Overall wind energy capacity has reached a new record in Ireland, hitting a peak that has the potential to regularly power over 1.6 million homes. Photo Arthur Ellis/Press22.

Energy suppliers paid up to €10m last year to wind-farm operators to power down, freedom of information documents supplied to the Sunday Independent reveal.

The cost of broken or shut-off wind turbines was up to €10m in 2013 and could be passed on to Irish consumers in their electricity bills, communications between EirGrid and the Department of Energy suggest. "The suppliers can, of course, pass this cost on to their consumers," an EirGrid executive said in an email on the subject to a senior civil servant at the Department of Energy.

The amount paid by Bord Gais, ESB and other suppliers for 2013 was up to €10m, according to EirGrid.

However, that cost looks set to soar as the power-down rate of 3 per cent for 2013 is estimated to rise to 10 per cent in 2014, according to EirGrid, suggesting a cost to conventional energy companies of over €30m and a knock-on cost to consumer energy bills. An EirGrid graph on wind curtailments shows them rising 50 per cent further by 2016, which would cost utility companies €40m.

Irish wind-farm operators receive payouts from other electricity providers in respect of "constraints" or "curtailments" where a transmission or distribution line is down for maintenance or where there is a local fault, or when there is high wind at a time of low-energy demand (for example, in the middle of the night) and turbines are shut down due to over-capacity. The same policy is applied internationally.

European energy regulators decided last year that wind farms would receive compensation from the energy market for these shutdowns and it is part of government policy as a way to stimulate the wind energy market.

Sunday Indo Business