This is a useful chart (though it would be nice if efficiency was included). https://en.wikipedia.org/wiki/Hydrogen_storage#/media/File:Available_storage_techn

This is a useful chart (though it would be nice if efficiency was included). https://en.wikipedia.org/wiki/Hydrogen_storage#/media/File:Available_storage_technologies,_their_capacity_and_discharge_time.jpg https://en.wikipedia.org/wiki/Hydrogen_storage#/media/File:A...