> I'm assuming solutions like this are uneconomic You kinda answered your own question already, I feel. The energy efficiency of cycling a battery (70-90% for

> I'm assuming solutions like this are uneconomic You kinda answered your own question already, I feel. The energy efficiency of cycling a battery (70-90% for grid scale) or pumped hydro (70-85%) is simply much, much higher than chemical storage. Here's a pretty recent one [1] showing 23% efficiency even at lab scale, and as described in the article scale is a big drain on efficiency. [1] https://www.nature.com/articles/s41467-022-29428-9 https://www.nature.com/articles/s41467-022-29428-9