DNV and industry partners are teaming up to explore ways of reducing sulphur hexafluoride (SF6) in the UK’s electricity transmission network.
SF6, widely used to insulate live electrical parts, interrupts the flow of electrical current, and connects the generation and storage of renewable energy. Alongside numerous benefits it is the most potent greenhouse gas, trapping heat in the atmosphere with effects 23,000 times that of carbon dioxide.
The project’s key objective is to reduce SF6 emissions and foster the transition to SF6-free alternatives, aligning with the UK’s clean energy goals. It will focus on enhancing the understanding and handling of alternatives, developing new retrofill solutions for existing equipment, and developing energy-efficient disposal methods for SF6 once it is removed from assets.
Partners include National Grid Electricity Transmission (lead), The University of Manchester, SP Transmission, Scottish Hydro Electric Transmission, DILO Armaturen und Anlagen GmbH, and WIKA Instruments, which bring a combination of technical and economic perspectives.
Jack Thomas, Senior Consultant and DNV Project Lead, said, “By developing in-service knowledge of SF6-free alternatives and improving energy-efficient disposal methods, we are taking significant strides towards reducing SF6 emissions and supporting the UK’s clean energy transition.”
The outcomes hold relevance not only for the UK but also for other transmission system operators facing similar challenges globally. SF6 will also be phased out in all new equipment for electrical transmission (‘switchgear’) by 2032 in the EU.
Hari Vamadevan, Senior Vice-President and Regional Director for the UK and Ireland, Energy Systems at DNV, said by tackling the challenges posed by SF6 and devising effective strategies, industry and business can work together and share knowledge to pave the way for a cleaner and more resilient energy landscape.
Research by environmental experts at China’s State Grid Electric Power Research Institute revealed that using a mixture of SF6 and nitrogen gas in a 3:7 ratio instead of pure sulfur hexafluoride gas can effectively reduce emissions while ensuring the insulation performance of electrical equipment.
Hitachi Energy has commissioned what it claims is the world’s first high-voltage and medium-voltage gas-insulated switchgear (GIS) installation with a new ‘eco-efficient gas mixture’ as an alternative to SF6 for ewz, a power utility in Switzerland. The 170 kV substation deploys the GIS with a global warming potential of less than 1.
Hitachi Energy recently announced plans to invest $155m expanding manufacturing facilities across North America to meet rising transformers and switchgear demand.
It has also been working with SP Energy Networks, delivering 1,500m of EconiQTM GIL which contains no SF6 and makes use of an alternative insulation gas mixture which eliminates CO2 equivalent emissions throughout the lifecycle.
