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.
Customers taking part will be given 24 hours’ notice of a “test” day where they will be asked to reduce their peak-time electricity use if they can during a one-hour period identified by National Grid, likely to be between 16:00 and 19:00.
That could include delaying use of a tumble-dryer or washing machine, or cooking dinner in the microwave rather than the oven.
National Grid said it will pay energy suppliers, which will be required to sign up to the scheme to operate it for customers, £3 for every kilowatt-hour during the test periods.
Individual suppliers will decide how much customers will receive and whether the money is taken off bills, credited to accounts, or if there’s an option to withdraw the cash.
National Grid is testing the idea, which it calls its “Demand Flexibility Service” at scale for the first time, to establish a system that can serve as an “insurance policy” if it needs to ease demand on the grid this winter.
Households have been warned of power cuts lasting up to three hours at a time if gas supplies run extremely low, and National Grid is hoping the new scheme can, along with other measures, prevent that happening.
The electricity network operator said the service had been approved by the UK’s energy regulator Ofgem, which meant electricity suppliers and providers could sign up and then advertise the scheme to customers.
It is understood many of the UK’s larger energy firms are looking to take part in the trial, after being consulted in recent months on how it would work.
The scheme is also open to businesses which could, for example, change production schedules or switch to batteries or generators at peak times.