Airborne Wind Energy (AWE) is extremely mass-sensitive, because it takes energy to maintain heavier-than-air mass aloft. This is a parasitic factor compared to conventional turbines bolted atop a tower. AWE therefore applies fully tensile structure in the form of soft power kites to make flying versions of wind turbines. The compression forces required are comprised from air itself, a neutrally buoyant medium.
A single power kite can be made to loop under a classically self-flying pilot-lifter kite, and produce reciprocating (pumping) power without active digital controls. Classic Kites are so well optimized, by vast empirical practice, they even self-relaunch, with hardly any “stuck” states.
Here is a 2012 Looping Foil prototype, pumping air, that set an AWES (AWE system) session endurance record of two weeks (only limited by field logistics). This same rig generated electricity last year in another video. Using standard COTS TRL9 kites, multi-kW Looping Foil AWES are cheap and simple to create.