> Storage cost is falling even faster than generation,
Citation please. The high demand for EVs and other battery-hungry devices has led to a situation where grid scale energy storage costs are currently increasing year over year and expected to continue doing so [1]. And pumped hydro storage is not something that will flexible enough for general deployment.
> and there are zero physics problems to be solved,
> just practical civil engineering.
Alchemy is not a solved problem, and there is only so much lithium to go around.
Batteries are the most expensive storage. The overwhelming majority of storage will not be batteries. Of what is batteries, the overwhelming majority will not be lithium. Lithium batteries are well adapted for cars and phones. Other qualities are favored for utility storage.
There are lots of exciting battery chemistries, and some boring ones. It is impossible to say which ones will win out, in the end. The one thing certain is that whichever wins will have the best performance per unit cost, and thus better than all the others.
Other exciting chemistries include molten antimony/calcium, zinc/bromine, and iron/air. The antimony/calcium one would never wear out or catch fire. Zinc/bromine is most compatible with current lead/acid battery tech. Iron/air is very, very cheap. None are very attractive for cars, so utilities will not be in competition with the car industry for access to batteries.
a mix of hydro and non-lithium batteries. for grid scale batteries, you don't care about weight, and if you make it big enough can hear the battery if it helps. as such there are a lot of very cool battery technologies in various stages of commercialization that will never go in a phone, but make a lot of sense when you scale them up to a few thousand pounds.
[1] https://cleanenergynews.ihsmarkit.com/research-analysis/grid...