I think an important thing to note about gravity batteries is how environmentally friendly they are, even relative to lithium ion batteries. Lithium mining is a

I think an important thing to note about gravity batteries is how environmentally friendly they are, even relative to lithium ion batteries. Lithium mining is an insanely tight bottleneck in LI battery production, mostly outsourced to countries where we don't think much about it (Australia is a big one right now, but in terms of untapped reserves, Chile Argentina and China are all huge). They require complicated manufacturing processes that are centralized into maybe four or five advanced manufacturing companies around the planet. When speaking about LI packs, especially to enterprises deploying them at grid scale, their expected life has to enter into the equation. Maybe 15 years? 25? So, millions up-front, and millions more every couple decades; its not an impossible sale, but relative to other options (like hydro storage, which is excellent but also limited to areas with existing reservoirs) its not obviously the best option. They may be better, but I don't feel that means gravity batteries don't have a place. The mechanical pieces to raise and harvest the energy likely aren't carbon-zero, but the weight itself can be built out of anything. They don't experience leakage of stored energy over time (barring a failure of the retention system keeping the weight elevated) (though, obviously, there is loss in the addition of energy to the storage, as the machines which raise the weights are not perfect). They can be reused essentially indefinitely (excepting continuing upkeep of the retention and raise/harvest systems, and proper weather protection of the weight). Their failure mode is "falls", which can be designed far, far safer than a typical LI pack failure of "explodes in a fire that literally cannot be put out". None of the systems in-play are particularly technically advanced, and a ton of the cost is up-fronted. There's a lot of reasons to think they will represent a component of green energy storage in the future; likely not as large at LIo packs, but the world is a big place.