Operator says energy system should be more resilient after UK’s biggest outage in a decade

This article is more than 1 year old

This article is more than 1 year old

National Grid will accelerate plans for new blackout safeguards to avoid another energy system shock after more than a million homes were left without electricity last month.

The grid operator admitted after Britain’s biggest blackout in a decade that the energy system’s standards should be more resilient against the risk of unexpected power plant outages.

In a report for Ofgem, the industry regulator, it conceded that it would need to bring forward a programme to upgrade its safeguards, due by 2022, which could have helped to prevent the mass blackout on 9 August.

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It has also called for a review into whether it has enough backup power to cope with outages after admitting that it did not have enough in reserve to avert the energy system failure.

After the blackout the energy system controller blamed a lightning strike for causing shutdowns at Orsted’s Hornsea windfarm off Yorkshire and RWE’s Little Barford gas plant in Bedfordshire.

The 94-page report confirmed that the pair of outages had stripped almost 1,400MW of power from the energy system within seconds, and wiped out National Grid’s 1,000MW reserve.

It found that the situation had been made worse when a string of small-scale generators totalling almost 500MW had automatically shut down at about the same time because of the sudden change in the grid’s energy frequency.

Under National Grid’s existing security standards, agreed with Ofgem, it needs to hold a backup reserve only as large as the biggest power plant that is running. The rule means National Grid is likely to be unprepared for any situation in which more than one power plant trips offline, or multiple small-scale power plants trip too.

Ofgem said it would review the report as part of its investigation into National Grid’s role in the blackout. The system operator also faces an investigation from an emergency government committee.

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National Grid faces rising criticism from industry sources that it has been aware of the growing potential for a wide-scale blackout “for years” but has failed to take action quickly enough.

Steve Shine, chairman of the battery firm Anesco, said: “Our national grid is vulnerable to power cuts and is getting more vulnerable by the year. National Grid should have seen something like this coming.”

The Guardian revealed last month that the grid’s energy frequency had fallen to multi-year lows three times in the three months before the blackout. Energy experts have confirmed that the sudden drops have become more common, and could wipe out energy supply if power plants automatically disconnect as a result.

Shine said: “If they had contracted more fast-response battery storage on the network, this power cut could have been prevented. For that reason National Grid should urgently take action to encourage the building of more energy storage to support the UK’s energy security.”