Sulphur hexafluoride (SF6) is a manmade gas that combines excellent electrical properties with chemical stability and low toxicity. This has led to its widespread and enthusiastic adoption by the energy industry, which uses roughly 85% of all the SF6 produced. Within the industry, the gas is used as an insulating medium for medium and high voltage gas insulated switchgear.
SF6 is also the world’s most potent greenhouse gas. So much so that it is 23,500 times stronger than CO2. Its annual emissions are comparable to the yearly CO2 emissions produced by approximately 100 million cars. Its environmental impact, and extremely high global warming potential have made it a subject of regulatory and governmental scrutiny in various places around the world. The industry however has been trying to deny the climate impact of SF6’s use in switchgear and has been rather reluctant to move away from SF6.
A number of recent market developments demonstrate that that SF6-free technologies are the only future for the energy industry. “Any other gas except for air is dead” – was coined at the Hannover fair this year by one of the distribution system operators. And this could not be more true: in the midst of Climate Change, market players are coming to one common denominator – the only long-term solution that the industry has to eventually adopt is the one that best coexists with our environment.
California as an example of how to win from losing SF6
California has been at the forefront of SF6-free revolution: the California Air Resources Board (CARB) set December 31st, 2024 as a target date for SF6 to be phased out from all equipment of 72kV or less, and by December 31st, 2030 – for all high voltage ranges.
The industry has also been proactive in this regard: PG&E have been increasingly committed to reducing their SF6 footprint since 1999. In fact, they have recently announced that they are phasing out SF6 in all their equipment based on the following data that they had gathered over 15 years:
One leakage of SF6 is estimated to cost approximately $25,000
The real leakage rate in California is around 2%, which is 20 times higher than the official data
The most cost-effective and environmentally friendly solution is dry air/vacuum
(More about PG&E and their research)
The European Commission urges for SF6 alternatives
In 2014, the European Commission reinforced a 2006 F-Gas regulation No. 517/2014 with the aim of reducing the EU’s F-gas emissions by two-thirds from 2014 levels by 2030. Within the EU, SF6 was banned for most of its applications, except for its use in the energy industry – its main consumer. To a large extent, this was due to the fact that - at the time - there was no proven alternatives to the SF6-based switchgear. The regulation will be revised this year with the aim of evaluating new solutions in the market, and potentially further restricting the use of SF6 in the energy industry.
A significant step was made in this direction at the end of 2018 when the European Commission issued a new tender that aims, among other, to “investigate the existence of alternatives to sulphur hexafluoride (SF6) in switchgear and assess their feasibility and market potential“ and “identify appropriate policy measures for different types of electrical installations using SF6 including switchgear, in particular the use of prohibitions and cap/phase-down schemes, and make recommendations as to their design to be fit-for-purpose including the need for exemptions”. The policy adjustments based on the research are planned to be implemented in 2022.
The industry reacts fast: understanding the urge for SF6-free alternatives it is trying to find new solutions
This is evidenced by a number of big players launching research projects focused on SF6-free solutions:
At June’s CIRED fair in Madrid - the world’s largest international electricity conference and exhibition – a record 10 abstracts will be presented focused on SF6-alternatives by original equipment manufacturers including Siemens, Schneider, ABB and also nuventura
Western Power Distribution, one of the British distribution network operators, conducted a review of alternatives to SF6-based switchgear that have the potential to eventually replace SF6. nuventura was mentioned as one of the alternatives suitable for the UK market
SF6 has been an accepted solution for many years now. But if we are honest with ourselves: do we really believe that a gas that is 23,500 stronger than CO2 will survive the much needed transition to more sustainable forms of energy generation and distribution? Based on the market and policy adjustments described, we must be realistic: it is only a matter of time before SF6-based technologies are replaced by the greenhouse gas-free alternatives. Why not be prudent and start preparing for that change now?