Moving on to the Materials Science of "polymerizing the sky" with kite networks, to sustainably harvest abundant kinetic energy of upper wind. A barrel of oil made into power kites can offset hundreds of barrels that might otherwise be burned for energy.
The key power soft-kite utility parameter is strength or power-to-mass. One material stands out, Ultra High Molecular Weight Polyethylene (UHMWPE), about 10x stronger than steel by mass. Ethylene is the non-toxic waxy coating many plants use to conserve moisture. Under heat and high pressure, the ethylene hydrocarbon monomer is extended into parallel crystals >100k units long, the carbon atoms double-bonded, and crosslinked by hydrogen bonds. Short of graphene tubes, with triple bonded carbon, UHMWPE is the best engineering fiber since Nylon.
UHMWPE is a liquid-crystal (it will creep), but its Debye temperature is comparable to diamond, so its physics are native QM, not just analogous, over a large scale-invariant spectrum. The speed-of-sound in tensioned UHMWPE can reach 50km/sec, similar to diamond. Elsewhere I have cited an example of a ship hawser towing a ship by a ship with a power of work of 10MW, yet remains cool to the touch. This sort of wonderful phonon physics frozen-wave power super-conductance has hardly been seriously studied, "hidden in plain sight". A few related physics concepts exist, like second-sound and ballistic-conductance.
This is the original 1970 paper describing UHMWPE as novel fiber-
Oddly enough, Nylon remains a mainstay polymer in state-of-the-art rigging, complimenting the low-stretch property of UHMWPE. In applications with shock and surge loads, Nylon can absorb the excess energy and return it after the load peak, where UHMWPE might violently shatter or vaporize, or shock-damage other components.
A final introductory aspect of AWE is Kite Network Metamaterial Topology, a fast emerging AWE engineering paradigm in acoustic and mechanical metamaterials. Networked Kitematter fulfills all criteria cited that identify a MetaMaterial as such. A future kite network with km scale cells would easily comprise both the largest and least dense engineered material (neglecting density of entrained air).
Mechanical Metamaterials take many novel forms but share fundamental properties, like negative-index phonon refraction, topological-insulator/edge-modes, and auxetic response. Puzzle challenge: Identify specific kite-based metamaterial mechanisms (answers soon).
Recopying this paper link Paul provided, that I missed earlier. Another representative paper in a proliferating literature. Will post some missing domain survey links when I relocate them.