Britain’s electricity supplies will be at their tightest level in a decade this winter, forcing the country to rely on emergency measures to ensure the lights stay on, according to official forecasts.
The closure of three power stations has increased the risk of blackouts since last winter, new analysis by National Grid shows.
The ‘safety buffer’ margin between peak winter electricity demand in and the output from Britain’s ageing power stations is likely to fall to just 1.2 per cent – down from 4.1 per cent last year, it finds.
But an emergency system of backup power plants, first introduced last winter, will be in place again this year to help prevent blackouts, the company said.
Even with the backup plants in place, the effective spare margin last winter was 6 per cent and this year will fall to 5.1 per cent – the lowest since 2007-08, Grid data shows.
The backup power plant operators will be paid £37 million to guarantee they can fire up if needed in an emergency, and more if they are actually called upon.
Cordi O’Hara, National Grid’s director of market operation, said: “It’s clear that electricity margins for that coldest, darkest half hour of winter are currently tighter than they have been, due to power stations closures.
“As system operator, we feel we’ve taken a sensible precaution again this winter to buy some extra services. Together with the tools we already use to balance the network these additional services will significantly increase the energy reserve available this winter.”
The backup measures were not needed last winter because the weather was particularly mild, National Grid said.
Peter Atherton, analyst at Jefferies, said: “The underlying position of the network is becoming more and more fragile, which is requiring more emergency measures. Only three or four things could go wrong and we would have a serious problem.
“The reason we have this issue is that the new build [power plant] programme is running late and the closure programme is running to time.”
New solar farms had been built but that was “not useful on a dark winter evening”, he said.
Experts have also questioned how much wind can be relied upon, with some of the coldest periods of last winter coinciding with the lowest wind power output.