The grid says electricity margins will be ‘tight but manageable’ and has asked companiesto be ready to cut output at peak times

National Grid has said it is more likely to draw on additional sources of power to keep the country’s electricity running after the chance of blackouts rose to its highest in a decade.

The operator of pipes and pylons said it had enlisted power stations to provide extra capacity and asked companies to be ready to reduce usage to help it meet peak demand.

The additional capacity means forecast requirements are manageable, National Grid said. The measures will cost the average electricity customer less than 50p a year, it added.

This years forecast capacity margin – the difference between available supply and expected peak demand – is 1.2% before the additional measures, the lowest since 2005-6. With the additional capacity included it rises to 5.1%.

In its winter report, National Grid said: “The winter view analysis has informed our procurement of additional contingency balancing reserve. These additional balancing services are in place and there is an increased likelihood we will use these tools to help us balance the system over the winter period.

“We expect electricity margins to be tight but manageable for this winter. We have procured our contingency balancing services which we may need to use in order to help us balance the system.”

National Grid has faced criticism for allowing a fall in spare capacity from a peak of 16.8% – excluding additional sources – as recently as 2011-2012. This winter it will have less breathing space after closures and reduction in output at a number of power stations.

Amber Rudd, secretary of state for energy and climate change, said: “Keeping the lights on is non-negotiable. National Grid has the right tools in place to manage the system this winter and we will ensure that they continue to do so in future.”

The solar energy industry has blamed the antiquated state of Britain’s electricity grid for preventing new connections to the system. The distribution network operator for the Midlands, south-west England and Wales has closed the grid to new large renewable projects in Cornwall, Devon, Somerset and Dorset for up to six years.

The solar sector has also criticised the government for lack of support after a series of solar panel providers going into liquidation. The government has placed a cap on the total amount of money available to renewable energy businesses as part of efforts to cut the budget deficit.

Doug Parr, chief scientist at Greenpeace, said: “Every year the National Grid say they can keep the lights on, but every winter some still say our energy infrastructure will struggle to cope.

“George Osborne needs to empower cities and towns to provide local, decentralised energy which can help provide the resilience that the country needs, alongside a smart interconnected grid and clean energy.”

Peak demand periods during the winter are expected to be weekdays between November and February. Demand will be at its highest in mid-December, and supply will be tightest in the weeks beginning 26 October and 11 January, National Grid said.

“We currently expect there to be sufficient generation and interconnector imports to meet even the tightest week,” it added.