Hi Pierre: See, this is what I’ve been saying all along: Even the most basic ABC;s of wind energy are lost on the AWE wannabes. I mean “it seems”? As though this was ever in question? What about car engines? DO more powerful engines tend to be bigger and heavier? Of course! I mean, isn’t such a basic fact as something more powerful tends to be heavier the most basic starting point for sus[enmding them in the air? isn;t weight the first factor considered in aviation? You knaw that aviation diagram, thrust versus drag, lift versus weight?
And you’ve repeated the claim that kiteX turbines are lighter for the weight? Well, i congratulate kiteX on two things: 1) realizing the overspeed protection is the most important thing, and 2) realizing a generator has to be big (heavy) enough to produce its rated power for unlimited time periods without burning out (heat dissipation). Just like a car engine or any other powerplant. (Gee, ya think?")
What I’m NOT seeing is their turbine being lighter than others for the output. To me, it seems similar to what is already out there, maybe even a bit heavier. The weight savings seem to be in the tower, or lack thereof. The idea is to place more swept area closer to the ground, thereby lowering costs, with pitch control limiting damage from overpowering the generator. Anyway, at least they have something that works, which is more than we can say for so many wind energy efforts! 
I’m not saying something absurd: being lighter relative to weight makes no sense.
So I’ll repeat what I wrote. I’m talking about mass relative to power. In one case, we have a large, lightweight wind turbine (relative to its size, not its weight, which is meaningless) producing its rated power in low wind speeds. In the other case, we have a smaller wind turbine producing its rated power in strong winds. In both cases, we have the same mass for the same power output, but with different characteristics. This isn’t obvious and still needs to be verified, because the parameters differ.
But since you’re hitting a roadblock right from the start, it’s not possible for you to refine the analysis to that point.
It’s hard difficult to find one good metric to use for comparison of performance of turbines.
In the Danish market (a likely most if not all future markets) you need a high capacity factor for your turbine to provide valuable energy. Energy produced when it’s very windy is worth much less. So based on that I think it’s reasonable to compare our turbine with other turbines based on rotor diameters. Our Cp is likely a bit lower, so perhaps a Cp adjusted diameter would 10 meters.
The actually mass of the generator is in our design not very important as we used a geared generator. If our turbine was 1kW the system weight would still be approx 300 kg. If it was 10kW I would expect we would end up with 430 kg.
Indeed, that makes sense. We more often have winds of 7 m/s than of 11-13 m/s. And therefore, a wind turbine with a 10 m diameter rotor will produce much more kWh over the year for a nominal power at 7 m/s wind speed than a much smaller wind turbine of similar mass but producing its nominal power at 12 m/s wind speed.
On the other hand, it seems that certain aspects of the construction of the TWT-11 are inspired by AWE techniques.
If one wanted to adapt a similar turbine for a (stationary) fly-gen AWES for stronger and more consistent winds at high altitude, one would be satisfied with a slightly higher mass as that of the TWT-11 but for these stronger winds.
One could then apply the KiteX principle (large lightweight wind turbine for moderate and frequent winds to achieve a higher capacity factor, hence a higher production, for a given mass) to AWES, shifting the nominal power to a wind speed of, say, 10 m/s, instead of a higher wind speed requiring a still heavier construction.
Hi Pierre:
That must have been a typo. Obviously I must have meant lighter weight for the output.
I do think their reasoning for maximizing the capacity factor makes sense in general, and especially for their unique case. i had a pretty influential “real wind person” tell me, several years ago, his impression that maximizing the capacity factor was the only way to go. I call it “generator worship” because the “capacity” being referenced is the capacity of the generator. I think it depends on your use case and the target wind resource. In reality, there is more to turbine design than getting full power out of a generator as often as possible as the sole design driver. One could just as easily go down the path of “rotor worship”, “tower worship” etc. Here, with our 10 kW turbine on a 120-foot tower, the tower itself and all the heavy steel guy cables (tethers?), I could see placing two of the same turbine at a lower height, yielding more output for perhaps the same cost, using less total material. Hard to say, but I admire that at least these guys came up with an idea, and are getting it to work. How well they survive remains to be seen, but if the overspeed keeps working well, maybe the turbines survive.