COLORADO ANEMOMETER LOAN PROGRAM
 

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MONTROSE SOUTH - 9/29/2004 through 4/18/2005

LOCATION DETAILS
Latitude:
N 38° 23.0280’ or N 38° 23’ 2”
Longitude:
W 106° 37.9398’ or W 107° 48’ 38”
Township:
48 N
Range:
9 W
Section:
25
Elevation (ft.):
6,147
Tower Type:
NRG Tilt-Up
Tower Height:
20 m (65.6 ft)
Vane Offset (deg):
+354° (See below)
Direction Basis:
Unknown
Site Number:
0667
Wind Explorer S/N:
0667

DATA DETAILS

September 29, 2004 through April 18, 2005:

The anemometer tower was installed on September 29, 2004. The site was located approximately 7 miles south-southeast of the town of Montrose, at the southern end of a large mountain valley that slopes down in the northwest direction. The tower was situated in pasture next to rural residences. Buildings are roughly 100 to 200 feet to the north and east of the base of the tower.

All data was collected using an NRG #40 Anemometer and NRG #200 Wind Vane mounted on a tilt-up tower located on the landowner's property at a height of 20m. This equipment fed into an NRG Wind Explorer data logger. All data plugs were sent into the Governor's Energy Office and then to the University of North Dakota 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
Montrose_South_0667_2005_0224_0418.A05 Montrose_South_0667_2005_0224_0418.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 an offset of +354° to the wind vane data, but the wind vane was installed incorrectly and did not record the wind direction properly and should be disregarded. The corrected data and wind resource summary report are available here:

CSU was chosen as the contractor for the program on September 14, 2007. From the UND data, an analysis of the wind resource was developed using Windographer 1.13. For this data, an offset of +9° was applied to the wind vane data. 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:

Complete Wind Resource Summary

The anemometer tower was removed from the site on April 18, 2005. Thus, the tower was only in place for 6.6 months - the data below reflect this reduced time period. Highlights of the wind resource at this site for the entire data collection period using the Windographer for the data adjusted for data quality and offset by +9° are shown below:

Data Properties
Variable
Data Set Starts:
9/29/2004 10:50
Height above ground (m)
20
Data Set Ends:
4/18/2005 14:00
Mean wind speed (mph)
5.98
Data Set Duration:
6.6 months
Median wind speed (mph)
5.51
Length of Time Step:
10 minutes
Min wind speed (mph)
0.00
Elevation (ft.):
6,147
Max wind speed (mph)
32.44
Calm threshold (mph):
0
Mean power density (W/m²)
25
Wind Power Coefficients
Mean energy content (kWh/m²/yr)
219
Power Density at 50m:
35 W/m²
Energy pattern factor
2.572
Wind Power Class:
1 (Poor)
Weibull k
1.477
Wind Shear Coefficients
Weibull c (mph)
6.61
Power Law Exponent:
0.126
1-hr autocorrelation coefficient
0.629
Surface Roughness:
0.01 m
Diurnal pattern strength
0.116
Roughness Class:
0.780
Hour of peak wind speed
4
Roughness Description:
Rough Pasture
Mean turbulence intensity
0.338
Note: The wind power density and wind power class at 50m are projections of the data from 20m. 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 this to calculate the roughness class and the power law exponent shown above.
Standard deviation (mph)
4.00
Coefficient of variation (%)
67
Frequency of calms (%)
5.95
Possible records
28,963
Valid records
28,101
Missing records
862
Data recovery rate (%)
97.0

 

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
20
5.98
65.03
0.03
0.19
1,600
2.5
Bergey Excel-S
6.7
10
20
5.98
42.86
0.01
0.23
2,100
2.3
Bergey XL.1
2.5
1
20
5.98
21.09
0.03
0.03
300
3.4
Southwest Skystream 3.7
3.7
1.8
20
5.98
60.69
0
0.07
600
3.9
Southwest Whisper 500
4.5
3
20
5.98
65.03
0.03
0.12
1,100
4.0
Northern Power NW 100/20
20
100
25
6.17
75.90
0
1.46
12,800
1.5
Vestas V47 - 660 kW
47
660
65
7.05
54.52
0
20.3
177,500
3.1
GE 1.5s
70.5
1,500
80.5
7.27
62.41
0.03
34.0
297,900
2.3
Vestas V80 - 2.0 MW
80
2,000
100
7.49
60.67
0.01
76.8
672,800
3.8
GE 2.5xl
100
2,500
110
7.59
52.00
0.06
112.0
981,800
4.5

 


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Last updated: June 2009
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