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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.
Oh, I understand that perfectly well. The question is: that thing is a tethered balloon. If they expect to have it float 10 Km up, it has to be tethered with a cable at least 10Km long, which should be able to withstand the forces created by wind resistance, plus its own weight, and be conductive, so some lightweight cable won't cut it, metal will have to be involved, and not some lightweight signal cable, but hefty metal. Will that thing be buoyant enough to lift that cable?
Oh sorry, I think I was responding to someone else. As for cable weight, I was playing around with this calculator and for a pure copper wire less than 3mm thick and 10km long, you only need to overcome 300kg in weight.
If you use the standard 20mm wide cables, then yes weight becomes a huge problem. But then maybe you use more balloons, or just secretly hook it over a few satellites when no one's looking