The National Grid, the UK’s grid transmission and distribution operator, has commenced upgrade work at its Didcot substation in Oxfordshire to support data center growth in the region.

The substation is located close to the former Didcot A coal power station, which has been earmarked for development as a new large-scale data center.

In addition, the substation is also located just two miles from the UK’s first AI Growth Zone at Culham, with the upgrade work expected to support the addition of these two new large loads to the grid.

The upgrade will support extending the existing 400kV outdoor air-insulated substation by adding three new bays and three supergrid transformers. The National Grid also plans to construct a new 132kV indoor gas-insulated switchgear (GIS) facility next door to the substation. The GIS facility will use Hitachi Energy’s EconiQ switchgear technology as a sustainable alternative to sulphur hexafluoride (SF6), a commonly used electrical insulator.

“Our Didcot substation extension marks another step forward in powering the UK’s digital future. By enabling new data centers and battery storage systems to connect to the grid, we’re supporting both the energy transition and the growth of the digital economy regionally and nationally,” said Peter Hancock, project director at National Grid Electricity Transmission.

In addition to the data centers, the substation upgrade will also support the connection of 650MW of new battery energy storage systems, which the transmission operator said will enhance grid flexibility.

Linxon has been appointed as the principal contractor to deliver the substation upgrades. The construction firm has already collaborated with the National Grid on several projects, including the London Power Tunnels and Bengeworth Road substation.

The substation extension announcement follows the start of construction at National Grid’s Uxbridge Moor substation in Buckinghamshire, which is expected to supply electricity to more than 12 new data centers. The substation, which will be the largest in the UK when built, is expected to be completed by 2029.

The National Grid has seen a surge of data center requests over the past year. Last week, during the company’s Q3 earnings results, it revealed that it expects to connect up to 19GW of new capacity by 2031, half of which from data centers.

As a result of projected increases, National Grid estimates that data centers could consume up to nine percent of electricity demand by 2035, up from 2.6 percent today.