The first SF6-free gas-insulated transmission substation in the UK is under construction
National Grid
Connecting millions of people to the energy they use, while making the energy system clean, fair, and affordable.
In a first for the UK, high-voltage SF6-free switchgear is being installed at our new Bengeworth Road substation, part of the £1 billion London Power Tunnels 2 project.
High-voltage EconiQ gas-insulated switchgear and gas-insulated lines developed by Hitachi Energy have arrived on site ready for installation. This marks a key milestone in the construction of the first gas-insulated transmission substation in the UK to be free of sulphur hexafluoride (SF6) gas.
What is SF6?
SF6 is commonly used in high-voltage electrical equipment around the world owing to its chemical stability and insulating properties, which help prevent short circuits and keep supplies safe.
However, SF6 is one of the most potent greenhouse gases and is 24,300 times more effective at trapping infrared radiation than an equivalent amount of CO2[1], leading to solutions being developed to replace it with greener alternatives.
The first gas-insulated transmission substation to be free of SF6, in the UK
The new 400kV Bengeworth Road substation is situated in the centre of the 32.5km London Power Tunnels 2 route, helping to reinforce the capital’s electricity network by providing a 132kV connection for local grid operator UK Power Networks to distribute electricity to homes and businesses in the area.
The installation of SF6-free technology at the substation – which is being built together with construction partner Linxon – represents a crucial step towards our ambition to reduce emissions of the gas from our network by 50% by 2030.
SF6 is one of the most potent greenhouse gases and is 23,500 times more effective at trapping infrared radiation than an equivalent amount of CO2.
Trialling SF6-free technology on our network
SF6-free technology has been trialled on our network before, notably at our 400kV Richborough substation in Kent where engineers successfully removed SF6 from an existing gas-insulated busbar and replaced it with a greener alternative.
The recently energised 400kV Littlebrook substation in Kent is also partially SF6-free and features GE Vernova’s g3 gas-insulated busbar equipment, which is helping us save 5.6 tonnes of SF6 from our network.
Ensuring reliable electricity supplies
Substations and their technologies play a vital role in helping to ensure safe and reliable electricity supplies, with transformers and switchgear changing voltage levels up or down and switching electricity flows to make sure power can be transmitted and distributed safely around the country.
[1] According to the Intergovernmental Panel on Climate Change’s (IPCC) sixth assessment report.
Site Supervisor / NG Person
6moHappy to supervise this works for you. Great project to be part of.
Project Director at CPC Project Services Ltd
7moDavid Nicholl Daniel Allen Adam Sheth MRICS
High Voltage Cable Jointing Specialist
7moDaniele Giustini Neil Cowap CEng MBA
Assistant project manager
7moWe are currently doing the same in Lewes with termination of the 132kv into the equipment happening next week!
Director at Electrical Consulting Ltd
7moI thought at the time it was odd to be using such a dangerous gas. It was an aspixiant, carsenagenic if involved in arcs, and a greenhouse gas. The drivers were reduced space and quick to build but there are as ever always negatives.