this post was submitted on 26 Jul 2024
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Climate - truthful information about climate, related activism and politics.

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Discussion of climate, how it is changing, activism around that, the politics, and the energy systems change we need in order to stabilize things.

As a starting point, the burning of fossil fuels, and to a lesser extent deforestation and release of methane are responsible for the warming in recent decades: Graph of temperature as observed with significant warming, and simulated without added greenhouse gases and other anthropogentic changes, which shows no significant warming

How much each change to the atmosphere has warmed the world: IPCC AR6 Figure 2 - Thee bar charts: first chart: how much each gas has warmed the world.  About 1C of total warming.  Second chart:  about 1.5C of total warming from well-mixed greenhouse gases, offset by 0.4C of cooling from aerosols and negligible influence from changes to solar output, volcanoes, and internal variability.  Third chart: about 1.25C of warming from CO2, 0.5C from methane, and a bunch more in small quantities from other gases.  About 0.5C of cooling with large error bars from SO2.

Recommended actions to cut greenhouse gas emissions in the near future:

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[–] [email protected] 1 points 3 months ago (2 children)

Disclaimer: I'm not a sponsor, I just believe this is the future of wind based energy. It doesn't require any sort of braking mechanism, and also takes up far less land space..

https://youtube.com/watch?v=7tsaFPd03w4

https://harmonyturbines.com/

[–] [email protected] 1 points 3 months ago* (last edited 3 months ago)

I saw the video and at some point it say something like

"no danger to animals".

This is a bold claim to make, especially since the effects of wind turbines on (migratory or not) birds and bats are vastly documented.

The "tricky" part with wind energy are other living creatures. It affects them and by default they are not able to participate in the conversation. We actively need to take them into consideration.

Though of adding a relevant link on Large-scale effects of offshore wind farms on seabirds of high conservation concern

[–] [email protected] 5 points 3 months ago (1 children)

Last time I asked about this I was told that the vertical style wind turbines have a lot higher wear/failure rate and don't scale up as well.

Ok for small scale stuff, but not for your big, stick it on top of a hill or out to sea turbines.

[–] [email protected] 1 points 3 months ago* (last edited 3 months ago) (1 children)

How much can really wear out on them though? The bearings? Those can be replaced as necessary of course.

I'd think their only true weakness would be during strong storms like hurricanes or tornadoes where wind gust speeds rapidly change faster than the mechanism can manage to furl and unfurl to keep up. In those situations, you'd basically have to completely close them up and shut them down until the bad weather passes.

I dunno, but other than that it seems like a promising technology, and you can pack a whole lot more of them onto a smaller space of land.

[–] [email protected] 7 points 3 months ago* (last edited 3 months ago) (4 children)

The weight of the blades on a typical windmill is aligned with the plane of rotation, so most of the forces are taken up by radial bearings:

They do need thrust bearings as well, but only to resist the force of the wind that isn't converted into rotation.

Vertical windmills, however, rotate perpendicular to their load and require a thrust bearing to support the full weight of the blades at all times:

This means that vertical windmills wear down the single thrust bearing that supports their weight significantly more quickly than others who can distribute the weight of the blades across multiple radial bearings. It's not a huge problem at a small scale where the weight is minimal, but as the weight per bearing increases, the rate of wear does as well.

[–] [email protected] 2 points 3 months ago

Non-engineer here, thank you for a strong ELI-average-adult.

[–] [email protected] 2 points 3 months ago

I was going to respond, but you did way better than I would have!

[–] [email protected] 1 points 3 months ago (1 children)

True that, and very well explained I might add.

Now, if I were on their engineering team, I'd probably try a combination of magnetic and roller bearings. Use magnetic bearings to support the weight, while securing everything in place with radial bearings.

That way, the mechanical bearings don't have to support the weight, magnets can take care of most if not all of that, saving undue wear and tear on the mechanical bearings.

I dunno, just a thought.

[–] [email protected] 2 points 3 months ago* (last edited 3 months ago) (1 children)

Actually, magnetic bearings experience wear as well.

So called "permanent" magnets gradually lose their charge over time through interactions with opposing magnetic fields, heat, and mechanical stresses. Neodymium, for example, loses about 0.1% of it's field strength per year even when it isn't being used for anything. This is why you can't use magnets to make perpetual motion machines:

Magnets are basically batteries that store energy in the form of a magnetic field, eventually they run out of charge and need to be re-magnetized.

This makes passive magnetic bearings really tricky to design, so most of those in use are active types that also employ sensors and electromagnets to ensure stability. These electronics also degrade over time, so usually a mechanical bearing is a better choice unless the use-case requires a frictionless axle.

[–] [email protected] 1 points 3 months ago

Everything degrades over time, that's a given, nothing lasts forever. But if they relieve the weight from the mechanical bearings with magnets, then they might last quite a bit longer before needing service.

[–] [email protected] 2 points 3 months ago

Fantastic explanation and diagram inclusion