Fears are growing that homes and small businesses will face power cuts this winter as Ireland’s electricity system faces increased problems, including unreliable wind power and older generators.
Low wind and electricity imports, along with unexpected power-plant shutdowns, squeezed supplies on Tuesday, increasing the risk of a power cut.
National grid operator Eirgrid issued a system alert, confirming that the buffer between electricity supply and demand was lower “than optimum”, but stressing that there was no loss of power to customers.
It is understood the ongoing squeeze on electricity supplies has left senior Eirgrid figures pessimistic about getting through the winter without cutting electricity supplies to parts of the Republic when demand is high, known as “load shedding”.
Homes and small businesses are thought likeliest to suffer if this happens. Manufacturers and other industries that need large amounts of electricity may have backup generators that they can use should power be cut.
However, sources acknowledge that where large energy users do not have backup this will present extra “political” difficulties, as many are significant employers.
Supplying these organisations while cutting families’ and small businesses’ electricity would be unpopular even if maintaining big employers’ power protects jobs.
Eirgrid confirmed that “social and economic growth; the reliability of an ageing fleet of conventional generators and; the failure of contracted generation to deliver” had tightened electricity supplies.
The company added that it was working with generators to maximise power plant availability and to optimise its operation of the grid.
ESB Networks, which distributes power through the last leg of the system that transmits electricity to customers, decides where to cut power, not Eirgrid. Once Eirgrid instructs ESB Networks that it must reduce demand to secure the entire electricity system, the company does this in a “safe, controlled and fair manner”, according to a regulator-approved code.
Industry sources say a potential European gas shortage could worsen problems that include intermittent wind power and increasingly unreliable, older conventional electricity generators. Unexpected problems that shut down some of these plants were partly responsible for Tuesday’s system alert.
Eirgrid figures show that up to one in four Irish power plants were unexpectedly shut down at any one time during 2021.
ESB confirmed that one of its three generators at Moneypoint shut on Monday “due to a plant issue” and will return on Saturday. The coal-burning plant, that generates 900 mega watts (MW) in total, has supplied large amounts of electricity over the last two years.
Another unit is shut until next month for planned work fitting equipment meant to aid the use of renewable electricity.
SSE Airtricity confirmed that both its oil-fired generators at Tarbert are on scheduled shutdowns, with one due back in on September 4th and the other in March. They produce 444MW in total.
ESB was due to provide 200MW of emergency power at North Wall, Dublin, by October. However, Eirgrid ended the contract after a legal challenge by EP UK Investments, majority owner of Tynagh Energy, which did not go ahead.
ESB says it is on schedule to provide another emergency generator at the same site late next year.
The Commission for the Regulation of Utilities, responsible for energy security, confirmed that margins would remain tight this winter. It added that it was working to implement extra measures to cut risks.