It's a nightmare. It is very leak-prone and has a very wide range of concentrations-in-air that will ignite. The energy to ignite it is also much lower than for LNG, for example.I have not looked closely but how is clean hydrogen supposed to be produced and distributed and stored on the scle needed? I actually don't know the answer. It would have to be liquified, it seems to me? and isn't it extremely prone to leakage?