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While emissions of sulfur hexafluoride (SF6), the world’s most potent greenhouse gas, have fallen sharply in the U.S. in recent decades, actual emissions are significantly higher than the official government estimates, a new study concludes.

Across the United States, 390 metric tons of SF6 were emitted into the atmosphere in 2018, the most recent year for which data are available, according to a new study resulting from a joint initiative between the National Oceanic and Atmospheric Administration and the Environmental Protection Agency. The study, designed to better quantify SF6 emissions in the U.S., was published in the journal Atmospheric Chemistry and Physics.

SF6, a man-made gas used by electric utilities to quickly interrupt the flow of electricity in high voltage circuit breakers, is also the most potent greenhouse gas ever studied by the Intergovernmental Panel on Climate Change. The gas is 25,200 times more effective at warming the planet than carbon dioxide, making even small releases of SF6 cause for concern.

The volume of SF6 released in 2018 is less than half of what it was a decade prior, but still equaled the annual greenhouse gas emissions of 2.1 million automobiles, according to the Environmental Protection Agency’s greenhouse gas equivalency calculator.

https://acp.copernicus.org/articles/23/1437/2023/acp-23-1437-2023.pdf

So about that solar energy?

I don't know if the situation is getting better but, sf6 is used in every HV system as the gaseous dielectric medium. Wind turbines add to that more than ever.

Also, its lifetime in the atmosphere is 3200 years; even more than co2.

This seems like bad news if we want to electricfy the grid more doesnt it?

I don’t know why it couldn’t be controlled better than it currently is. And I suppose that’s a pun.

….2.1 million cars? California alone almost has that offset with their close to a million EV’s. It feels like we’re barking up the wrong tree here

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Not really. There are alternatives. SF6 is preferred because it is cheap and works well, but there is no reason you couldn't electrify the grid without it.

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Quick explainer: They use sulfur hexafluoride because it prevents arcing.

In electrical equipment, you are always worried about an arc forming at switches. You mitigate this by putting space between the two points. This is true for all electrical equipment, even the light switch in your house. The distance an arc can occur is based on the conductivity of the medium. Air is the medium typically used. But with really high-voltage equipment, you need very large gaps. Alternatively, you can use something different than air. That is where hexafluoride comes into use. It allows us to make much smaller equipment for high voltage, because it is less conductive and therefore needs far less spacing.

The alternative to using hexafluoride are:

• bigger equipment
• alternative gases, which are more expensive and more hazardous

Both of those things cost money, so the utility industry hasn't been in a big hurry to fix it. But there is no reason we couldn't use an alternative if it was mandated.

Then why don't they?

Well this certainly has left me here with my EV speechless.

Yeah, it's basically clickbait trying to deflect from the real problems. It's like how nukes being far more powerful than guns doesn't mean much when more guns kill more people every single year than nukes ever have. Sure, one may be 25,000x more powerful, but there's way waaaaaay more than 25,000x difference in quantity.

It feels like this article was written by big oil.

“But look at this! It’s way worse than co2!”

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>because it's cheap and works well,

That's precisely why. If they can save a few cents, and nobody stops them, why would they change?

I know your answer is money, but it seems like being able to more quickly adapt the technology and making it cleaner would be good thing, leading to more customers and mo ey down the road.

>but it seems like being able to more quickly adapt the technology and making it cleaner would be good thing

You're thinking too much like a smart person.

You have to dumb it down for them. If they change now, it costs them money, and that's bad. So they don't change. Anything in the future is "potential" even if it's highly likely to occur, so right now all it would do is cost, no matter the future gains.

Utilities have next to zero incentive to invest in/upgrade existing infrastructure, especially if they're privatized. It looks way better on the balance sheet if they just repair it when it breaks.

"leading to more customers".
Where are you living that you get to pick your utility service provider?

One of the big selling points of SF6 equipment has been that it's more compact size and higher electrical efficiency, actually results in lower global warming, because the CO2 savings from improved efficiency outweigh climate effects from escaping SF6.

The counterpoint is that unless properly maintained the equipment may develop unacceptable rates of leakage - and that this may be happening in a widespread fashion.

That SF6 is a serious problem is well known - in the 1997 Kyoto protocol, it was named as 1 of the 6 main greenhouse gases, and it is regulated by governments across the world because of this. Extensive research into alternatives has also been performed since that time.

That SF6 is so good is part of the problem - it has proved extremely difficult to find alternative gases which have similar performance, and which could be used in similar equipment. The last 2 or 3 years have seen some significant progress, with a number of potentially viable alternatives being named such as 2,3,3,3-tetrafluoro-2-(trifluoromethyl)propanenitrile which is approaching commerically ready. The alternatives are much better, but have the disadvantage of toxicity, significant GWP (but nowhere near as high as SF6), and as perfluoro-compounds are potentially "forever chemicals".

It’s much heavier than air, so does it just like, stay close to the ground?

The biggest problem would be find a gas that do all that and isn't so problematic for greenhouse effect.

I also came here for this question. It's about 5x denser than air, wouldn't it just settle to the ground?

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Or just build slightly bigger switchgear and use nitrogen

Third alternative: solid dielectric devices, often coupled with vacuum interrupters. Also typically more costly, and introduce some operational/safety concerns (e.g., SF6 and air-insulated switches often have visible gaps, which are desired - and in some cases required - for utility operations. Vacuum interrupters are fully encapsulated, so the open gap is not visible.)

This is the deep voice gas right? Isn’t it super dense?

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It might be heavier than air but it's still a gas so it's really light, weather events, temperature, wind will all cause enough turbulence to disperse a plume and vertical mixing will send it up into the atmosphere. Think about it like a pile of feathers, they are light and a good gust of wind will send them scattering.

i knew it. Those electric cars will be the end of us.

Go back to oil-filled and air blast circuit breakers. Problem solved.

no surprise we focuse way to much on cars then anything else.

Great answer, thanks

Oh man I can’t wait to see what tax credit will fix this problem

Not necessarily. It is something to consider and address in conjunction with other emission reduction acts. This is also a good time to do it since the push towards EVs will require substantial expansion of the electrical grid. Currently only about 1% of the cars on the road are EV. As that number increases, so will the grid and use of SF6. So why not address that now and avoid having to rework the electrical grid later when it is a much bigger problem? Tackling just one aspect of the greenhouse gas issue is not enough. Per the EPA, vehicle emissions account for only 27% of greenhouse gasses so there are a lot of other areas to improve too.

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I know Schneider electric has developed LV-MV switchgear that is SF6 free using air under presser insulation and vacuum interruptors in their Aireset range, working with them currently and the airset stuff is definitely picking up more and more over the SF6 stuff as companies look to brand themselves more sustainable and better for the environment, don't know about Hv switchgear much though