The chapter 12 is available on
The vertical trajectory for Magnus Effect-Based AWES is described as I mentioned. See the Fig. 1.24 page 26, “Table 1.3 Parameters of the MW scale Magnus rotor” page 23, and page 24:
[…] the net output power is found to be 1.37 MW for X = 4.3, which corresponds to an energetic performance of 1.37 kW/m². This is consistent with the results of the medium scale system 1.48 kW/m² and 1.25 kW/m² found in [Milutinovic2015].
Now let us try to compare the efficiency (kW/m²) with also a Magnus Effect-Based AWES, but flying by “crosswind trajectories” (from the abstract of Modeling and control of a Magnus effect-based airborne
wind energy system in crosswind maneuvers https://hal.science/hal-01514058/document), the Fig. 6 page 7 representing a figure-eight. See also 4.2 Simulation parameters, then in page 8:
This results in a mean power of the full cycle of 1.47MW.
It can be assumed that the two Magnus-effect AWES have been optimized. The second one covers half the area for a comparable or even identical power.
My temporary comment: the vertical trajectory is also a crosswind trajectory, but it operates over only one side around the quasi center of the flight window compared to a horizontal crosswind trajectory. The other side would be underground… On the other hand, the vertical trajectory can start at a lower altitude, closer to the maximum power area of the flight window, but ends at a high elevation angle where the harvested power is lesser.
In the end, the horizontal crosswind trajectory has the advantage of being able to sweep the two sides around the quasi center of the flight window, which could explain the better performance in simulation, but at the cost, at least for the Magnus cylinder, of greater maneuvering complexity and a limit to scalability due to turn requirement.