Unique heat pump tested at the straw plant in Harlev

8. February 2021

Aarhus company, Fenagy has developed a unique heat pump based on CO2, which must now be tested as a contributor to the district heating at AffaldVarme Aarhus.

A significant part of the green transition is about converting district heating from fossil fuels to green district heating based on green electricity. Here, heat pumps play a significant role, and the heat pump from Fenagy provides sustainable technology, using CO2 as a refrigerant.

Fenagy’s 600 kW heat pump was developed and designed during the autumn of 2020. In collaboration with the Danish Technological Institute in Aarhus, the heat pump was tested in December and January in terms of function and performance, and its unique feature is that it uses CO2 as a refrigerant, instead of ammonia.

“There is huge interest in our CO2 heat pump, and we appreciate the support from AffaldVarme Aarhus and the City of Aarhus, where the Green Investment Pool has also helped finance the project,” says Kim Christensen, CEO and Head of Sales at Fenagy.

Now, the heat pump is on its way to AffaldVarme Aarhus’ straw heating plant in Harlev and will be operated in interaction with the straw boiler and oil boilers for peak load and backup. With DKK 250,000 in support from the Green Investment Pool, Fenagy is now starting the installation, and AffaldVarme Aarhus is purchasing the heat from the heat pump for the district heating network.


Interesting perspectives

At AffaldVarme Aarhus, heat pumps are part of long-term heat planning, together with other technologies, such as geothermal energy, which is one of the reasons why AffaldVarme Aarhus has said “Yes” to the test project.

“All technology that is sustainable is interesting when we look to the future, and the heat pump from Fenagy is a project that we are very much looking forward to following,” says Lasse Sørensen, Head of Business Development at AffaldVarme Aarhus.

The goal is to have the heat pump set up within the next month; something all parties are looking forward to.

“It’s fantastic that, in collaboration with AffaldVarme Aarhus, we have the opportunity to test the heat pump under real conditions”, says Kim Christensen, CEO and Head of Sales at Fenagy. “The goal was to achieve it this winter, so we also get to test the heat pump at low outdoor temperatures. Here we must focus on the function of the large amount of energy absorption from outdoor air, both during operation and defrosting.”

The project requires a building permit and environmental approval before it can finally start.


Kim Christensen, CEO and Head of Sales at Fenagy, Tel. +45 20 94 35 05

Lasse Sørensen, Head of Business Development, AffaldVarme Aarhus, Tel. +45 29 20 93 48

You can watch Kim Christensen talk about the tests at the Danish Technological Institute HERE.