The Republic faces a high risk of power cuts during the build-up to Christmas and over the new year, when electricity demand will be highest, a report from national grid operator EirGrid shows.
Potential record demand and declining or unreliable supplies have left the Republic facing periods where it may not have enough electricity, says the State company’s winter outlook 2022/23.
“There is a high probability of the system entering the emergency state at times due to insufficient generation being available to meet demand,” EirGrid says.
EirGrid’s winter outlook 2022/23 says that it expects “late November to mid-December and early January to mid-February” to be the periods where the margins between electricity demand and supply will be tightest.
The company calculates that, on average, electricity consumers could be without supplies for about four hours in total this winter.
However, its report cautions that this “does not necessarily mean that consumers will be without supply for any period”.
The State company also stresses that there no risk of system-wide blackouts in either the Republic or Northern Ireland under any circumstances this winter.
EirGrid and ESB Networks have an agreed system for dealing with emergencies in electricity supplies.
This involves demanding that the bigger energy users, mostly industries and data centres, shut off demand first. Many of these organisations have their own back-up generators.
The approach means homes, hospitals, prisons and some public services are largely protected.
The company expects electricity demand to peak at between 5,456 mega watts (MW) and 5,786MW in the Republic this winter.
That would break the record high set on December 8th last year, when demand hit 5,391MW at 5:24pm. The previous record was 5,375MW, reached in early December 2020.
EirGrid states that it has based its winter outlook on the assumption that gas supplies from both the Corrib Field off the northwest coast and the Moffat interconnector with Scotland will not be interrupted.
The company believes the Republic will endure system alerts at times this winter. This is where demand has stretched supplies to the point where electricity reserves are lower than ideal.
This could increase the risk of power cuts in areas where demand is high, particularly if something unexpected, including a sudden generator shutdown, were to happen.
Unexpected power plant shut downs caused by technical or other issues are a growing problem on the Republic’s network and were partly behind the most recent alerts issued by EirGrid in August.
The company’s outlook shows that these shutdowns – known in the industry as “forced outages” – hit 20 per cent of the Republic’s total electricity-generating capacity last winter.
That was well above the 9.5 per cent that the grid operator calculated when it was preparing for last winter. The high shutdown rate was mainly due to problems with three generators.
Alerts are likeliest during cold periods when wind speeds are low, cutting or eliminating electricity supplies from renewable generators and imports from Britain are reduced.
On 10 evenings last winter when demand was high, the Republic imported 398 mega watt hours, roughly equal to one gas-fired power station, from Britain.
The mild winter last year meant there were no system alerts, but EirGrid has several times in recent weeks pointed out that the Republic’s electricity supplies are slightly lower than they were a year ago.