National Grid secures land for what could be UK's largest substation

National Grid Electricity Transmission has agreed to acquire more than 70 acres of land on Teesside for a new 400kV substation expected to become the largest in the UK.

The agreement covers land at Dorman Point, within the Teesworks industrial estate, where National Grid is planning a major new connection to the electricity transmission network.

Known as the Tees Dock substation, the facility would connect the national transmission network to a private electricity network operated by Steel River Power. The infrastructure is intended to support a major data centre development and a proposed battery energy storage system.

The land agreement, first reported by Sky News, represents progress towards delivering the project, which has been somewhat of a rollercoaster in recent years. 

Initially BP wanted to build a hydrogen plant at Teeside, and while it initially received backing from the UK Government for the project, it ultimately withdrew the plans after it went up against locally-backed plans for a major AI data centre development.

With that AI data centre now set to go ahead, it’s important to get the electricity connection in place to support it. After all, the lack of electricity has plagued many other data centre developers across the country, and National Grid had already warned that Teesworks lacked the necessary transmission infrastructure to support the contracted connection without overloading – which is where this new substation comes in. 

National Grid's preferred design for the site uses an indoor 400kV gas-insulated substation, rather than a conventional air-insulated installation.

Gas-insulated switchgear takes up less space, allowing the equipment to fit within the land being acquired. According to National Grid's regulatory submission, an alternative design could have required compulsory purchase of additional land, potentially delaying the project by 12 to 24 months.

The coastal location has also influenced the design, with National Grid identifying exposure to salt pollution from the nearby River Tees estuary as a consideration for long-term equipment reliability.

The project follows National Grid's upgrade of its Didcot substation, where additional electrical infrastructure is being installed to connect new data centres and 650 MW of battery storage.

Both projects show how growing demand from data centres is driving investment in high-voltage infrastructure. However, National Grid is still struggling to keep up with the insatiable demand from the data centre sector. That’s led the UK Government to consider further steps, including allowing developers to build their own transmission infrastructure, and now even the possibility of colocating power generation with the data centre itself. 

For National Grid in Teesworks, however, it’s hoping to get ahead of the curve. It’s hoping to get construction on the new substation underway next year, subject to the necessary approvals, of course.