How Much of Ireland's Metered Electricity Goes to Data Centers: The Statistics Office's Release for 2025

Data centers used 23% of Ireland's metered electricity in 2025, up from 5% in 2015. That is the first key finding of a release from Ireland's Central Statistics Office, the CSO, which counts the electricity passing through the meters of the country's data centers, year by year. The statistician's comment says the office "has today (07 July 2026) published" the release, though a line near the top of the same page reads "CSO statistical release, 07 July 2025, 11am." Parts of the release follow, not the whole.

A year of growth

Metered consumption by data centers rose from 6,973 GWh in 2024 to 7,663 GWh in 2025, which the office gives as an increase of 10% "in a single year." GWh is gigawatt hours, a unit the release's notes define. Consumption by all other users, households and other businesses among them, went up by 2% over the same period. Both rates are the office's own, for the same year.

The longer series runs by quarter. Data center use grew from 291 GWh in the first quarter of 2015 to 1,991 GWh in the last quarter of 2025. Households move differently, and the page says so in one sentence between its two tables, that "households drive massive seasonal spikes in the winter months (Q1 and Q4) due to heating and lighting," while "the data centres consumption tends to increase with every quarter, with a slowdown in first quarter of the year, as was observed in 2024 and 2025."

Households rise and fall with the seasons, and data centers, in the office's account, mostly climb. For whoever must supply that load, it is a demand to plan for in every quarter, not only in winter.

Beside the other users

All metered electricity in Ireland rose by 34% between 2015 and 2025. The group with the largest share is what the office calls Large Energy Users, a group that "includes significant data centres". It took 33% of the total in 2025, and its annual use rose 9% since 2024 to reach 10,812 GWh. Because that group includes significant data centers, its share and the data centers' share count some of the same electricity.

Households come next in the findings. Homes in town and country together used 28% of the electricity, against 23% for data centers. The office sets the two side by side.

How the office counts

The page explains how the office finds them. "As data centres are not separately classified in the source data," the office uses "various approaches to identify them including name searches for known data centre operators, information from industry reports and internet searches, and examination of high consumption customers to determine the business sector they are in." The Background Notes say the data "covered all meters connected to the mains electricity network," and that the office "examined around 2.6 million meters" to find those "considered as primarily being used for data centre activity." Most of the data centers' metered electricity went to "A small number of data centres", the notes say.

The notes also state the limits. "There is no agreed definition of a data centre." "Data for all years are subject to revision." Revisions "may arise" from adding meters that belong to existing data centers or from removing meters that were "incorrectly included". And a new data center "may initially be below the search thresholds used to subset the 2.6 million electricity meters." So a new data center can be missing from the count at first.

A count taken at the grid's meters sees what passes through them. The notes do not say whether any data center makes power of its own, and a series built this way would not show it if one did.