Householders are being stung again by rising electricity prices, with ESB hiking charges 12% adding about 120 euro to annual bills.
The increase will hit the company's 1.2 million customers from October 1 and follows similar rises by Bord Gais and Airtricity earlier this summer.
The company, which has been rebranded to ESB Electric Ireland, said it regretted the increase which it blamed on a 40% rise in international wholesale gas prices over the last year.
General manager Liam Molloy said: "We will continue to work with our customers who are facing difficulties in dealing with their electricity accounts.
"International energy prices have risen steeply over the past year and unfortunately we can no longer continue to absorb these increased costs without reflecting them in the prices we charge our customers.
"We have held off increasing electricity prices for as long as possible."
Earlier this month Airtricity announced plans to increase gas tariffs by 21% and electricity by 12% from the end of next month, adding about 160 euro a year to household gas bills and about 144 euro on electricity.
Bord Gais was given the all-clear by the Energy Regulator in July to hike its charges for household gas by 22% from October. That adds about 160 euro to the average bill.
The company also put up its electricity charges 12% that month, adding 144 euro to consumers' bills.
ESB Electric Ireland said it lost about 800,000 customers from 2010 after Bord Gais and Airtricity undercut its prices.