The Graf Zeppelin, the Hindenburg's older sister, was fueled with gasified coal. Blimps are an energy efficient form of transport of cargo that DOESN'T absolutlely, possitively have to be there overnight.
The Zeppelins had the one flaw: Hydrogen lifting gas. Of course, a mix of rust and powdered aluminium didn't help. Helium came from Texas gas wells and was stockpiled by us. For helium blimps, there is a limited amount of helium with none left in the ground since we Yanks had the monopoly.

While blimps are energy-efficient, you can't replace the planes with them due to lack of new helium reserves. We already had a full depletion cycle!