Aerial view of the Greenergy Data Centers campus in Hüüru: the data halls, the operations building, the rooftop cooling plant and the adjoining electrical substation, surrounded by fields. — Harku 330 kV substation
Adjacent Elering transmission grid substation with dual redundant connections to our site, ensuring up to 200 MW of available power capacity.
Closed-loop cooling plant
No water used to cool servers. Siemens AI optimisation, PUE below 1.2
Data halls
2 MW colocation; 22 MW built-to-suit AI ready hall being fitted out inside the building; air-cooled and direct-liquid-cooled racks
Operations building
24/7 in-house NOC, Level 3 availability since 2022. EN 50600, ISO/IEC 22237, ISO 27001, ISO 9001, PCI DSS AOC
Next capacity, 2028
Built-to-suit phase designed for NVIDIA Vera Rubin. Reservations open

Hüüru, Tallinn, next to Elering's Harku 330 kV substation. EN 50600 certified.

The most energy-efficient and secure data center in the Baltics

2 MW of colocation space (server and IT equipment hosting) and a 22 MW built-to-suit hall for the latest NVIDIA generation, on an EN 50600-certified campus next to the national grid. Current built-to-suit capacity is leased; the next built-to-suit phase, direct liquid cooled and designed for NVIDIA Vera Rubin, opens in early 2028 on a site heading for 200 MW.

Reserve 2028 capacity Read the specification

Services

Two ways in: colocating services, or a hall built around your cluster.

2 MW of colocation on air-cooled racks and a 22 MW built-to-suit hall with direct liquid cooling for the latest NVIDIA generation share the same 2N utility power and carrier-neutral fibre. Current built-to-suit capacity is leased; the 2028 phase is built-to-suit and reservations are open, further colocation space is still available.

Colocation

2 MW of racks, cages and private suites.

Colocation, or server and IT equipment hosting, in operating halls: single cabinets, cabinets in cages, or in private suites, with dual-feed power, air-cooled hot-aisle containment and carrier-neutral connectivity in place. The halls are almost fully leased, but we still have some space

Capacity: 2 MW of rack capacity
42U Standard: 600 × 1200 × 2200 mm
42U Premium: 800 × 1200 × 2200 mm
Cooling: Air-cooled
Availability: Almost fully leased, but we still have some space

Further details

Built-to-suit

A 22 MW hall engineered around your GPU cluster.

Dedicated halls for AI and HPC at scale: direct liquid cooling, closed-loop plant, 2N utility power and the security envelope you specify. The first 22 MW hall goes live in late 2026; the campus is heading for a 200 MW peak.

Leased: 22 MW built-to-suit hall, live late 2026
Hardware: Latest NVIDIA generation: GB300 today, Vera Rubin 2028
Cooling: Direct liquid cooling, closed loop, no water
Further capacity: Early 2028, built-to-suit; campus peak 200 MW

Further details

Facility datasheet

The numbers your architects will ask for.

Figures reflect the campus as operated and as announced in July and August 2026. Request the full technical documentation through the sales team.

Power

Campus peak: 200 MW grid connection
Colocation: 2 MW of rack capacity
Built-to-suit: 22 MW hall for the latest NVIDIA generation, live late 2026
Next capacity: Early 2028, designed for NVIDIA Vera Rubin
Grid: Adjacent to Elering's Harku 330 kV substation; dual utility feed ↗
Redundancy: UPS and generators in N+1 and 2N configurations

Cooling

Liquid: Direct liquid cooling (DLC) for the latest NVIDIA generation: GB300 today, Vera Rubin-ready 2028 ↗
Air: Hot-aisle containment for air-cooled racks
Water: Closed loop; no water is used to cool servers
Efficiency: PUE below 1.2 with Siemens AI cooling optimisation ↗

Connectivity

Neutrality: Carrier- and cloud-neutral
Carriers: multiple providers in the facility, including Arelion, Telia, Tele2, Elisa, RETN and others
Fibre: Eight backbones entering from four directions; multi-duct for customer fibre
Latency: Helsinki 1.6 ms, Stockholm 7.8 ms, Frankfurt 25.1 ms round trip

Security

Perimeter: 3 m fencing, automatic road blockers, thermal and motion cameras with analytics
Staffing: 24/7 armed security, 300+ cameras with AI-driven detection
Access: Multi-level access control with anti-passback, encrypted cards and palm biometrics
Fire: Oxygen-reduction fire prevention
Shielding: EMP shielding available

