Flow batteries for grid-scale energy storage. Really!

How many batteries do we need to make unreliable solar and wind power work on a large scale?

"In the coming decades, renewable energy sources such as solar and wind will increasingly dominate the conventional power grid. ... " Really MIT????

"... However, the electrolyte in a flow battery can degrade with time and use. While all batteries experience electrolyte degradation, flow batteries in particular suffer from a relatively faster form of degradation called “crossover.” ...
Demand for vanadium will grow, and that will be a problem. “Vanadium is found around the world but in dilute amounts, and extracting it is difficult,” ...“So there are limited places — mostly in Russia, China, and South Africa — where it’s produced, and the supply chain isn’t reliable.” As a result, vanadium prices are both high and extremely volatile — an impediment to the broad deployment of the vanadium flow battery. ..."

Flow batteries for grid-scale energy storage | MIT News | Massachusetts Institute of Technology A modeling framework developed at MIT can help speed the development of flow batteries for large-scale, long-duration electricity storage on the future grid.