New National Grid substation fully operational, transmitting clean power to 1.5 million homes

  • National Grid’s new Littlebrook 400kV substation in Dartford, Kent is now fully energised. 
  • The facility enables the transmission of 2GW of low carbon and renewable energy from interconnectors and offshore wind farms off the coast of Kent to power around 1.5 million homes.
  • New technology deployed to reduce emissions at the site.

National Grid has successfully commissioned a new, state-of-the-art substation, in Dartford, Kent, enabling 2 gigawatts (GW) of low carbon and renewable energy to power around 1.5 million homes. 

National Grid and its contractors Balfour Beatty and GE Vernova’s Grid Solutions have been working since June 2019 to build a replacement for Littlebrook 400kV substation. 

The new facility will help to reduce the use of sulphur hexafluoride (SF₆), a gas commonly used in the electrical industry to prevent short circuits and to keep the network safe and reliable.

Construction of the new substation is now complete, and all circuits have now been successfully commissioned. The project included the installation of underground cabling, overhead line connections and GE switchgear – the circuit board used to control, protect, and isolate electrical equipment. Four existing super grid transformers have been moved from the old substation to the new one, and a brand-new transformer was delivered in July 2022.

Engineers are using GE Vernova Grid Solutions’ innovative g3 gas-insulated busbar equipment which is SF6- free. A total of 5.6 tonnes of SF₆ gas has been saved, forming part of National Grid’s ambition to reduce its SF₆ emissions by 50% by 2030 and removing all SF₆ gas from electrical assets by 2050.

Teams have also deployed net zero construction methods throughout the project to reduce the environmental impact of the works, including steel manufactured in Britain, solar powered electrics, electric vehicle charging points, biodiversity net gain plan for the local area and an onsite biodigester to manage wastewater, all saving 5229 tonnes of CO₂ emissions during construction. 

Laura Mulcahy, Senior Project Manager for National Grid Electricity Transmission, said: We are delighted the new Littlebrook substation is now fully energised and connected to our network. 

“Getting Littlebrook completed is a huge achievement for the team. We’ve had to overcome some difficult engineering and programme challenges along the way, and so to reach this milestone is a real testament to the commitment and strong relationships of everyone involved. I send my sincere thanks out to them all.”

Mark Wilson, Head of Service, UK & Ireland at GE Vernova’s Grid Solutions business said: “National Grid has been a leader in removing SF6 from its network. They energized our very first g3 product at their Sellindge substation in 2016. We are very proud to continue contributing towards National Grid's ambition to remove SF6 entirely by 2050 and to be part of the Littlebrook substation project, saving 5.6 tonnes of SF6 from the network.

“This project represents the latest vote of confidence in GE Vernova’s SF6-free products which deliver the same performance and product footprint as traditional SF6 equipment, while delivering a 99% reduction in the gas contribution to global warming.”

Tony Wilson, Managing Director at Balfour Beatty Power Transmission and Distribution, said: “We are proud to have delivered this vital work on behalf of National Grid, utilising our extensive knowledge and integrated solutions in power transmission, to supply secure power to over 1.5 million homes for generations to come.”


Contact for media information only

Paige Phelps
National Grid Electricity Transmission
T: 07543 312572
[email protected]