Well at least Raaaid tried to answer my question. That's better than most. Yes, I'm bitter.
My main problem with "free" sources of energy means that if things lined up correctly in the universe, a self-substaining release of "free" energy could result, releasing more energy, gaining more, until the universe blows up. So I'm not a big believer in perpetual motion or "free" energy.
Another idea is that somehow the motion of the airfoil through the air unleashes the potential energy of the compressed air. Air is under pressure after all. Then the wake and vortexes are the areas of "low energy" left behind, eventually corrected by gravity.
Just an idea....
I search on.