Lower risk of electricity supply disruption this winter

EirGrid said work done on security of supply 'will have a positive impact on generation capacity'. Picture: Denis Minihane

The risk of the electricity grid being disrupted and experiencing amber alerts this winter has reduced since last year's colder months, but it cannot be ruled out, says EirGrid.

The more upbeat assessment has been published in its Winter Outlook, where it says that work already done on security of supply "will have a positive impact on generation capacity".

An alert or amber state is when a single event on the electricity power system could potentially end with failure to meet the demand, while an emergency state is when a number of events happen at the same time leading to actual failure.

However, there is no risk of a system-wide blackout, defined as a total loss of control of the electricity system, solely due to insufficient generation under any circumstances this winter, the Winter Outlook said.

There is an expectation that the system will enter the alert state at times, EirGrid warned, most likely at periods of low wind and low interconnector imports. There is also a chance, albeit low, of an emergency situation occurring, it said.

"Electricity consumers could potentially be without supply for up to two hours over the winter period," said EirGrid. 

'Emergency protocols'

"However, emergency protocols are in place with large energy users that would mitigate the impact on homes and businesses, where sufficient notice of an event can be provided."

It stressed that this assessment does not necessarily mean that electricity consumers will actually be without supply for any period during the winter. 

In last year’s outlook before winter took place, it was suggested that consumers could end up without power for four hours, yet consumers experienced no loss of power during the winter due to capacity issues, it said. 

The middle of December is expected to be the most difficult period if capacity is challenged, EirGrid added.

EirGrid chief executive Mark Foley said: "It is encouraging to see that the risk of disruption to electricity supplies due to insufficient generation has reduced for this winter. 

It is worth noting that there were no system alerts last winter when the risk of going into alert was significantly higher than it is this winter."

The margin between supply and demand this winter may be tight at times, particularly over the 5pm-7pm evening peak, he said. 

EirGrid has temporary emergency generation units that will gradually become available from next month as an "insurance policy" in any event, he added.