Price increases announced last month by Electric Ireland came into effect yesterday.
The rises will increase residential gas bills by 29.2% and residential electricity bills by 10.9% from 1 August.
This equates to an average of €13.71 per month on the average electricity bill and €25.96 on the average gas bill.
There were over 35 price hike announcements last year from Irish energy suppliers and the trend has continued into this year with all the major suppliers including Bord Gáis Energy, Energia and PrePayPower announcing price hikes.
Head of Communications with price comparison website Bonkers.ie Daragh Cassidy said around 1.1 million electricity customers will be affected by Electricity Ireland's price hike along with about 200,000 gas customers.
Speaking on RTÉ's Morning Ireland, he said that will mean an increase of about €300 a year for every customer.
"All suppliers have been raising prices by absolutely astronomical amounts and we're heading into a winter with gas prices, electricity prices at really, really high levels," Mr Cassidy said.
He said he does not think there will be electricity blackouts this winter but added that it is "almost certain that we're actually going to see even more price increases".
Mr Cassidy said there is a lot of competition between energy providers and customers can still get substantial discounts by switching.
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But he said no one is going to be able to offset some of the price increases seen "and we're all going to be paying more for gas and electricity than we were at this time last year".
However, the Public Service Obligation levy has been reduced by the energy regulator and will result in a credit on bills of around €90, Darragh Cassidy also said today/
He advised that everyone can reduce energy demands in their homes with energy light bulbs, tackling drafts, cooler washes in washing machines and unplugging appliances at night.
"I know these are things that we probably feel like we've all heard before. But this is really the year when people need to start doing them," he added.
Meanwhile, senior research officer at the ESRI Dr Muireann Lynch said an emergency energy shortage this winter is "still unlikely".
Dr Lynch said that if fuel rationing were to be introduced it would be the first time such a measure has been taken since World War II.
Speaking on RTÉ's Today with Philip Boucher Hayes, she said that in this situation there would be a need to prioritise essential workers who rely on private transport to get to work.
However, the logistics of implementing such a measure have yet to be "hashed out".
"I think the way it will probably be done is if you're an essential worker then you get to purchase fuel and if you're not an essential worker then you don't, but then there's the question of how do you make sure? How do you decide who an essential worker is and all the rest of it, so the logistics certainly have to be worked out."