Cook Strait cable work underway

Remedial work on the Cook Strait cable is under way and should be completed by early April, Transpower says.

The cable, one of three high-voltage direct current (HVDC) cables on the floor of Cook Strait, has been out of action since October 5.

Since then, the maximum amount of electricity able to be sent north through the HVDC link has been restricted to 886MW rather than the usual 1040MW.

Transpower wants the HVDC link back to full capacity before autumn inflows to southern hydro lakes begin tapering off.

The cause of the damage to the cable is not known but it is expected to cost millions to repair.