Small data centres repurpose waste heat for Finnish district heating networks

Finnish district heating companies are increasingly turning to small-scale data centres that sell excess heat to local networks, a solution that has grown rapidly in recent years, reports Yle.

Saarijärvi Energy, a district heating provider in central Finland, will soon integrate a 2 MW data centre built by French energy firm Eddu Energy. The facility will supply 1.6 MW of waste heat—enough to cover the town’s entire heating demand from May to August and reduce annual biomass consumption by a third.

“Just a few years ago, I had no idea data centre waste heat could be viable outside large-scale operations,” said Tuomo Vilkkilä, CEO of Saarijärvi Energy. “Suddenly, it’s a real option even for smaller plants like ours.”

The project, Eddu Energy’s first in Finland, reflects broader interest from foreign firms in Finland’s district heating market. The company is planning similar small-scale facilities across the country, totaling 35 MW in capacity. “Recovering waste heat is central to cutting carbon footprints in district heating,” said Edouard Dubrana, Eddu Energy’s CEO, adding that the firm aims to expand into other Nordic countries.

Negotiations over grid capacity with national operator Fingrid and local provider Elenia had delayed the Saarijärvi project, but Vilkkilä confirmed the data centre is now on track for completion by next winter. The waste heat will replace more expensive wood chips in production, with costs comparable to peat-based heating.

Finland currently hosts around 20 such data heat plants, with operators drawn to the model’s efficiency and sustainability. Saarijärvi Energy had previously explored alternatives like geothermal energy, heat pumps, and biogas, but high costs or insufficient capacity ruled them out.