Microsoft has signed a heat reuse deal with Danish heat transmission firm VEKS and Denmark’s largest district heating company, Høje Taastrup Fjernvarme, to supply waste heat to a local district heating network in Høje-Taastrup, Denmark.

The deal will see Microsoft provide waste heat from one of its data centers in the region into the local network, which, according to the companies, will cover the annual heating needs of approximately 6,000 households in Høje-Taastrup.

VEKS will be responsible for the production, transmission, and distribution of the waste heat. According to Microsoft, the project is one of its first where waste heat recovery has been directly integrated into one of its data centers. It said that this was possible as the facility is close to both the existing district heating network and to a nearby residential area in Høje-Taastrup.

“There is significant potential in utilizing surplus heat from data centers in Greater Copenhagen. This agreement is a concrete contribution to VEKS’ ambition to deliver even more environmentally friendly and sustainable district heating in the years ahead,” said Steen Christiansen, chair of VEKS.

While not explicitly confirmed in the press release, it seems likely that the data center supplying the surplus heat is Microsoft’s facility in Høje-Taastrup. The data center is one of three being built to provide a Danish Azure availability zone announced in 2020.

The data center was announced and approved in 2022 and included plans to recycle heat from the start, according to Mikael Mikkelsen, data center director at Microsoft.

“Our data centers are intended to be among the most sustainable in the world. We have made substantial investments in energy efficiency as part of establishing our new data centers in Denmark. The agreement with VEKS is an important step towards building a more climate-conscious Danish data center region, where surplus heat benefits both local residents and the environment,” said Mikkelsen.

While the project is Microsoft’s first where it has integrated waste heat recovery from the ground up, the company has several other ongoing projects that also intend to provide waste heat to local networks. The most notable of which is happening in Finland, where the company has partnered with local utility Fortum to supply waste heat from its first two facilities planned there. When completed, the facilities are expected to provide around 40 percent of the district heating needs of Espoo, Kauniainen, and Kirkkonummi.