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Power plant shutdowns and low imports: Electricity system alerts now common

Reserve buffer between electricity demand and supply less than ideal, increasing the risk of power cuts

On two of the hottest days of the year, on Tuesday and Wednesday, national grid operator Eirgrid warned of a squeeze in electricity supplies. The system alerts, as they are known, said that low wind and energy imports, combined with unexpected power plant shutdowns, had narrowed the gap between supply and demand.

This meant the reserve buffer between electricity demand and supply was less than ideal, increasing the risk of power cuts should anything else go wrong, such as another generator getting knocked out for some reason. However, there was no actual loss of supply to any customers.

System alerts are quite common. There were at least half a dozen through 2021, when low wind speeds and power plant shutdowns were again among the culprits. These problems continue to dog electricity supplies.

Some of those conventional plants, which burn gas or other fuels, are ageing and so becoming more prone to problems that result in unexpected shutdowns. Others are switched on and off frequently to accommodate wind power, when it is available, but are not designed for this, so that creates other technical problems.


It remains to be seen whether the exact circumstances of the last few days will be mimicked in winter, when there is obviously more demand for electricity. Some power plants are shut down for scheduled maintenance, which is regularly done in summer. They should running again by autumn.

Unfortunately, the system’s underlying problems are poised to continue, aggravated by the absence of emergency back-up generation that was scheduled to come on stream this winter and now will not now do so. Both Eirgrid and the Commission for the Regulation of Utilities (CRU) acknowledged this week that supplies will be tight. A possible gas shortage presents a third challenge.

Most of these problems became obvious some years ago. Successive governments are on the hook for failing to address them. While the Coalition acknowledged last year that building new gas plants was a national priority, that will take time. Meanwhile, for the third winter in a row, what is supposed to be a developed western economy cannot guarantee homes and businesses that they will have enough power to get through winter.