In a hybrid airship the hydrogen would not necessarily be liquid.
Then you get a volume problem. The problem is that while hydrogen supplies three times the energy per pound of gasoline it has only one tenth the density when the hydrogen is in a liquid form and very much less when it is stored as a compressed gas. This means that hydrogen fuel tanks must be large. In addition they need to be insulated.
Even an insulated tank will leak about 2% energy
pr day.
So, you get a storage and logistical problem on on the ground as well.
Large tanks in an aircraft means either
- Less payload
- More volume -> more drag & mass
XPM