In yo-yo mode, the reel-out phase is the power phase, while the reel-in phase is the recovery phase.
But we could design an airborne wind turbine, for example a torus shrouded wind turbine, where both are power phases, the reel-in phase being the more powerful phase.
The torque is used to operate a generator, as with any wind turbine.
During the reel-out phase where the apparent wind is lower than the true wind, part of the power is retained.
During the reel-in phase where the apparent wind is higher than the true wind, extra power is added, and the power is far higher than during reel-out phase in spite of the required power to recovery the wind turbine.
By a variant, reel-in phase acts a ground-based generator, like for any yo-yo system, the generator aloft being disengaged.
It is interesting to note that what is the power phase in a “classic” yo-yo mode (where there is also a consumption reel-in phase) is the lower power phase in this configuration.
Of course, using this airborne wind turbine in stationary mode is preferable.