A major project connecting Shetland to the the National Grid on the UK mainland is said to have reached its “final milestone” following the appointment of its main contractors.
Scottish and Southern Electricity Networks (SSEN) Transmission, which is leading on the interconnector project, made the announcement today (Monday) following Ofgem’s final approval last week.
SSEN said everything was now in place to start main construction later this month.
The link, which will connect Shetland to the GB transmission system for the first time, is integral to the 103 turbine Viking Energy wind farm project as well as the emerging proposals for a Shetland Energy Hub.
Both projects require a connection to the National Grid to export energy generated in Shetland.
It has also been welcomed by the oil and gas energy as a means to provide a secure supply of energy for offshore installations in the Shetland area.
However, it has attracted a considerable opposition from those concerned about the impact of the Viking wind farm on Shetland’s landscape. Aquaculture businesses have also raised concerns about the project’s impact on its operations near the coastal connection in Shetland.
The project consists of a substation at Kergord, which is required for the connection of renewable electricity generators on Shetland. These works will be led by Siemens BAM, which has extensive experience constructing substations on behalf of SSEN Transmission across the north of Scotland.
The power will then be converted from AC to DC at a HVDC converter station, also at Kergord, before being transported around 270km via underground and subsea cable to a switching station at Noss Head, Caithness, in the north of Scotland. Global marine cable solution provider, NKT, will be responsible for the manufacture and installation of the subsea cable; with BAM Nuttall delivering all civil engineering works, including the construction of all buildings. Leading HVDC technology provider, Hitachi ABB Power Grids, will be delivering and commissioning the HVDC system.
The power will then be transported via the Caithness Moray HVDC link before being converted back to AC for transmission across the north of Scotland and beyond.
All four contractors played a major role in the construction of the Caithness Moray HVDC link, which has been operational since January 2019.
Enabling works are due to begin at Kergord and Noss Head towards the end of August, with full construction of the AC Substation, and HVDC Convertor and Switching Stations, due to commence in early 2021. The subsea cable installation will take place in 2022 and 2023.
Sandy Mactaggart, SSEN Transmission’s director of offshore delivery, said: “We are delighted to have finalised contracts with our supply chain partners for the Shetland HVDC link, building on the experience and strong track record we have collectively established over recent years following the construction and operation of the Caithness Moray link.
“All four contractors are leading specialists in their field, building the high quality and reliable infrastructure required to meet Shetland’s future energy needs and contribute to UK and Scottish net zero targets.
“The Shetland HVDC link will deliver substantial socio-economic and environmental benefits to Shetland’s, Scotland’s and the UK’s economy, supporting hundreds of skilled jobs in the process as part of the green recovery from the coronavirus pandemic.
“With all major milestones complete, we now look forward to working closely with the Shetland and Caithness communities and other stakeholders throughout the construction and future operation of these critical national infrastructure assets.”
All construction works are scheduled to be complete in December 2023, with energisation and full commissioning due to be complete in July 2024.
At its peak, in the summer of 2022, the project is expected to employ almost 250 people.