Customers who get both gas and electricity could see rises of €426 per year.
Energia customers will see a major increase in their electricity and gas bills from next month.
Both its electricity and gas customers will see their bills rise by 15% on average from 25 April onwards.
The increase means that customers paying for electricity with Energia will spend around €246 more on their bills each year, while gas customers will pay around €180 more.
In a statement the company said the increase was "the result of a sustained period of elevated global energy market prices".
Energia's Director Republic of Ireland Customer Solutions, Andy Meagher, said the price changes are unavoidable and the company had made every effort to absorb the wholesale costs.
It comes soon after
Bord Gáis announced a major increase in its prices earlier this month.
The company increased the average electricity bill by 27% and the average gas bill by 39%, with the changes to take effect from 15 April.
Bord Gáis said the price hike comes as high global wholesale energy costs and market volatility are expected to continue for some time.
