The fire-damaged power link between the UK and France, known as the IFA interconnector will not be fully restored for another two years.
A key substation at Kent was left damaged by a fire in September. It forced the shutdown of one of the most important power cables, which brings electricity from France to the UK.
National Grid said: “Following a detailed assessment on the 1,000MW of capacity that is offline due to damage caused by a fire at our site in Sellindge in September, we need to carry out extensive work to safely return it to service.
“We will bring 500MW back to service from October 2022 through to May 2023.”
The company added that will result in 1,500 of available capacity going into next winter.
It will then be able to undertake further work to bring the full 2,000MW back by October 2023.
However, National Grid said that it has been able to reduce the outage time of 1,000MW of capacity at the IFA interconnector so that it will come back to service three days ahead of its previously published plan: “We are completely focused on getting IFA safely returned to service as soon as possible and ensuring we are able to support the security of supply.”