SSEN Transmission has started main construction of the Lewis Hub project, a central part of the interconnector that will link the Scottish Western Isles to the UK national electricity transmission network for the first time.
The groundbreaking, which marks the project’s progression from initial site preparation into main construction, was held on November 5 at the Lewis Hub site at Arnish Moor near Stornoway.
Lewis Hub will comprise a high-voltage direct current (HVDC) converter station and AC substation and will form a central part of the wider Western Isles HVDC Link.
The 1.8 GW interconnector will consist of approximately 83 kilometers of underground cable and 81 kilometers of subsea cable, connecting the Lewis Hub HVDC converter station and AC substation on the Isle of Lewis to the mainland.
In the same week the groundbreaking took place, Highlands-based civil engineering contractor RJ McLeod signed a contract to deliver the first major package of construction works that will prepare the site for the HVDC converter station, AC substation and associated infrastructure.
“Breaking ground on the Lewis Hub is a hugely significant moment for the project and for the Western Isles. A direct connection between the Western Isles and the main GB transmission network has been an ambition for decades. Through the Lewis Hub and wider Western Isles Connection, we are now turning that ambition into reality, unlocking the islands’ vast renewable energy potential and strengthening the electricity network for generations to come,” said Sandy Mactaggart, Director of Offshore Delivery at SSEN Transmission.
“But our ambition is about much more than delivering new infrastructure. We want this investment to create a lasting legacy for the islands, supporting local infrastructure, developing skills and creating opportunities for local businesses, while working with key partners to find mutually beneficial solutions that support long-term economic growth.”
The Western Isles HVDC Link is a key component of SSEN Transmission’s planned £22 billion investment program to upgrade the north of Scotland’s electricity transmission grid.
The Scottish Government Marine Directorate at the beginning of 2026 granted the variation to the existing marine license, approved in 2021, for the subsea cable link, greenlighting the needed increase in capacity.
Hitachi Energy is delivering the HVDC converter stations for the project and NKT the power cable system.
“We are proud to support SSEN Transmission by delivering the complete 525 kV HVDC power cable system, covering design, production, installation and testing across the onshore and offshore sections,” NKT said. “This is the scale of infrastructure needed to turn renewable energy potential into a more secure and interconnected power system. We are proud to be part of Western Isles and look forward to the milestones ahead.”
According to SSEN Transmission, the Lewis Hub project is expected to support more than 70 apprenticeship and trainee opportunities and is already delivering wider benefits to the local community, with a £1.06 million (approximately €1.27 million) Lewis Hub Local Fund due to launch soon.
Together with future local funds associated with proposed transmission projects in the Western Isles, the fund is expected to contribute to more than £5 million in community benefit funding, subject to the relevant projects securing consent and progressing to main construction.
