remains with one party from concept to operation.

Which heat sources can you integrate?

aalborg hc systems integrates multiple heat sources within one system, including:

  • wastewater
  • geothermal energy
  • ambient air
  • industrial excess heat

Solutions are designed as source-agnostic systems, optimised for local conditions.

What do you need to get started?

A project can start with a limited set of data:

  • heat demand profile (load curve)
  • supply and return temperatures

Based on this, aalborg hc systems defines a first system concept and integration approach.