Flow batteries have no where near the energy density W/kg of lithium, the only thing that approaches petrol in any practical sense currently. So for vehicles, m

Flow batteries have no where near the energy density W/kg of lithium, the only thing that approaches petrol in any practical sense currently. So for vehicles, maybe coupled with a 5-10% supercapacitor for an electronic flywheel, will dominate transport requirements for some time. Flow batteries, given a non toxic electrolyte, are hard pressed to be beaten for the closest thing to base load a battery is going to get. The need of the application is everything currently as it is all edge cases and probably will be for an indefinite future, without some kind of totally off the radar break through.