Energy customers are set to be hit with an increase in the carbon tax from tomorrow, 1 May.

The carbon tax is a charge applied to carbon-emitting fuels such as coal, peat, oil and natural gas.

Introduced in 2010, the tax is intended to reduce carbon dioxide emissions and is part of Ireland's strategy to support a greener and cleaner environment.

The tax was raised by €7.50 to €33.50 per tonne of CO2 in last October’s budget.

However, the increase was postponed until May on home heating fuels such as coal, peat, natural gas and home heating oil.

Daragh Cassidy, Head of Communications at comparison and switching website said the new charge will work out at close to 0.69 cent (including VAT) for every kWh of gas used.

"Considering that the average Irish household uses 11,000 kWh of gas every year, the increase in the carbon tax will add an additional €17 (or €76 in total) to the average household's annual natural gas bill, which works out at around €13 on every bi-monthly bill. However those in homes with three or more bedrooms or with a poor BER are likely to end up paying more," he explained.

Mr Cassidy said the increase in the tax also means it now adds around €3.52 in total to a 40kg bag of coal, 76 cent in total to every bale of briquettes and €84 in total to every fill of a 900-litre home heating oil tank.

The tax already adds around 8.5 cent to every litre of petrol and diesel.

Mr Cassidy said there is still some debate as to whether a carbon tax is effective at reducing CO2 emissions by households, given people still need to heat their homes and use energy for the most basic of day-to-day tasks.

"However, one thing that we do know is that the tax has raised around €4 billion euro since it was first introduced and many hard-pressed Irish consumers will be asking themselves where that money has gone and what environmental initiatives have been achieved since the tax was first introduced," he said.

Mr Cassidy said there is also concern that it affects those on lower incomes the most.

In terms of offsetting the tax and price increases, Mr Cassidy said the easiest thing for gas customers to do is to switch supplier.

"Customers who switch can get discounts of up to 40% from their new supplier for an entire year, which would more than negate the increases,' he said.

He said investing in a retrofit and looking for ways to make your home more energy efficient is also an option.