The ESB says it expects electricity prices to rise between 10 and 20 per cent next year on the back of higher fuel costs.
At the launch of the company's annual report today, ESB Chairman Tadhg O'Donoghue said while he hoped the increase would be 10 per cent it "could well be in the high teens."
This follows increases of almost 9 per cent in 2004, 4 per cent in 2005 and 3 per cent this year.
The current average price of a bill is €123 every two months and the predicted increase could push that up by up to €24.
ESB Chairman Tadhg O'Donoghue
The company has submitted several revenue projections to the Commission for Energy Regulation (CER) based on varying prices for oil and gas. The regulator is due to announce its decision in October.
The company today reported a pre-tax profit of €240 million for 2005, up 31 per cent on the previous year.
But the ESB said the figure was due in the main to once-off sales of businesses and property.
The company said its payroll costs had decreased by €24 million in 2005 with a reduction of close to 1,000 employees year-on-year.
But Mr O'Donoghue: "The continued rise of global fuel costs is obscuring the extent of the cost efficiencies achieved across ESB, in Payroll and work practices."
"The end user price tariff is affected more by fuel costs than any internal measures implemented by ESB," he added.
The ESB said its market share in power generation continued to fall during 2005 to 63 per cent of the market and is expected to fall to 50 per cent by the end of this year.
ESB chief executive Padraig McManus said the ESB would continue to seek growth opportunities in the International market while decreasing the company's presence in the Irish market.
ISME - the Independent Business Organisation - warned the ESB's request to raise prices - if granted - would force many small businesses, particularly in manufacturing, to downsize or shut down totally.
ISME chief executive, Mark Fielding said: "This is a company that can afford to pay one of the highest average wages in the economy, average €75,000 per employee, €250,000 per person for redundancy, pay workers not to work and still produce profits of the magnitude announced today.
"It is obvious that there has been no attempt to address the inefficiencies that currently exist within the company.
"The regulator has rewarded inefficiency by allowing exorbitant increases in prices, which has culminated in Irish electricity prices going from being among the cheapest in Europe to the highest, within a five-year period, so much for competition," he added.