A £30million project to replace one of two submarine electricity distribution cables connecting Orkney to mainland Scotland is now complete.
SSE’s networks business SSEN has installed the new 37km cable ensuring strengthened resilience of electricity supply to the islands ahead of winter.
The development involved significant offshore works using specialist marine vessels – the Normand Clipper and Global Symphony – working with principal contractor, Global Offshore, to successfully install and bury the 33 kilovolt (kV) cable between Murkle Bay, near Thurso and Rackwick Bay on the island of Hoy.
Working in partnership with Aviemore-based McGowan Environmental Engineering Ltd, the installation of the new subsea cable also allowed for the removal of approximately 7km of existing overhead power lines in Rackwick, Hoy, which have now been replaced by underground cable. The existing overhead line will be dismantled in the coming weeks.
Local firms Pentland Ferries and storage and distribution specialists McAdie and Reeve played a key role in the successful delivery of the land cable works, with a bulk cargo vessel chartered to deliver 5,000 tonnes of high specification sand to Lyness harbour, and almost 30 large items of equipment and vehicles shipped from Gills Bay to Lyness under specialist charter on Pentland Ferries’ MV Pentalina.
"The Pentland Firth East project is one of the biggest standalone projects we’ve completed in the north of Scotland and we’d like to thank our contract partners, archaeological and ecological experts, engineering teams and local suppliers for their professionalism and dedication to ensure the successful delivery of the subsea cable installation and land-based works on Hoy.
Mark Rough Director of Customer Operations at SSEN
“Ensuring a safe, secure and reliable supply of electricity to our customers is our main priority at SSEN. We’d like to take this opportunity to thank the local community for their ongoing support as we worked to deliver this significant investment which will strengthen resilience of supplies to the Orkney Islands for years to come."
"The new cable will secure Orkney’s electricity supply well into the future and I am delighted this crucially important work has been completed successfully.
James Stockan Leader of Orkney Islands Council
“In addition, I am pleased that the onshore work at Rackwick and beyond had been carried out to a very high standard in an area renowned for its wildlife and natural beauty – a challenging task undertaken with great skill and sensitivity."
SSEN is undertaking a programme of investment to replace around 90km of submarine cables connecting Scotland’s island communities by 2023 – a fifth of the total number currently in operation.
The Pentland Firth East cable was identified for replacement after routine inspections found it was coming to the end of its operational life. In July 2019, SSEN successfully completed repairs to the cable in Rackwick Bay following a cable fault. While customer power supplies were not impacted by this fault, a long-term solution was required to maintain a safe, secure and reliable power supply to homes and businesses in Orkney.