Data centers aren't the sole cause of Ireland's high electricity prices, but they do contribute to them. The biggest cause is Ireland's reliance on imported natural gas.
That said, data centers are heading for 30% of the country's electricity use, and they contribute significantly to high prices. Effectively a subsidy from Irish consumers to Big Tech. There are other externalized costs, too. E.g. Supporting Big Tech data center infrastructure is delaying house building. Ireland is lucky in that most of Big Tech pays its European taxes to the Irish government, so there's a quid pro quo here. But that is less true for other parts of the world.
Some people think AI may need as big a share of other countries' electricity - who should be paying for this?
Government warned of rising household bills as data centres strain grid
Large high volume purchasing always comes at a discount. It shouldn't for something like energy but it does.