An early prototype was tested at 350 feet in the air, though the design is meant to reach 1,000 feet. The energy produced high above is transmitted to ground level with the use of tethers, like the ones used by the Makani AWT. In addition to proving more efficient, these airborne crafts may reduce problems such as noise and interference with bird migrations, precisely because they reach higher elevations and are further removed.

Vertical Axis Turbines:

Wind engineers have long favored turbines in which the rotor is attached to a horizontal shaft and the blades point into the wind. This horizontal axis wind turbine (HAWT) is thought to be more efficient and less susceptible to damage and the stability problems that have plagued turbines in which the rotor is set vertically. But with renewed focus on so-called vertical axis wind turbines (VAWTs), there are some like John Dabiri, the director of the Center for Bioinspired Engineering at Caltech, who see the potential for improving efficiency and lowering costs in this alternative. Taking the opposite strategy of the airborne wind turbine designers, Dabiri and his collegues have focused on wind currents closer to the ground than are normally targeted. They contend that the wind power available at 30 feet far exceeds the global electricity usage if it is fully captured.

The VAWTs installed by Dabiri for field experiments in 2010 rise only slightly higher than 30 feet. The smaller size is said to make maintenance easier, and the vertical-axis design allows for a much closer arrangement of turbines than is possible with HAWTs.