Blackout prevention system mobilised as Britain battles low winds
A backstop system designed to prevent blackouts was mobilised for the first time in two years as Britain’s power grid battles low winds and nuclear outages.
The surprise notice for the capacity market, which issues a warning to Britain’s electricity generators, was issued by the National Energy System Operator (Neso) just after midday on Monday.
It told generators to be ready for when demand spikes at 4:30pm, amid fears the amount of spare power capacity had grown unacceptably small compared to demand.
However, the notice was withdrawn just after 2pm.
A spokesman for the Neso insisted it was “confident that electricity margins are sufficient for this evening” and stressed the triggering of the original notice was automatic.
The warning was the first of its kind since November 2022, when a similar notice was also issued and withdrawn as low wind speeds and nuclear power outages piled stress on the electricity system.
Moments after the notice was issued, the Neso insisted it was “confident that electricity margins are sufficient for this evening” and stressed the notice was automatic.
The warning was the first of its kind since November 2022, when a similar notice was issued but later withdrawn as low wind speeds and nuclear power outages piled stress on the electricity system.
Kathryn Porter, an independent energy analyst at Watt Logic, said the likely causes this time around were lower-than-expected wind output, as well as greater-than-expected demand for electricity.
At the same time, publicly available data showedthe grid was expecting power to be flowing out to Europe via interconnectors on Monday evening, suggesting the Neso might have had to intervene to ensure power flows into the UK instead, she added.
The warning also comes after the Sizewell B nuclear power station, in Suffolk, was temporarily shut down for refuelling on Friday.
The 1.2 gigawatt site is not expected to return to full capacity until December, according to owner EDF.
Ms Porter said: “What [the Neso] is saying is that the electricity market is looking tight.”
On Monday at 12.30pm, grid data showed that gas power stations had been fired up to meet roughly 53pc of the country’s electricity needs, with wind and solar providing just 10pc each.
In a statement, the Neso said: “Neso is confident that electricity margins are sufficient for this evening. However, a capacity market notice (CMN) has been triggered by the automated system.
“CMN forecasts are issued automatically and are only based on information in the public domain. They do not take into account all the factors which our engineers are working on.
“A CMN is a standard tool used to remind capacity market providers of their obligations.”
But Tom Greatrex, chief executive of the Nuclear Industry Association, warned that the notices risked becoming more commonplace as Britain’s ageing nuclear power stations were switched off this decade.
On current schedules, the Hartlepool and Heysham 1 nuclear power stations are due to be retired in March 2026, followed by Heysham 2 and Torness in March 2028.
EDF has said short lifetime extensions may be possible but no decisions have been made yet.
Of those currently in use, only Sizewell B is currently due to stay online beyond 2030.
Hinkley Point C, the only new nuclear power station under construction, is not expected to come online until 2030 at the earliest.
Mr Greatrex said: “This warning shows we are grappling with the reality of our nuclear power stations retiring without replacements and underscores why we need new investment urgently to build new nuclear power plants alongside lifetime extensions of the current nuclear fleet.
“Without fresh investment and decisions on new nuclear projects at Sizewell C and Wylfa as well as small modular reactors, these warnings will become more commonplace and we will have to continue relying on volatile gas markets to fill the gaps in supply, threatening out energy security and driving up bills and emissions.”