I've been toying around with an experimental idea for an efficient way to store hydrogen for use in hydrogen fuel cells, but recently I haven't been able to think of much more to add to it. I've thought of using cooling and pressure together to put the hydrogen to a liquid form for more compact storage, but the energy use of such a device would outweigh the production. If any of you have better ways of dealing with this idea, please post feedback. It would be appreciated **If I've put this thread in the wrong category please tell me. Thank you.