The 2021 electricity consumption by Irish data centres increased by some 223%, from 1,236 to 3,993 gigawatt hours (GWh), when comparing that used in 2015, according to the Central Statistics Office (CSO).

This major increase in electricity consumption means that data centres used 14% of all Irish electricity supplied in 2021, up from 5% in 2015.

This jump equates to an additional 2,757 GWh being taken by data centres from the national grid when comparing 2015 and 2021 figures. Meanwhile, in total in 2021, rural dwellings across Ireland used a lower 12% from the grid.


The rate of increased energy consumption by data centres has spiked further over the last year, with an increase of some 32% between 2020 and 2021 alone, the highest rate of increase since CSO analysis began and up from the 22% increase between 2019 and 2020 consumption.

The electricity use data used by the CSO to make their findings was extracted from meter data received from the Electricity Supply Board (ESB Networks).

Overall, metered electricity consumption increased by 16% or 3,906 GWh between 2015 and 2021 in Ireland, from 24,600 to 28,506 GWh.

However, almost three-quarters (2,757 GWh) of this additional consumption can be attributed to data centres. Electricity use by non-data centre metered users has increased by a much lower 1,149 GWh or 5%.

Overall increase

Commenting on the findings, CSO environment and climate division statistician Niamh Shanahan said: "Data centre consumption increased from 290 GWh in January to March 2015 to 1,058 GWh in October to December 2021.

“The increase in consumption was driven by a combination of existing data centres using more electricity and new data centres being added to the grid.

“Large energy users with very high consumption accounted for 23% of total metered consumption in 2021. The total metered electricity consumption in 2021 was 28,506 GWh which was a 5% increase on 2020."

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