Airborne wind turbines, energy from high altitude

Makani Power is developing Airborne Wind Turbines (AWT) to extract energy from the powerful, consistent winds at high altitudes. Makani's AWT is a rigid wing that flies at altitudes between 300 and 600 meters. Turbines on the leading edge of the wing face into the wind as it flies and generate energy, which is transmitted to the ground along a tether. Makani AWTs will produce energy at an unsubsidized real cost competitive with coal-fired power plants, the current benchmark of the lowest cost source of power.

 

The wing flies in circles navigated by the autonomous controllers running on state of the art avionics systems. Power is extracted by wing mounted rotors by slowing the wing down. Generated power is transmitted down the tether to the ground station where the bank of lights on the ground station is illuminated to dissipate excess power.

 

 

The Makani AWT operates using the same principles as a wind turbine. As wind moves air across turbine blades, their airfoil shape forces them to rotate perpendicularly to the wind. The blades are attached to a central hub and rotate as the wind blows, driving a central generator that produces electricity. Like a sailboat with a large sail on a tall mast, wind turbines are more effective when they have longer blades to access larger areas. However, as conventional wind turbines grow in size, manufacturers are fast approaching the limits of possibility given the strength and cost of current materials.

 

In the Makani system the blade is a wing, anchored to the ground by a tether so that it is free to fly in large circles. The wing flies across the wind by the same principles that cause a wind turbine to rotate. This system makes the Makani AWT more materials efficient: there is no tower, hub or nacelle.

 

 

For more read Energy Harvesting and Storage for Electronic Devices 2011-2021 

 

And attend Energy Harvesting & Storage Europe 15-16 May 2012 Berlin, Germany