Inside National Grid's Plans for a Sustainable Substation

National Grid has announced plans to work on a new substation that is set to power data centres in the UK. 

Situated in Buckinghamshire, the proposed Uxbridge Moor substation is set to integrate more than a dozen new data centres into its energy network.

This initiative is part of National Grid's continuous efforts to upgrade its transmission network in response to increasing electricity demands.

The setup aims to sustain the growth of emerging sectors like data centres, providing new economic and job opportunities.

“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,” says Laura Mulcahy, Project Director at National Grid Electricity Transmission. 

“It will enable new jobs and investment in Buckinghamshire, and will support the UK's digital future.”

Building new capacity to meet data centre demand

The new establishment will include two substations – one 400kV and one 132kV – both designed as indoor gas-insulated facilities (GIS), aiming to minimise the development's footprint by about 70%.

National Grid says Uxbridge Moor will also spearhead as one of the initial GIS substations in the UK to exclude sulphur hexafluoride (SF6), an electric insulator known for its potent greenhouse gas emissions.

Using an alternative gas means the project will mark a critical key step towards National Grid’s goal of reducing SF6 emissions from its network by 50% by 2030.

Laura adds: “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.”

The principal contractor, Murphy, is set to construct the Uxbridge Moor substation and carry out underground cabling to link the 400kV substation to the neighbouring overhead transmission line.

Liam Corr, Managing Director of Energy at Murphy, says: “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.”

Harnessing the grid sustainably 

The development follows the Heathrow Airport outage caused by a substation fire in West London, prompting concerns about the UK's national infrastructure and its capacity to accommodate more data centres amidst expanding development ambitions.

Data centres remain critical to the digital economy and hope to create highly skilled job opportunities in London and across the UK, whilst also providing the essential infrastructure needed to drive continued technological innovation and growth.

National Grid’s new substation site borders its existing Iver 400kV substation in Buckinghamshire, which has reached its capacity limits.

The utility has also faced scrutiny regarding its emissions increase to 7.4mt CO₂e, as reported in May 2025.

The organization plans a £35 billion (US$47.37m) investment from 2026 to 2031 to connect significant power consumers like data centres and gigafactories, as well as newer electricity generation sources such as wind and solar.

“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,” explains Energy Minister Michael Shanks.

“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.”

Requests from data centres to connect to the Uxbridge Moor substation 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.

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