A quadrupling in electricity use by data centres in just eight years has alarmed environmentalists, writes Ken Murray.

The centres' share of power use jumped from 5% in 2015 to 21% in 2023 - the same as all homes in the country, recent Commission for Regulation of Utilities (CRU) figures show.

Green Party member Ciarán Cuffe called on the Government to "get real" over the electricity being consumed by data centre operators.

"I think it's a wake-up call. I think it should push the Government to think again about allowing more data centres," the former MEP said.

"Certainly during our time in government, we said unless you are able to run these centres by renewable energy, we don't want to talk to you."

Ireland has had significant success in the delivery of renewable energy production to date, according to the CRU report.

But Mr Cuffe, a former junior minister, added: "A message has to go out to data centres that they cannot expand indefinitely in Ireland or anywhere else if we wish to keep within our climate tarin gets."

The report says the scale of these targets is a strong signal of Ireland's potential to become a global leader in renewable energy.

The latest figures have also caused alarm in the Irish branch of environmental group Extinction Rebellion, which lobbies for radical action on climate change and against biodiversity loss.

Spokesman Fiachra O'Cinnéide said: "We think that Ireland already has more than its fair share of data centres so we need a moratorium on more being developed.

"The 92 data centres in Ireland currently use more electricity than all of the houses in the country combined."

Mr O'Cinnéide referenced how Micheál Martin recently said that "anyone who is opposed to data centres are completely disconnected with the realities of economic life", adding that the Taoiseach "is disconnected from the fact that we are living in a climate crisis that threatens every aspect of our society and our economy".

A data centre is a facility that stores digital information. Estimates put the amount of water used to cool processors in data centres at anywhere between 500,000 and 5 million litres per day.

The CRU is calling on the public to have their say on the way forward on the prevalence of data centres in Ireland.

It has published a consultation paper on the Review of Large Energy User Connection Policy.

The outcome of this will inform any resulting CRU decisions that will apply to all new connection contracts for new or additional capacity.

Responses are invited from interested parties until the close of business on April 4.

This feedback will inform a decision that will be published later in 2025.

A Department of Environment spokesman said: "Data centres, like all large energy users, have to exist within the boundaries of our climate legislation and targets.

"The Programme for Government recognises the challenges regarding the sustainability of data centres, and their alignment with our climate goals, and commits to enhancing data centres' use of renewable energy sources, energy-efficient technology and effective solutions, such as waste heat capture to reduce their carbon footprint.

"This is why the Programme for Government also includes the commitment to develop a comprehensive plan to accelerate energy generation, connectivity, and planning processes.

"This plan will guide the development of data centres in Ireland and provide certainty to industry with regards to making short and medium-term investments.

"Data centres are a core infrastructure enabler of a technology-rich, innovative economy, which makes Ireland a location of choice for a broad range of sectors and value-added activities."