Is there a data centre moratorium in Ireland?
Not in law. In November 2021 the CRU directed that new data-centre connection requests be judged on location, on-site generation matching demand, and flexibility (CRU/21/124). In Dublin that stopped new contracts. EirGrid later counted one new data centre contracted under those rules by mid-2025 (AIRAA 2026–35, p.14). In May 2026 it described Dublin as "fully constrained".
Yet data-centre electricity use kept rising: 9.9% in 2025 alone, to 7.7 TWh (CSO). The freeze stopped new entrants. It did not stop growth.
How much grid capacity do data centres hold?
Three public figures, from three dates, tell the same story:
| Source | What it counts | MVA |
|---|---|---|
| CRU/21/124 (Nov 2021) | Connected | 931 |
| CRU/21/124 (Nov 2021) | Contracted, not yet connected | 1,017 |
| CRU/21/124 (Nov 2021) | Total exempt from the direction (Dublin: 1,884) | 1,948 |
| EirGrid Constrained Area Overview (May 2026) | Contracted data centres | 2,000 |
| EirGrid AIRAA 2026–35 | Contracted, incl. some other new-technology loads | 2,400 |
EirGrid's own figures agree. It put data-centre demand at 959 MVA in 2024 against 2,400 MVA contracted, about 40%. Its median forecast for 2035 is 1,870 MVA, still below what is already contracted.
Capacity held before November 2021 is exempt from that direction. Almost all of it is in Dublin.
Grid capacity held by data centres, against what they actually draw
Data centres drew an average of 875 MW in 2025 but hold contracts for about 1.9 GW (2.3 GW counting other new loads): only 38–46% is in use. On paper that leaves room to grow under contracts signed before the 2021 rules, but the grid's 900 MW load-rejection limit and the MPID 345 caps now restrict how much more sites that can't ride through faults may draw.
Energy (GWh in a year) becomes average power (MW) by dividing by the hours in that year: 7,662 GWh ÷ 8,760 = 875 MW. The grey bars are grid capacity EirGrid reports as contracted to data centres, converted from MVA to MW at a power factor of 0.95. The gap between the red line and the end of the grey bar is capacity already promised to existing operators but not yet used; on paper even EirGrid's 14.6 TWh forecast for 2034 (about 1,667 MW on average) fits inside it, though for sites that can't ride through faults the grid's stability limit now binds before their contracts do. On top of this, the system operators' market sounding found about 5.8 GW of possible new data-centre demand. Big sites with EPA licences measured 776 MW of that draw themselves; peaks are higher than averages.
EstimateMVA-to-MW conversion, utilisation and unused headroom are StackPath estimates (3 Oct 2026); the 2034 average is EirGrid's TWh forecast divided by 8,760 hours.
Sources: CSO MEC02, 7 Jul 2026 · EirGrid All-Island Resource Adequacy Assessment 2026–2035, Dec 2025 · EirGrid Constrained Area Overview, May 2026 · EirGrid forecast as cited in CRU2025236, 12 Dec 2025 · EPA annual environmental reports, 3 Oct 2026
Who holds the unused capacity?
Public records name only part of it, about 384 MW:
| Campus | Operator | Unused MW | Measured against |
|---|---|---|---|
| Amazon (AWS) Cruiserath | Amazon (AWS) | 151 | contracted MIC |
| Microsoft Huntstown | Microsoft | 150 | stated demand (not a contract) |
| Meta Clonee | Meta | 45 | stated demand (not a contract) |
| Amazon (AWS) Belgard, Tallaght | Amazon (AWS) | 37 | stated demand (not a contract) |
Amazon's Cruiserath campus holds a 240 MVA connection agreed in June 2017, before the rules changed, and ramped in annual steps to 2029. In 2025 it drew 76.6 MW on average (EPA annual environmental report).
The rest cannot be assigned site by site from public data. Contract sizes are not published.
Why it matters
Our reading. Incumbents hold a moat. Holders of pre-2021 capacity can keep growing into it with grid power. A newcomer needs its own dispatchable plant, 80% new Irish renewables and, in Dublin, a connection that EirGrid says cannot be progressed. Little new competition is likely before 2030.
It also explains forecasts. EirGrid's forecasts have data centres reaching about 32% of demand by 2030, largely on existing contracts (as reported; unchecked against the forecast document). The system operators' market sounding found about 5.8 GW of possible new demand on top (cited in CRU2025236).
For anyone reading a headline about a "moratorium", the useful question is not whether data centres can grow. It is who can.