Compliance

EN 50600: Availability Class 3: TÜV NORD CERT certificate 661370.26 (TSI.EN50600), valid till 3 Nov 2028 ↗
ISO/IEC 22237: Availability Class 3: TÜV NORD CERT certificate 661469.26 (parts 1, 2, 3, 4 and 6), valid till 3 Nov 2028 ↗
Information security: ISO 27001 ↗
Quality: ISO 9001 ↗
Payments: PCI DSS AOC ↗
Audit: Drees & Sommer operational maturity 83% (industry benchmark 80.5%) ↗

Operations

Staffing: 24/7 in-house NOC
Availability: Level 3 availability since 2022 commissioning
Monitoring: 3,000+ infrastructure monitoring sensors

Sustainability

Energy: Certified renewable energy with PPA options
Water: None used for server cooling

Location

Site: Low-risk site away from hazardous traffic and industry

Ownership

Operator: MCF Group Estonia builds and runs the facility
Shareholder: Three Seas Initiative Investment Fund (3SIIF) ↗
Adviser to 3SIIF: Amber Infrastructure ↗
Shareholder: Tensor Estate ↗

Customers

Sectors: Banks, payment processors, utilities, technology companies and AI cloud operators

EN 50600 certificate 661370.26 issued by TÜV NORD CERT GmbH for Tallinn DC-1, valid 29.10.2026 to 03.11.2028. View the certificate (PDF) ↗

ISO/IEC 22237 certificate 661469.26 issued by TÜV NORD CERT GmbH for Tallinn DC-1, valid 29.10.2026 to 03.11.2028. View the certificate (PDF) ↗

Keeping the modern world online

Built for the systems nobody supposed to notice.

Card payments, the power grid, online banking, AI training clusters: the customers here run services that people only think about when they stop. The building is designed so that they don't: Level3 availability since commissioning in 2022.

About Greenergy

Layered security

Three-metre perimeter fencing, automatic road blocks, thermal and motion cameras with video analytics, 24/7 armed guard, multi-level access control with anti-passback, palm biometrics and AI-supported mantraps. EMP shielding where it is needed. PCI DSS AOC for payment service industry customers.

Everything duplicated

Dual utility feed from the Harku 330 kV substation, UPS and generators in N+1 and 2N, redundant cooling, eight fibre backbones from four directions and 3,000+ sensors watching the facility. Oxygen reduction keeps fire from starting at all.

Liquid, closed loop, renewable

Direct liquid cooling for GB300-class racks on a closed loop that uses no water. Certified renewable energy with PPA options and Siemens AI optimisation holding PUE under 1.2.

A hand held over a biometric palm reader at a data hall entrance.

Yellow single-mode fibre patch cables running into the ports of network switches.

Success stories

Customer Experiences

Banks, payment processors, utilities, technology companies and an AI cloud operator on what they needed, what they feared and how the move went.

SEBBanking

Why is a major bank protecting a new server center from EMP weapons?

Read the story

Nets EstoniaPayments

How Digital Infrastructure Ensures the Reliability of NETS Estonia's Millions of Transactions?

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NebiusAI cloud

Why did an AI cloud company choose Tallinn for its first Baltic deployment?

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ZoneInternet infrastructure

How did the idea of moving Zone to Greenergy Data Centers come about?

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All 9 stories

Contact

Reserve a built-to-suit capacity for 2028.

Tell us the power envelope, cooling and timeline you are planning for, or ask about colocation (server and IT equipment hosting) availability. The commercial team replies promptly, usually the same working day.

General: info@greenergydatacenters.com, +372 7700 252
Sales: commercial@greenergydatacenters.com
NOC, 24/7: noc@greenergydatacenters.com, +372 7700 250

Shareholder

MCF Group Estonia is owned by the Three Seas Initiative Investment Fund, advised by Amber Infrastructure, a fund investing in critical infrastructure across Central and Eastern Europe. About the Three Seas Initiative Investment Fund ↗

Part of the Tensor Estate platform

MCF Group Estonia builds and operates the campus. Tensor Estate, the developer of AI factories, is a shareholder that brings international customers to the site and plans the next phases of capacity. About Tensor Estate ↗