COLORADO ANEMOMETER LOAN PROGRAM
 

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FOWLER

8/31/2007 to 8/21/2009

LOCATION DETAILS
Latitude:
N 38° 10’ 9.96" or N 38.16943°
Longitude:
W 104° 1’ 1.02" or W 104.017°
Township:
22 S
Range:
59 W
Section:
4
Elevation (ft.):
4,562
Datum:
WGS 84
Tower Type:
NRG Tilt-Up
Tower Height:
20 m (65.6 ft)
Vane Offset (deg):
+0°
Direction Basis:
Magnetic North
Mag. Declination:
8° 44' E, changing by 7' W/yr
Wind Explorer S/N:
1322
Site No.:
1322

 

DATA DETAILS

August 31, 2007 to August 21, 2009:

This anemometer tower was borrowed from the Western Area Power Authority (WAPA) under WAPA’s anemometer loan program.. It was installed above Fowler on the shoulders of the Arkansas River valley on August 31, 2007 and removed on August 21, 2009.

All data was collected using an NRG #40 Anemometer and NRG #200 Wind Vane mounted on a tilt-up tower at a height of 20m. This equipment fed into an NRG Wind Explorer data logger. All data plugs were sent into the Wind Powering America program for analysis. All data plug files and text versions of these files are given below.

Raw Wind Data Files
NRG Data Plug Files
Txt Files
Fowler_1322_2007_0831_1001.txt
Not available
Fowler_1322_2007_1001_0115.txt
Fowler_1322_2008_0115_0327.N08 Fowler_1322_2008_0115_0327.txt
Fowler_1322_2008_0327_0505.N08 Fowler_1322_2008_0327_0505.txt
Fowler_1322_2008_0505_0716.N08 Fowler_1322_2008_0505_0716.txt
Fowler_1322_2008_0716_0916.N08 Fowler_1322_2008_0716_0916.txt
Fowler_1322_2008_0916_0106.N08 Fowler_1322_2008_0916_0106.txt
Fowler_1322_2009_0106_0312.Q09 Fowler_1322_2009_0106_0312.txt
Fowler_1322_2009_0312_0611.N09 Fowler_1322_2009_0312_0611.txt
Fowler_1322_2009_0611_0821.N09 Fowler_1322_2009_0611_0821.txt

It is important to note that the temperature was not recorded during this period.

Using this data, an analysis of the wind resource report was developed using Windographer 1.45. For this report, a validation analysis was performed on the data. This data was filtered two ways:

  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 wind direction varied by less than 3 degrees over 6 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 the validation analysis), and the Windographer files (with and without the validation analysis) are given below:

Highlights of the wind resource to date at this site are shown below:

Data Properties
Variable
Data Set Starts:
8/31/2007 17:00 MDT
Height above ground (m)
20
Data Set Ends:
8/21/2009 9:20
Mean wind speed (mph)
11.347
Data Set Duration:
24 months
Median wind speed (mph)
10.10
Length of Time Step:
10 minutes
Min wind speed (mph)
0.0
Elevation (ft.):
4,562
Max wind speed (mph)
53.40
Calm threshold (mph):
0
Mean power density (W/m²)
177
Wind Power Coefficients
Mean energy content (kWh/m²/yr)
1,553
Power Density at 50m:
287 W/m²
Energy pattern factor
2.538
Wind Power Class:
2 (Marginal)
Weibull k
1.576
Wind Shear Coefficients
Weibull c (mph)
12.622
Power Law Exponent:
0.177
1-hr autocorrelation coefficient
0.775
Surface Roughness:
0.0989 m
Diurnal pattern strength
0.234
Roughness Class:
1.99
Hour of peak wind speed
21
Roughness Description:
Few trees
Mean turbulence intensity
0.2156
Note: The wind power density and wind power class at 50m are projections of the data from 20m. A surface roughness of 0.1 meters was assumed for this projection. This is the surface roughness for an area with a few trees. This value was then used this to calculate the roughness class and the power law exponent shown above.
Standard deviation (mph)
7.322
Frequency of calms (%)
0
Total data elements
311,334
Suspect/missing elements
3,717
Data completeness (%)
98.8

 

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 18%. 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
20
11.35
30.65
3.59
1.2
10,400
15.9
Bergey Excel-S
6.7
10
20
11.35
16.98
2.15
1.3
11,600
13.3
Bergey XL.1
2.5
1
20
11.35
7.98
5.34
0.2
1,600
18.2
Southwest Skystream 3.7
3.7
1.8
20
11.35
28.63
0
0.3
2,900
18.5
Southwest Whisper 500
4.5
3
20
11.35
30.62
4.47
0.6
5,100
19.6
Northern Power NW 100/21
20
100
37
12.65
24.41
0
16.7
146,300
16.7
Vestas V47 - 660 kW
47
660
65
13.98
22.31
1.47
129.2
1,131,500
19.6
GE 1.5s
70.5
1,500
80.5
14.52
27.02
6.59
274.2
2,402,200
18.3
Vestas V80 - 2.0 MW
80
2,000
100
15.09
25.12
4.22
445.0
3,898,600
22.3
GE 2.5xl
100
2,500
110
15.34
19.53
7.98
621.2
5,442,000
24.8

 

 


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Last updated: June 2009
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