Method for airborne kinetic energy conversion

1. A method to harvest renewable energy, comprising:

flying an aircraft in untethered flight in an open airspace, the aircraft having an airborne kinetic energy conversion system attached to an airframe of the aircraft, the airborne kinetic energy conversion system comprising a turbine, a generator connected to the turbine, and an energy storage device connected to the generator;

gaining excess kinetic energy of the aircraft by gaining excess aircraft speed over an aircraft cruise speed by flying the aircraft into an identified wind resource in untethered flight;

converting excess kinetic energy of the aircraft into electricity while in untethered flight, using the kinetic energy conversion system by driving the turbine at the excess aircraft speed; and

storing the electricity from the kinetic energy conversion system using the energy storage device.

2. The method of claim 1 , further comprising:

providing a solar power system; and

converting solar energy into electricity using the solar power system.

3. The method of claim 1 , further comprising providing a propulsion system comprising an electric motor and a propeller.

4. The method of claim 3 , wherein the propulsion system is operable as the kinetic energy conversion system so that the electric motor is operable as a generator and the propeller is operable as a turbine.

5. The method of claim 1 , wherein the excess speed is greater than the pitch speed of the turbine.

6. The method of claim 1 , further comprising gaining excess potential energy.

7. The method of claim 6 , wherein gaining excess potential energy comprises gaining excess altitude.

8. The method of claim 1 , further comprising identifying one or more of a vertical updraft, horizontal wind shear, a wind gust, or a cloud zone.

9. The method of claim 1 , further comprising identifying a wind gust, wherein converting excess kinetic energy into electricity comprises operating the turbine when the airspeed exceeds its pitch speed.

10. The method of claim 1 , further comprising identifying wind shear, wherein increasing kinetic energy comprises performing a dynamic soaring maneuver.

11. The method of claim 1 , further comprising:

identifying a vertical updraft; and

increasing the aircraft's altitude, wherein increasing kinetic energy comprises a simultaneous decrease in aircraft altitude and increase in aircraft speed.

12. The method of claim 1 , further comprising:

identifying a cloud zone; and

increasing the aircraft's mass by collecting atmospheric water, wherein increasing kinetic energy comprises a simultaneous decrease in aircraft altitude and increase in aircraft speed.

13. The method of claim 1 , further comprising searching and finding one or more of a vertical updraft, horizontal wind shear, a wind gust, or a cloud zone.

14. The method of claim 1 , further comprising providing an autopilot and flight control electronics for controlling the flight of the aircraft.

15. The method of claim 14 , wherein the autopilot is configured to perform flight maneuvers resulting in excess kinetic energy in the presence of one or more of a vertical updraft, horizontal wind shear, a wind gust, or a cloud zone.

16. The method of claim 1 , wherein gaining excess kinetic energy includes:

gaining potential energy of the aircraft by gaining altitude of the aircraft; and

converting the potential energy of the aircraft into excess kinetic energy by performing a dive maneuver to drive the turbine.

17. The method of claim 1 , further comprising:

using the kinetic energy stored in the energy storage device for sustained flying of the aircraft at a cruise speed in untethered flight in open airspace.

18. The method of claim 1 , further comprising:

identifying a wind resource suitable for powering the aircraft; and

flying the aircraft into the wind resource to gain the excess kinetic energy.