SSEN Transmission gets to work on HVDC Switching Station in Caithness

SSEN Transmission and its principal contractor for all civil works, BAM Nuttall, will begin construction of the Caithness HVDC Switching Station on the 30th of November; marking a key milestone for the Shetland HVDC project.

Once complete the Caithness HVDC Switching Station will play a key role in facilitating the connection of renewable energy from Shetland to the GB transmission system via a 250km subsea cable. The switching station at Noss Head will allow the flow of electricity to be managed between three underground HVDC circuits - one from a converter station at Spittal in Caithness, one from a converter station at Kergord in Shetland and one to a converter station at Blackhillock in Moray. Making it possible to take the energy from where it is generated to where it is needed.

The Direct Current Switching Station (DCSS), is the first of its kind to be built in Europe, making this a landmark occasion for SSEN Transmission, its contractors and for the Caithness region. This is the second time within the last 5 years that Caithness has been at the forefront of HVDC technology development, with the Spittal HVDC converter station going on-line in December 2018.

Over the next couple of months, the team will be focusing on the initial civil engineering which will involve the creation of a new access tracks and a haul road to the site, as well as setting up a temporary site compound and welfare facilities. Once the early enabling works are complete the team will focus on site drainage, minor watercourse diversion work and the installation of environmental mitigations, ahead of commencing the general earthworks early next year.

There will also be activity in the area off site as work commences on the undergrounding of sections of existing overhead power lines in the area in January. This activity is scheduled to be complete in Spring 2021

Lead Project Manager, Fionán Doonan, said

“The Caithness Switching station is a key component of the Shetland HVDC project, enabling up to 600MW (MegaWatts) of clean renewable energy to connect to the grid. Once complete it will play a key role in facilitating the transition to net zero emissions.

We have been working hard over the last couple of months to prepare for construction, and we are delighted that work will soon be getting underway. We have also been working closely with the local supply chain ahead of the commencement of work on the project, opening up contract opportunities for local companies.

As a responsible developer, we will continue to work closely with the local community throughout the construction phase to ensure we actively mitigate any impact of construction activities and minimise disruption where possible.”

The Shetland HVDC link is being delivered in partnership with SSEN Transmission’s supply chain partners, all leading specialists in their fields of expertise. Siemens BAM are responsible for all traditional substation works; global marine cable solution provider, NKT, will be responsible for the manufacture and installation of the subsea cable; BAM Nuttall will deliver all civil engineering works, including the construction of all buildings; and leading HVDC technology provider, Hitachi ABB Power Grids, are responsible for delivering and commissioning the HVDC system.

To find out more about the Shetland HVDC link project, please visit https://www.ssen-transmission.co.uk/projects/shetland/