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Electricity · CSO metered data

How much electricity do data centres use in Ireland?

Data centres used 7.7 TWh of electricity in 2025, 23.2% of all metered electricity in Ireland, up from 5% in 2015 (CSO, published 7 July 2026). That is 84% of what every Irish home used combined, and use grew 9.9% on 2024.

Updated 3 October 2026 · data build 2026-10-10 · how we know · corrections

Data centres metered electricity consumption, 2015–2025

Figure 1

Out of every 100 units of metered electricity

Data centres used 23.2% of Ireland's metered electricity in 2025, up from 5.0% in 2015, not far below the 28% used by every home in the country combined.

Data centres' share of Irish metered electricityOut of every 100 units of metered electricity, data centres used 5.0 in 2015 and 23.2 in 2025. Homes used about 28 in 2025.2015: data centres 1,240 GWh of 24,599 GWh (5%)2015: 5.0%1,240 of 24,599 GWh2025: data centres 7,662 GWh of 32,987 GWh (23.2%)2025: 23.2%7,662 of 32,987 GWh×6.2 IN 10 YEARS7.7 TWhdata centres, 20259.1 TWhevery home in Ireland, 2025Each square = 1% of allmetered electricityData centresHomes (all residential)Everyone else
Data centres' share of Irish metered electricityOut of every 100 units of metered electricity, data centres used 5.0 in 2015 and 23.2 in 2025. Homes used about 28 in 2025.2015: 5.0%1,240 of 24,599 GWh2025: 23.2%7,662 of 32,987 GWh×6.2 IN 10 YRS7.7 TWh data centres9.1 TWh all homes1 SQUARE = 1%Data centresHomesEveryone else

Each grid is all electricity measured by meters in Ireland in one year, split into 100 squares. In 2015 data centres took 5 of them; in 2025 they took 23 (7,662 of 32,987 GWh), a 6.2-fold rise in 10 years. Homes, for comparison, used 9,075 GWh in 2025. This is a share of electricity only; electricity is about a fifth of all the energy Ireland uses, so data centres' share of all energy is much lower.

Sources: CSO, Data Centres Metered Electricity Consumption (MEC02), 7 Jul 2026 · CSO, Metered Electricity Consumption 2025 - Key Findings, 7 Jul 2026

TWh024685%20155.8%20166.8%20178.2%20189.4%201911.2%202014.1%202117.7%202220.7%202321.9%202423.2%2025
YearData centres, GWhAll metered, GWhShare
20257,66232,98723.2%
20246,97431,90421.9%
20236,33930,58120.7%
20225,27429,82517.7%
20214,01328,50614.1%
20203,03127,05611.2%
20192,48926,5049.4%
20182,18326,7308.2%
20171,76225,7266.8%
20161,48325,3555.8%
20151,24024,5995%

GWh · CSO MEC02, updated 2026-07-07. Share = data centres ÷ all metered electricity.

Which sites use it

Which operators draw it, 2025 (TWh)

Amazon3.72 · 49%
Microsoft1.35 · 18%
Meta1.18 · 15%
Google0.23 · 3%
Equinix0.16 · 2%
K20.15 · 2%
Everyone else (by difference)0.86 · 11%

The 16 EPA-licensed sites that file annual reports drew 6.8 TWh from the grid in 2025, equal to 89% of the CSO's 7.7 TWh for all data centres (Amazon alone: 49%). Read the shares as upper bounds: taken at face value they leave only about 99 MW for every other campus, the low end of what those sites plausibly use. Some of the gap is real (several campuses run partly or wholly on their own gas, which the CSO's meter data doesn't count), and the CSO says it may miss new or small sites. Amazon's share is roughly 40–50%.

EPA annual environmental reports × CSO MEC02

How much grid capacity they hold

Figure 2

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.

Grid capacity held by data centres vs power drawnData centres used 7,662 GWh in 2025, an average draw of 875 MW. Contracted grid capacity is 2,000–2,400 MVA, about 1,900–2,280 MW usable, so 38–46% is in use.0 MW5001,0001,5002,0002,400 MVA × 0.95 = 2,280 MW usable2,400 MVA contracteddata centres + other new loads (EirGrid AIRAA)2,000 MVA × 0.95 = 1,900 MW usable2,000 MVA contracteddata centres only (EirGrid, May 2026)14.6 TWh ÷ 8,760 h = 1,667 MW averageEirGrid 2034 forecast14.6 TWh a year as an average7,662 GWh ÷ 8,760 h = 875 MW875 MW average draw, 20257,662 GWh ÷ 8,760 hours (CSO)Sum of 2025 average grid draw in EPA reports: 776.2 MW776 MW measured at 16 big sitesEPA annual environmental reports, 2025≈1.0–1.4 GW held but unused38–46% of contracted capacity in use
Grid capacity held by data centres vs power drawnData centres used 7,662 GWh in 2025, an average draw of 875 MW. Contracted grid capacity is 2,000–2,400 MVA, about 1,900–2,280 MW usable, so 38–46% is in use.0 MW5001,0001,5002,0002,400 MVA × 0.95 = 2,280 MW usable2,400 MVA contracteddata centres + other new loads (EirGrid AIRAA)2,000 MVA × 0.95 = 1,900 MW usable2,000 MVA contracteddata centres only (EirGrid, May 2026)14.6 TWh ÷ 8,760 h = 1,667 MW averageEirGrid 2034 forecast14.6 TWh a year as an average7,662 GWh ÷ 8,760 h = 875 MW875 MW average draw, 20257,662 GWh ÷ 8,760 hours (CSO)Sum of 2025 average grid draw in EPA reports: 776.2 MW776 MW measured at 16 big sitesEPA annual environmental reports, 2025≈1.0–1.4 GW held but unused38–46% of contracted capacity in use

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

38–46%
Of contracted grid capacity actually used, 2025
875 MW average vs 2,000–2,400 MVA
1–1.4 GW
Unused capacity already contracted
growth needing no new contract
1,948 MVA
Protected when the 2021 rules came in
1,884 MVA of it in Dublin
1
New data-centre contract under the 2021 rules
EirGrid
The moat the rules created. Freezing new connections protected whoever already held contracts. They are using well under half of what they hold, so existing operators can roughly double their draw while newcomers wait.

Unused capacity we can tie to named sites (MW)

Amazon (AWS) Cruiserath151
Microsoft Huntstown150
Meta Clonee45
Amazon (AWS) Belgard, Tallaght37

Only Amazon Cruiserath publishes both a contract (240 MVA, 2017) and its 2025 draw. Others compare draw with demand stated in planning or EPA papers, which is not a contract. Average draw understates peak use. MVA converted at power factor 0.95.

EirGrid AIRAA 2026–35 and Constrained Area Overview (May 2026) · CRU/21/124 · EPA annual reports · CSO · quotes checked · as of 2026-10-03

Questions people ask

What percentage of Ireland's electricity do data centres use?
23.2% of metered electricity in 2025 (CSO, published 7 July 2026). Against Ember's measure of total demand, which includes losses and other unmetered use, the share was 22.1%.
Is that a fifth of Ireland's energy?
No. Electricity is only part of the energy Ireland uses. As a share of all final energy (oil, gas, electricity and the rest), data centres were about 4.9% in 2024 (SEAI energy balance).

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