I have been following them for a few years and they are making some slow and steady progress
From their page: As the world generates more electricity from intermittent renewable energy sources, there is a growing need for technologies which can capture and store energy during periods of low demand and release it rapidly when required.
At Gravitricity we are developing innovative, long-life, underground technologies which store energy safely and deliver it on demand at a lower lifetime cost than current alternatives.
I think Gravitricity (obligatoy, stupid name) is trying to make it more space efficient and consolidated, rather than occupying massive amounts of land.
Water also isn’t the safest thing when in massive reservoirs, nor is it all too easy to get it there in the first place.
So while you’re correct in the sense that we have GPE batteries, they aren’t super easy to build nor maintain. I think this is where [stupid name here] is trying to place themselves.
You are probably correct, there’s probably gravity energy applications where water isn’t the best option.
The only way to make this crane system work reliably would be to enclose it entirely to protect it from wind, and/or build a huge frame around it to keep the blocks sufficiently aligned… making it a much larger undertaking than just a crane with a bunch of blocks around it.
“Underground” is mentioned in the text above. I know that some people are considering to store heavy blocks connected to ropes in the shafts (?) of old coal mines that go down hundreds of meter. Use a single, very heavy block and you’re good to go. Though I don’t think that it holds a significant amount of energy (too lazy to calculate and no feeling for the possible dimensions of such a block). Also, digging new shafts should be prohibitively expensive for energy storage.
Ah yeah I missed that underground part, I mixed it up with another proposal for a freestand crane doing the same…
Putting the blocks onto some internal rail is probably the easiest way, with wheels in constant contact, similar to an elevator.