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Northern Arizona Wind Resource

VIEWS: 7 PAGES: 23

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									     Nebraska Wind Resources

              Dennis Elliott
  National Renewable Energy Laboratory



Meeting with Nebraska Public Power District
              NREL/NWTC
            November 19, 2007
 2005 Nebraska Wind Resource Mapping Project
 Collaborative effort involving:
• DOE/NREL Wind
  Powering America
  program
• State of Nebraska
• NREL’s wind
  resource group and
  expert consultants
• AWS Truewind
http://www.eere.energy.gov/windandhydro/
     windpoweringamerica/wind_maps.asp
Unvalidated wind
speed maps
generated by model
for 70m and 100m
heights
 High-Resolution Wind Mapping Approach
               for Nebraska
• Comprehensive modeling and validation process produced
  detailed wind resource maps with a spatial resolution of 200 m
• AWS Truewind used a numerical weather model with climatic
  data and wind flow model to produce the preliminary maps
• NREL and meteorological consultants validated preliminary
  maps of 50-m annual average wind resource using
   – Available high-quality wind measurement data
   – Experts knowledge of wind flow and wind resources in Nebraska
• Final wind resource maps developed based on revision of
  preliminary maps from validation results
       Logic of Numerical Mapping Method

• Model Design and Outputs
  – MesoMap - created by AWS Truewind
  – A numerical weather model (MASS) coupled to a wind flow
    model (WindMap) and global weather, topographical, and land
    cover data
  – NCEP/NCAR Reanalysis (200-km grid) - most important global
    weather input for MASS
  – MASS simulates weather conditions (including winds) over 365
    random days selected from a 15-year period
  – For Nebraska, MASS runs to 2.5 km and WindMap to 0.2 km
  – Model output grids provided to NREL for review and validation
                     Validation Process
• NREL completed a spreadsheet used in the validation
  process
   – Each measurement location
       •   Site coordinates and elevation
       •   Measurement heights and period of record
       •   Measured speed and power
       •   Adjusted speed and power to map height
       •   Map estimates for speed and power
       •   Qualitative comments
• NREL & AWS Truewind reviewed validation results
• AWS Truewind adjusted preliminary maps based on
  quantitative and qualitative inputs
Nebraska Validation

Over 50 measurement
stations used for
validation:
35 Airport (6-14 m)
 8 UWRAP (40-50 m)
 6 RAWS (6 m)
 1 DOE/TCS (30 m)
 1 State (40 m)
 3 Proprietary (24-80 m)


Estimated accuracy of final
wind maps
    Within 10% of annual speed
    and 20% of annual power at
    80% of individual sites
Annual average shear exponents can vary from 1/7 to 0.25,
causing considerable uncertainty in vertical extrapolations
of wind resource
•Even if 50-m wind resource is known, potential variations in shear exponents
cause considerable uncertainty in wind resource at heights of 80-100 m
•Measured shear exponent at Goodland is 0.235, with much higher wind resource
at 90 m than estimated by 1/7 shear estimate
•High wind shear locations can have considerably higher capacity factors at 80-
100 m than low shear locations, given similar capacity factors at 50 m
•Goodland’s capacity factor of 42.5% at 90 m is considerably higher than
would be estimated by using typical shears of 1/7 to 0.2
    Quantifying Available Windy Lands
       and Wind Electric Potential
• Class 3 and higher resource areas used as base for available
  windy lands

• Potentially sensitive environmental lands excluded

• Potentially incompatible land use excluded

• Some additional lands excluded by other factors
 Land Exclusions from Wind Potential
• Potentially sensitive environmental lands:
   – National Park Service, Fish and Wildlife Service, Wilderness, and Recreation
     Areas on federal land (predominately Forest Service and BLM lands)
   – Some state and private environmental lands where data was available
   – Half of the remaining Forest Service and Department of Defense lands were
     excluded to represent current dedicated use of land
• Potentially incompatible land use:
   – Urban areas, airports, wetlands and water bodies
   – Half of non-ridge forested areas
• Other factors:
   – Slopes greater than 20% were excluded
   – A 3 km area surrounding environmental and land use categories that were
     completely excluded (except water bodies) was also eliminated
   – Small, isolated class 3 and greater resource areas were eliminated using a
     minimum density criteria
  Wind Electric Potential Estimation

