The margin between UK electricity availability and peak demand this winter is predicted to fall to a 10-year low.
In a report National Grid said the margin this year would have been 1.2 per cent had it not acted to increase supply and curb demand at peak times, which pushed it up to 5.1 per cent.
A margin of less than 1.2 per cent has not been seen since 2005-6, when it hit 0.9 per cent. The margin is calculated by taking the sum of generators declared as available during peak demand and subtracting predicted demand at that time.
Gemma Stokes, corporate media relations manager at National Grid, said: “Margins are tighter. That has got tighter over the years because a lot of power stations are closing. Demand has stayed flat but power stations have closed.”
Stokes said 25GW of power capacity had been lost from the system over the past year due to closures. However, she said doing deals with closed or closing power stations to produce energy as a last resort, and paying big users to alter their power use, would produce 2.6GW of capacity.
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.”
Last winter National Grid said peak demand hit 53.2GW, against a capacity of 70GW.
Energy minister Andrea Leadsom said: “Our priority is to ensure that British families and business have access to secure affordable energy supplies that they can rely on.
“National Grid have confirmed that our plan to power the economy is working – and it means that the lights will stay on this winter as well as making sure our homes and businesses have the gas and electricity they need in the future.”