Computer Weather Forecasts forComputer Weather Forecasts forWind Energy PlantsWind Energy Plants

Khanh T. TranKhanh T. TranAMI EnvironmentalAMI Environmental

206 Black Eagle Ave, Henderson, NV 89015

(702)564-9186(702)564-9186http://www.amiace.comhttp://www.amiace.com

Wind Energy ForecastsWind Energy Forecasts

Growing Wind Energy DevelopmentGrowing Wind Energy Development Wind Energy is IntermittentWind Energy is Intermittent Reliable Forecasts needed for Load Reliable Forecasts needed for Load

SchedulingScheduling Forecasts of 48-Hour and LongerForecasts of 48-Hour and Longer Forecasts Updated Twice DailyForecasts Updated Twice Daily Facility located in Complex TerrainFacility located in Complex Terrain

AMI Forecasting SystemAMI Forecasting System

AMI System ModulesAMI System Modules Mesoscale Model MM5/WRF Mesoscale Model MM5/WRF

>> Nested Grids of 36,12,4,1.33 km Nested Grids of 36,12,4,1.33 km spacingspacing> ETA/AVN Forecasts for IC/BC> ETA/AVN Forecasts for IC/BC

Diagnostic Wind Model Diagnostic Wind Model > 100 m spacing or less> 100 m spacing or less

Adaptive Statistical Module Adaptive Statistical Module > Bias Removal> Bias Removal> Recent Onsite Data> Recent Onsite Data

Internet-based Forecast Delivery (website, Internet-based Forecast Delivery (website, email)email)

System Runs on Linux Multiprocessor PC System Runs on Linux Multiprocessor PC

System TestingSystem Testing

Testing at FPL Southwest Mesa Plant in Testing at FPL Southwest Mesa Plant in southwest Texassouthwest Texas

12-month Testing (April 2002-March 12-month Testing (April 2002-March 2003) sponsored by US DOE NREL and 2003) sponsored by US DOE NREL and EPRIEPRI

Forecasts by AMI, TrueWind and Risoe Forecasts by AMI, TrueWind and Risoe 48-Hour Forecasts twice daily at 00 UTC 48-Hour Forecasts twice daily at 00 UTC

and 12 UTC (wind speed, wind direction, and 12 UTC (wind speed, wind direction, ambient temperature and wind energy)ambient temperature and wind energy)

FPL Southwest Mesa FPL Southwest Mesa PlantPlant

MM5 Modeling DomainMM5 Modeling Domain

Domain TopographyDomain Topography

System Performance System Performance EvaluationEvaluation

Forecasts compared against actual Forecasts compared against actual observations (wind speed and observations (wind speed and energy)energy)

Forecasts compared against Forecasts compared against persistence and climatological persistence and climatological forecastsforecasts

Statistical measures (mean error Statistical measures (mean error ME, mean absolute error MAE, skill ME, mean absolute error MAE, skill score) score)

Sample Wind Speed Sample Wind Speed ForecastForecastApplied Modeling Wind Speed Forecasts

Southwest Mesa Forecasts Beginning at 1800, July 18 2002

0

2

4

6

8

10

12

14

0 6 12 18 24 30 36 42 48

Forecast Hour Number

Win

d S

pee

d m

/sec

Meteorology Fcst Persistence Fcst Climatology Fcst Observed Data

Sample Wind Energy Sample Wind Energy ForecastForecast

Applied Modeling Wind Generation ForecastsSouthwest Mesa Forecasts Beginning at 1800, July 18 2002

0

10,000

20,000

30,000

40,000

50,000

60,000

70,000

80,000

0 6 12 18 24 30 36 42 48

Forecast Hour Number

Win

d G

ener

atio

n k

W

Meteorology Fcst Persistence Fcst Climatology Fcst Observed Data

Forecast Performance StatisticsForecast Performance Statistics Wind Speed Wind Speed (m/s) (m/s)

