Scotland's electricity transmission owner, SSEN Transmission, has submitted to the energy regulator, Ofgem, robust proposals to reinforce the Argyll transmission network from 132kV to 275kV operation.

At an estimated cost of around £400m, this investment is being taken forward as part of the SSE Group's Net Zero Acceleration Programme, which will see £12.5bn invested in the five years to 2026, or £7m every day. SSEN Transmission alone expects to invest around £4bn over this period as it delivers a network for net zero emissions.

The Argyll 275kV strategy is required to support the connection of several new renewable electricity generation schemes across Argyll and to transport that power to areas of demand across Scotland and beyond. It will support the connection of at least 560MW of new renewable electricity generation, enough to power more than 500,000 homes.

The Argyll 275kV strategy consists of the following five main components:

• A new substation at Creag Dhubh connecting to SP Transmission's existing Dalmally-Windyhill transmission line via around 14km of new overhead transmission circuits;


• Around 10km of new overhead transmission circuits connecting Creag Dhubh substation to the existing Inveraray-Crossaig circuits;

• The replacement of existing substations at An Suidhe and Crarae along the route of the Inveraray-Crossaig line;

• Establishing a new substation at Craig Murrail and relocation of the Port Ann Grid Supply Point to this site; and

• Establishing a new substation in the vicinity of the existing Crossaig substation.

Rob McDonald, Managing Director of SSEN Transmission, said: "Submission of our Initial Needs Case for the Argyll 275kV strategy marks another key milestone in delivering a network for net zero emissions.

"With the existing network in Argyll close to capacity, the project is essential to increase the operational capacity of the Argyll transmission network, supporting the connection of new renewable electricity generation in the area and to transport that power to areas of demand."

Rob continued: "We now look forward to working constructively with Ofgem and our stakeholders to unlock the investment required in a timely manner. This investment will create hundreds of skilled jobs throughout the supply chain as well as boosting local and national economies, supporting a green recovery from the coronavirus pandemic."

In parallel with the regulatory approvals process SSEN Transmission continues to progress the detailed designs for the various components of the Argyll 275kV strategy. Following significant stakeholder engagement, which has led to several changes to SSEN Transmission's proposals, planning applications are due to be submitted in the coming months to Argyll and Bute Council for all substation works; and to the Scottish Government for all overhead transmission line works.

Subject to necessary regulatory and planning approvals, SSEN Transmission expects construction to be underway in 2024 with the scheme fully energised in April 2027.