Will there be power cuts in the UK this winter?

The short answer for winter 2026/27

Nationally, no. NESO — the National Energy System Operator, which balances Britain's grid — published its full Winter Outlook in October and expects Britain's electricity supplies to remain secure through winter 2026/27, with a de-rated margin of 5.9 GW, a 9.5% buffer over expected peak demand. It says there may still be tight days when it uses its standard tools, including system notices, most likely in December or January outside the Christmas period.

Locally, yes — there always are. The power cuts that actually reach households are caused by weather damaging the local network: a tree on an overhead line, ice on a cable, a flooded substation. Those are the cuts worth preparing for, and they have nothing to do with whether the country has enough generation.

What to have ready

The government's own list for a power cut is short. A torch for every person rather than candles (a head torch leaves both hands free), a battery or wind-up radio for updates when the mobile network is down, a charged power bank so your phone can reach 105, and warm layers and blankets because the heating goes off with the lights.

Keep the fridge and freezer doors shut: our food safety in a power cut guide has the Food Standards Agency's time limits. Save 105 in your phone now, and know where your fuse box is so you can tell a trip from a cut. Our power cut preparation guide walks through the rest, room by room.

Where the power cuts actually come from

Look at our live power-cut tracker on any given day and you will see dozens of small local faults being fixed, and after a named storm you will see tens of thousands of homes off supply at once. That is the real pattern. The storm names and weather warnings trackers are a better predictor of a power cut at your address than anything NESO publishes.

Most cuts are restored within hours. Rural homes on long overhead lines wait longer, and after a major storm the last properties can be off for days while crews work through the damage. Your electricity network operator — not your supplier — fixes the fault, and 105 reaches them free from any phone in England, Scotland and Wales.

If your power is off for a long time, you may be owed compensation by your network operator: our compensation guide has the current figures and how to claim, and the calculator works out what you may be owed.

Power stations and generators: who actually needs one

Most households do not. A charged power bank keeps phones alive through the longest realistic cut, and that is the item that matters. A portable power station earns its price in three situations: powered medical equipment at home, working from home in an area that loses power often, or a rural property on a long overhead line where multi-day cuts are a known risk. Outside those, it is a comfort purchase, and it is fine to say so.

Petrol generators are a different category of risk. They run outdoors only, well away from doors and windows, because carbon monoxide from a generator in a garage or conservatory kills people every winter. If you are considering one, read our generator safety guide first.

If someone at home relies on electricity

If anyone in the house depends on powered medical equipment, is older, disabled or has a young baby, sign up to the Priority Services Register. It is free, you register through your energy supplier or network operator, and it gets you advance notice of planned work and priority help during a cut. Our energy bill help hub explains who qualifies and how to register.

For medical equipment specifically, talk to the network operator in advance about what they can provide during a long cut, and keep the equipment's own battery back-up charged and tested.

What NESO's numbers mean

The de-rated margin is the gap between the electricity the system can realistically count on at the coldest, darkest, stillest moment of the winter and the demand it expects at that moment. It is de-rated because not every power station or wind farm can be assumed to be running; the figure already discounts for that. NESO describes margins at that level as adequate, within the Reliability Standard and comparable to recent winters (last winter's was 6.1 GW, 10.0%). The 5.9 GW comes from a new modelling method: on its old method, the like-for-like figure is 5.2 GW (8.4%), against the 5.5 GW (8.8%) in its June early view, so part of the rise since June is the method rather than a change in the system.

When margins tighten — a cold, still evening in January when the wind drops — NESO can issue a notice asking generators to make more capacity available. Those notices make headlines, but they are a routine tool for keeping the margin healthy, not a warning that the lights are about to go out. NESO usually flags a tight evening to the industry from the day before or several hours ahead, so the market has time to respond, as it did on 28 September and 6 October.

The most recent notice came on Tuesday 6 October 2026. At 11:55pm on Monday 5 October NESO issued an Electricity Margin Notice for 3pm to 11pm on the Tuesday, saying it was 1,840 megawatts (MW) short of the spare capacity it wanted above expected demand, with 750 MW of generation left out of its count because of system constraints. The expected gap was 1,880 MW at its 6:45am update, 679 MW at 12:55pm, when the window was shortened to 4pm to 11pm, and 321 MW at 2:15pm. At 3:45pm, before the 4pm window opened, it cancelled the notice.

A NESO spokesperson said there was no risk to customer electricity supplies, that this was not a warning of power cuts and that customers did not need to take action (reported by Yahoo Finance UK and Energy Live News, 6 October). Oilprice.com, citing Elexon data compiled by Bloomberg, reported that wind output that day was expected to be about a quarter of this year’s average so far. When we checked on 9 October NESO’s news page had no fuller account of what constrained the system.

The one before it came on Monday 28 September 2026. Just after midnight NESO issued an Electricity Margin Notice for 4pm to 7pm, saying it was 1,400 MW short of the spare capacity it wanted above expected demand, with 1,900 MW of generation left out of its count because of system constraints. At its noon update the expected gap was 104 MW, and shortly afterwards NESO said the industry had responded. At 3pm, before the 4pm window opened, it cancelled the notice. In posts on X it said there was no risk to customer electricity supplies, that this was not a warning of power cuts and that customers did not need to take action. It was reported as “Britain’s electricity grid operator cancels call for power” (PA) and “Neso issued electricity margin notice for GB grid, before later cancelling it” (New Civil Engineer). By the morning of 29 September NESO had not published a fuller account of what constrained the system that day.

Margin notices in winter are rare. The system operator’s own reviews record no Electricity Margin Notices in winter 2023/24, one in 2024/25 (for 8 January 2025) and none in 2025/26. This year they have come outside winter instead: the 28 September notice was the fifth since June, after notices for 24 and 26 June, 9 July and 12 August, each later cancelled; the one on Tuesday 6 October, also cancelled, was the sixth. The Elexon record shows none between April and September in 2023, 2024 or 2025. In its June early view NESO said there may be days this winter when it needs system notices like these, most likely in mid-to-late January, and that it expects margins to be adequate and within the reliability standard; its full Winter Outlook, published in October, says such days are most likely in December or January, outside the Christmas period. For households nothing changes: a margin notice is a message to the electricity industry, and the preparation that matters is for local cuts.

The honest summary is that the national picture is a reason to watch the weather forecast, not the grid.

For the gas side, and Ofgem’s October stress test, see is the UK’s gas and electricity supply OK this winter?.