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. But National Grid said it has contingency plans in place to manage supply, including paying big firms to switch off on cold winter evenings. Since 2012, 15 power plants have been closed or partially closed, taking out a large chunk of the UK’s energy-generating capacity.