Stratta-Bâche-Kite can be translated into Stratta-Tarp-Kite. I put again the informations on What kite plans do you like?, thinking it can be a major innovation to make AWE a reality. Indeed this is the first real kite made with a tarp with almost no transformation. So in some way the kite for AWE use is already marketed as a tarp, and is cheap.
Some links (again): https://groups.yahoo.com/neo/groups/AirborneWindEnergy/conversations/topics/25571,
https://cv.ffvl.fr/node/112,
XF-film ( https://www.supreme.co.in/xf-films-products.php, https://www.arktarps.com.au/comparison-to-woven-tarps/ ) I mentioned has a very long lifetime I tested for more than three years outdoor, compared to some weeks of months for a soft crosswind kite in full operation.
In yoyo mode the power is 15% (4/27) the wind power of a given swept area. 15% is a very high value within a whole kite-farm. With 10 m/s wind speed 1 m² provides 1/2 x 1.2 [air density] x 100 x 3.33 [reel-out speed] x 4/9 [downwind loss of apparent wind] = roughly 90 W, so 15% of 600 W (wind power before Betz limit).
10000 m² produce 900 kW, for a kite mass about 1 ton, so a similar power/weight ratio as a MW scale rigid crosswind kite, but with a better possibility to reduce spacing between the unities, and perhaps a safer use.
Lifetime of xf-film: several years (vs lifetime of a soft crosswind kite several months).
Possible maximization of the space: yes.
Reliability and safety: perhaps yes.
Low LCOE: yes.
The Stratta-Bâche looks to be a (if no the) real possibility for a viable (here static, not crosswind) AWES, in pumping mode. The two lines can work the two winches and in the same time improve the active stability, using a simple automated control to study for improving the passive stability. A low crosswind mode is also possible. In all ways collisions between kites are without serious damage thanks to both low motion and kite flexibility.
The low efficiency as it is a static kite (apart reel-out move) is compensated with both a higher lifetime due to less strengths on the kite, and less spacing between the unities within a kite-farm. So in the end a better maximization of the available power can be reached in the whole kite-farm area.