Cliff Notes
- Britain faces the lowest winter power blackout risk in six years, attributed to augmented battery capacity and a new subsea electricity cable to Ireland.
- A record 54.5% of electricity in Britain came from renewables in recent months, significantly lowering reliance on volatile fossil fuel markets.
- While supply margins have improved, the National Energy System Operator warns of potential “tight” days, particularly in December and January.
Britain’s winter blackout risk the lowest in six years – but ‘tight’ days expected | Money News
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Britain is at the lowest risk of a winter power blackout than at any point in the last six years, the national electricity grid operator has said.
Not since the pre-pandemic winter of 2019-2020 has the risk been so low, the National Energy System Operator (NESO) said.
It’s thanks to increased battery capacity to store and deploy excess power from the likes of windfarms, and a new subsea electricity cable to Ireland that came on stream in April.
The margins between expected demand and supply are now roughly three gas power stations greater than last year, the NESO said.
It also comes as Britain and the world reached new records for green power.
For the first time, renewable energy produced more of the world’s electricity than coal in the first half of 2025, while in Britain, a record 54.5% of power came from renewables like solar and wind energy in the three months to June.
More renewable power can mean lower bills, as there’s less reliance on volatile oil and gas markets, which have remained elevated after the invasion of Ukraine and the Western attempt to wean off Russian fossil fuels.
“Renewables are lowering wholesale electricity prices by up to a quarter”, said Jess Ralston, an energy analyst at the Energy and Climate Intelligence Unit (ECIU) thinktank.
In a recent winter, British coal plants were fired up to meet capacity constraints when cold weather increased demand, but still weather conditions meant lower supply, as the wind didn’t blow.
Those plants have since been decommissioned.
But it may not be all plain sailing…
There will, however, be some “tight” days, the NESO said.
On such occasions, the NESO will tell electricity suppliers to up their output.
The times Britain is most likely to experience supply constraints are in early December or mid-January, the grid operator said.
The NESO had been owned by National Grid, a public company listed on the New York Stock Exchange, but was acquired by the government for £630m in 2023.