? What on earth are they thinking? Have they forgotten the Hindenburg?
Hydrogen by mass is energy dense, by volume it is not.
Generally at present hydrogen is made from fossil fuels and is used in industrial processes.
It is unlikely to ever be used as a transport fuel on the large scale, simple physical limitations probably preclude there ever being a hydrogen economy (It has been talked about since the OPEC oil crisis of 1974).
The old era of ‘Town Gas’ was probably as close as one got to a hydrogen economy.
Hydrogen could be created from biocoal, particularly for producing carbon neutral fertilizer (ammonium nitrate)