Britain should have enough electricity and gas to get through winter 2026/27, according to two official assessments published on 23 October 2026.
The National Energy System Operator (NESO) forecasts an electricity margin of 5.9GW over the winter, about 9.5% above its assessment of peak demand. On the same day, the Department for Energy Security and Net Zero (DESNZ) published its gas supply risk assessment. It concludes that the gas system can still meet demand on an exceptionally cold day even if its largest single piece of infrastructure fails.
Electricity: margins similar to last winter
NESO’s Winter Outlook covers every day from 31 October 2026 to 31 March 2027 and tests 30,000 scenarios, from cold, still days with high demand to mild, windy ones. NESO says margins are broadly similar to those forecast for winter 2025/26 and higher than during the 2022 energy crisis. It credits new battery storage, wind and gas-fired power stations.
The margin is higher than in NESO’s June early view. NESO says this reflects changes to its assessment method, not a better outlook. Peak demand is expected to rise, but new capacity is expected to balance it, and supply is forecast to stay within the government’s reliability standard.
NESO warns that some cold days may still be tighter than others. On those days it may issue Capacity Market Notices or Electricity Margin Notices, which it describes as routine tools rather than a sign of risk to supply. It says it is not forecasting blackouts, and that imports over interconnectors should be available when needed.
Gas: diverse supply, but some longer-term risks
The DESNZ assessment says that in 2025 the UK used 62bcm of gas, with peak-day demand reaching 392mcm. Domestic production and Norwegian pipeline imports each provided around 40% of supply, liquefied natural gas (LNG) around 17%, and imports from Belgium and the Netherlands less than 1%.
The key test is the “N-1” standard. It checks whether supply capacity can meet demand on the coldest day expected once in 20 years after the loss of the largest single piece of infrastructure. The UK scores 103.6% for winter 2026/27; anything at 100% or above passes.
The report lists risks to watch: geopolitical instability, competition for LNG cargoes, cyber threats, severe weather and the economics of storage. It notes that the 2026 Middle East conflict did not physically interrupt UK supplies, because only about 1% of UK gas comes from the region, but it did push up prices. Many European storage sites are entering winter less full than usual. DESNZ judges the chance of a supply interruption from this to be very low, though prices could be higher during periods of stress.
Over the longer term, DESNZ is concerned that falling gas demand could make storage sites and interconnectors less profitable, even though they remain important insurance on cold days. The UK’s eight storage sites hold about 3.2bcm. The government says it is exploring possible commercial support for the sector.
What it means for households
Both reports are about having enough energy, not about what it costs. DESNZ itself notes that competition for gas can raise prices at times of stress, and wholesale prices feed through to household bills via the price cap. Our energy price cap tracker shows how the cap has moved.