National Grid PLC (LSE:NG.) (National Grid PLC (LSE:NG.)) has warned of possible three-hour power cuts if Russia cuts off gas supplies and Britain experiences a cold snap.
The company said it was cautiously confident there would be enough electricity to meet the demands of businesses and consumers this winter.
But in the "unlikely event" of a shortage of gas, it said some consumers could be without power for certain periods of the day to “ensure the overall security and integrity of the electricity system across Great Britain”.
Jess Ralston, senior analyst at the Energy and Climate Intelligence Unit said: “Last year the grid stood solid during the winter, but the gas crisis has changed the outlook this year because there is still a large unknown around how high the gas price will go and what will be available...
"Had investment in energy efficiency and onshore wind gone ahead over the past few years, we’d be much more certain about meeting demand. Every spin of a wind turbine and loft lagged means less gas we need to try to buy."