• Distance from transmission lines and roads not
  included in windy land calculations

• Windy land  electric potential
  – Direct conversion from sq. km to potential
    installed capacity - 5 MW per km2 of available
    windy land
          Nebraska Wind Electric Potential
                (Installed Capacity)
            Total before exclusions   Developable
•   Class 3 +      803 GW              764 GW
•   Class 4 +      162 GW              156 GW
•   Class 5 +      2.7 GW               2.5 GW
•   Class 6 +     <0.1 GW              <0.1 GW

    5% of the raw Class 3+ lands excluded
    3% of the raw Class 4+ lands excluded
 Stations Selected for Analysis of
Monthly and Diurnal Characteristics
                                Nebraska - Average Monthly Wind Speeds at 40m
                   8.5


                    8


                   7.5
Wind Speed (mps)




                    7


                   6.5


                    6


                   5.5

                                                                                     Imperial 40
                    5
                                                                                     Kimball 40
                                                                                     Stuart 40
                   4.5                                                               Valentine 40
                                                                                     Winnebago 40

                    4
                         Jan   Feb   Mar   Apr   May   Jun   Jul   Aug   Sep   Oct       Nov        Dec
                                 Nebraska UWRAP Stations - 40m Diurnal Wind Speeds
                    8




                   7.5
Wind Speed (mps)




                    7




                   6.5




                    6




                   5.5                                                                     Imperial 40
                                                                                           Winnebago 40
                                                                                           Kimball 40
                                                                                           Valentine 40
                    5                                                                      Stuart 40
                         0   1   2   3   4   5   6   7   8   9   10   11   12   13   14   15   16      17   18   19   20   21   22   23   24
                                                                  Hour of Day
                                                 Kimball, NE - Wind Speeds by Hour
                    9


                   8.5


                    8


                   7.5
Wind Speed (mps)




                    7
                                                                                                                                             Kimball 10
                                                                                                                                             Kimball 25
                   6.5
                                                                                                                                             Kimball 40
                                                                                                                                             Kimball 50
                    6


                   5.5


                    5


                   4.5


                    4
                         0   1   2   3   4   5    6   7   8   9   10   11   12   13   14   15   16   17   18   19   20   21   22   23   24

                                                                   Hour of Day
                                               Imperial, NE - Wind Speed by Hour
                   9


             8.5


                   8


             7.5
Wind Speed (mps)




                   7


             6.5


                   6


             5.5


                   5
                                                                          Imperial 10
                                                                          Imperial 25
                                                                          Imperial 40
             4.5
                                                                          Imperial 50

                   4
                       0   1   2   3   4   5   6   7   8   9   10    11     12    13    14   15   16   17   18   19   20   21   22   23   24
                                                                    Hour of Day
                                    Nebraska UWRAP & Kansas Stations
           11
                                         40m Diurnal Wind Speeds
                                                             Imperial 40
                                                             Winnebago 40

           10                                                Kimball 40
                                                             Valentine 40
                                                             Stuart 40
                                                             Jewell 50
           9
                                                             Jewell 80
WS (mps)




                                                             Jewell 110


           8




           7




           6




           5
                0   1   2   3   4   5   6   7   8   9   10   11   12       13   14   15   16   17   18   19   20   21   22   23   24
                                                         Hour of Day
   Summary of Nebraska Wind Resources
• Good resource areas (Class 4) are located throughout the
  state
• Areas of excellent resource (Class 5) are dispersed over the
  northern half of the state.
• Winter-Spring maximum wind resource
• Prevailing wind directions are from west-northwest
  (winter) and from south (spring and summer)
• Tall-tower measurements (up to 80-100m+) and remote
  sensing (sodar/lidar) needed to
   – Estimate the wind shear at elevated heights of 50-100m+
   – Characterize wind resource at hub-heights of advanced wind
     turbines

								
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