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Home/ The Hüüru project

The building
at Hüüru.

Running since 2022, twenty minutes west of Tallinn, now being upgraded so AI computers can be installed inside it. What is documented in public sources, and separately what is not.

Aerial view of the Greenergy Data Centers campus at Hüüru
The Greenergy Data Centers building at Hüüru
The Greenergy Data Centers building at Hüüru

31.5 MW
total campus power[3]
14,500 m²
floor area, two levels[3]
2022
year the facility opened[4]
€200M
investment target by end of 2026[2]

01The facility

What the operator publishes about the building.

Location Alajaama tee 1 76911 Hüüru küla, Saue vald, Harju County.[3]
Legal entity MCF Group Estonia OÜ Trading as Greenergy Data Centers. Registry code 14069314.[3]
Campus power 31.5 MW Total complex power for the site.[3][4]
Floor area 14,500 m² Flexibly sized data rooms across two floors, about two football pitches.[4]
Efficiency Target PUE under 1.2 Around 25% more efficient than the sector average.[3][4]
Energy 100% renewable The operator states the facility runs entirely on renewable energy.[3][4]
Resilience EN 50600 Level 3/4 Duplicated cooling, and 100% uptime reported since opening.[3]
Fire prevention Oxygen reduction Oxygen levels are lowered so fire cannot start. Reported as the first in Estonia.[4]
Neutrality Carrier and cloud neutral Customers choose their own carriers and cloud providers.[3][4]
Certification EN 50600, PCI DSS, ISO Reported as the only EN 50600 certificate in the Baltics and Finland.[3][4]

02The AI upgrade

About €200 million, spent mostly inside a building that already exists.

The same walls. New space inside them, built for cabinets that draw ten times what the old ones do.[2]

2022
The facility opens
Greenergy Data Centers begins operating at Hüüru, described as the largest and most energy efficient data centre in the Baltics.[4]
 31.5 MW
28 July 2026
Tensor Estate becomes a shareholderRecent
A minority stake in MCF Group Estonia, a joint supervisory board, and capital described as expansion capital for AI demand.[5]
 Minority stake
In progress
Fitting out for AI
Additional space is being developed inside the existing building rather than on a new site.[2][6]
 Over €70m invested
End of 2026
Investment target
Approaching €200 million in total, close to €100 million of it from Estonian entrepreneurs.[2][6]
 About €200m

03Who owns it

Two shareholders, one supervisory board.

Correction we made

Some coverage says Tensor Estate owns the data centre. The announcement is more precise: it is a minority shareholder in MCF Group Estonia, and the Three Seas Initiative Investment Fund remains the majority.[5]

Majority shareholder
3SIIF
The Three Seas Initiative Investment Fund, described as remaining fully committed.[5]
Minority shareholder
Tensor Estate
Joined 28 July 2026 with expansion capital for AI demand.[1][5]
Operating company
MCF Group Estonia
Owns and operates the facility, trading as Greenergy Data Centers.[3][5]
Governance
Joint board
A joint supervisory board with representatives of both owners.[5]

Named people

Miko Niinemäe heads Tensor Estate. Kert Evert is founder and chief development officer of Greenergy Data Centers, and Tõnu Grünberg is chief executive.[2][4]

Estonian investors named in reporting

Kristjan Rahu Jüri Käo Enn Kunila Markus Villig Urvo Männama

Reported as the entrepreneurs behind close to €100 million of the funding.[6]

04The honest part

What is not public, and what we refuse to guess.

?

How much of the 31.5 MW is for AI

The figure covers the whole campus and predates the AI programme.

?

Which chips will be installed

No vendor, model or quantity has been announced.[2]

?

Whether liquid cooling is installed

The operator describes duplicated cooling, but does not specify direct liquid cooling.[3]

?

Whether waste heat is reused

Cited as an Estonian opportunity in general, with no confirmation for this site.[1][17]

?

Phase capacity

No source, including third party registries, breaks the 31.5 MW total into phases. What ships first and what comes later is not public.[16]

?

Customers and pricing

Described only as primarily Estonian so far. No names, contracts or prices are public.[2]

05The country case

Why anyone would build this in Estonia.

Published by Tensor Estate, a party with an interest in the answer. Listed as their claims, not as neutral findings.[1]

0%
corporate tax on reinvested profits[1]
PLI 75
construction prices, 25% below the EU average[1]
35%
lower average power price than leading EU markets[1]
68% / 41%
renewables as a share of Estonian production, against consumption, 2025[18]
Read that last number carefully

Tensor Estate presents Estonia as 66% renewable, which describes what the country generates.[1] Elering puts renewables at 68% of production but only 41% of consumption for 2025, because Estonia imports a large share of what it uses.[18] For a data centre, the consumption figure is the honest one unless the site buys renewable supply under contract, as Greenergy says it does.[3]

#1 OECD Tax Competitiveness Index 2024 #1 in the EU, Global Cybersecurity Index < 3 ms Tallinn to Helsinki NATO CCDCOE cyber defence centre, in Tallinn eu-LISA EU border systems agency
A grid change worth knowing about

On 8 February 2025 the Baltic states left the Russian-controlled BRELL system, and synchronised with the Continental European grid the next day, without blackouts.[19] It is the largest change to Estonia's electricity picture in decades, and it happened after most published comparisons were written.

Construction figures are attributed to Eurostat price level indices for 2024.[1]