National Grid, the UK’s largest electricity distribution network, is starting work on its new Uxbridge Moor substation in Buckinghamshire which will connect over a dozen new data centres to its network.
The new site forms part of National Grid’s upgrade to its transmission network to meet growing demand for electricity, ensuring it can continue to support the growth of new sectors such as data centres as well as the economic and employment benefits they can bring.
The site will feature two substations – one 400kV and one 132kV – both of which will be indoor gas-insulated facilities (GIS), reducing the footprint of the development by around 70% and minimising its impact on the environment.
Uxbridge Moor will be among the first GIS substations in the country to be free of sulphur hexafluoride (SF6), a commonly used electrical insulator that is also a potent greenhouse gas. Using an alternative insulating gas means the project marks another key step towards National Grid’s ambition to reduce SF6 emissions from its network by 50% by 2030.
Principal contractor Murphy will build the Uxbridge Moor substation, as well as delivering ancillary facilities, underground cabling, and associated work to connect the 400kV substation to the nearby overhead transmission line.
National Grid is planning £35 billion of investment between 2026 to 2031 to connect both large sources of demand (such as data centres and gigafactories) and new sources of electricity generation (such as wind and solar).
The requests from data centres to connect at Uxbridge Moor will require around 1.8GW of new capacity, equivalent to adding a mid-sized city to the grid on the outskirts of London. When built, it will be the largest new substation on National Grid’s network by gigawatt capacity.
The new substation site borders National Grid’s existing Iver 400kV substation in Buckinghamshire, which has reached capacity and cannot be expanded to meet the demand from data centres and other customers for connections in the area.
Energy Minister Michael Shanks says, “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.”
Laura Mulcahy, Project Director at National Grid Electricity Transmission, comments, “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.”
Liam Corr, Managing Director of Energy at Murphy, states, “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.”
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