EU directive to encourage more data centers to share surplus heat

There are both jobs, local growth and potential surplus heat to be gained for many of the municipalities that are actively working to attract data centers to the area.

Especially in relation to surplus heat, it can be a pure win-win situation, where the energy-intensive data centers can forward surplus heat to the local district heating network for the benefit of local citizens and climate accounting.

However, it is not always that the surplus heat from the data centers ends up in the district heating network. Therefore, the EU wants more data centers to contribute with surplus heat with a new directive, which is supported by Dansk Fjernvarme.

- We always support that surplus heat should be utilized in all places that make sense economically, technically and in terms of climate, says Jens Christian Nielsen, chief consultant at Dansk Fjernvarme, to DK Nyt.

He points out that there are more data centers on the way to both Denmark and Europe, and that one should therefore ensure that the surplus heat from the energy-intensive facilities is utilized in the best possible way.

But even though it may sound straightforward, it can be difficult to utilize the surplus heat, says Jens Christian Nielsen.

This is an enormous amount of energy, and it is enough to supply the local area with heat. However, it can be difficult to utilize, among other things because of the large amount of energy that must be adapted to the existing district heating system, and it is also necessary to refine the heat from the typically 30 degrees hot water that comes from the data centers to the typically 70 degrees that is sent out into the district heating network.

Carrot and stick

The upcoming EU directive, which is currently being consulted on, is intended to help increase the energy efficiency of surplus heat plants. Therefore, the EU will, among other things, require that companies conduct a cost-benefit analysis of whether it is profitable to connect the data center to the district heating network and share the surplus heat.

If it is profitable, it will subsequently be a requirement that the surplus heat is utilized.

And this is supported by Dansk Fjernvarme, which, however, hopes that the Danish implementation will be made simpler than what is initially planned by the EU.

- It is important that we do not make it unnecessarily bureaucratic. We support the need to conduct a cost-benefit analysis, but we believe that it should be part of the project executive order, so that the processing by the authorities becomes simpler, says Jens Christian Nielsen.

This year, Danish politicians have also helped to make it easier to utilize surplus heat by removing the so-called price cap, which was supposed to protect against increased heat prices, which, however, helped to make it harder for district heating companies to invest in new plants and technologies.  

- We are pleased that the price cap for surplus heat has been removed this summer, so that it has now become possible to implement even more projects, says Jens Christian Nielsen. 

Only one data center will contribute heat

Microsoft expects to open three new data centers in Gadstrup in Roskilde Municipality, in Høje Taastrup and in Køge in the first half of 2026. However, this is only one of the locations where the data center will contribute surplus heat. 

In Køge, this is partly due to the fact that the data center in the municipality is located in such a way that it is more difficult to connect it to the district heating network.

Already in 2022, at the start of construction, Mayor Marie Stærke (S) was annoyed that it was not possible to set political requirements for where and how the data centers should be located.

- It would have been nice if we had been able to set requirements for being able to utilize their surplus heat. If we had, it could have heated the entire Municipality of Køge. And it is a terrible shame that this is not happening, said Marie Stærke.