Sulphur Hexafluoride
Sulfur Hexafluoride (SF6) is a synthetic fluorinated compound.
According to the U.S. Environmental Protection Agency “Because of its unique dielectric properties, electric utilities rely heavily on SF6 in electric power systems for voltage electrical insulation, current interruption, and arc quenching in the transmission and distribution of energy.
Yet it is also the most potent greenhouse gas known to-date. Over a 100-year period, SF6 is 23,500 times more effective at trapping infrared radiation than an equivalent amount of carbon dioxide (CO2). SF6 is also a very stable chemical, with an atmospheric lifetime of 3,200 years. As the gas is emitted, it accumulates in the atmosphere in an essentially un-degraded state for many centuries. Thus a relatively small amount of SF6 can have a significant impact on global climate change.”
China
A recent article in Nature Communications has assessed the effects of SF6 emissions from the surging expansion of the power production programme in China, and estimated that between 2011 and 2021, Chinese emissions from SF6 increased from 2.6 Gg/yr to 5.1 Gg/yr. This was equivalent to 125 Million Tonnes of CO2 per year, or comparable to the annual CO2 emissions of the Netherlands, Nigeria, Belgium, Qatar or Bangladesh.
India
India’s market for SF6 is “set to soar” according to some market commentators, which would fit with its anticipated power demand growth of 25%, and huge investments being made in renewables projects such as the investment of the Adani Group in a renewables project five times the size of Paris at is Khavda Renewable Energy Park.
The implications of overhead power lines on critically endangered bird species were closely studied by the Indian Supreme Court in a recent case on which we have reported separately M.K. Ranjitsinh v Union of India. It may well be that the continued increase in reliance upon SF6 by the electrical power and distribution systems will also in due course require intervention by the Supreme Court.
The EU
In the EU, the revised F-gas Regulation EU 2024/573 came into force on 11 March 2024, and will start to apply controls and restrictions on SF6 use by 2026.
The UK
The UK’s National Grid says that while it has taken drastic action to reduce its use of SF6, and is working to research alternatives, it does not anticipate being able to phase out use of SF6 altogether until 2050. This is despite its being claimed that the UK National Grid had energised the first SF6-free 420kV gas-insulated power line in 2017.