1. 2 1 Quantifying the Hurricane Risk to Offshore Wind Turbines Stephen Rose, Paulina Jaramillo, Jay Apt, Mitch Small, Iris Grossmann Carnegie Mellon University May 21 st, 2012

2. 2 2 U.S. Has Good Offshore Wind Resources

3. 2 3 Wind Turbines are Vulnerable to Hurricanes Typhoon Maemi, Okinawa, 2003 Takahara, et al (2004)

4. 2 4 We Fit a GEV Distribution to Hurricane Intensity

5. 2 5 We Model Probability of Tower Buckling by a Log-Logistic Function

6. 2 6 We Model Distribution of Turbines Destroyed in 20 Years No replacement: Phase-Type distribution Replacement: compound Poisson distribution Assumptions: - Single wind farm - Each turbine experiences same conditions

7. 2 7 Turbines Designed to Survive Category 1 Hurricane 50-turbine wind farm

8. 2 8 Turbines Destroyed in 20 Years 50-turbine wind farm Not yawing Yawing

9. 2 9 Turbines Destroyed in 20 Years 50-turbine wind farm Not yawing Yawing

10. 2 10 Turbines Destroyed in 20 Years 50-turbine wind farm Not yawing Yawing

11. 2 11 Turbines Destroyed in 20 Years 50-turbine wind farm

12. 2 12 High-Category Hurricanes Cause Most Expected Damage

13. 2 13 Engineering Changes Can Reduce Risk Backup power for yaw system –Survival depends on active system –Wind vane must survive –Turbine must yaw quickly Stronger towers and blades –More steel in tower –More fiberglass in blades –20 – 30% cost increase

14. 2 14 Careful Siting Can Reduce Risk

15. 2 15 Future Research: How Much Reserve Power is Needed?

16. 2 16 Quantifying the Hurricane Risk to Offshore Wind Turbines Stephen Rose, Paulina Jaramillo, Jay Apt, Mitch Small, Iris Grossmann Carnegie Mellon University May 21 st, 2012