Sometimes we create our own problems.

Why not do something with all that power?

This is a relatively new problem, so it will take awhile for the market to respond to make industries optimized to take advantage of this.

I saw an article a few months ago (couldn't find it quickly just now) about a small manufacturing company (metals maybe?) that set up shop specifically to run during the excess power events. So its starting to happen, but its not going to be a perfect fit. It means spending lots up front for infra, but only being able to use it a few hours a day cost effectively.

In the past there were some projects where they pumped water upstream when there was too much power on the grid. Then on low energy times, the water was released making energy again.

This is already done with pump hydro. But this needs existing hydroelectric infrastructure to take advantage of. Even then there are usually holding ponds upstream and they themselves have limited capacity.

Or make hydrogen (I think it was hydrogen).

This is being done too at small scales right now. There's difficulties with it. Hydrogen really sucks to try store and transport. The H2 molecule is so small it leaks out through valves and gaskets that are fine for containing nearly all other gases and liquids. So this means the gear needed is hugely more expensive up front. What a few are doing is using the hydrogen to quickly make Ammonia (NH3), which is much easier to store and contain. However, the efforts doing this are still fairly small.

Or do AI stuff

AI aside, this is one place I haven't seen develop yet. That being: cheaper compute costs during excess power events.

I suspect its the same problem for the manufacturing. It means spending money on expensive compute infrastructure but only able to use it during the excess power events. As in, the compute in place is already running flat out at full capacity all the time. There's no spare hardware to use the excess power. If you had spare hardware, you'd add it to your fleet and run it 24/7 making more money.

Or use it on large scale computing for protein folding simulations, or something.

And yeah, gravity batteries is the best I think we have, with water being the most common medium with pumped-storage hydroelectricity. But the scales of the things are kind of incongruent and... Autoincorrect actually got it right trying to correct that to inconvenient. Still really cool. I think we may need some innovations to cut down on scale issues though. Although it looks like the total power storage available is about one day worth of power for the US in PSH, I'm curious if the instantaneous output is sufficient for the grid and how spread out the storage locations are, as I somewhat doubt they're often in flatter regions. All in all, I'm not a power engineer, I just know a few and I should bug them sometime.

We still have hydroelectric turbines that can reverse themselves to pump water to a higher elevation reservoir to store surplus energy. We call them pump-gens at my job. The problem is that, as nearby areas develop, that water gets reserved for other things, so they can't pump it back up because it's needed further downstream for irrigation or communities or whatever.