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Green Mountain FRA-Mainz / Green Rocks Campus

Ingelheimer Aue, Mainz, RP, GermanyUnder construction
Capacity
No public figure
Lead participant
Green Mountain
Operator
Last updated
Aug 26, 2026
Most recent public record update

About Green Mountain FRA-Mainz / Green Rocks Campus

Green Mountain and KMW are building a three-building data center campus on Ingelheimer Aue in Mainz. Current sponsor pages disagree between 54 MW and 80 MW, and the first section is targeted for Q4 2026.

Capacity

Operating capacityAn operating IT-capacity figure has not been publicly disclosed.

No additional capacity claims are published.

Development

4 phases · 5 milestones
Building 1 / first sectionUnder Construction

18 MW original phase; current RFS target Q4 2026.

1 building

Building 2 / second sectionUnder Construction

Second section started; 18 MW and about 6,000 sqm IT space.

1 building

Building 3Announced Or Preconstruction

No verified construction start.

1 building

Anchor-customer staged handoverAnnounced Or Preconstruction

Capacity handover over roughly 3.5 years; phase allocation undisclosed.

3 buildings

Oct 30, 2023
Official construction start marked
Completed
Feb 7, 2025
Campus topping-out milestone
Completed
Sep 1, 2025
36 MW long-term tenant agreement announced
Completed
Jan 21, 2026
Building 2 construction begins
Completed
Jul 20, 2026
54 MW emergency-power plant approved
Completed

Infrastructure

Electric GridUnder Construction

54 MW

Green Mountain current figure and original approved plan.

Electric GridUnder Construction

18 MW

Per-building IT figure for three-building plan.

Site FacilityUnder Construction

18,000 sqm

Three buildings of about 6,000 sqm each.

Heat ReusePlanned Or Represented

60 MW thermal

Heat output, not IT load or electrical generation.

Onsite GenerationPermitted Or Installed

54 MW electrical

Twelve-engine H2-ready plant; also expected to serve grid hours.

Electric GridPlanned Or Represented

110 kV

Redundant supplies; renewable-energy portfolio claim.

Cooling SystemPlanned Or Represented

Rhine water cooling with heat-reuse priority.

Project map

0 of 1 project point mapped
Infrastructure facts
7
Mapped records
1
Capacity figures
6

No map point available

Power & interconnection: 3Generation & storage: 1Cooling & water: 2Site systems: 1

Facts & sources

Published claims and their source links.

8 facts
Ready For Service Target
Q4 2026
Forecast
Milestone Transaction Close
Green Mountain and KMW form 50:50 project company
Actual
Milestone Construction Start
Official construction start marked
Actual
Milestone Construction Progress
Campus topping out milestone
Actual
Milestone Customer Commitment
36 MW long term tenant agreement announced
Actual
Milestone Construction Start
Building 2 construction begins
Actual
Milestone Ready For Service Target
Current sponsor/utility target
Actual
Milestone Permit Approved
54 MW emergency power plant approved
Actual