Major milestone in construction of new National Grid substation in Kent
- National Grid is constructing a new 400kV substation at Wallend on the Isle of Grain, Kent, to enhance the resilience, flexibility and capacity of the electricity network.
- The substation will enable connections for several major energy projects, including NeuConnect – the first 1.4GW high-voltage direct current (HVDC) interconnector linking the UK and Germany.
- The project has now reached a significant milestone with the completion of the main building structure that will house the electrical equipment including including Hitachi Energy’s EconiQ® 420kV SF₆ free gas-insulated switchgear (GIS) technology
- The project represents a nationally significant investment in the UK’s energy future and forms part of National Grid’s £2.7 billion investment to maintain, upgrade and develop the electricity network in the South East.
- Local community organisations can now apply to National Grid’s Community Grant Programme, offering grants of up to £20,000 for projects delivering lasting local benefits.
Construction of National Grid’s new substation at Wallend on the Isle of Grain, Kent, which will play a key role in strengthening the UK’s electricity transmission network, has achieved a key milestone with completion of the building hall that will house the gas-insulated switchgear (GIS).
The Wallend Substation is a vital new piece of infrastructure that will play a key role in supporting the transition to cleaner, more secure energy. The next phase of this major infrastructure project will now focus on the installation and testing of the GIS And associated electrical equipment before the substation connects to the electricity network.
Once operational, the substation will facilitate the connection of NeuConnect, a new 1.4 gigawatt (GW) HVDC interconnector that will link the UK and Germany energy markets for the first time. Located alongside key strategic assets including Grain LNG and the BritNed Interconnector, Wallend Substation further reinforces the Isle of Grain’s position as one of the UK’s most important energy hubs. The new infrastructure will improve grid stability, enhance system flexibility and support the UK Government’s Clean Power 2030 ambitions.
Construction programme sees strong progress
Main construction works began in 2025, with National Grid working alongside Principal Contractor Balfour Beatty who are leading the design and build of the new substation. The project has now reached a significant milestone, with the completion of the main building structure, including foundations, steelwork and external cladding.
The next phase will see the installation of EconiQ GIS technology from Hitachi Energy, which is free from sulphur hexafluoride (SF₆), a potent greenhouse gas. This represents another step in National Grid’s commitment to reduce SF₆ emissions by 50% by 2030. Factory acceptance testing for the GIS has already been successfully completed, enabling installation to commence.
The completed cladding provides effective weather protection and insulation in readiness for the installation of the substation’s electrical systems, while also helping to reduce operational noise once the site is energised.
Supporting the local community
Local community organisations can apply to National Grid’s Community Grant Programme (CGP), which is designed to support projects in areas directly affected by the construction of Wallend Substation. Grants of up to £20,000 are available for initiatives delivering clear social, economic or environmental benefits.
The programme supports projects focused on inclusion, education, health and wellbeing, employability, conservation and energy efficiency, helping to ensure a positive and lasting legacy alongside the delivery of nationally significant infrastructure.
Hannah Ward, EPC Project Manager at National Grid Electricity Transmission, said:
“The Wallend Substation represents a key investment in strengthening the UK’s electricity network and enabling cleaner, more secure power for the future. Completion of the main building structure is an important milestone in the construction programme and a clear sign of the progress being made on site.
“We are proud to be delivering this critical infrastructure while working closely with our partners and the local community to ensure it brings lasting benefits to the Isle of Grain.”
Tony Wilson, Managing Director of Balfour Beatty’s Power Transmission & Distribution business, said:
“Completion of the main building structure at the new 400kV Wallend Substation marks an important milestone in this nationally significant project.
“Working in close partnership with National Grid, we are proud to be strengthening the electricity network and enabling the delivery of cleaner, more secure energy. We now turn our focus to the next phase of the programme, installing the critical equipment that will connect the substation to the wider network and support the UK’s long‑term energy needs.”
Nigel Gregory, Project Manager (Wallend) at Hitachi Energy said:
“Reaching this milestone at Wallend is an important step toward delivering a more sustainable, resilient and future‑ready electricity network for the UK. We are proud to be supplying our EconiQ™ 420kV SF₆‑free gas‑insulated switchgear—technology that delivers the same performance and compactness as traditional solutions while significantly reducing environmental impact.
“Our close collaboration with National Grid and Balfour Beatty ensures that this critical infrastructure is built with the highest standards of innovation, safety and reliability, supporting the country’s journey toward clean power by 2030.”
Further information on the Community Grant Programme, including how to apply, is available via the application website.
For more information about the Wallend Substation project, visit www.nationalgrid.com/wallend-substation
Anyone with questions or wishing to speak to the project team can contact the dedicated community information line on 0800 130 3767 or email [email protected].