Green light for SSEN’s £488m Skye power line upgrade

SSEN’s £488 million proposal to upgrade power lines between Fort Augustus and the Isle of Skye has been given the green light.

Ofgem approved the plans after ruling that “there is sufficient evidence of a clear needs case for the Skye project on the basis that there is the need for asset intervention and that new generation has shown enough progress to warrant adding additional capacity to the Skye circuit”.

The plans include replacing the existing single 132kV overhead line (OHL) which spans across 160km between Fort Augustus on the mainland to Ardmore on the Isle of Skye.

The project is mainly driven by the need to address the deteriorating condition of current assets. However the proposed designs include an upgrade to the OHL and new underground cabling to enable future renewable generation in the Skye area to connect.

The scope of work for the project consists of:

• 110km of new build 132kV double circuit OHL between Fort Augustus and Edinbane substations
• 24km of new build 132kV double circuit underground cables between Fort Augustus and Edinbane substations, and associated sealing end compounds at the cable remote ends
• 24km of new build 132kV single circuit OHL between Edinbane and Ardmore substations
• Establishing a new 132kV Gas Insulated Switchgear (GIS) switching station at the existing Broadford substation to connect to the current and planned additional 132kV Grid Supply Points (GSPs) and required reactive equipment as part of underground cable works
• A 132kV GIS switching station at the existing Edinbane substation to connect to the current and planned additional 132kV infrastructure and required reactive compensation equipment

Responding to the consultation on the plans, SSEN Transmission senior regulation analyst Cara Dalziel said that the project is a “key piece of the net zero puzzle”.

“The existing Fort-Augustus to Skye overhead line is fast approaching the end of its operational life and its planned replacement is essential to maintain network reliability and security of supply to homes and businesses along its route, as well as to the Western Isles. At the same time, the existing Skye 132kV circuit is already oversubscribed with no new generation able to connect to the Skye network in over 10 years,” Dalziel adds.

“Reinforcement of the line is now required to enable the connection of additional generation and support the UK and Scottish Government’s targets to transition to net zero.

“The Skye project is a key piece of the net zero puzzle and supports the clear vision of both the UK and Scottish Governments to accelerate the transition away from fossil fuels towards low carbon generation.”

In total, the upgrade will provide capacity to connect over 500MW of additional generation.

The project is being considered under the LOTI mechanism as part of the RIIO-2 price control.

SSEN has indicated that it expects to obtain all material planning consents by December 2023.

In a further boost to the delivery of its network investment plans, SSEN Transmission has also announced the preferred bidders for delivering all onshore transmission infrastructure as part of its Pathway to 2030 programme of projects.

Shortlisted bidders include Balfour Beatty, Siemens Energy BAM, J. Murphy & Sons, Wood Power Solutions, Omexom Morgan Sindall Infrastructure, Burns & McDonnell, Morrison Energy Services, Linxon, IQA and NKT.

Rob McDonald, managing director of SSEN Transmission, said: “Our Pathway to 2030 network redevelopment programme will play a huge role in delivering Scotland and the UK’s net zero targets and the selection of this group of preferred bidders for crucial elements of that redevelopment work is a massive step forward in delivering that.

“As we aim to conclude contract negotiations in the coming weeks and months, we look forward to working with each of the selected contractors in the delivery of our ‘Pathway to 2030’ projects.

“Not only will this work support the delivery of UK and Scottish Government net zero and energy security targets, but our forthcoming investments will provide significant local and national economic opportunities, helping unleash the economic potential of the north of Scotland.”