CREDIT: GETTY IMAGES
COOLING THE BOOM
The clearest sign that green energy and AI have fused sits in Mäntsälä, Finland. There the AI-cloud company Nebius runs a data centre so hot with computation that it pipes the waste heat straight into the town’ s district-heating network, 19.5 GWh of it in 2025, enough to cut residents’ heating bills by roughly a tenth.“ We use the energy once for AI, and then again to heat people’ s homes,” says Andrey Korolenko, Nebius’ s Chief
Infrastructure & Product Officer. The company’ s sites run at a powerusage effectiveness of 1.25 against an industry norm of 1.54, and it estimates its 2025 design avoided 102 GWh of electricity, the yearly use of about 9,800 US homes. The infrastructure the record capital is funding increasingly looks like this: engineered, metered and, by necessity, green.
Source: Nebius’ s 2025 Sustainability Report