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'Windmill': China tests world’s first megawatt-level airship to capture high winds
(interestingengineering.com)
This is a most excellent place for technology news and articles.
In all your examples there is the ground to provide a counteracting force. Maybe I am misunderstanding what you mean by untethered, but any initial airspeed difference between the wind and your system will eventually vanish and you'll move along with the surrounding air.
I co-founded an AWE startup 8 years ago and let me tell you, literature does not support your claim.