Danish renewable energy specialist Aalborg CSP has secured an order for an integrated heat pump system for the production of district heating using green technology. The order is awarded by the Danish district heating plant Brønderslev Forsyning and is a turnkey contract for a 1 MW electrical air-to-water heat pump. The heat pump will recover heat from the district heating plant’s existing biomass boilers as well as the outdoor air, thereby supporting Brønderslev Forsyning in further optimizing the efficiency of their energy production.

Synergies between heat pump, solar, and biomass improves efficiency

The order for Brønderslev Forsyning is a turnkey contract consisting of a 1 MW air-to-water heat pump with associated pipes and exchangers, as well as integration with the district heating plant's existing energy system, which includes a 26,929 m2 solar heating system and two biomass boilers.

The new heat pump system is tailored to fit the existing district heating plant, focusing on efficient and cost-effective heat production by utilizing excess energy.

The heat pump is designed to recover energy from the waste heat generated by the district heating plant's existing biomass boilers and the outdoor air.

Thorkil Neergaard, CEO of Brønderslev Forsyning, states: "We have a strong focus on integrating various renewable energy technologies and thus benefit from both solar, biomass, and heat pump, while utilizing the synergies between them in an intelligent way. With the new heat pump, we can now recover energy in two different ways."

When the biomass boilers are running, a great deal of waste heat is generated in the boiler room. This waste heat is extracted by an air cooler. Subsequently, the energy from the waste heat is converted by the electric heat pump, compressing the energy into usable district energy at the desired flow temperature. When the temperature in the boiler room is suitable, the energy for the heat pump is extracted from the outdoor air using energy absorbers, which are located next to the district heating plant.

This intelligent integration enables the district heating plant to switch between energy sources and adapt the operation of their facilities according to the existing conditions, such as weather and electricity prices.

Thinking ahead ensures stable heat prices

At Brønderslev Forsyning, thinking ahead has played an essential role in keeping the district heating plant's prices low in a challenging market. Over the past year and a half, the energy market has been highly influenced by the conflict in Ukraine as well as the rising energy prices. Likewise, security of supply and energy independence has been on the top of the agenda.

Aalborg CSP and Brønderslev Forsyning continues the great collaboration

The new heat pump system is not the first project for which Aalborg CSP and Brønderslev Forsyning have collaborated. In 2017, Aalborg CSP also delivered a 16.6 MW solar heating system consisting of 26,929 m2 parabolic trough collectors. The system in Brønderslev is the world's first combined heat and power plant that combines concentrated solar power (CSP) with a biomass boiler. Through an advanced Organic Rankine Cycle (ORC), the energy is converted into both electricity and district heating. This innovative technology has helped Brønderslev Forsyning achieve a high efficiency, lower energy prices, and a long-term secure and clean energy solution, where dependence on fluctuating prices of traditional fuels is no longer a concern.

"We are proud that Brønderslev Forsyning has once again chosen to collaborate with us in the establishment of green solutions. When it comes to developing energy systems, they think ahead, and we are pleased that the long-term value creation in Aalborg CSP's solutions and integration could secure the order," says Svante Bundgaard, CEO of Aalborg CSP.


  • Client : Brønderslev Forsyning
  • Capacity of the heat pump: 1 MW
  • System supplier: Aalborg CSP A/S
  • Scope: Turnkey EPC contract including integration with the existing plant
  • Placement: Brønderslev, Denmark