'... lets you store store hydrogen for long periods of time' is not as easy as you suggest. It's well known that hydrogen makes most (possibly all) metals become brittle over time. Hydrogen also leaks easily through metals because the atoms are so small. Consequently very expensive tanks are require to '..store hydrogen for long periods of time...'. It's a near certainty that storing energy for long periods is more effectively done with Megapacks of batteries. A little googling will show that Tesla (and others) are now making a booming business in this technology whereas, to my knowledge, not one substantive hydrogen storage plant has been built to date, because of the problems stated above.