Cool to see this come up! I recently had to write a (mock) proposal regarding different efforts to store excess green energy and I had a blast reading about gravity batteries and pumped hydro. Hopefully, these projects come along sooner than later, as widespread adoption will take much longer than the first several implementations.
Another neat tidbit I learned while researching pumped hydro is that hydroelectric dams actually use the remaining inertia of the spinning generators to pump water back up the dams, which is much like the idea of regenerative braking in EVs.