Project record, campus
Nebius second Mäntsälä data centre
Nebius announced in August 2026 a second data centre at Mäntsälä with up to 70 MW coming online from 2027. Caverion said in October 2026 it will deliver a EUR 15 million 70 MW substation for the site, to be completed in autumn 2027. Caverion says the new 70 MW building sits beside the existing 75 MW site, and that delivery of the substation alone will employ about 80 energy sector professionals and electricians.
Reported figures
| Figure | What it measures | Delivery state | Scope and date | Used in totals | Source |
|---|---|---|---|---|---|
| up to 70 MW Third-party reported Upper bound | Otherbasis unclear Site capacity, upper bound. MW basis not stated Source wording: "capacity of up to 70MW coming online from 2027" | Planned Stage stated in source: Planned | campus 13 Aug 2026 | No. Basis unclear (not stated as IT, facility, grid or thermal). Never summed. | datacenterdynamics.com (opens in a new tab) |
| 70 MW Official source | Grid connection Substation rating Source wording: "The substation will have a capacity of 70 megawatts" | Planned Stage stated in source: Under construction | campus 2 Oct 2026 | No. Marked not summable by research: Substation rating | caverion.com (opens in a new tab) |
Each figure is shown as reported, with its own definition. IT, facility, grid and thermal figures are never added together. Capacity definitions.
Power and grid
70 MW substation by Caverion, due autumn 2027. caverion.com (opens in a new tab)
Sources (2), last checked 19 Oct 2026
- Nebius expands European presence, announces deployment in Estonia and second data center in Mäntsälä, Finland (opens in a new tab), DatacenterDynamics, published 13 Aug 2026, accessed 19 Oct 2026
- Caverion Finland will deliver a EUR 15 million substation for AI cloud company Nebius (opens in a new tab), Caverion, published 2 Oct 2026, accessed 19 Oct 2026
Last checked 19 Oct 2026 by CoolPower Index research (automated, sourced). Report a correction.