COLORADO ANEMOMETER LOAN PROGRAM
 

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CALHAN

4/26/1996 through 4/30/1998

LOCATION DETAILS
Latitude:
N 38.94028°
Longitude:
W 104.30833°
Township:
13 S
Range:
62 W
Section:
2
Elevation (ft.):
6,936

DATA DETAILS

April 26, 1996 through April 30, 1998:

This site was part of the Utility Wind Resource Assessment Program (UWRAP). Data provided by the Utility Wind Interest Group in cooperation with AWS Truewind, National Renewable Energy Laboratory, Electrotek Concepts, and Xcel Energy - Public Service Company of Colorado. The site was located approximately 6.5 miles south of the town of Calhan.

The collected data includes the following data fields:

  • Wind speed, standard deviation of the wind speed, and data quality flag for an anemometer at 10m height and facing SW
  • Wind speed, standard deviation of the wind speed, and data quality flag for an anemometer at 25m height and facing SW
  • Wind speed, standard deviation of the wind speed, and data quality flag for an anemometer at 40m height
  • Wind direction, standard deviation of the wind direction, and data quality flag for a wind vane at 25m height
  • Wind direction, standard deviation of the wind direction, and data quality flag for a wind vane at 40m height
  • Temperature from a sensor mounted at a height of 4m

Wind speed data at 40 meters represent a combination of data from primary and redundant sensors.

Only a text data file is available from this site. You can find this file here.

The file includes suspect data and when that data occurs, the value is generally a negative number. There is also a flag filed that indicates these suspect data values. For a version of this wind data with blanks rather than negative numbers, you can download here.

CSU was chosen as the contractor for the program on September 14, 2007. Using the raw data from all data plugs for this site, an analysis of the wind resource report was developed using Windographer 1.21. No data quality analysis was performed for this data other than what was available from the flag data fields included in the data. The suspect data was first removed from the collected data. Windographer was then used to add in synthetic data to these intervals with suspect data. The Windographer files (with blanks for the suspect data and with the blanks filled with synthetic data) are given below:

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

Data Properties
Data Set Starts:
4/26/1996 00:00
Data Set Ends:
5/01/1998 00:00
Data Set Duration:
24 months
Length of Time Step:
60 minutes
Calm threshold (mph):
0
Wind Power Coefficients
Power Density at 50m:
355 W/m²
Wind Power Class:
3 (Fair)
Wind Shear Coefficients
Power Law Exponent:
0.127
Surface Roughness:
0.00756 m
Roughness Class:
0.72
Roughness Description:
Lawn grass

 

Variable
WS40
WS25SW
WS10SW
Height above ground
40 m (131 ft)
25 m (82 ft)
10 m (33 ft)
Mean wind speed (mph)
15.63
14.49
13.06
Median wind speed (mph)
14.34
13.01
11.74
Min wind speed (mph)
0
0
0
Max wind speed (mph)
65.63
63.84
59.81
Mean power density (W/m²)
332
274
204
Mean energy content (kWh/m²/yr)
2,904
2,401
1,783
Energy pattern factor
1.97
2.04
2.07
Weibull k
2.03
1.98
1.97
Weibull c (mph)
17.69
16.39
14.78
1-hr autocorrelation coefficient
0.9
0.9
0.9
Diurnal pattern strength
0.06
0.06
0.08
Hour of peak wind speed
20
18
15
Mean turbulence intensity
0.22
0.22
0.23
Standard deviation (mph)
8.13
7.75
7.02
Coefficient of variation (%)
52
53.5
53.8
Frequency of calms (%)
0.01
0.02
0.05
Possible records
17,640
17,640
17,640
Valid records
15,440
13,035
13,422
Suspect records
2,200
4,605
4,218
Data completeness (%)
87.5
73.9
76.1

 

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
40
15.63
12.79
6.64
2.06
18,100
27.5
Bergey Excel-S
6.7
10
40
15.63
4.44
4.13
2.31
20,300
23.1
Bergey XL.1
2.5
1
40
15.63
1.12
10.32
0.31
2,800
31.4
Southwest Skystream 3.7
3.7
1.8
40
15.63
9.91
0
0.54
4,700
29.8
Southwest Whisper 500
4.5
3
40
15.63
12.66
8.41
0.99
8,700
32.9
Northern Power NW 100/20
20
100
40
15.63
20.45
0
18.9
165,500
18.9
Vestas V47 - 660 kW
47
660
65
16.53
11.20
1.45
169
1,477,400
25.6
GE 1.5s
70.5
1,500
80.5
17.01
15.78
6.97
355
3,109,700
23.7
Vestas V80 - 2.0 MW
80
2,000
100
17.51
15.04
3.97
566
4,956,200
28.3
GE 2.5xl
100
2,500
110
17.74
10.29
8.34
789
6,907,300
31.5

 

 


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