Energy prices - as tracked by the Bord Gáis energy index - fell by 7% in May from April largely due to a 15% drop in oil prices over the period.

That was the biggest monthly fall in crude prices in two years.

But the fall in oil prices has coincided with a fall in the value of the euro compared to the US dollar.

That means Irish consumers, in common with our euro zone peers, are not seeing the full advantage of falling oil prices.

Crude oil is priced in dollars so the stronger dollar is offsetting some of the benefits of weaker oil price.

Crude oil is priced in dollars so the stronger dollar is offsetting some of the benefits of weaker oil price.

The Bord Gáis Energy Index fell to 142 points in May. This makes it 1% higher than the same time last year. Bord Gáis has said that if the euro had not weakened against the dollar and sterling, it index would have fallen another 4% month on month to 11%.

During the month the oil element of the index fell by 9% month on month to 151. The price of a barrel of oil fell in May by almost $18 due to the political uncertainty in Europe, global economic weakness, increased oil supplies from OPEC and easing concerns over Iran's nuclear programme.

The natural gas element of the index was down 3% month on month to 203. Prices started to fall in the middle of the month as healthy supplies of gas were sent from the LNG terminals and Norwegian gas flows resumed after scheduled maintenance.

But the coal element of the index rose by 4% to 122 with the fuel finding some support from the power generation sector as healthy European dark power spreads means that it is economical to burn coal across Europe to produce cheaper electricity.

The electricity element of the Bord Gáis index fell by 5% to 116. As most of the power produced in Ireland is generated from gas, a 3% fall in the average monthly wholesale UK gas price in euro terms put downward pressure on the cost to produce electricity here.

John Heffernan, power trader at Bord Gáis Energy said that fuel commodity prices dropped last month as the markets nervously assessed the uncertain global economic and political repercussions of the current crisis in the European Union.

''As a consequence, money managers channelled funds away from commodities in favour of safe have assets such as Us and German government bonds,'' he added.