National Grid warns of lower winter power capacity

National Grid has warned that its capacity to supply electricity this winter will be at a seven-year low due to generator closures and breakdowns.

Spare electricity capacity, which ran at about 5% over the winter months last year, would be nearer 4% this year, National Grid said.

Three years ago the margin was 17%.

But National Grid said it has contingency plans in place to manage supply, including paying big firms to switch off on cold winter evenings.