I might be mistaken on storing hydrogen, but all that takes in a high pressure container. I can imagine putting those solar-to-hydrogen plants up at sunny but remote places with plenty of space. Once a month when the containers are full a train comes along, unhooks cars with empty containers and goes off with the full ones. If you were to do that with any sort of battery you'd need two batteries, one be charged, one being used/discharged elsewhere, and your battery (for lack of a better term) efficiency (Total cost of usage?) basically halves.