Data centres consume as much electricity as urban houses, CSO figures show

National grid operator issues amber system alert due to low winds and and generator outages

Data centres in the Republic used as much electricity as urban households last year despite an effective moratorium on new connections to the grid in the Greater Dublin Area, according to new figures from the Central Statistics Office (CSO). It comes as the national grid operator separately issued an amber alert on Monday due to low wind generation in the electricity system and generator outages.

Electricity consumption by data centres increased by 31 per cent in 2022 from 2021, accounting for 18 per cent of total consumption across the economy. Despite an overall 10 per cent decline in consumption by households in 2022, urban residences also represented 18 per cent while consumption by rural households accounted for 10 per cent of the total.

It means that the roughly 75 data centres in operation in the Republic last year consumed 400 per cent more electricity in the final quarter of 2022 compared with the same period in 2015.

“The consumption by urban residential and rural residential tariff groups decreased by 10 per cent and 9 per cent respectively between 2021 and 2022, and non-residential consumption increased 9 per cent over the same period,” said Niamh Shanahan, statistician in the CSO’s environment and climate division.


Dublin postal districts, meanwhile, had the highest proportion of residential consumption in 2022 at 19 per cent followed by Cork (12 per cent), Dublin county (6 per cent), Galway (6 per cent) and Kildare (5 per cent), according to the CSO. “Counties with dwellings that use electricity as their main space heating fuel and the total number of meters present are underlying factors determining county residential demand,” Ms Shanahan said.

But total metered electricity consumption was 29,500 gigawatt hours in 2022, she said, an increase of 3.5 per cent on 2021 driven mostly by large users.

Overall, large energy users – a category that includes larger data centres as well as other energy intensive manufacturing businesses – accounted for 27 per cent of total consumption last year.

This represents an increase of 20 per cent between 2021 and 2022 and by 116 per cent between 2015 and 2022, the CSO said.

Amid concern about the growth of data centres, national grid operator EirGrid in 2021 decided to stop connections for new data centres until 2028, a de facto moratorium on the building of new facilities in the Greater Dublin Area.

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EirGrid has estimated that data centres could account for as much as 29 per cent of all electricity consumed in the Republic by 2028.

Speaking on the News at One on RTÉ Radio 1, Jennifer Whitmore, Social Democrats leader Jennifer Whitmore said the Government needs to take greater responsibility for the supervision of data centres.

“The Government does not seem to have a strategy for oversight. There needs to be strategic management of data centres,” Ms Whitmore said. Households had reduced their energy use because of higher costs and concerns about climate change, but their efforts were being negated by data centres, she said.

Separately, the Single Electricity Market Operator (Semo) issued an amber alert on Monday, an early warning sign indicating that the supply of electricity may fall short of demand.

In a statement on social media, EirGrid said the system alert was issued “due to low wind and solar and forced outages at a number of generators which has resulted in a reduced capacity to meet demand”.

“The alert means that the buffer between the demand for electricity and the available supply is currently smaller than optimum. It does not indicate a loss of electricity supply to customers,” the company said.

“EirGrid is continuing to work on a range of actions to address this supply-demand shift for the medium and long-term. But in the short term we are closely monitoring the situation and working with conventional generators to ensure that plant performance and availability is maximised as well as working to optimise our operation of the grid.

Ian Curran

Ian Curran

Ian Curran is a Business reporter with The Irish Times