On 30 September, representatives of Innargi, Kredsløb and Aarhus Municipality laid the traditional foundation stone entering the next phase of the project to supply geothermal heat to the district heating network of Denmark’s second biggest city. After the successful drilling of two 2.5 km deep wells at the Skejby site earlier this year, the construction of the heat plant is the last piece missing before the geothermal heat can be delivered. It will harvest the heat from the 70-degree geothermal water pumped to surface using heat exchangers and heat pumps and start to send it via the district heating network to Aarhus’ citizens in 2025.

While drilling the two wells caused nuisance for the neighbours for three months, the neighbourhood can look forward to a good neighbour for the next 30 years once the heating plant is completed. The final plant has been designed with the citizens and municipality in mind and only takes up the space of a penalty box on the football field. It emits no noise or smell, allowing the surrounding area to be used by locals to train or walk their dogs once again.

For Innargi, the first site in Skejby is not only about building the first heat plant, but also about gathering valuable insights and experience about the local subsoil, the heat exchange for Kredsløb’s systems and the plant for such a project, which will be taken further in the assessment and development of geothermal plants elsewhere in the city.

For Kredsløb, geothermal energy plays a key role in the transformation of district heating as it is not only renewable but also ensures a robust supply and a stable price development in the future. When all wells and plants are completed in 2030, Aarhus will have the largest geothermal district heating plant in the EU. It can cover 20% of the heat demand and is expected to reduce annual CO2 emissions by approximately 165,000 tonnes.

The example of Aarhus can be replicated at many other places in the EU, as there is suitable subsurface and the need to phase out fossil fuels in district heating to reach climate targets, but also to ensure energy security and competitiveness. That’s why geothermal heating and cooling should be high on the agenda of the incoming European Commission when developing its proposals in the context of the Clean Industrial Deal and the measure to achieve the soon-to-be-set 2040 climate target.

Aarhus: Innargi enters last phase of first geothermal heat plant