'Windmill': China tests world’s first megawatt-level airship to capture high winds
(interestingengineering.com)
Neat.
Any real reason you can't fill them with hydrogen? A fire can't start inside the bubble, because there's no oxygen. If a fire starts on the outer surface, then it doesn't really matter if it's hydrogen or not. It's also cheaper and slightly better at lifting. There is some more danger with handling it on the ground, but you should be able to mitigate that with safety procedures.