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0 pointsbob10295y ago0 comments

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 idea, and powered exclusively by the grid itself.

You wont be able to ride out a scenario where there is a long-term lack of generation capacity, but this flywheel could buy the precious seconds/minutes required to spin up peaker plants and other contingencies.

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TremendousJudge5y ago

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

craftinator5y ago

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

generatorguy5y ago

Rotational energy goes up worth both the square or the radius and the speed, so it is much better bang for your buck to have a the mass centered on an outer rim connected to a hub by spokes and spinning really fast rather than just something uniformly heavy. The mass close to the centre doesn’t do anything for you.

The heavier it is also requires bigger more expensive bearings and accompanying system to get the thing spinning in the first place.

I looked at a flywheel that spun at 12,000 rpm. It was going to be located in an underground vault in case it ever got off its pedestal bearings it wouldn’t mow people down.

Like anything that stores energy but doesn’t generate the economics aren’t great.

bob1029OP5y ago

No clue - I was hoping for numbers myself.

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