National Grid will invest up to £400 million to extend the life of the electricity link between Britain and France until at least 2050, the company announced on Thursday 29 October, as the connection marks 40 years in operation.

What the investment will fund

The Interconnexion France-Angleterre, known as IFA, is jointly owned by National Grid and the French grid operator RTE. It remains Britain's largest subsea electricity connection by capacity and can carry enough power for around three million homes a year.

Why interconnectors matter for winter supply

The programme will upgrade technical equipment, buildings and facilities at the interconnector site. National Grid said the work would keep electricity flowing in both directions between the two countries, strengthening energy security on either side of the Channel.

Electricity has typically flowed from France to Britain through the link, but it can also run in the opposite direction when market conditions favour exports. Since the link began operating in 1986, net imports through it have totalled an estimated 409 terawatt-hours, according to the company.

Britain has 10 operational power links with France, Ireland, Northern Ireland, Denmark, Norway, Belgium and the Netherlands. Net imports through those links supplied around 9% of Britain's electricity last year, according to government data cited by Reuters.

The IFA investment forms part of National Grid's wider plan to invest at least £70 billion across the group up to March 2031. Interconnectors give grid operators flexibility to move power quickly to where demand is highest, a role that grows in importance as more wind and solar capacity joins the system.

Sources: Reuters and Offshore Energy.