I might have looked closer at this, but just now it doesnt seem worthwhile to me. Perhaps if they release something more than a 3D rendering…
Let me just say this: Like the Laddermill (Laddermill, third post), the wings are generating crosswind energy, but at the same time moving the wings for power generation perpendicular to the wind direction (wing moving upwards and wind horizontal). This does not scale well I think with higher rotational speeds. You get a lot of force at low speeds, but little power when combined with fast rotation.
The reason that generating energy with motion perpendicular to the wind direction is a consecuence of apparent wind. With such a movement, apparent wind will work very hard against the wing motion. It would be very similar to a Kitemill/Makani Yoyo rig producing directly upwards. Anyone familiar with kites will know that once the tether is released somewhat (and kite moves upwards), the tether force will immediately be almost slack. It’s a matter of geometry, a bit hard to explain.
Another way to approach this is to understand that when harvesting wind energy, you are harvesting the difference in speed wind relative to ground. The tether force acting in the direction component directly against the wind is the basis for your power generation. If the tether is pointing mostly upwards (to reach high altitudes), you are probably not going to harvest much energy because the tether needs to be very strong for a small horizontal component.
Add to this that if you divide the circular motion into four quadrants, forward, aft, up down, only the forward quadrant (a bit simplified) is generating energy, up and down are pure transport while down is a pure loss (but necessary for the function of the device). So only 1/4 of the time, the wing is active.
It might be better if the device was headed mostly downwind instead of upwards into jetstreams.