Plans progress to repair electrical cable

After a fault developed on a new £30million subsea electrical cable — one of two which connects Orkney to the Scottish mainland — the old cable which it replaced is set to be temporarily reconnected and a section of overhead lines will be reinstated in Rackwick in the interim.

There is no impact to customer power supplies as a result of the fault on the Pentland Firth East cable but contingency measures are in place including the limited operation of the backup power station in Kirkwall where required.

Scottish and Southern Electricity Networks (SSEN) Distribution has confirmed that plans are progressing to restore the network to normal operation.

Initial investigations on the subsea cable, which runs between Murkle Bay in Thurso and Rackwick in Hoy, have identified a fault around the midway point of a cable only installed in summer 2020.

SSEN will now carry out additional testing to determine the exact location of the fault and will mobilise a specialist marine vessel to carry out further investigations and instigate a restoration plan.

This plan will include the reconnection of the old cable which has returned positive test results according to SSEN. This will be used until a full restoration of the new cable can be completed.

In addition, new overhead lines will be constructed. This follows around seven kilometres of lines being removed following the successful installation of the new cable.

An SSEN spokeswoman said: “Following positive test results, plans are now being progressed to temporarily reconnect the cable until full restoration of the new cable is complete.

“This includes the construction of 1.5km of overhead line between the old and new subsea landing points in Hoy. SSEN is currently reviewing construction timescales but expects short-term works to be complete by late February 2021, subject to suitable weather conditions.”

The spokeswoman added: “There will be some restriction to electricity generation export during the period of the fault. SSEN remains committed to engaging with all generators connected to Orkney’s Active Network Management system to manage any generation constraint that may be required and will look to minimise disruption wherever possible.

“SSEN will provide regular progress updates to stakeholders throughout the period of the fault.”