The Makani Airborne Wind Turbine (AWT) is a tethered wing outfitted with turbines. It flies between 250 and 600 meters (800 and 1,950 feet), where the wind is stronger and more consistent. Makani is developing a 600 kW AWT, for utility scale generation at a cost below conventional solar and wind.
The Makani AWT operates like a wind turbine. Air moving across the turbine blades forces them to rotate, driving a generator to produce electricity.
Due to its speed, the tip of a conventional wind turbine blade is the most effective part and is responsible for most of the energy produced. The Makani AWT takes advantage of this principle by mounting small turbine/generator pairs on a wing that itself acts like the tip of a traditional turbine blade. The wing flies across the wind in vertical circles, fixed to the ground by a flexible tether.
Wing Operation Diagram – Click to open fullscreen
Makani has developed hybrid rotors with symmetrical, uncambered foils that let them generate energy as a turbine or apply thrust like a propeller. The rotors are used as propellers to keep the wing aloft during short lapses in the wind, allowing the wing to stay aloft if the wind dies.