Pumped storage hydro makes far more sense. Which is why it's already in use.
Maybe the efficiency can be improved upon with a small-scale 'gravity battery', but water has massive advantages when it comes to scaling it up, as well as being able to combine it with traditional hydro, where nature moves much of the water for you.
Plenty of issues with hydro, but in the grand scheme of things, it does seem like by far the most accessible, actionable, least polluting option.
I've often wondered what scale of a system would be required to power a fully off the grid home at say 30kwh/ day, for say, 6 days? I'm imagining a tank based system with two tanks where the fluid is effectively just exchanged (so one doesn't have to account for the environmental impacts of a dam or for losses due to evaporation)..
