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.
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:
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:
-
Any wind speed data where the wind speed was less than 1 mph for 3 hours or more was deleted.
- 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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