3 ms·
Kinetic (water gravity, flywheel) or thermal (molten salt baths which can be supplemented with solar thermal). None of these things exist at a large scale exce
by zdragnar 4y ago
Kinetic (water gravity, flywheel) or thermal (molten salt baths which can be supplemented with solar thermal).
None of these things exist at a large scale except for pumped hydro / water gravity, and that requires very convenient topography and geology to work. Generally, any non-chemical storage system is overpriced (too inefficient) or a maintenance disaster.
- sanderjd 4y agoDo you think those technologies will be scaled such that batteries are a "negligible fraction" of utility storage, or are you just giving examples of possibilities?
- ncmncm 4y agoNumerous technologies will be scaled. Those mentioned adjacent are just very easily understood examples. Utilities will have criteria other than "easily understood", cost chief among them.
- User23 4y agoFlywheels and molten salt both have pretty gnarly failure modes too. Not Chernobyl bad, but still no fun.
- ncmncm 4y agoUnderground flywheels are perfectly safe, and more easily kept evacuated. But they won't be used much at utility scale, because they are expensive per Wh stored. Maximum storage is dictated by tensile strength of the wheel material, and each wheel needs its own motor / generator.
- ncmncm 4y agoA negligible fraction of storage will be in flywheels.
- ncmncm 4y agoPumped hydro is not kinetic. Not much storage exists because it has not been built yet. It has not been built yet because we haven't the renewable generating capacity to charge it from yet. Thus, we are spending on renewable generating capacity first, and lately factories that will build storage systems. Battery storage is the most expensive variety. Round-trip efficiency is not very important anymore. I.e., other concerns dominate now. Anyway, gravity storage efficiency has always been fine.