Following the unexpected system outage on Friday 16 October, SSEN can confirm that a fault has been identified on the 33,000-volt subsea electricity distribution cable that connects Lewis and Harris to the Scottish mainland. Initial location testing indicates a fault on the 32km cable, which runs from Ardmore, Skye to Beacravik, Harris, around 15km from shore and in an area of deep water.
SSEN is committed to restoring the network to full operation as soon as is practicably possible. Further investigations are underway to identify the root cause of the fault, including to understand any instance of third-party damage, and to implement a restoration plan. This will establish whether a repair can be undertaken or, given the fault location, an end-to-end cable replacement is required.
There is no impact to the supply of electricity to homes and businesses on Lewis and Harris as a result of the fault. In line with established network operation procedures, Battery Point Power Station will remain in full operation for the duration of the fault alongside on-island renewable generation. Further contingency measures, including coordination of additional fuel deliveries to the power station, are in place to ensure a continued safe and secure supply of electricity.
As a result of the fault, there will be some restrictions to electricity generation export during the period. SSEN is in close contact with generators on Lewis and Harris to manage any generation constraint required and will look to minimise disruption wherever possible.
SSEN Distribution undertakes a comprehensive inspection and maintenance programme of its subsea cable assets. An end-to-end subsea survey of the Skye to Harris cable was undertaken this summer which did not identify any risk to the integrity of the network.
A further update will be provided once investigations are fully complete and a restoration plan is in place.