IN Brief:
- SP Energy Networks awarded Linxon a multimillion-pound engineering and materials contract on 29 October.
- The work supports the Tealing to Kincardine upgrade and developments at Conland, Devonside, Mossmorran and Westfield.
- Hitachi Energy will provide high-voltage equipment, including SF₆-free switchgear, alongside digital substation and monitoring technology.
SP Energy Networks has awarded Linxon a multimillion-pound contract for substation engineering and equipment sourcing across central Scotland and Fife. The work supports reinforcement of transmission circuits from 275kV to 400kV and planned substation developments associated with the Tealing to Kincardine overhead line upgrade. Hitachi Energy is due to provide high-voltage electrical equipment and digital technologies for the installations, including switchgear designed without sulphur hexafluoride insulating gas.
The 29 October contract forms part of SP Energy Networks’ £12bn transmission investment programme. Linxon’s scope includes substation design and the sourcing of materials for construction, while the wider programme will involve upgrades to overhead lines in Fife and expanded transmission facilities at Conland, Devonside, Mossmorran and Westfield. This distinguishes the new engineering and materials award from completion of the physical reinforcement: design, construction, testing and energisation remain separate delivery stages across the named locations.
The Tealing to Kincardine programme includes uprating existing overhead lines in Fife from 275kV to 400kV, alongside changes at Conland, Devonside, Mossmorran and Westfield. Moving a circuit to the higher voltage requires insulation clearances, protection settings and connected substation equipment to be designed for the revised electrical stresses. Those interfaces must be engineered together: a line equipped for 400kV operation still needs compatible switching, transformation and protection arrangements at the points where it meets the wider grid.
The reinforcement is intended to increase the electricity that can be transferred through central Scotland, including between areas of renewable generation and other network connections. Actual transfer capability will depend on conductor thermal ratings, voltage regulation, stability limits and the substations through which power flows. Conductor and insulator changes on existing towers, where included in the programme, must be coordinated with the new substation interfaces so the resulting route can be operated at its intended voltage.
Hitachi Energy will supply EconiQ switchgear designed without sulphur hexafluoride, together with digital substation, automation and monitoring technology. SF₆ is an effective insulating and arc-quenching gas but has a high global warming potential, creating environmental liabilities where equipment leaks or requires gas handling. Using an alternative technology in new high-voltage plant can reduce that exposure. The specific configurations and ratings for each location will be settled through detailed design and equipment procurement rather than inferred from the product family alone.
Digital protection and monitoring systems will sit alongside the new primary plant. Circuit breakers, disconnectors, busbars and transformers carry or control the electrical power, while secondary systems collect measurements, issue alarms and operate protection functions during abnormal conditions. Their integration requires careful management of interfaces, time synchronisation, communications reliability and cybersecurity. Remote monitoring can give operators better information about asset condition, but the effectiveness of the new installation will depend on sensor coverage, configuration and how the information is used in operating procedures.
Eastern Green Link 4, the proposed 2GW high-voltage direct current connection between Fife and Norfolk, will depend on suitable interfaces with the alternating current transmission system. At Westfield and associated sites, the local network must be able to receive or deliver power transferred by the HVDC converters. The 275kV-to-400kV line and substation upgrades will help prepare the surrounding grid to operate alongside that interregional transfer route, with converter stations and subsea cables forming further parts of the EGL4 system.
Construction and commissioning at the named substations will be sequenced around operating transmission equipment. New bays, transformers and related control systems need electrical testing and protection verification before they are connected to live circuits. The programme must also accommodate planned outages and arrangements that preserve supply through the existing network during the changeover. Linxon’s immediate role is design and materials sourcing, with subsequent physical installation and energisation governed by the individual project delivery plans.
Linxon’s Glasgow office, opened earlier in 2026, has expanded to approximately twice its initial capacity, and the contract is expected to support dozens of additional jobs in Scotland. Hitachi Energy has also established an office in Glasgow. The engineering workload spans primary high-voltage plant, controls and construction interfaces, which have to be coordinated early enough for factory testing and installation to follow a consistent design. The value of Linxon’s individual contract is described as multimillion-pound within the wider £12bn SP Energy Networks investment programme.
The next measurable steps are completion of substation designs and procurement of the specified high-voltage and automation equipment. Installation at Conland, Devonside, Mossmorran and Westfield will then have to be coordinated with the 275kV-to-400kV line upgrades and the developing Eastern Green Link 4 connections. The contract adds design and supply capacity to that programme ahead of site commissioning and the eventual operation of the reinforced transmission network.
