Consumer guide: How to cut  your energy bills

ESB is slashing bills by up to €126 a year after being freed to compete with Bord Ghais and others with price cuts

But the chief executive of the National Consumer Agency, Ann Fitzgerald, says certain aspects of today's ESB announcement on price cuts are 'unfair'.

The ESB said its price cuts would save households on average €120 a year, but were available only to customers whose accounts were not in arrears.

More than 100,000 ESB customers have fallen into arrears over the past 12 months.

Ms Fitzgerald said it was unacceptable for a State company to preclude customers in arrears from availing of the price cuts. She said her agency was writing today to the Energy Regulator and the ESB outlining its concerns.

Responding to comments by Ms Fitzgerald, the ESB pointed out that its customers availing of a free electricity allowance were eligible for the new price plans.

The ESB earlier said that it was cutting its electricity prices for households from today. It is also entering the gas market.

Savings of up to €190 for electricity and gas combo

The company, which has been rebranded ESB Electric Ireland, says its electricity customers will save on average €120 a year, while those who avail of a gas and electricity package will get average savings of €190.

For the last two years, the ESB has been forced to stand back and look on as it lost hundreds of thousands of household customers to Bord Gáis and Airtricity.

That is because the Energy Regulator wanted to introduce competition for the monopoly provider in the retail electricity market.

ESB now has less than a 60% market share so it is being allowed to fight back. It is also entering the residential gas market and going after Bord Gáis's gas customers.

For consumers who take both their gas and electricity with ESB Electric Ireland, the company says it could mean savings of up to €190 a year. That is equivalent to around a 17% saving.

To avail of the offer, customers must observe several terms and conditions including paying by direct debit, receiving bills online and setting up a direct debit. They must also not have been in arrears during the previous 12 months.