Beginning the removal of SF₆ greenhouse gas from our operations

The journey to net zero is not just replacing fossil fuels with renewable power. There are other important environmental goals, like eliminating the need to use SF6 – a  greenhouse gas used in the electricity industry that most people have never heard of.

Chris Bennett, Interim president at National Grid Electricity Transmission, outlines how we are collaborating with Hitachi Energy to replace SF6 in existing high voltage equipment.

SF6 gas has been used extensively across the electrical industry as an insulating gas for switchgear for 50 years or more. Even 10 years ago a small number of large coal power plants used to supply energy to millions, but as greater numbers of smaller generators have come online, the amount of electrical equipment, and SF6, has increased. It’s a reliable electrical insulator, but while leaks are relatively rare, its global warming potential is high and it’s an issue we’ve been looking to solve for many years.

Back in 2017 National Grid achieved a huge industry milestone with the energisation of GE’s SF6 alternative insulation gas, g3 in newly constructed equipment specially designed for the gas at our 400kV substation in Sellindge, Kent. In October last year, we set out our commitment to reduce greenhouse gas emissions to net zero by 2050, which includes reducing all SF6 emissions by 50% by 2030 and eliminating all SF6  gas from all assets by 2050.

Read more about NGET's environmental commitments

So I’m delighted we’re celebrating another major milestone on this journey to entirely SF₆ free equipment, in partnership with Hitachi Energy. Together we’ve worked on a pilot project at National Grid’s 400kV substation in Richborough, Kent to replace SF6 with a greener alternative. Hitachi Energy’s EconiQTM   retrofill is the world’s first SF6 replacement for installed gas-insulated lines, meaning we can replace the gas without changing the equipment – reducing cost and environmental impact.

This project has innovation at the very heart of it and I’d like to thank every person involved for their hard work and dedication in reducing the environmental impact of our own activities. Being a truly responsible business is one of our top priorities and I’m confident that, with projects like these leading the way, we can leave a lasting, sustainable legacy.