I wanna ask the stupid question...I don't understand the concept too well. But I read up about this a while ago, doesn't liquid Hydrogen require an extremely cold environment to remain in a liquid form? What about the dangers of having a leak etc. Just a simple question i'm sure since it appears most of you guys seem like you know what you are talking about.
Not necessarily, but it sure helps. You have two choices to turn a gas into a liquid. Lower the temperature, or increase the pressure. (Or both of course...)
It would take far too much energy to lower the temp sufficiently, so you would have little choice but to increase the pressure. (Just like with propane tanks for your grill.) Of course, it takes a lot more pressure to make liquid hydrogen, and God help you if the tank ruptures....