On Monday evening, Britain’s grid operator paid the Langage gas power station near Plymouth the equivalent of £1.4 million an hour, according to market transparency data cited by the Telegraph, as low wind output ran into a third day.
The National Energy System Operator (Neso) was paying around £1,500 per megawatt hour to at least three gas plants to cover the evening peak, about 10 times the average. Langage, Rye House in Hertfordshire and Seabank near Bristol collected similar sums between 3:30pm and 5pm. At that rate, 90 minutes at Langage comes to roughly £2.1 million.
Neso issued an electricity margin notice at 7:17pm on Sunday for the 6am to 11am window on Monday, flagging a 1,388 MW shortfall against a 808 MW contingency requirement and asking generators to say what extra capacity they could bring. After a 4am review the shortfall was cut to about 500 MW, the Guardian reported, and the notice was withdrawn Monday morning. Neso called it “a routine and precautionary measure” and said, “This is not a warning of power cuts, there is no risk to customer electricity supplies.”
Notices like this have become far more common with seven issued so far this year, against one for the whole of 2025, the Telegraph reported. They were once reserved for cold winter evenings. One on Sept. 28 flagged a 1,400 MW shortfall between 4pm and 7pm that was later cut to 104 MW and cancelled, and another on Oct. 6 had the margin falling 1.88 GW.
A Neso spokesman said the number of notices “can vary significantly from year to year and there have been comparable periods of EMN use in the past,” calling them “a routine operational tool.”
Energy analyst Kathryn Porter, quoted by the Telegraph, said a notice for a Monday morning was “unusual.”
“EMNs normally cover the evening peak, not the morning,” she said. “The question is, what happens if the modest wind recovery forecast for tomorrow evening is delayed, or if demand is higher than forecast – given the size of Neso’s forecast errors, when margins are this thin there could be trouble.”
In fact, the bill for a bad day can run far higher than Monday’s.
When a margin notice hit in January 2025 with a 1,700 MW shortfall, Neso paid up to £5,750 per megawatt hour to the gas-fired Rye House and Connah’s Quay plants, and about £17 million went to gas responders through the balancing mechanism, Solar Power Portal reported. Octopus Energy founder Greg Jackson called it “another example of our malfunctioning energy system,” and the company urged Neso to “pay people, not power plants.”
Shadow Energy Secretary Andrew Bowie said: “With barely any wind, it’s gas keeping Britain’s lights on.
Yet Labour is now legislating to ban new North Sea oil and gas exploration licences.” He added: “We need gas, but Labour would rather we import it than produce our own.”
The Nuclear Industry Association’s Tom Greatrex used the episode to say “Britain cannot afford to lose its nuclear capacity.”
Neso’s own early outlook for this winter puts the de-rated margin at 5.5 GW, or 8.8% of peak demand, and expects “some tight days, mainly in mid and late January, that could require the use of system notices.”
