National Grid has started work on a new substation in Buckinghamshire that will support over a dozen new data centres, boosting local economic growth and helping meet the UK’s growing electricity demands.
The Uxbridge Moor site, located near the existing Iver 400kV substation, will feature two indoor substations using gas-insulated switchgear (GIS) technology. These substations—one 400kV and one 132kV—are designed to reduce the site’s footprint by around 70% while also lowering its environmental impact.
The project is part of National Grid’s broader plan to invest £35 billion in its transmission network between 2026 and 2031, aiming to connect high-demand users like data centres and large-scale power generators such as wind and solar farms.
Uxbridge Moor will be among the first GIS substations in the country to be built without sulphur hexafluoride (SF6), a potent greenhouse gas typically used in switchgear. National Grid is using an alternative insulating gas to help reduce SF6 emissions across its network by 50% by 2030.
Laura Mulcahy, project director at National Grid Electricity Transmission, said: “Our new Uxbridge Moor substation will provide vital access to power for data centres that are at the heart of Britain’s innovation and economic growth. It will enable new jobs and investment in Buckinghamshire, and will support the UK’s digital future.”
“Alongside these significant benefits, we are working to keep the substations’ environmental impact to a minimum. By using the latest SF6-free gas-insulated switchgear, we’re reducing the size of this crucial site by around 70%, and ensuring its technology is sustainable and resilient long into the future.”
Principal contractor Murphy will deliver the substation and associated works, including underground cabling and links to the nearby overhead transmission line.
Liam Corr, Managing Director of Energy at Murphy, said: “Since 1951 Murphy has been a leading provider of innovative and integrated energy solutions – today we support groundbreaking transmission and distribution projects across the four countries in which we work.”
“We are proud to be delivering this project in the UK’s capital and building on our strong working relationship with National Grid to help to ensure energy security for decades to come.”
The planned data centres at Uxbridge Moor will require approximately 1.8GW of capacity—the equivalent of powering a mid-sized city—making this the largest new substation on National Grid’s network by gigawatt capacity.
Energy Minister Michael Shanks said: “Upgrades to the electricity network like this are at the heart of building the industries of our future and support our Plan for Change to deliver economic growth and skilled jobs across the UK.”
“It comes as we progress our reforms to the grid connections queue that will speed up the time it takes to get high-growth firms, like data centres and AI hubs, plugged into the grid – while also fast-tracking projects that will scale up clean, homegrown power by 2030.”
The new facility is a key part of preparing the UK’s infrastructure for a digital and low-carbon future.
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