Households will be offered discounts on their electricity bills if they cut peak-time use on a handful of days over the winter, as part of National Grid’s efforts to avoid blackouts.
The network operator has announced details of the scheme, which it said could save households up to £100.
There will be 12 “test” days initially, designed to see how customers respond, between November and March.
But only homes with smart meters will be able to take part.
Only 14 million, less than half, of households in England, Scotland and Wales, where the scheme is being tested, have a smart electricity meter installed.