Engineer wearing orange overalls and a hard hat standing inside National Grid's London Power Tunnel

National Grid avoids emissions at London Power Tunnels substation with green grid technology

  • £1bn project to rewire London will see the replacement of ageing high-voltage electricity cables and expand network capacity to meet the increasing electricity demand

  • A new substation at Bengeworth Road in Lambeth is at the heart of the project and will be built by Linxon using Hitachi Energy’s SF6 free gas insulated switchgear technology in a UK first

  • The project forms part of National Grid’s ambition to have no SF6 in electrical assets by 2050

  • National Grid is investing a total of £1.3bn every year in electricity network infrastructure needed to help the UK decarbonise and reach net zero emissions


​​​​​​National Grid’s London Power Tunnels (LPT) project is a seven-year, £1 billion project, to rewire South London via deep underground tunnels. This vital work to replace ageing high-voltage cables will expand capacity and help keep Londoners connected to secure and reliable electricity supplies.

In total, 32.5km of 3m diameter tunnels are being constructed deep below the road network between Wimbledon and Crayford. UK Power Networks, the electricity distribution company which distributes electricity to consumers in the London area, requires National Grid to build a new connection to its high-voltage electricity transmission network.

To achieve this, we need to build a tunnel access shaft, substation and headhouse within UK Power Network’s existing substation site boundary at Bengeworth Road, Lambeth to connect to our London Power Tunnels (LPT) route.

Sulphur Hexafluoride (SF6 ) is used in the electricity industry in substations to prevent short circuits and to keep the network safe and reliable, but it has a high global warming potential. National Grid’s ambition is to reduce its SF6 emissions by 50% by 2030 and remove all SF6 gas from electrical assets by 2050.

Linxon is building Bengeworth Road substation for National Grid and to support the business in its transition to SF6 -free solutions, in a UK first, Hitachi Energy will deliver EconiQ™ 400-kilovolt (kV) gas-insulated switchgear (GIS) and gas-insulated lines (GIL) containing no SF6, to enable the transmission of energy over long distances. Installation is expected to begin in 2023, subject to prior approval of the substation by Lambeth Council.

This key power project will deliver a secure energy supply to the capital, and by using sustainable technology we are minimising the environmental impact of our operations and using transformational engineering to support the transition to net zero.

This follows National Grid’s announcement last year where Hitachi Energy’s EconiQTM retrofill solution was piloted at National Grid’s Richborough 400kV substation. On this project, SF6 was replaced in gas-insulated busbars without changing the equipment, avoiding the environmental impact and cost of replacing equipment in existing substations.

Onur Aydemir, Project Director for London Power Tunnels said: “We’re delighted that Bengeworth Road substation, at the heart of London Power Tunnels, will be SF6 -free. This key power project will deliver a secure energy supply to the capital, and by using sustainable technology we are minimising the environmental impact of our operations and using transformational engineering to support the transition to net zero.”

“Following the successful collaboration with National Grid on the world’s first replacement of SF6 in existing high-voltage equipment and award-winning project in Richborough, UK, we are proud to be supporting National Grid again in its transition to SF6-free solutions,” said Markus Heimbach, Managing Director of the High Voltage Products business at Hitachi Energy. “The EconiQ GIS is based on our breakthrough SF6-free 420 kV circuit-breaker that demonstrates the reliability and scalability of the technology for the lowest carbon footprint.”

“Linxon is building the infrastructure to power the world with carbon free energy. Thanks to strong collaboration with Hitachi Energy, Linxon is able to provide the pioneering EconiQ SF6-free solution from Hitachi Energy for the Bengeworth substation, supporting our client to meet their sustainability targets”, said Stefan Reisacher, CEO of Linxon.

For more information visit London Power Tunnels and view our Responsible Business Charter.

 

Media contact:

Helen Blake
T 07790 824788