I’ve been thinking about doing something like this with my excess solar.
https://qz.com/1355672/stacking-concrete-blocks-is-a-surprisingly-efficient-way-to-store-energy/
... basically with surplus energy they lift 55 gallon drums of sand with a crane and then when they want the energy they simply lower the barrels and recapture the energy.
Seems like something that could be done on a small scale with modified off the shelf parts, but I don’t know quite how yet.
