National Grid seeks ‘missing link’ in SF6 retrofill

National Grid has partnered with the University of Manchester on a project to test at scale how the UK can retrofill sulphur hexafluoride (SF6) across its network of high-voltage equipment.

SF6 is a gas commonly used in the power industry to provide electrical insulation and arc interruption. However, it is also a potent greenhouse gas with a global warming potential 25,200 times greater than Co2.

The £1.9 million project will see experts at the university help determine how National Grid can develop a retrofill solution to replace SF6 with an environmentally friendlier alternative without having to replace or otherwise modify the existing equipment.

This solution will be demonstrated at National Grid’s test facility, the Deeside Centre for Innovation.

In a separate pilot project last year National Grid and Hitachi Energy developed a solution at Richborough substation in Kent to replace SF6 with a greener alternative. The new demonstrator with University of Manchester will explore how the retrofill solutions might be applied across more of the network.

Together the university and National Grid will create a physical demonstration, complete with an inbuilt condition-based monitoring system, that will focus on the applicability of SF6 retrofill techniques.

It is anticipated the findings will give asset managers the information required for retrofilling significant quantities of SF6-filled equipment across the transmission network.

Dr Tony Chen, senior lecturer in high voltage engineering within Manchester’s Department of Electrical and Electronic Engineering, said: “This project will provide the missing link – taking the success of the research in this area so far, and creating a way to apply retrofilling at scale. By bringing together the expertise of two Manchester departments, we can address every element of this challenge, catalysing the development of real-world solution, which protects the environment while providing significant economical saving.”

Mark Waldron, technical lead at National Grid, said: “It’s exciting to be following the world-first SF6 retrofill in Richborough substation with this initiative taking us a step closer to a solution to replace the gas in more of our assets. The potent combination of Manchester’s expertise in this area and the innovation and demonstration capability at our state-of-the-art Deeside facility will deepen our understanding of retrofill solutions, and could boost our progress in the decarbonisation of the grid while achieving a significant cost benefit for consumers.”