A molten salt storage solution using sodium hydroxide
(I do some research in this space)There are lots of cheap ways of storing heat... The capacity cost of thermal storage has not been the bottleneck for commercialization, but rather the round trip efficiency. This seems academically interesting, but I doubt it will be much more than that.To a first order approximation, the cost of power from a storage system is going to be $/kWh_source_power/efficiency+ammortized cost of capital. No matter how cheap the second term is (and it can't be that cheap unless someone invents a 10x cheaper turbine), the first term tends to make storage uneconomical unless your RTE is above ~80%. This will get ~60% at best.(of course, I could always be wrong)