UK’s National Grid Investing Billions for Substation Site to Power Data Centers

National Grid in the UK has begun construction of a new Uxbridge Moor substation complex in Buckinghamshire, a project designed to connect more than one dozen new data centers to the electricity provider’s network.

The grid operator on June 3 said the new site is part of a £35 billion ($47.3 billion) investment for upgrades to its transmission network to meet growing demand for electricity, including from data centers, particularly in the region west of London. The site will feature two substations—one 400kV, and the other 132kV. Each will be indoor gas-insulated facilities (GIS), which National Grid said reduces the footprint of the development by about 70%, and also minimizes its environmental impact. Construction is expected to be complete in 2029.

National Grid on Tuesday said 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.” The use of an alternative insulating gas means the project aligns with National Grid’s strategy to reduce SF6 emissions from its network by 50% by 2030.

Michael Shanks, a UK energy minister, 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 centers and AI [artificial intelligence] hubs, plugged into the grid—while also fast-tracking projects that will scale up clean, homegrown power by 2030.”

J Murphy & Sons has received a multimillion-pound contract from National Grid to build the project, which will be adjacent to the existing Iver substation in Buckinghamshire. The Murphy group also will deliver ancillary facilities, underground cabling, and associated work to connect the 400kV substation to the nearby overhead transmission line.

Investment Also Supports Renewable Integration

National Grid said its investment, planned for projects from 2026 to 2031, will support grid connections from large sources of power demand such as data centers and gigafactories. The group also said the upgrades will support integration of renewable energy resources such as wind and solar.

The grid operator said connection requests from data centers for Uxbridge Moor will require about 1.8 GW of new generation capacity, or the equivalent of adding a mid-sized city to the grid on the outskirts of London. Uxbridge Moor will be the largest new substation on National Grid’s network by gigawatt capacity.

“Our new Uxbridge Moor substation will provide vital access to power for data centers that are at the heart of Britain’s innovation and economic growth,” said 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.”

Mulcahy added, “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, said, “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.”

—Darrell Proctor is a senior editor for POWER.