A shortfall in power left Ireland at risk of blackouts on Thursday after the Single Electricity Market Operator (Semo) issued another amber warning "due to a generation shortfall".
Semo, a joint venture between EirGrid and Northern Ireland grid operator SONI, issued the amber system alert to power suppliers, meaning there was expected to be enough energy to meet demand but possibly not enough in reserve should something go wrong.
The warning came just three days after Semo published an amber warning early on Monday and kept it in place until 10pm, with a separate warning in place for the North for about five hours.
EirGrid said the alert did not indicate a loss of electricity supply, but meant that the buffer between demand and available supply was “smaller than optimum”.
It said there were "a number of reasons" for the alert, including the ongoing offline status of the plants in Whitegate in Cork Harbour and Huntstown in north Dublin, which represent 15 per cent of conventional generation.
“Three of the four units at the Tarbert plant in north Kerry were also unavailable due to technical problems, and the output from the country’s wind farms was very low due to weather conditions,” its statement continued.
A number of other generators were also unavailable or had reduced capacity, while support from Britain via the East-West Interconnector was limited due to a tightness of supply there.
EirGrid described the task of maintaining the balance between supply and demand as “increasingly challenging”, but said it would continue to manage the evolving and complex situation.
The shortfall on Thursday led to the halting of the Moyle Interconnector, which usually exports electricity across the Irish Sea from Northern Ireland to Scotland.
This exacerbated near record-high electricity prices across Europe. Extreme volatility on wholesale markets saw an auction for UK intraday power prices clearing at £2,000 (€2,342) per megawatt hour from noon to 12.30 pm – a price that was nine times higher than the intraday power values that prevailed at 8am.
Spanish day-ahead electricity prices gained 7.5 per cent to a record €152.32 per megawatt hour, while France's benchmark power price for delivery next year rose 2.2 per cent to a record €99.50 per megawatt hour and there was a record €96.10 per megawatt hour price in Germany.
This week’s amber warnings come in the wake of concern that Ireland might not be able to generate sufficient electricity to avoid power cuts as demand for energy surges ahead of the winter.
These winter blackout fears have partially eased, however, amid more recent industry confidence that the generators at Whitegate and Huntstown will restart in October and November.
EirGrid said it was working “on a range of actions” to address the supply-demand shift for the medium and long term.
It said it was “closely monitoring the situation”, and working to optimise its operation of the electricity grid in the short term, as well as engaging with the Commission for Regulation of Utilities (CRU) and the Department of the Environment, Climate and Communications. – Additional reporting Bloomberg