Summary
- Ireland’s CSO says data centres used 23% of total metered electricity in 2025, up from 22% in 2024 and 5% in 2015.
- Data centre electricity consumption rose 10% year on year to 7,663GWh, while all other metered users rose 2%.
- The figures give Ireland’s grid, planning, and data centre policy debate a fresh official baseline.
Ireland’s Central Statistics Office says data centres accounted for 23% of total metered electricity consumption in 2025, up from 22% in 2024 and 5% in 2015.
Metered electricity use by data centres increased 10% in a single year, rising from 6,973GWh in 2024 to 7,663GWh in 2025. Consumption by all other metered users, including residential and other business customers, rose 2% over the same period.
The CSO’s 2025 data centre electricity release shows quarterly data centre consumption growing from 291GWh in Q1 2015 to 1,991GWh in Q4 2025. Annual consumption increased from 1,240GWh in 2015 to 7,663GWh in 2025.
A quarter-scale load class
The 23% share gives Ireland’s data centre debate a hard number. Data centres now sit close to total residential electricity consumption, which accounted for 28% in 2025 across urban and rural dwellings. Urban dwellings accounted for 18%, rural dwellings for 9%, and large energy users, a category that includes significant data centres, accounted for 33%.
That distribution changes the way grid planning is read. Data centres are no longer an emerging load class at the margin of Ireland’s power system. They are a structural part of national electricity demand, with a consumption profile that has grown every year since 2015 and more than tripled between 2019 and 2025.
The CSO’s methodology is also worth noting. Because data centres are not separately classified in the source electricity data, the agency identifies them through name searches for known operators, industry information, internet searches, and examination of high-consumption customers. That extra work reflects the political and planning value of isolating data centre demand from wider commercial and industrial use.
Ireland’s challenge is not only aggregate consumption. Data centres create concentrated load in specific regions, especially around established connectivity and cloud clusters. That local concentration can put pressure on transmission and distribution networks, connection policy, reinforcement programmes, and the sequencing of new generation and demand.
Growth now needs a grid answer
The figures sharpen the case for explicit data centre power strategy. Developers seeking new Irish capacity already face a tougher environment than earlier market entrants, with connection constraints, planning scrutiny, energy-security questions, and public concern over electricity use. A rising national share makes vague power narratives harder to sustain.
Projects will need clearer positions on grid connection, demand flexibility, renewable procurement, backup power, batteries, on-site generation, heat reuse, and location. A data centre can be efficient at facility level and still add a large continuous load to a constrained system. PUE alone does not answer whether the grid can accommodate more demand in the right place at the right time.
The CSO data also complicates sustainability claims. Ireland can host major cloud and AI infrastructure, but that capacity has to fit inside a power system being asked to decarbonise, electrify transport and heat, support industry, and maintain security of supply. Renewable matching helps the corporate carbon story, yet it does not automatically solve network congestion, peak demand, or the physical need for substations and transmission upgrades.
For policymakers, the release gives an updated basis for decisions on large energy users, planning, grid investment, and demand management. For developers, it makes power credibility a front-end requirement rather than a later procurement step. For utilities and grid stakeholders, data centre load has become too large to treat as a specialist issue managed through individual connection agreements alone.
Ireland’s position as a cloud and data centre hub was built on connectivity, talent, tax, enterprise demand, and international platform investment. The next phase will be defined by electricity. The CSO’s figures put that constraint in plain view: data centre demand is still rising, and the space available for easy growth is narrowing.
