People before Profit TD Bríd Smith says Ireland needs to have a dialogue about why we need to continually expand data centres here.
She was speaking as Data Centres Ireland is holding a trade show at Dublin's RDS, which will be picketed by protestors.
Deputy Smith told Newstalk Breakfast they could take as much as 26% of the national grid if they keep being built.
"We're trying to shine a light on the fact that we're facing down the barrel of blackouts this winter.
"We have a crisis in the provision and production of electricity - and most of this is because the data centre industry is taking 12% of the national grid currently.
"And if they keep growing the data centre business in this country, it could suck up up to 26%".
She says this would also hurt our carbon emission targets.
"Already we have 70 of them in the country, which is a huge amount for a country this size: 30 more have planning permission and seven or eight more are under construction.
"We are looking at a really deep crisis, plus this is linked with our climate action plan.
"If we keep growing data centres at this rate, we will utterly fail to meet our targets".
Deputy Smith says while she acknowledges the data centres are needed, other countries have put caps on them.
"There's no doubt that modern society needs data - me and you use data all the time.
"It is in our backyard, it's obscenely in our back yard; most countries don't allow that usage to take more than 2% on average of the national grid.
"And recently Singapore shut down any more development of data centres because it was sucking up 7%.
"We're now at 11% of the national grid and growing.
"I agree we need data, nobody will deny that - we have it, we have 70 of them here.
"But we never asked the question or have a dialogue on why we need to continually expand the data we use.
"And that needs to be a dialogue that we have".
She says trying to get more electricity supply needs to happen, but new centres should be on hold.
"By the time we create more supply, we could have another 30 of them built - this is my point.
"We need to stop it now - if they find solutions that are green, that don't mean that our emission targets are failed, and if they find solutions that are sustainable.
"At the moment it is not sustainable, the only solutions they have is back-up from gas and diesel-fuelled generators."