Power bills may rise amid winter capacity fears

Consumers will face higher energy bills to keep the lights on this winter as National Grid puts in place plans to ensure there is spare capacity in the system.

The closure of some power stations would have left a spare capacity of just 1.2%, and the electricity company has put mothballed plants on standby and is asking some industries to be ready to power down if needed.

The contingency measures for times of peak demand will secure 2.56GW of power and boost the capacity margin to 5.1%, the National Grid assessment shows, but has cost £36 million and will add 50p to the average consumer bill.

Last year's power capacity margin was 4.1% without additional provisions, which raised the breathing space to 6.1%.

But mild windy weather, high levels of electricity imports from the continent and greater than expected levels of available power plants meant the capacity margin was "adequate", and extra help to meet demand was not needed, the report said.

This winter the margins will be tighter, the assessment found, requiring more measures to be bought to balance the system and ensure the lights stay on.

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 station 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."