National Grid ESO has recommended SSE proceed with two further transmission reinforcement options in the north of Scotland in its 2021 Network Options Assessment report.
The system operator has called for construction of a new 400kV double circuit overhead line between the Beauly and Blackhillock substations.
It has also recommended replacing the existing Beauly – Shin – Loch Buidhe 132kV double circuit overhead lines with a higher capacity 275kV double circuit overhead line by 2030.
The two options, both non-binding, are included in the NOA report, which carries out detailed analysis on which strategic investments should progress to meet the future needs of GB’s electricity transmission system.
They join four SSE options which were already given a strong “proceed” recommendation in previous reports.
SSE said the six projects represent an estimated investment of over £5bn and will help unlock transmission capacity needed to accommodate the expected increase in renewable generation including from Scotwind offshore projects.
Two east coast onshore upgrades are included within SSE’s RIIO-T2 business plan for the price control period running from April 2021 to March 2026 with the remaining four expected to be constructed within the following RIIO-T3 period.
The first deals with upgrading one of the existing double circuit overhead lines running south from Kintore substation to enhance its capacity at the existing operating voltage of 275kV and establishing a new substation near Alyth by 2023.
Secondly, a further upgrade of the existing double circuit overhead line running south of Kintore, along with upgrades to the existing 275kV lines running between Blackhillock substation (near Keith), Peterhead substation and Kintore substation to operate at 400kV in 2026.
The plan also includes pre-construction development to support the delivery of both Eastern HVDC link projects.
The North East Scotland to North East England Offshore Link will see the construction of a subsea HVDC link from Peterhead substation to Drax substation in the north east of England by 2029.
The North East Scotland to South Humber offshore link will see the construction of a second subsea HVDC link from the North East of Scotland (provisionally Peterhead) to a substation within the South Humber area by 2031.