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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

#51

Post by dragonwriter »

baybal2 wrote: post #29
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.

> We don't really have the height, UK is an island, and you have highlands. Why not make some salt water lakes there?

Because saltwater is going to escape the artificial lakes even if they have impermeable beds, and we'll, there's a reason “salt the earth” is something that historically people have done, or at least talked about doing, to mortal enemies’ lands and not their own.

Re: Giant flywheel project in Scotland could prevent UK blackouts

#52

Post by ansible »

jeffbee wrote: post #50

This discussion of a test flywheel installation in California seems a lot more interesting than this article. https://ww2.energy.ca.gov/2019publications/CEC-500-2019-012/...

Thanks for the link. It is heartening to see utility-scale storage for a reasonable cost being developed.

20 years ago, there were a couple companies working on flywheel energy storage for mobile applications. They were using carbon-fiber flywheels, which could spin up to 100K RPM, but were expensive to manufacture. I would have predicted (back then) that carbon-fiber would have won out eventually for infrastructure applications as well, but I guess they were not able to get the costs down sufficiently.

Re: Giant flywheel project in Scotland could prevent UK blackouts

#53

Post by MrBuddyCasino »

msandford wrote: post #42
tpmx wrote: post #39

Earlier quoted context omitted.

What happens if the grid frequency disagrees too much with the rotation frequency of the flywheel, too quickly? The flywheel disintegrates and turns into a massive spherical weapon of mass distruction? Like this, but 20x worse? https://www.youtube.com/watch?v=bdcE3VyKv5U

The spinning flywheel doesn't just spin on its own. It gets spun up and kept spinning by an electric motor/generator I have to imagine. So you're limited as to how much power can go in or out by the size of that motor/generator. If it's a 100kw peak electrical machine then it can provide at most 100kw of instantaneous power to the grid while at the same time slowing down by however much is required to deliver that po…

Thats not the theoretical limit though. This is a physical device with moving parts. What if the bearing fails? What if the weight disintegrates due to a manufacturing fault?

Suddenly all that stored energy wants to go somewhere.

Re: Giant flywheel project in Scotland could prevent UK blackouts

#54

Post by epistasis »

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 storage is becoming cheap enough that it will hit the non-linear inflection point in deployment in the next few years. First, lots of lithium ion, and likely after that lots of flow batteries.

Re: Giant flywheel project in Scotland could prevent UK blackouts

#55

Post by rsynnott »

_whiteCaps_ wrote: post #4

> This is the first time a project of this kind will be used anywhere in the world and ESO believes it could be a “huge step forward” in running a zero-carbon electricity grid. I'm trying to find some stats on this, because flywheel UPS aren't a new idea: https://www.finning.com/en_IE/products/new/power-systems/ele... https://en.wikipedia.org/wiki/Flywheel_storage_power_system#...

> A flywheel-battery hybrid storage system has been installed in Ireland, a system that the companies involved claim is the first of its kind.

From 2016. Apparently part of the charm of flywheel storage systems is that they're always the first of their kind :)

(I suppose you could argue that the Irish one was the first with batteries and this is the first without, but really I suspect neither are either)

Re: Giant flywheel project in Scotland could prevent UK blackouts

#56

Post by LeoPanthera »

sloucher wrote: post #37
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.

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.

Re: Giant flywheel project in Scotland could prevent UK blackouts

#57

Post by mrow84 »

tankenmate wrote: post #45
neltnerb wrote: post #41

Earlier quoted context omitted.

Is this used in practice? It sounds like a rather substantial engineering challenging considering how much energy the wheel is storing. I remember MIT had one of these for sparking the old tokomak, they had to plan for it to fall off, destroy several buildings without killing anyone, and then land in the river... and that was a solid wheel that did nothing but spin. But isn't the point that it provides inertia toward…

As you say, I suspect it probably isn't used much in grid scale applications. The device image in the article would imply that it is just a simple damper, i.e. the angular momentum acts to reduce any frequency change, up or down. It doesn't look like it does any storage, but then the article is somewhat content free.

What you are describing is essentially a centrifugal governor: https://en.wikipedia.org/wiki/Centrifugal_governor, I think?

Re: Giant flywheel project in Scotland could prevent UK blackouts

#58

Post by VBprogrammer »

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.

I'm not sure where you are getting that frequently is proportional to voltage. Voltage in a synchronous generator is controlled by varying rotor excitation current. Frequently is controlled by varying the power to the prime mover.

But your main point is correct. This has to store energy to control frequency.

Re: Giant flywheel project in Scotland could prevent UK blackouts

#59

Post by PeterisP »

xhkkffbf wrote: post #32

Why do we care about keeping frequency stable when more and more products simply put the power through a rectifier to turn it to DC? The lamps all have LED "bulbs". The computers have power bricks. Do we really care if the compressors in the air conditioners and the refrigerators turn at a slightly different rate? Okay, maybe a rapid shift in frequency could be damaging, but a slight drift sounds okay mechanically. O…

This flywheel is exactly about compensating rapid changes in production/consumption so that they do not cause rapid shifts in frequency which can cause disruptions to the whole grid.

The household electric devices or the long term frequency drift are not relevant there, it's about keeping the huge turbines everywhere else running at a stable rate. The other way to achieve rapid compensation for frequency drop is to disconnect consumers, i.e. automatically triggered blackouts.

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