The interconnector between Northern Ireland and Scotland suffered a fault on Saturday that may take six months to repair.
Mutual Energy, the firm that operates the link, said that initial investigations suggested a cable fault in offshore waters 140m deep. As a result, the Southern Cable has been disconnected and the interconnector is running at half of its 500MW capacity.
The company said it was too early to determine whether the cable had been damaged by marine activity, but in the meantime, was sourcing resources – including specialist vessels and contractors – to fix the problem. It said a typical seabed repair could take six months.