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Giant flywheel project in Scotland could prevent UK blackouts

theguardian.com

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Re: Giant flywheel project in Scotland could prevent UK blackouts

#71

Post by ascorbic »

epistasis wrote: post #54
DrBazza wrote: post #8

This is a consequence of the UK having little capacity for pumped-storage, i.e. hydro-electric. We don't really have the height, and we have "areas of outstanding natural beauty" that cannot be built in easily, so we need alternatives to store the energy. The rest of the world just builds a dam, creates a new lake, and moves on.

Hydro storage and flywheel storage have very different use cases, typically. Flywheels contain tiny amount of energy, but can respond nearly instantaneously To provide frequency regulation on the grid. Hydro has massive amounts of energy storage (days+ worth of output), but takes a looot longer to respond than flywheels. I think we will see very little flywheel or dam construction in the coming decades; battery stora…

Hydro can be fast. The UK uses pumped hydro for frequency management among other things, and can spin up several GW in seconds.

Re: Giant flywheel project in Scotland could prevent UK blackouts

#72

Post by _sbrk »

rbanffy wrote: post #30
frobozz wrote: post #20

Earlier quoted context omitted.

Cofiwch Dryweryn!

And people say Hungarian is hard...

Lol. Reminds me of The Crown where Price Charles is learning Welsh.

However, at least all the letters are familiar. Asian languages are at least an order of magnitude harder for westerners.

Re: Giant flywheel project in Scotland could prevent UK blackouts

#73

Post by phtevus »

ladberg wrote: post #69
tpmx wrote: post #62

Earlier quoted context omitted.

Sorry, but this comment shows that you don't understand the physics that would be involved in something like this.

I think you're misunderstanding how this flywheel operates. It doesn't provide 50hz AC in the same way the grid operates, it just is attached to a DC motor that provides electricity which can then be converted into AC to power the grid. That means it can spin at any frequency and it doesn't really matter what state the grid is in.

The article states the flywheel will not be used to provide electricity to the grid.

Re: Giant flywheel project in Scotland could prevent UK blackouts

#74

Post by kitd »

jimnotgym wrote: post #66
DrBazza wrote: post #27

Earlier quoted context omitted.

I'm just cynically generalising - the rest of world compared to the UK has typically less stringent planning requirements, and more mountainous terrain. To store energy in other countries (except perhaps Holland..!) you build a hydro dam, and pump water into those dammed lakes using excess electricity to store it up for later release. We have mountains (Wales, Lake District, Scotland), but the likelihood of creating…

There are two pumped storage stations in Wales that I know of. Dinorwig (where the power station is inside the mountain, as a student I got to go in there) and Ffestiniog. Wales has a long history of having dams built to provide water to English cities, see the Elan Valley, Llyn Vyrnwy, Llyn Clewedog and many more. The displacement of people and 'theft' of water even spurned a terrorist organisation to stop it called…

Cofiwch Dryweryn!

Re: Giant flywheel project in Scotland could prevent UK blackouts

#75

Post by twic »

rbanffy wrote: post #30
frobozz wrote: post #20

Earlier quoted context omitted.

Cofiwch Dryweryn!

And people say Hungarian is hard...

It looks wild, but the pronunciation is very regular:

https://wikitravel.org/en/Welsh_phrasebook

Or rather, the orthography is - spoken Welsh is ancient, but the way of writing it with Latin letters is relatively new, so it was worked out fairly sensibly.

The actual grammar is headache-inducing, though.

Re: Giant flywheel project in Scotland could prevent UK blackouts

#76

Post by twic »

jeffbee wrote: post #48

Does it make sense for a flywheel to have a horizontal axis of rotation, as shown in the concept image? Seems like that would be the hard way, from the standpoint of engineering.

Maybe they could just spin the Falkirk Wheel round really fast.

Re: Giant flywheel project in Scotland could prevent UK blackouts

#78

Post by jrockway »

LeoPanthera wrote: post #56
sloucher wrote: post #37

Earlier quoted context omitted.

As I understood the article, this isn't about storing energy so much as just stabilising the frequency of the grid. (Yes, if we used more hydro-electric then that would do the job for us, but it's not the case that we need this in order to store energy).

Frequency is proportional to voltage, and the voltage drops when the supply is insufficient, so this is absolutely about storing energy.

That's not quite how the grid works. Consider a case where you wire two AC motors together. You spin one, and the other one spins. That is kind of like how the grid works; many loads are AC motors that spin at the line frequency, and generators try to also spin at that frequency. If the load on the motors increases, the load on the generators increases. Eventually there won't be enough energy going into the generator to spin at the nominal line frequency, and the motors attached to the mains will spin more slowly (and correspondingly use less power, and output less work).

This all becomes more complex when the loads are switch-mode power supplies and the generators are solar panels. The flywheel project adds some smoothing to the grid, as spinning generators are replaced with DC devices. But the principles are the same; without any extra devices, electricity has to be generated at the exact instant that it is consumed, and the consumers have a large physical effect on the generators.

(Frequency is not proportional to voltage in general, only in this spinning-generator connected to a spinning load case. You can obviously switch DC on and off at whatever frequency you desire, and a perfect on/off cycle consists of infinitely many frequencies at various amplitudes.)

Re: Giant flywheel project in Scotland could prevent UK blackouts

#79

Post by bob1029 »

TremendousJudge wrote: post #68
bob1029 wrote: post #61

Earlier quoted context omitted.

The point here is that the flywheel is so massive that the amount of energy required to bring it below (or above) the allowable frequency range is practically very large. Large steam/gas turbines running on the grid have a similar effect. Even without hot gas running through them, they can provide rotational inertia for grid stabilization purposes. This flywheel is basically an extremely heavy version of the same ide…

How much mass are we talking about here? I'm curious and the article doesn't give any numbers. Order of magnitude at least?

No clue - I was hoping for numbers myself.

Re: Giant flywheel project in Scotland could prevent UK blackouts

#80

Post by craftinator »

TremendousJudge wrote: post #68
bob1029 wrote: post #61

Earlier quoted context omitted.

The point here is that the flywheel is so massive that the amount of energy required to bring it below (or above) the allowable frequency range is practically very large. Large steam/gas turbines running on the grid have a similar effect. Even without hot gas running through them, they can provide rotational inertia for grid stabilization purposes. This flywheel is basically an extremely heavy version of the same ide…

How much mass are we talking about here? I'm curious and the article doesn't give any numbers. Order of magnitude at least?

I'm curious about this is well. I imagine it must be huge to handle the scale of the grid!
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