Britain is set to have sufficient electricity to meet demand throughout the upcoming winter despite households grappling with increased energy costs following the Iran war, according to the national energy system operator.
However, the National Energy System Operator (Neso) issued a caution regarding “tight days” that could arise during potential cold spells over the winter months.
Its early winter outlook predicts a surplus of 5.5 gigawatts (GW) within the electricity system between the end of October and March next year.
This projected surplus represents an 8.8% buffer against peak winter demand.
While this margin is slightly lower than the forecast for 2025, it surpasses figures from preceding years.
Neso, an independent, publicly-owned body, is responsible for ensuring a consistent balance between electricity supply and demand. Failure to maintain this balance could lead to the risk of blackouts across the country.
Neso said its modelling – which stress-tests thousands of scenarios based on electricity demand, weather conditions and generation – shows that Britain’s electricity system is expected to remain stable this winter.
Despite the recent energy shock from the Iran war, reserves are expected to be higher than during the 2022 energy crisis, when there was a smaller surplus.
This is because the UK gets most of its liquified natural gas (LNG) from the US and little comes from the Middle East, while Britain also gets energy supplies from the North Sea and renewable sources like wind generation and solar power.
Increased battery storage capacity and new gas-fired power generation is also expected to help meet peaks in demand.
However, gas prices for winter are more volatile than in recent years following the conflict in the Middle East and the effective closure of the Strait of Hormuz, a key international transit route, Neso said.
This means that the main impact of the crisis will be felt in household bills, with Ofgem’s energy price cap rising by 13% from July 1.
Higher prices could mean that some households use less electricity to combat bigger bills, which was seen after the 2022 energy crisis following Russia’s invasion of Ukraine, but this is not currently being forecast.
Neso instead cautioned over the potential for “tight days” where demand for energy is high, particularly during cold days when more people want to heat their homes.
This could require the use of system notices, which are how the grid operator informs the wider energy industry that electricity supply has not matched demand, allowing for production to increase if needed.
Early data suggest that these days are most likely to occur in mid- to late-January 2027.
Deborah Petterson, director of whole energy system resilience at Neso, said: “This has been a year of turbulence in energy markets and geopolitical uncertainty, however Great Britain’s electricity system has a strong track record of reliability.
“This early view shows a positive picture for the months ahead, with sufficient electricity margins expected throughout winter.
“While we will continue to monitor global energy markets, households and businesses can be confident that electricity supplies remain secure.”
