Bird or bat detection and identification for wind turbine risk mitigation

1. A method for mitigating risk of an airstrike to an airborne animal by a wind turbine, the method comprising the steps of:

optically imaging an airborne animal with an optical imaging sensor;

providing images from the optical imaging sensor to a controller;

analyzing the optical images with the controller to determine if the airborne animal is a likely member of a predetermined species;

sending a first signal to curtail operation of the wind turbine to a predetermined risk mitigating level for the airborne animal that is determined by the controller to be a member of the predetermined species and is at risk from the wind turbine; and

wherein the controller determines if the airborne animal is a member of the predetermined species at a distance from the wind turbine that is greater than a distance the predetermined species flies at a characteristic speed in a time required to curtail operation of the wind turbine to the predetermined risk mitigating level, wherein the characteristic speed is a maximum flight speed or an average flight speed of the predetermined species.

2. The method of claim 1 , further comprising the steps of:

continuing to optically image the airborne animal with the optical imaging sensor;

analyzing the optical images with the controller to determine if the airborne animal is at a reduced level of risk from the wind turbine; and

sending a second signal from the controller to the wind turbine to resume normal operation of the wind turbine for the airborne animal that is determined to be at the reduced level of risk from the wind turbine.

3. The method of claim 1 , wherein the characteristic speed is a maximum horizontal flight speed of the predetermined species.

4. The method of claim 1 , wherein the characteristic speed is a maximum horizontal flight speed or an average horizontal flight speed of the predetermined species.

5. The method of claim 1 , wherein the predetermined species is selected from the group consisting of:

a golden eagle;

a bald eagle, and

a golden eagle and a bald eagle.

6. The method of claim 1 , wherein the predetermined risk mitigating level comprises decreasing a rotation speed of the wind turbine that is less than 1 rpm over a time period that is less than 30 seconds.

7. The method of claim 1 , wherein the optical imaging sensors comprise a plurality of optical imaging sensors arranged to provide a combined field of view that envelops the wind turbine.

8. The method of claim 1 , wherein the optical imaging sensor comprises a digital camera.

9. The method of claim 1 , wherein the controller determines whether the airborne animal is approaching the wind turbine.

10. The method of claim 9 , wherein the first signal to curtail operation occurs for an airborne animal of the predetermined species that is within 800 m of the wind turbine and is approaching the wind turbine.

11. The method of claim 1 , wherein the analyzing step further comprises determining whether the airborne animal exhibits animal behavior of higher risk for an airstrike with the wind turbine.

12. The method of claim 1 , wherein the analyzing step to determine if the airborne animal is a member of a predetermined species comprises analyzing one or more of the airborne animal size, shape, color, or flight characteristic.

13. The method of claim 12 , wherein the analyzing step is of optical images of the airborne animal that is greater than 1000 m from the wind turbine and the first signal is sent before the airborne animal of the predetermined species is closer than 600 m to the wind turbine.

14. The method of claim 1 , wherein the optical imaging sensor images at an infrared wavelength to provide a low-light detection of an airborne animal.

15. The method of claim 14 , wherein the airborne animal is a bat.

16. The method of claim 1 , wherein the controller determines if the airborne animal that is a member of the predetermined species is in a hunting behavior, wherein the first signal is sent sooner for the predetermined species in the hunting behavior than the predetermined species that is in a non-hunting behavior.

17. The method of claim 1 , further comprising the steps of:

monitoring one or more meteorological conditions with a meteorological instrument; and

providing the controller with the one or more meteorological conditions for predicting and/or identifying a behavior of the airborne animal.

18. A method for mitigating risk of an airstrike to an airborne animal by a wind turbine, the method comprising the steps of:

optically imaging an airborne animal with an optical imaging sensor;

providing images from the optical imaging sensor to a controller;

analyzing the optical images with the controller to determine if the airborne animal is a likely member of a predetermined species;

sending a first signal to curtail operation of the wind turbine to a predetermined risk mitigating level for the airborne animal that is determined by the controller to be a member of the predetermined species and is at risk from the wind turbine;

wherein the controller determines if the airborne animal is a member of the predetermined species at a distance from the wind turbine that is greater than 600 m.

19. A method for mitigating risk of an airstrike to an airborne animal by a wind turbine, the method comprising the steps of:

optically imaging an airborne animal with an optical imaging sensor;

providing images from the optical imaging sensor to a controller;

analyzing the optical images with the controller to determine if the airborne animal is a likely member of a predetermined species and approaching the wind turbine; and

sending a signal to deploy a deterrent to the airborne animal if the controller determines the airborne animal is a member of the predetermined species, is closer than 600 m to the wind turbine and is approaching the wind turbine.