Stay informed with free updates
Simply sign up to the UK energy myFT Digest — delivered directly to your inbox.
Britain’s electricity grid operator will pay households to reduce electricity usage on Wednesday evening, marking the return of a system introduced at the height of the energy crisis last winter.
National Grid ESO on Tuesday said it would activate its voluntary “demand flexibility service” between 5pm and 6.30pm on November 29 as it warned electricity supply margins were “expected to be tighter than normal”.
It refused to give a reason for the intervention but analysts pointed to expected high demand for electricity as temperatures drop across the country combined with low wind speeds, which will reduce the output from wind farms that can supply more than half the UK’s electricity in blustery conditions.
“It’s cold, dark and the wind isn’t blowing in north-western Europe,” said Tom Edwards, senior modelling consultant at Cornwall Insight, the consultancy.
Britain regularly imports power from continental Europe when supply is tight, particularly from France, but Edwards added power prices indicated demand would be high there as well on Wednesday evening.
National Grid said the activation of the flexibility service on Wednesday evening did “not mean electricity supplies [were] at risk and people should not be worried”.
It added: “These are precautionary measures to maintain the buffer of spare capacity we need.”
National Grid introduced its demand-flexibility service last year ahead of the winter to try to cope with tight power supplies after France’s fleet of nuclear power stations was hit by unexpected outages. There were also concerns gas-fired power stations could struggle to get enough fuel because of cuts in supplies from Russia following its full-scale invasion of Ukraine.
The service was activated twice last winter, excluding multiple test events. Heading into this winter, France has resolved many of the issues affecting its nuclear fleet, while fears about gas supplies have also eased.
There is no set rebate for participating households with each supplier able to decide how much to reimburse customers. The amount National Grid pays suppliers is established via competitive tenders although during tests it was set at £3 per kilowatt-hour.
Over the longer term, National Grid is seeking to encourage behavioural changes among customers to become more flexible about when they use electricity to help them manage the system as a greater proportion of power supplies comes from intermittent wind and solar farms.
Electricity supply and demand has to be constantly matched to keep the grid balanced and avoid blackouts.