Energy (kw)Energy (kw)

Annual averageAnnual average 7.617.61 25,45025,450

Forecast ErrorForecast Error

Annual MEAnnual ME

Annual MAEAnnual MAE-0.02-0.02

2.282.281,3221,322

12,31912,319

Normalized Normalized ErrorError

Annual MEAnnual ME

Annual MAEAnnual MAE

-0.2%-0.2%

30%30%-5.2%-5.2%

48.4%48.4%

Skill ScoreSkill Score

vs. Persistencevs. Persistence

vs. Climatologyvs. Climatology26.1%26.1%

26.8%26.8%28.3%28.3%

28.1%28.1%

Normalized MAE for Normalized MAE for Wind SpeedWind Speed

Normalized Mean Absolute Errors for Applied Modeling Wind Speed Forecasts

Southwest Mesa FPL Energy, April 1, 2002 - March 31, 2003

0%

10%

20%

30%

40%

50%

60%

0 6 12 18 24 30 36 42 48

Forecast Hour Number

No

rma

lize

d M

ea

n A

bs

. Err

or

Meteorology Persistence Climatology

12-Month Average Wind Speed = 7.61 m/sec

Normalized MAE for Wind Normalized MAE for Wind EnergyEnergy

Normalized Mean Absolute Errors for Applied Modeling Wind Generation ForecastsSouthwest Mesa FPL Energy, April 1, 2002 - March 31, 2003

0%

20%

40%

60%

80%

100%

0 6 12 18 24 30 36 42 48

Forecast Hour Number

No

rma

lize

d M

ea

n A

bs

. Err

or

Meteorology Persistence Climatology

12-Month Average Wind Generation = 25,450 kW

Normalized Monthly MAE Normalized Monthly MAE for WSfor WS

Normalized Monthly Mean Absolute Errors for AMI Wind Speed Forecasts

Southwest Mesa FPL Energy, April 1, 2002 - March 31, 2003

0%

10%

20%

30%

40%

50%

60%

70%

Apr

il 200

2 M

ay Ju

ne Ju

ly

Aug

ust

Sep

tem

ber

Octo

ber

Nov

embe

r

Dec

embe

r

Janu

ary 2

003

Feb

ruar

y

Mar

ch

Month

No

rma

lize

d M

ea

n A

bs

. Err

or

Climatology Meteorology Persistence

Normalized Monthly MAE Normalized Monthly MAE for WEfor WE

Normalized Monthly Mean Absolute Errors for AMI Wind Generation Forecasts

Southwest Mesa FPL Energy, April 1, 2002 - March 31, 2003

0%

20%

40%

60%

80%

100%

120%

Apr

il 200

2 M

ay Ju

ne Ju

ly

Aug

ust

Sep

tem

ber

Octo

ber

Nov

embe

r

Dec

embe

r

Janu

ary 2

003

Feb

ruar

y

Mar

ch

Month

No

rmal

ized

Mea

n A

bs.

Err

or

Meteorology Persistence Climatology

Comparison of Forecast Comparison of Forecast SystemsSystems

Annual Mean Absolute Errors of Wind Speed and Energy Forecasts

0%

10%

20%

30%

40%

50%

60%

Wind Speed Wind Energy

No

rma

lize

d M

ea

n A

bs

. Err

or

Risoe TrueWind AMI

Southwest Mesa FPL Energy, April 1, 2002 to March 31, 2003

ConclusionsConclusions

AMI Forecast System based on AMI Forecast System based on advanced models advanced models

AMI system tested for 12-month in AMI system tested for 12-month in southwest Texas southwest Texas

AMI system provides accurate wind AMI system provides accurate wind speed and energy forecastsspeed and energy forecasts

AMI system is more accurate than AMI system is more accurate than other systemsother systems

AMI system runs on Linux PC and can AMI system runs on Linux PC and can be easily adapted to other sites.be easily adapted to other sites.