In among the tsunami of news coverage (especially at the BBC and the Guardian) about COP27, another story emerged today, reported on by the Guardian with a somewhat alarming heading: “World’s ‘most potent greenhouse gas’ escaped during work on UK windfarm”.

There are several worrying aspects to the story. The greenhouse gas in question is sulphur hexafluoride (SF6), which can apparently cause respiratory problems in humans. It is colourless and odourless, which presumably makes it difficult to detect (and, given its potential for causing respiratory harm, therefore dangerous). We learn that workers on offshore windfarms are concerned about this:

The incident occurred in June and has been brought to light by the North Sea trade unionist Jake Molloy, of RMT. Molloy told Energy Voice that “the Seagreen incident is one event that did get reported to the trade unions by worried offshore workers.

But how many go unreported, how is this policed and regulated, what are the reporting procedures? We need to know. It has to be properly managed.”

Secondly, it turns out that this is a particularly potent greenhouse gas. Wikipedia tells us that:

According to the Intergovernmental Panel on Climate Change SF6 is the most potent greenhouse gas. Its global warming potential of 23,900 times that of CO2 when compared over a 100-year period. Sulfur hexafluoride is inert in the troposphere and stratosphere and is extremely long-lived, with an estimated atmospheric lifetime of 800–3,200 years.

The Guardian confirms that it’s not just the IPCC that is worried about it:

The US Environmental Protection Agency deems it the most damaging greenhouse gas and National Grid describes it as “one of the most potent greenhouse gases we know”.

Despite these issues, it seems it’s a vital ingredient for wind turbines. And so, despite being generally banned in Europe, an exception has been made “for use in power generation where it is used as an insulating gas in switchgear machinery”.

And it seems that it’s not easy to find replacements:

A spokesperson for SSE, which is responsible for the construction phase, said: “At the time of contract signing for the procurement of the transformer switchgear destined for the Seagreen project, which is currently under construction, there were no viable SF6-free alternatives available, capable of operating at all voltage levels needed, that could be considered for deployment to the project.”

Oh dear, the Law of Unintended Consequences strikes again. As well as the other environmental damage associated with wind farms, now we learn that their construction and operation requires the use of one of the world’s most powerful greenhouse gases, which is potentially dangerous to the workers involved in the construction projects. Perhaps Just Stop Oil should re-focus their efforts and re-name themselves Just Stop Wind.


  1. “Its global warming potential of [sic – is?] 23,900 times that of CO2 when compared over a 100-year period.”

    I’m in no way belittling the health hazards associated with sulphur hexafluoride but can anyone explain what the above means (even after correcting the Grauniad’s wording)?


  2. Dave Bruce,

    The Guardian’s convoluted language is often difficult to interpret. In this case, I think the suggestion is that because SF6 hangs around so much longer than CO2, over a 100 year period, SF6 is 23,900 x more potent than CO2 in warming/climate-changing potential.


  3. Having searched all parts of the BBC website where this story might be covered (business, science & environment, Scotland, including regions) I can’t find it. I might have missed it, but my guess is that the BBC is ignoring it – nothing to see here, move along. To that extent, then, fair play to the Guardian for reporting on it.

    Liked by 1 person

  4. I wouldn’t believe them if they said tomorrow will be Wednesday.

    If it is genuinely bad for Glowbull Warming, you should consider that Big Wind is likely releasing it deliberately in order to counteract the obvious facts that (a) it isn’t getting warmer and (b) there is absolutely nothing remotely unprecedented about the weather.


  5. That’s very interesting, and a bit worrying, when I had a detatched retina fixed in France, they used a gas bubble to do the repair. As far as I rmember it was SF6 sulfur hexafluoride.


  6. I can’t think of a more toxic molecule than that. I am sure it does not occur in nature. when they say 24,000 times more powerful than Co2 I think they mean per molecule and since SF6m in the atmosphere is at a very very low concentration then I am sure that the total effect is pretty close to zero


  7. We have a lot of SF6 in our power stations’ electrical equipment. It is near essential to quench the arc in high voltage circuitbreakers when they operate. Some on the large 220kV ones have about 150kg of gas in them. Some on the 11kV CBs have less than 1kg. One of my jobs each year is go round to inspect all the vessels.
    It is hard to degas CBs when work needs to be done on them. Invariably the gas escape is from something happening during this process. If it wasn’t for the climate change hysteria, it would be much ado about nothing.

