Captain Planet

Though it was first discovered by Ben Franklin when he flew that kite, atmospheric energy was abandoned long ago as a viable source of cheap, renewable electricity.  Occasionally, researchers revisit the idea, which is typically presented as something like a weather balloon with a long cable attached to it.  This is potentially very portable.  One company claims to have workable patents, but every article I could find about them has the same information, as if the journalists were instructed to stick solely to the press release.  However, I am interested in renewable energy, so I made a handy chart of options: