SSEN Transmission plans to begin onshore construction for the Western Isles HVDC Link in early 2026, with construction of the Lewis Hub HVDC converter station and AC substation near Stornoway expected to start early in the year, alongside early works on the mainland cable route at Dundonnell where contractor RJ McLeod will commence culvert replacement and associated traffic management in January 2026 to prepare for later cable laying.
On 19 January 2026, SSEN Transmission awarded NKT the final turnkey contracts for the 525 kV HVDC power cable systems for the Western Isles HVDC link and the Spittal to Peterhead project, with a combined value of about €2 billion. The award confirms NKT as the contracted cable supplier responsible for design, manufacture and installation of approximately 170 km of combined onshore and offshore HVDC cable for the 1.8 GW Western Isles link, a key element of SSEN Transmission’s Pathway to 2030 grid reinforcement programme.
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The Western Isles HVDC Link is a planned 1.8 GW high‑voltage direct current (HVDC) transmission connection to link the Isle of Lewis (Arnish/Stornoway area) to the Scottish mainland (Dundonnell / Beauly), intended to unlock large volumes of onshore and offshore renewable generation and improve lo...
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Western Isles HVDC connection, Western Isles Connection Project, Western Isles connection, Western Isles subsea link, Western Isles subsea cable, Western Isles link, Western Isles (Arnish–Beauly) HVDC link, Arnish to Beauly (Western Isles) HVDC link, BIDC
In early January 2026, the Scottish Government Marine Directorate granted a variation to the existing marine licence for the Western Isles HVDC subsea cable link, allowing an increase in the link’s capacity. This variation, welcomed by SSEN Transmission, represents a key milestone in enabling the higher-capacity 1.8 GW connection as part of the Pathway to 2030 upgrade of the north of Scotland’s transmission grid.
On 16 December 2025, SSEN Transmission awarded Hitachi Energy major contracts to deliver the high-voltage direct current (HVDC) converter stations for the proposed Western Isles HVDC subsea cable link between the Western Isles and the Scottish mainland, covering the design, procurement, manufacturing, installation and commissioning of the converter technology as part of SSEN’s wider transmission investment programme.
Planning consent was granted for the Lewis Hub, the onshore converter station and substation complex on the Isle of Lewis that will form the western terminal of the Western Isles HVDC Link. The consent enables construction of the converter station site that will house the Hitachi Energy HVDC converter equipment.
On 20 November 2025, Comhairle nan Eilean Siar granted planning consent for SSEN Transmission’s Lewis Hub, a high-voltage direct current converter station and associated AC substation on Arnish Moor near Stornoway. This approval, following over two years of development and consultation, authorises a core onshore component of the Western Isles HVDC Connection Project that will connect the Western Isles to the GB transmission network and enable 1.8 GW of new renewable generation.
By March 2025, Hitachi Energy had been identified as the supplier that will deliver the HVDC converter stations for the Western Isles HVDC link, as part of paired projects with the Spittal–Peterhead link. Articles describing SSEN Transmission’s planning application for the Lewis Hub and later reporting on the marine licence variation and project approvals state that Hitachi Energy will develop the HVDC link’s converter infrastructure, indicating its role as the preferred converter station supplier ahead of any separately announced final contract award.
On 18 March 2025, SSEN Transmission submitted a formal planning application to Comhairle nan Eilean Siar for the Lewis Hub project, comprising a new HVDC converter station and AC substation near Stornoway. The Lewis Hub is a key onshore element of the Western Isles Connection Project, enabling the subsea HVDC link from Lewis to the Scottish mainland and unlocking 1.8 GW of new renewable generation.
On 14 March 2025, Linxon announced it had been selected by SSEN Transmission to undertake Early Contractor Involvement design work and reserve manufacturing capacity for 400/132 kV SF6-free EconiQ GIS substations and related systems in the Western Isles. This scope covers the AC substations required to connect generation to the Main Interconnected Transmission System and to transfer the 1.8 GW bipole from the Western Isles HVDC link being developed by Hitachi Energy, confirming Linxon as the contracted substation supplier for this phase of the project.
On 26 February 2025, further pre-application public consultation events were held for the Western Isles Connection Project’s Lewis Hub, with Comhairle nan Eilean Siar publishing "Public Consultation Event 1" and "Event 2" materials. These documents set out updated proposals for the Lewis Hub HVDC converter station and AC substation near Stornoway and invited community feedback prior to planning submission.
On 22 August 2024, SSEN Transmission opened a pre-application public consultation for the Western Isles Connection Project, publishing a detailed consultation booklet describing the existing network and proposed HVDC connection, including the Lewis Hub converter station, subsea cable, and mainland works. This consultation sought feedback from local communities and stakeholders ahead of formal planning applications for the Western Isles HVDC Link infrastructure.
On 15 July 2024, SSEN Transmission and Danish cable manufacturer NKT confirmed a partnership to develop two Scottish HVDC projects, including the Western Isles HVDC link. Under this partnership, NKT was identified as the supplier to provide design, production and installation of both onshore and offshore 525 kV HVDC cable systems, positioning the company as the preferred cable supplier ahead of final contract award for the Western Isles project.
In December 2022, Ofgem approved the Western Isles HVDC connection, providing regulatory authorisation for the 1.8 GW subsea power cable linking the Isle of Lewis to the Scottish mainland and allowing the project to progress beyond its earlier stage of regulatory uncertainty.
In July 2022, National Grid ESO published its Pathway to 2030 Holistic Network Design (HND), which explicitly confirmed the need for a new 1.8 GW Western Isles HVDC link from the Western Isles to the Scottish mainland, replacing previously planned 600 MW link proposals and forming part of the wider transmission blueprint to meet UK renewable electricity targets.
In 2021, the Scottish Government Marine Directorate approved the original marine licence for the Western Isles HVDC subsea cable link. This permit authorised the installation of the subsea cable between the Western Isles and the Scottish mainland, forming a critical regulatory foundation for the interconnector project.
Between November 2011 and December 2013, additional HVDC cable route surveys were carried out for the Western Isles transmission reinforcement, alongside a tender revalidation process, resulting in revised cost estimates of around £750 million for the link. These further route investigations, which revealed changes in soil resistivity on the onshore portion of the cable, contributed to significant cost increases passed through to Western Isles generators under the prevailing transmission charging methodology.
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