2026-03-12Nordic sitesEngineering

Waste heat recovery: a design input, not an afterthought.

Every megawatt drawn by a server rack produces low-grade thermal energy. In a Nordic town, that heat has a buyer. GreenGridLabs engineers the offtake path into every site from day one — so that when commissioning begins, the infrastructure is already there.

One kilowatt, two uses.

A datacenter runs year-round. A Nordic district heating network needs year-round thermal energy. The temperatures a modern cooling loop produces are the temperatures a well-designed low-temperature network can absorb. When the two are connected, the kilowatt that powered a training run leaves the site a second time — as heat for a school, a factory or a municipal building.

The result is a better outcome for the host community, a stronger sustainability case for the customer, and an effective PUE that no chiller optimisation alone can match.

Engineered in from the first line drawing.

At a GreenGridLabs site, the offtake path is one of the first design decisions, not the last. Before engineering begins, the local team establishes the key parameters with the district heating network operator: supply-side temperature requirements, thermal power absorption capacity across seasons, and the network's upgrade trajectory over the next decade. Those answers shape the datacenter thermal envelope, cooling-loop temperatures and piping layout.

The offtake is not bolted on — it is one of the constraints the site is built around. That is why it will work when it is commissioned.

Dalsbruk: the first full implementation.

Dalsbruk on Kimitooen sits adjacent to the Ovako steel-wire plant at Brukviken, with the municipal district heating network a short pipe run away. That proximity informed the site selection: the thermal profile of the planned compute load aligns with what the industrial neighbour and the local heat network can absorb. The heat path is engineered around a plate heat exchanger designed to transfer energy into a low-temperature loop serving whichever offtaker calls for heat.

Commissioning of the offtake arrangement is planned in parallel with the broader Dalsbruk build-out. Once complete, the site is designed to deliver three outputs from a single 10 kV connection: green compute, grid-balancing services and district heat for the surrounding community.

The value of heat recovery is not a lower PUE number. It is that a datacenter, a local industry and a municipal heat network become a single integrated system — improving the economics, the emissions profile and the community value for all three.
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