The National Energy System Operator (Neso) has confirmed that Britain has sufficient electricity supply to meet demand throughout the upcoming winter, even as households face higher energy bills due to the ongoing conflict in Iran. In its early winter outlook, Neso forecasts a surplus of 5.5 gigawatts (GW) between the end of October and the end of March next year, representing an 8.8% buffer above peak winter demand. This margin is slightly below the forecast for 2025 but exceeds the buffers seen in previous years.
Stability Despite Geopolitical Tensions
Neso, the publicly-owned body independent of government, is responsible for balancing electricity supply and demand to prevent blackouts. Its modelling, which stress-tests thousands of scenarios involving electricity demand, weather conditions, and generation, indicates that Britain’s electricity system will remain stable this winter. Despite the energy shock from the Iran war, reserves are expected to be higher than during the 2022 energy crisis, when the surplus was smaller.
The UK sources most of its liquefied natural gas (LNG) from the US, with minimal imports from the Middle East. Additionally, domestic energy supplies from the North Sea and renewable sources such as wind and solar power contribute to the buffer. Increased battery storage capacity and new gas-fired power generation are also expected to help meet peak demand.
Impact of Iran War on Household Bills
However, Neso noted that gas prices for winter are more volatile than in recent years due to the conflict in the Middle East and the effective closure of the Strait of Hormuz, a key international transit route. 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 lead some households to reduce electricity usage, as seen after the 2022 energy crisis following Russia’s invasion of Ukraine, though this trend is not currently forecast.
Potential for Tight Days
Neso cautioned over the potential for “tight days” when energy demand is high, particularly during cold snaps when more people heat their homes. This could necessitate system notices, which inform the energy industry that supply has not matched demand, allowing for increased production if needed. Early data suggests these tight 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.”
