Microsoft Grange Castle (Dublin) data center, Dublin, County Dublin

Microsoft's Grange Castle data center campus, on Nangor Road in south Dublin, Ireland, is getting its own gas-fired power station, because Dublin's grid has no room for new data centers. When The Irish Times toured the campus in February 2026 it counted 13 data centers there, and Noelle Walsh, president of Microsoft cloud operations, said the company would get back to expanding now that the Dublin moratorium on new data centers had been lifted, pointing to "pent-up demand from the pause."

Two buildings there, DUB14 and DUB15, won planning permission in 2021 and together cover 56,246 square meters, part of a 900 million euro development. In December 2022 Microsoft applied to Ireland's Environmental Protection Agency for an industrial emissions licence, the permit that lets a facility legally release pollution, to run a 170 megawatt gas-fired plant and 21 emergency diesel generators, telling the agency the new buildings sat in an area constrained for electrical capacity.

The constraint is formal: EirGrid will accept no new data center grid connection applications in Dublin until 2028, a refusal that pushed Interxion to pause its expansion and preceded Dataplex going into voluntary liquidation after being denied power contracts.

The Environmental Protection Agency granted the licence, and the plant, reported at about 100 million euro, is licensed to run eight hours a day every day of the year to meet the energy regulator's flexible demand policy, which requires standby generation that can be called on when the grid is stretched. The plant may not export power and is backed by up to 150 diesel generators if it fails; the plan also includes a 75 megawatt fuel cell installation.

"The gas engines and generators will be used solely for the purpose of generating power for the installation," the agency said. Madeleine Johansson, a People Before Profit councillor, objected: "The plan for a private gas power plant is clearly a way for Microsoft to circumvent the new stricter criteria for data centres in the Dublin Region."

Gas, she said, "is a fossil fuel and needs to be phased out", and while the plant does not add to grid congestion it adds to Irish emissions.

Eoin Doherty, Microsoft's head of data center operations in Europe, the Middle East and Africa, told The Irish Times the campus serves governments, small businesses and large global companies. The gas plant remains Microsoft's answer to Dublin's grid constraint, which EirGrid does not expect to ease before 2028.