A series of interconnected risks, including extreme weather and the switch to renewable energy, is making Britain more vulnerable to power outages, experts have warned.
Britain has one of the most reliable electricity systems in the world, but the outdated grid faces a plethora of challenges that make the chance of power outages more likely.
Some warn blackouts could happen this winter if Europe is hit with extreme weather and say households should be prepared for it to happen.
Meanwhile, a report published this week found there are “high levels of stress and concern” amongst control room staff at the body in charge of Britain’s electricity network over the “state of the energy industry” and their ability to keep the lights on.
Could Britain run out of power?
While localised power outages happen most years, Britain has never experienced a nationwide blackout in the 76 years since the National Electricity Transmission System was established.
However, the grid is undergoing major changes as part of the transition to net zero that make managing the electricity system more challenging.
The UK’s grid was built almost 100 years ago to transport electricity generated from giant coal power stations, which behaved very predictably. Over a third of the country’s electricity now comes from wind and solar farms, which are smaller, in different locations and with an output that’s harder to forecast.
“The system is changing and that’s a risk in itself,” said Callum MacIver from the UK Energy Research Centre, however, he said this didn’t “inherently” mean there was an increased risk of power outages.
The addition of renewable power means the grid operator NESO has a more difficult job in ensuring the system remains within safe limits, but the question of whether this could lead to blackouts is hotly debated.
A number of whistleblowers within NESO contacted the Shadow Energy Secretary Claire Coutinho following an incident during June’s heatwave when the electricity system fell below its normal operating range.
This was due to a series of issues including high demand, low wind generation and reduced capacity from gas power stations.
Whistleblowers claimed they were instructed to hide how close Britain came to a widescale blackout, however, an independent investigation published this week did not substantiate the allegations. The investigation did, however, find that control room staff have concerns about their ability to keep the lights on.
What is the risk this winter – and how can households prepare?
NESO has said it is confident in its ability to avoid blackouts this winter, but admitted there will be “tight” days, particularly in January, when it will need to activate measures such as asking generators in the UK and abroad to provide additional energy.
Andrew Larkins, an energy consultant and former Ofgem adviser, said it is possible the UK could experience power outages if a number of things all went wrong at once.
“If there is a long cold spell with little wind, conditions could get very tight in terms of supply and demand,” Larkins said. This is because cold weather drives up demand while a lack of wind would reduce the UK’s renewable capacity.
“Then what it takes is to have a major fault on maybe one of the large power stations, or one of the large transmission lines,” he said.
While a nationwide energy shortage remains unlikely, the likelihood of local outages due to extreme weather is increasing. Thousands of homes were without power across Cornwall and Devon on Friday due to Storm Austen.
Storms remain one of the main causes of power outages in the UK; over three million customers lost power in the winter of 2024/25 due to Storms Darragh and Éowyn.
Britain’s electricity network is also increasingly exposed to flooding; research by the Committee on Climate Change has found 22.1 per cent of the electricity infrastructure is currently at risk of flooding and this is expected to increase to 25.9 per cent by 2040.
Heatwaves, storms and flooding are all happening more frequently in the UK due to climate change, meaning the UK’s electricity system is more exposed to these risks.
A report published last year by the National Preparedness Commission found the UK’s energy system was facing a series of “interconnected and cascading risks”, including extreme weather, the expansion of renewables and cyber attacks.
The Government itself has said Britons should be prepared for multi-day power outages by keeping battery or wind-up torches, at least three days’ worth of bottled water and non-perishable food such as tinned fruit and meat.
The “Be Ready” campaign, which was launched this week, warned that gas ovens, boilers, mobile phones and home internet won’t work during a prolonged blackout.
It also urges people to keep a small amount of cash for essential purposes in case electronic payments or ATMs are disrupted.
Where in the UK is most exposed to blackouts?
When it comes to weather-related outages, rural areas are usually the most exposed as their power is transported by long overhead lines that can be damaged in storms.
Official data shows customers in the north of Scotland currently experience the most outages (68.9 minutes per year), followed by Yorkshire (51.2 minutes) and central southern England (51.2 minutes).
London is currently the least exposed to power outages, with customers losing an average of 10.5 minutes.
In the case of a nationwide energy shortage, the Government would order emergency power cuts on a rotating area-by-area basis, meaning there isn’t one single area that is most exposed.