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WALSENBURG AIRPORT SOUTH (MAPES)

2/21/2006 through 6/2/2009

LOCATION DETAILS
Latitude:
N 37.6740°
Longitude:
W 104.8011°
Township:
27 S
Range:
66 W
Section:
29
Elevation (ft.):
6,105
Tower Type:
NRG Tilt-Up
Tower Height (ft.):
98
Tower Height (m):
30
Vane Offset (deg):
+354° (see below)
Direction Basis:
True North
Mag. Declination:
9° 31' E, changing by 7' W/yr
Site Number:
0837, 0004, and 1301
Wind Explorer S/N:
0837

DATA DETAILS

February 21, 2006 through March 6, 2007:

This anemometer tower is owned by the San Isabel Electric Association. It was installed in a pasture by SIEA on February 21, 2006. Also known by the name Mapes. The site is approximately 3.5 miles north-northwest of the town of Walsenburg, Colorado. Interstate Highway 25 is located about 300 feet west of the tower.

All data is being collected using an NRG #40 Anemometer and NRG #200P Wind Vane mounted on a tilt-up tower located on the landowner's property at a height of 30m. This equipment feeds into an NRG Wind Explorer data logger. Seven data plugs were sent into the Governor's Energy Office and then to the University of North Dakota for analysis. The data plug files and text versions of these files are given below.

Raw Wind Data Files
NRG Data Plug Files
Txt Files
Walsenburg_Airport_South_Mapes_0837_2006_0727_1017.A06 Walsenburg_Airport_South_Mapes_0837_2006_0727_1017.txt
Walsenburg_Airport_South_Mapes_0837_2006_1017_0111.A06 Walsenburg_Airport_South_Mapes_0837_2006_1017_0111.txt
Walsenburg_Airport_South_Mapes_0837_2007_0111_0306.A07 Walsenburg_Airport_South_Mapes_0837_2007_0111_0306.txt

It is important to note that these are the raw files without any compensation for offset. It is also important to note that the temperature was not recorded during this period.

For this data, UND applied no offset to the wind vane data. The data from February 21, 2006 through October 17, 2006 using no offset and the wind resource summary report for the same period are available here:

March 6, 2007 through June 2, 2009:

CSU was chosen as the contractor for the program on September 14, 2007. Data collected since is given below:

Raw Wind Data Files
NRG Data Plug Files
Txt Files
Walsenburg_Airport_South_Mapes_1301_2007_0306_0511.A07 Walsenburg_Airport_South_Mapes_1301_2007_0306_0511.txt
Walsenburg_Airport_South_Mapes_1301_2007_0511_0927.A07 Walsenburg_Airport_South_Mapes_1301_2007_0511_0927.txt
Walsenburg_Airport_South_Mapes_1301_2007_0927_0314.txt
Walsenburg_Airport_South_Mapes_1301_2008_0314_0527.A08 Walsenburg_Airport_South_Mapes_1301_2008_0314_0527.txt
Walsenburg_Airport_South_Mapes_1301_2008_0527_0903.A08 Walsenburg_Airport_South_Mapes_1301_2008_0527_0903.txt
Walsenburg_Airport_South_Mapes_1301_2008_0903_1120.A08 Walsenburg_Airport_South_Mapes_1301_2008_0903_1120.txt
Walsenburg_Airport_South_Mapes_1301_2009_1120_0109.A09 Walsenburg_Airport_South_Mapes_1301_2009_1120_0109.txt
Walsenburg_Airport_South_Mapes_1301_2009_0109_0602.A09 Walsenburg_Airport_South_Mapes_1301_2009_0109_0602.txt

Wind Vane Offset

Based on measurements taken by SIEA personnel during the tower installation, the wind vane boom was pointing at 356° 27' W from true north. Other measurements showed that when the wind vane was pointing 114° 13' the datalogger was showing 114°, indicating that an offset of 0° should be applied to the wind vane data.

