SSEN Unveils Future Energy Plans for Shetland’s Infrastructure

SSEN Transmission has announced significant developments regarding future energy infrastructure in Shetland. The company has been conducting consultation events to gather community feedback on various projects, including the establishment of substations and overhead lines.

One of the most notable projects involves the creation of a northern substation hub, for which SSEN Transmission plans to submit a planning application in 2024. If approved, construction is expected to commence between 2028 and 2032, with full integration into the network anticipated by 2035.

The potential locations for this hub have been narrowed down to four sites in the Scatsta/Sullom Voe area: Scatsta airfield, Scatsta Ness, Fraw Houll, and Toft Camp. This infrastructure aims to support the integration of offshore wind projects, including Statkraft’s Beaw Field and Energy Isles wind farms in Yell, alongside a proposed second High Voltage Direct Current (HVDC) cable linking Shetland to the Scottish mainland.

The hub would incorporate a 2GW converter station to facilitate power export to the mainland, along with a 400kV substation to enable connections for both offshore and onshore generation. Consultation documents indicate that the hub will cover approximately 40 hectares and is set to be commissioned by 2034. Additionally, a 220kV substation is planned to support future connections from third-party developers.

In relation to the second HVDC cable, SSEN initially identified 23 potential landfall sites in Shetland, 16 of which have been eliminated due to engineering, community, and environmental concerns. Currently, four sites are moving to detailed design: Grunnavoe, Toft Ness, Wethersta, and Toft Camp. SSEN officials have indicated that Wethersta is the most suitable site at this stage. A marine licence application for this project may be submitted in 2028, with completion expected by 2035.

The development of a new “Kergord 2” substation is also on the agenda to upgrade the network voltage from the existing Kergord substation from 132kV to 220kV. Preliminary designs suggest this substation will require a switchgear building measuring approximately 64 metres in length, 21 metres in width, and 15 metres in height. Three separate “super grid transformer” buildings, each about 74 metres in length and 40 metres in width, are also planned. Two potential locations for this development have been identified, with SSEN favoring a site just south of Lower Voe.

A contentious issue among local residents concerns the proposed overhead lines between the northern hub and the Kergord 2 substation, as well as from the Kergord 2 to the existing Kergord substation. SSEN’s plan includes two metal lattice structures, often referred to as pylons, positioned in parallel between the Kergord substation and Kergord 2, with 250 metres separating the structures. These pylons could reach heights of 28 metres, compared to the existing 18-metre wooden poles.

SSEN noted that eight structures are required per kilometre for this segment. However, the project proposes even taller lattice towers, measuring 38 metres, for the route from Kergord 2 to the northern hub, albeit with a single line instead of two in parallel. The energy regulator Ofgem has questioned SSEN’s choice of 220kV technology over the more common 275kV, which would necessitate larger structures. SSEN contends that the smaller 220kV structures strike a better balance between performance and minimizing visual and environmental impacts.

Cath Swan, Lead Project Manager for onshore projects, explained that the lattice towers would have less environmental impact than undergrounding the cables. Three routes have been proposed between Kergord and the Scatsta area, with a preference for one that follows the path of the Dales Lees road. This choice is based on its reduced potential landscape and visual impact, accessibility via the main road network for construction and maintenance, and avoidance of sensitive upland peatland areas. If consents are approved, construction could begin in 2028 and finish in 2032.

SSEN has also been consulting on developments in Yell, necessary for the planned Energy Isles and Beaw Field wind farms to export power. A new 220kV circuit will connect a proposed substation in Yell to the northern hub. Possible landfall locations for a new subsea cable to Yell include Burravoe or South Wick of Sound, while on mainland Shetland, Mossbank, Grunnavoe, Toft Camp, and Toft Ness are under consideration.

The timeline for these projects suggests completion could be achieved by 2032. SSEN emphasized the need for enhanced energy infrastructure in Shetland, stating, “The Shetland Islands are uniquely positioned to support Great Britain’s journey to net zero, with a growing number of renewable energy projects.” The company acknowledged that the existing electricity transmission framework requires investment to accommodate the increasing demand arising from new developments, including the first HVDC link and the Viking wind farm.

Community members still have opportunities to provide feedback on the various projects through online consultations.