You gotta love stuff like this! I wonder if there is enough helium to deploy this on a significant scale worldwide?
I suppose it would not be the worst thing in the world to use hydrogen. An explosion of an unmanned airship turbine might not be more catastrophic than, say, a large helium leak that causes the thing to crash to the ground. I doubt these things would be deployed over populated areas. A crash would probably be no worse than a wind turbine tower falling over. Do a Google image search for: wind turbine accidents . . . and you will see plenty of them. - Jed