Onsite readings taken on September 3, 2008 showed that when the wind vane was pointing to 90° magnetic north the datalogger was reading 105°. Allowing the a magnetic declination of 9°E, the offset to true north is (90° + 9°) - 105° = 354°. Further measurements will be taken onsite to attempt to confirm the correct offset

Using the raw data from all data plugs for this site, an analysis of the wind resource report was developed using Windographer 1.45. For this data, an offset of 354° was applied to the wind vane data for the period from March 6, 2007 through September 3, 2008. A data validation analysis was then performed on the wind speed and wind vane data. This data was filtered as follows:

  1. Any wind speed data where the wind speed was less than 1 mph for 3 hours or more was deleted.
  2. Any wind direction data where the direction changed less than 3° over 8 hours was deleted.

Windographer was then used to add in synthetic data to these intervals with suspect data. The combined data files (with and without data validation and offset), and the Windographer files (with and without data validation and offset) are given below:

Current Wind Resource Summary

Highlights of the wind resource at this site through the most recent data ending on June 2, 2009 are shown below:

Data Properties
Variable
Data Set Starts:
2/21/2006 16:00
Height above ground (m)
30
Data Set Ends:
6/2/2009 9:00
Mean wind speed (mph)
14.033
Data Set Duration:
3.3 years
Median wind speed (mph)
12.500
Length of Time Step:
10 minutes
Min wind speed (mph)
0.524
Elevation (ft.):
6,105
Max wind speed (mph)
63.4
Calm threshold (mph):
0
Mean power density (W/m²)
299
Wind Power Coefficients
Mean energy content (kWh/m²/yr)
2,623
Power Density at 50m:
358 W/m²
Energy pattern factor
2.376
Wind Power Class:
3 (Fair)
Weibull k
1.637
Wind Shear Coefficients
Weibull c (mph)
15.669
Power Law Exponent:
0.121
1-hr autocorrelation coefficient
0.799
Surface Roughness:
0.01 m
Diurnal pattern strength
0.056
Roughness Class:
0.780
Hour of peak wind speed
16
Roughness Description:
Rough Pasture
Mean turbulence intensity
0.1809
Note: The wind power density and wind power class at 50m are projections of the data from 30m. A surface roughness of 0.01 meters was assumed for this projection. This is equal to that of a rough pasture. This value was then used to calculate the roughness class and the power law exponent shown above.
Standard deviation (mph)
8.74
Frequency of calms (%)
0
Total data elements
516,978
Suspect/missing elements
1,110
Data completeness (%)
99.8

 

Windographer was used to match up the wind at this site with the performance curves of some common turbines of various sizes and various heights, allowing for losses of about 13%. The table below shows the results. For the larger turbines, the tower height was increased to account for the larger turbine blades - the wind resource was extrapolated to these higher heights. Keep in mind that the larger and the higher the turbine, the better the wind and the greater the output. But of course, as the tower heights and turbine sizes increase so does the cost.

Turbine
Rotor
Diameter
meters
Rotor
Power
kW
Hub
Height
meters
Hub
Height
Wind
Speed
mph
Time
At
Zero
Output
percent
Time
At
Rated
Output
percent
Average
Net
Power
Output
kW
Average
Net
Energy
Output
kWh/yr
Average
Net
Capacity
Factor
%
Bergey Excel-R
6.7
7.5
30 14.03 24.54 7.57 1.8 15,700 23.8
Bergey Excel-S
6.7
10
30 14.03 12.55 4.57 2.0 17,700 20.2
Bergey XL.1
2.5
1
30 14.03 5.05 10.93 0.3 2,400 27.2
Southwest Skystream 3.7
3.7
1.8
30 14.03 22.19 0 0.5 4,000 25.6
Southwest Whisper 500
4.5
3
30 14.03 24.37 9.19 0.8 7,400 28.2
Northern Power NW 100/10
20
100
30 14.03 22.19 0 17.9 156,700 17.9
Vestas V47 - 660 kW
47
660
65 15.64 20.27 1.64 158.6 1,389,500 24.0
GE 1.5sle
70.5
1,500
80.5 16.11 19.67 2.55 361.4 3,165,500 24.1
Vestas V80 - 2.0 MW
80
2,000
100 16.61 23.90 5.27 526.4 4,610,900 26.3
GE 2.5xl
100
2,500
110 16.83 18.05 10.52 724.8 6,349,500 29.0

 

 


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Colorado State University, Fort Collins, CO 80523 USA (970) 491-7709
Last updated: June 2009
Email questions & comments to: michael@engr.colostate.edu
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