Electricity Ireland's gas and electricity prices will increase from August 1st, with unit price and standing charges set to rise.
The unit price of gas will increase by 29.2 per cent, while electricity unit prices will jump by 10.9 per cent. These respective increases will also be applied to standing charges.
Figures from Bonkers.ie show the price increases will add approximately €312 each year to gas customers' bills, and around €165 for electricity customers.
This follows an earlier price increase, announced in May, when Electric Ireland increased the unit price for electricity by 22 per cent and for gas by 25 per cent.
Other suppliers, such as Bord Gáis Energy, Energia and PrePayPowers, also announced similar increases this year.
The Electric Ireland changes will impact approximately 1.1 million electricity and 145,000 gas customers.
"Today’s news was expected unfortunately, and given Electric Ireland's size, it will be felt badly by many households nationwide," Bonkers.ie's head of communications Daragh Cassidy said.
"We’re heading into next winter with gas and electricity prices at absolutely astronomical levels, and it might even get worse.
"To say these are unprecedented times for the energy sector is an understatement. More price hikes from all the other suppliers are likely to follow and more price hikes from Electric Ireland later in the year can’t be ruled out," he added.