Oklahoma Wind Power Assessment Initiative

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Oklahoma Wind PowerInitiative(OWPI)Tim Hughes
(OU)Mark Shafer (OU) Troy Simonsen (OU)Jeremy
Traurig (OU)Nick Mirskey (OU)Steve Stadler
(OSU)Pete Earls (OSU)
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Wind Energy Cost of Wind-Generated
Electricity 1980 to 2005 Levelized Cents/kWh
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(No Transcript)
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OWPI GOALS

• Resource Assessment
• Policy Study
• Outreach
• Educational programs
• Community meetings
• Promote Economic Development

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The Oklahoma Mesonet
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The Oklahoma Mesonet

• 115 Active stations, spaced 32 km
• 5-minute resolution data
• Standard Meteorological variables following WMO
  standards
• 10-meter wind speed and direction scaled to
  50-meters using
• U/Ur (Z/Zr)1/6
• Rural sites generally good fetch conditions
• 1994-2000 data used in study

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OWPAI
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Oklahoma Wind Resource Maps
Purple class 5 or better, blue class 4, lt.
blue class 3
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Steps for Developing Models

• Review Mesonet site surroundings to qualify
  fetch conditions of site, using
• aerial photos (DOQQs)
• vegetation (LU/LC)
• site panorama photos
• Assign subjective ratings of poor, fair,
  good or excellent

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NORMAN Air Photo (zoomed)
250 m
NORM wind rose
500 m
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Steps for Developing Models

• Combine information from
• Mesonet Station data (wind, pressure, temperature
  - 735,000 readings of each per station)
• DEM elevation data
• Vegetation data (roughness)
• Input into two different models
• analytical model (Windmap)
• empirical model (using neural networks for
  non-linear relationship)

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WindMap Software (Analytical)
INPUTS
OUTPUTS
W I N D M A P

ArcView
Final Winds Map
DEM Data
Elevation Grid
ArcView
Power Density Map
LULC (GAP) Map
Roughness Grid
10 Meter Winds
Turbine Output Map
A GIS Software Package
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MODELED LONG-TERM AVERAGE WIND POWER DENSITY 50
METERS (164 FT.) Above Ground Level
OWPI
DRAFT 9/2001
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Neural Network (Empirical)

• Correlate wind power values calculated at Mesonet
  sites, with neural network scheme, to
• site elevations
• north and south terrain exposures
• north and south average roughness
• Get equations for wind power density as function
  of the above
• Fill in grid for whole state

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Average Wind energy rose using wind data from 78
stations with good-excellent rating on fetch
conditions Wind energy in N S wedges 89 of
total Realizable energy from turbines gt 95
from N S
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Sample calculated WPDs and elevation, terrain
exposure, and roughness averages
57 more .
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Wind Power Map for Oklahoma (Empirical Model
using Neural Networks)
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Analytical Model Findings

• Initial run underestimated wind power density at
  most Mesonet sites
• Linear regression of predicted vs. calculated
  wind power density yielded correction factor of
  1.33
• Better agreement with field data from validation
  site, but still under-estimates in Southeast
  Oklahoma

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Empirical Model Findings

• Emphasizes ridge lines (areas of good exposure
• Low Roughness
• Good Terrain Exposure
• Compared to WindMap and Tower data, likely
  underestimates, especially in Southeast Oklahoma

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NREL Resource Maps
Purple class 5 or better, blue class 4, lt.
blue class 3
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Analytical Model
OWPI
DRAFT 9/2001
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Empirical Model
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OWPIs Oklahoma Wind Climatology Products
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Wind Climatology Cheyenne Mesonet Site Station
ID CHEY
Class 3 Site (January 94 December 00) Average
10 m Wind Speed 5.70 m/s (12.8 mph) Average 10
m Power Density 189 W/m2
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Cheyenne Wind Energy Rose
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Cheyenne
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Cheyenne
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For information on OWPI

• Oklahoma Wind Power Initiative
• www.seic.okstate.edu/owpai
• Contact Tim Hughes thughes_at_ou.edu

For information on OREC

• Oklahoma Renewable Energy Council
• www.seic.okstate.edu/OREC