National Grid has commenced construction on a new high-capacity substation at Uxbridge Moor in Buckinghamshire, set to deliver power to over a dozen new data centres — part of the UK's wider digital and economic expansion.

The facility will feature two indoor gas-insulated substations (GIS) — a 400kV and a 132kV unit — using SF6-free switchgear, reducing the environmental footprint by approximately 70%. SF6 is a potent greenhouse gas traditionally used in electrical insulation, and eliminating it aligns with National Grid’s target to halve emissions of the gas by 2030.

The substation will support around 1.8GW of new capacity, equivalent to powering a mid-sized city, making it the largest new substation by capacity on National Grid’s network. It will also help relieve pressure on the nearby Iver 400kV substation, which has reached full capacity.

The project is being delivered by principal contractor Murphy, which will also handle underground cabling and infrastructure to link the new substation to the existing overhead transmission line.

This development comes amid National Grid’s plan to invest £35 billion between 2026 and 2031 to support growing electricity demand from sectors like data centres, AI, and clean energy generation.

Michael Shanks, UK Energy Minister, emphasized that such upgrades are central to accelerating grid connections for high-growth sectors, while Laura Mulcahy of National Grid said the site would play a key role in powering the UK’s digital future sustainably.

Source: nationalgrid.com