Vanadium news, page-10

I believe the biggest disadvantage of V-flow battery technology is the currently low rate of implementation on electrical power grids. Despite the many apparent advantages of V redox flow batteries for balancing electrical power supply on the grid, there are only two V flow battery facilities larger than 10MW currently operating worldwide (Wikipedia).

Electricity grid operators are conservative and risk averse because they provide an essential service often in monopoly or low competition environments. This (the largest) customer group for V-flow battery technology will likely require a longer history and more demonstrated examples of successful V-flow battery operation before they invest. But if/when that occurs, uptake rate should increase exponentially. The 200 MW V-flow battery currently being built in China should provide impetus for greater acceptance.

Wikipedia link: https://en.wikipedia.org/wiki/Vanadium_redox_battery