Heat pumps

Reducing fuel dependency by using wastewater heat in Egedal Fjernvarme

21. December 2022
Reducing fuel dependency by using wastewater heat in Egedal Fjernvarme

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A 1.5 MW wastewater heat pump for Egedal Fjernvarme shows how treated wastewater can be used as a reliable and cost-efficient heat source for district heating.

OUR IMPACT

A 1.5 MW wastewater heat pump system is being delivered to Egedal Fjernvarme in Denmark under a turnkey EPC contract. The system is designed to recover energy from treated wastewater and convert it into usable district heating.

The solution includes the full system scope—heat pump units, heat exchangers, piping, purification and plant integration—tailored to the local operating conditions.

Wastewater offers a stable and relatively high-temperature heat source compared to ambient air or seawater. This makes it particularly well suited for efficient heat pump operation in district heating systems.

In operation, heat is extracted from purified wastewater before it is discharged. The heat pump then lifts the temperature to district heating level, typically up to around 75°C, ensuring direct usability in the network.

The system uses CO₂ as a natural refrigerant and is configured to maximise heat output per unit of electricity. It is also designed to handle seasonal variations in wastewater temperature while maintaining stable performance.

The project responds to a broader shift in district heating. As fuel prices increase and gas dependency becomes less viable, utilities are increasingly turning to heat pumps and local heat sources such as wastewater to secure supply and stabilise costs.

WHY IT MATTERS

Wastewater is a continuous and underused heat source.
 Heat pumps make it possible to turn this low-temperature energy into reliable district heating capacity.

 

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.