They'll need to discover a decent substitute to Gallium Chloride first, because Gallium is likewise a rare earth with a comparable crust distribution and necessitates extensive processing. It would be fantastic if we could find a non-rare earth solution for large-scale storage.
Mechanical batteries, on the other hand, may be used for large-scale storage. The traditional method of storing water in a tiered reservoir works well, albeit that specific gravity fed battery isn't the most environmentally friendly choice and can only be created in certain places. Similar mechanical battery concepts, on the other hand, may be profitable if they can be scaled up to compensate for the energy density.
