Dont you forget something- hydrogen if hydrolizes takes place in situa - aka directly below a windpower or solar-plant, has the lowest conversion loss right there.. Also storage can be improved by now chemically - meaning you bind it to a https://en.wikipedia.org/wiki/Hydrogen_storage#Liquid_organi...

and reduce that to a nearly solid material with extremly high energy density. Its okay to be a tesla fanboi, its not okay to propagate ancient technological "insights".