Scottish and Southern Electricity Networks (SSEN) has submitted marine license applications to Marine Scotland to replace three subsea power cables connecting mainland Shetland to the islands of Yell and Unst.

The new submarine cables - one from Mossbank to Yell and two between Yell and Unst - will replace existing cables which are now nearing the end of their scheduled functional life. This will ensure the continued safe, reliable and robust supply of electricity to homes and businesses across the Shetland Isles.

The proposed replacements to install 33 kV electricity cables would involve the submarine cables being laid across the surface of the seabed, with rock filter bags or concrete mattresses placed on the cable at roughly 50m intervals for stability. There would also be underground cabling at the existing shore ends, where the new cables would then join the existing overhead line network. On Unst, this new cable will also allow the dismantling of some sections of existing overhead line.

As a responsible network operator, Scottish and Southern Electricity Networks has proposed to schedule the installation to minimize disruption on local marine life, with the works planned to avoid the key breeding seasons for local seals and key bird populations. This approach will reduce risks to the marine life and birds, protect natural habitats as well as helping to provide a cost-effective power network across the islands.

Kirstine Wood, Lead Engagement and Submarine Policy Manager at SSEN, said, “We are committed to doing all we can to provide our customers with a safe, secure and reliable supply of electricity, and this proposed work is an essential part of our commitment. These cable replacements are essential for securing the power supplies to the islands of Yell and Unst and will also support the security of supply to the neighbouring islands”.

Until 2023, around 90 km of submarine cables connecting Scotland’s island communities will need to be replaced - a fifth of the total number currently in operation. The full proposal can be viewed at a number of venues in Shetland, including the library in Lerwick and on the SSEN website at:

Any comments on the proposal should be submitted directly to Marine Scotland by 13 July.