Wow, this sounds like a promising concept I've never heard of before. To me, the main three questions are round-trip efficiency, max storage time and environme

Wow, this sounds like a promising concept I've never heard of before. To me, the main three questions are round-trip efficiency, max storage time and environment impact. https://en.wikipedia.org/wiki/Vanadium_redox_battery https://en.wikipedia.org/wiki/Vanadium_redox_battery mentions 75% to 80% efficiency, though I don't know how well that applies to such big systems. http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.194.9741&rep=rep1&type=pdf http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.194... mentions a better environmental profile compared to lead acid batteries, but that might be a low bar.