1. Computer Weather Forecasts for Wind Energy Plants Khanh T. Tran AMI Environmental 206 Black Eagle Ave, Henderson, NV 89015(702)564-9186http://www.amiace.com

2. Wind Energy Forecasts Growing Wind Energy Development Growing Wind Energy Development Wind Energy is Intermittent Wind Energy is Intermittent Reliable Forecasts needed for Load Scheduling Reliable Forecasts needed for Load Scheduling Forecasts of 48-Hour and Longer Forecasts of 48-Hour and Longer Forecasts Updated Twice Daily Forecasts Updated Twice Daily Facility located in Complex Terrain Facility located in Complex Terrain

3. AMI Forecasting System

4. AMI System Modules Mesoscale Model MM5/WRF Mesoscale Model MM5/WRF > Nested Grids of 36,12,4,1.33 km spacing > ETA/AVN Forecasts for IC/BC Diagnostic Wind Model Diagnostic Wind Model > 100 m spacing or less Adaptive Statistical Module Adaptive Statistical Module > Bias Removal > Recent Onsite Data Internet-based Forecast Delivery (website, email) Internet-based Forecast Delivery (website, email) System Runs on Linux Multiprocessor PC System Runs on Linux Multiprocessor PC

5. System Testing Testing at FPL Southwest Mesa Plant in southwest Texas Testing at FPL Southwest Mesa Plant in southwest Texas 12-month Testing (April 2002-March 2003) sponsored by US DOE NREL and EPRI 12-month Testing (April 2002-March 2003) sponsored by US DOE NREL and EPRI Forecasts by AMI, TrueWind and Risoe Forecasts by AMI, TrueWind and Risoe 48-Hour Forecasts twice daily at 00 UTC and 12 UTC (wind speed, wind direction, ambient temperature and wind energy) 48-Hour Forecasts twice daily at 00 UTC and 12 UTC (wind speed, wind direction, ambient temperature and wind energy)

6. FPL Southwest Mesa Plant

7. MM5 Modeling Domain

8. Domain Topography

9. System Performance Evaluation Forecasts compared against actual observations (wind speed and energy) Forecasts compared against actual observations (wind speed and energy) Forecasts compared against persistence and climatological forecasts Forecasts compared against persistence and climatological forecasts Statistical measures (mean error ME, mean absolute error MAE, skill score) Statistical measures (mean error ME, mean absolute error MAE, skill score)

10. Sample Wind Speed Forecast

11. Sample Wind Energy Forecast

12. Forecast Performance Statistics Wind Speed (m/s) Wind Speed (m/s) Energy (kw) Energy (kw) Annual average 7.6125,450 Forecast Error Annual ME Annual ME Annual MAE Annual MAE-0.022.281,32212,319 Normalized Error Annual ME Annual ME Annual MAE Annual MAE-0.2%30%-5.2%48.4% Skill Score vs. Persistence vs. Persistence vs. Climatology vs. Climatology26.1%26.8%28.3%28.1%

13. Normalized MAE for Wind Speed

14. Normalized MAE for Wind Energy

15. Normalized Monthly MAE for WS

16. Normalized Monthly MAE for WE

17. Comparison of Forecast Systems

18. Conclusions AMI Forecast System based on advanced models AMI Forecast System based on advanced models AMI system tested for 12-month in southwest Texas AMI system tested for 12-month in southwest Texas AMI system provides accurate wind speed and energy forecasts AMI system provides accurate wind speed and energy forecasts AMI system is more accurate than other systems AMI system is more accurate than other systems AMI system runs on Linux PC and can be easily adapted to other sites. AMI system runs on Linux PC and can be easily adapted to other sites.