    Liked by 1 person

  8. I can do no better than repost Chris Morris’ last sentence above. ” If it wasn’t for the climate change hysteria, it would be much ado about nothing.” Indeed the mass hysteria around this whole subject has developed beyond any remotely objective intercourse. It is the exemplar of groupthink for our age. When a diverse group of not unintelligent people are detached from their sanity and hurled into a bubbling cauldron of false data, false assumptions and false conclusions. Sheer madness.


  9. In response to Mark Hodgson’s remark about the BBC missing this most interesting story (thanks again, Paul), I fear that this is precisely the sort of news story the BBC would prefer not to report, especially during COP27


  10. Thanks for all the comments. I should add that SF6 does have several uses, including in medicine, and as per Chris Morris’ comment. There have been quite a few comments along those lines at Paul Homewood’s site, where he gave this article a plug (thanks, Paul :-)). As I said there:

    I don’t much disagree with the comments. For me, there is a health risk (however slight), and a huge irony in a powerful greenhouse gas being banned in Europe, save (in part at least) to the extent that it helps Big Wind. My writing was slightly tongue-in-cheek, but there is a serious point also – “green” energy isn’t so green as they would have you believe.

    As for the BBC, they have swerved the story this time round, but as was also noted at Paul Homewood’s place, they have banged this drum in the past (via Matt McGrath, over 3 years ago):

    “Climate change: Electrical industry’s ‘dirty secret’ boosts warming”

    It’s the most powerful greenhouse gas known to humanity, and emissions have risen rapidly in recent years, the BBC has learned.

    Sulphur hexafluoride, or SF6, is widely used in the electrical industry to prevent short circuits and accidents.

    But leaks of the little-known gas in the UK and the rest of the EU in 2017 were the equivalent of putting an extra 1.3 million cars on the road.

    Levels are rising as an unintended consequence of the green energy boom.

    And that is something worth thinking about. If the intention is to grow wind energy exponentially (as seems to be the case from the noises coming out of the UK government, Scottish government, and sundry movers and shakers at COPs), then over time that will be the equivalent of putting tens of millions – perhaps hundreds of millions – of new cars on the road in terms of GHG emissions “equivalent”.


  11. “Op-ed: The EU needs to crack down on climate-damaging F-gases”

    As Europe moves toward climate neutrality by 2050, ensuring the technologies powering our economies contribute to decarbonization is key — this includes ensuring electrical grids are free of fluorinated greenhouse gases.

    [This op-ed was originally published in Politico on 8 March 2023]

    Man-made fluorinated greenhouse gases (F-gases) have a super-global warming effect, far worse than CO2, and have long been widely used in electrical switchgear (key hardware components found throughout electrical infrastructure). They contribute to climate change by ‘trapping and locking’ heat in the atmosphere. Some F-gases are also known as PFAS or ‘forever chemicals’, which when used in switchgear, risk serious harm to the environment and human health.

    Given the significant risks they pose, and to meet Europe’s ambitions in the fight against climate change, it is crucial to ban the use of F-gases for new installations in electrical grids in the EU. The ongoing review of the F-gas Regulation represents a unique chance for policymakers to live up to that expectation and recognize the investments the majority of switchgear manufacturers have already taken towards F-gas free alternatives within their product portfolio. In this context, the recent report from the European Parliament’s Environment, Public Health and Food Safety Committee is a step in the right direction.

    NB the website is a campaigning one:

    Who we are
    We are the six leading power equipment manufacturers demonstrating global leadership with a clear commitment to support the EU to set global standards for a cleaner future. Already today the majority of T&D manufacturers have based their solutions upon Natural-Origin Gas.

    We have been relentless in our quest for new technologies based on Natural-Origin Gases. Many applications are now available and successfully proven in operation. We will close the remaining portfolio gaps in accordance with the proposed transition times outlined in the F-Gas Regulation.

    With the Switching Gears for Net Zero Alliance, we convey a simple message: power grids can and should be F-gas free


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