COLORADO ANEMOMETER LOAN PROGRAM
 

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ELIZABETH - 7/3/2006 through 7/16/2009

LOCATION DETAILS
Latitude:
N 39° 28.161' or N 39° 28' 9.66"
Longitude:
W 104° 31.136' or W 104° 31' 8.16"
Township:
7 S
Range:
64 W
Section:
2
Elevation (ft.):
6,407
Tower Type:
Com tower mounted
Tower Height (ft.):
98
Tower Height (m):
30
Vane Offset (deg):
+80° and +270° (see below)
Direction Basis:
Mag. North
Mag. Declination:
9.133° E
Wind Explorer S/N:
1240
Site No.:
1240


DATA DETAILS

July 3, 2006 through May 22, 2007:

All data was collected using an NRG #40 Anemometer and NRG #200 Wind Vane mounted on a communications tower located on the landowner's property at a height of 30m. This equipment fed into an NRG Wind Explorer data logger. 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
Elizabeth_1240_2006_0703_0712.A06 Elizabeth_1240_2006_0703_0712.txt
Elizabeth_1240_2006_0901_1028.txt
Elizabeth_1240_2007_0409_0522.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 +270° to the wind vane data until April 9, 2007. For the period from April 9, 2007 through May 22, 2007, no offset was applied. This data and wind resource summary report are available here:

May 22, 2007 through May 20, 2009:

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

Raw Wind Data Files
NRG Data_Plug Files
Txt Files
Elizabeth_1240_2007_1015_1226.txt
Elizabeth_1240_2007_1226_0307.txt
Data plug from 3/7/2008 through 7/20/08 lost in the mail
Elizabeth_1240_2008_0720_1025.A08 Elizabeth_1240_2008_0720_1025.txt
Elizabeth_1240_2008_1025_0118.A08 Elizabeth_1240_2008_1025_0118.txt
Elizabeth_1240_2009_0118_0520.A09 Elizabeth_1240_2009_0118_0520.txt
Elizabeth_1240_2009_0520_0716.A09 Elizabeth_1240_2009_0520_0716.txt

Again, it is important to note that these are the raw files without any compensation for offset or temperature.

From both the UND and CSU data, an analysis of the wind resource report was developed for the period from July 3, 2006 through October 15, 2007 using Windographer 1.13. For this data, an offset of 270° was applied to the wind vane data. The summary report, the combined data file, and the Windographer files are listed below:

In addition, a wind resource report was developed for the period from July 3, 2006 through December 26, 2007 using Windographer 1.13. Again, an offset of +270° was applied to the wind vane data

For this report, a data validation analysis similar to the UND analysis was performed for the data from July 3, 2006 through December 26, 2006. 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 10° 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 data validation analysis), and the Windographer files (with and without the data validation analysis) are given below:

For the most recent data, the raw data plug files from UND were combined with subsequent raw data plug files this report to correct the offset issue with the UND data from April 9, 2007 through May 22, 2007. A data validation analysis was performed on all data from July 3, 2006 through March 7, 2008. 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 5° over 8 hours was deleted

Windographer was then used to add in synthetic data to these intervals with suspect data.

The data from March 3, 2008 at 4:30 p.m. through July 29, 2008 at 8:40 a.m. is missing due to a data plug lost in the mail. For this interval, the blank data was included and synthetic data was not included.

In addition, during a visit to the site on May 20, 2009, the offset was checked. When the datalogger was reading 31°, an electronic compass showed that the wind vane was pointed about 111°. Thus, the actiual offset is 111° - 31° = 80°. This new offset was then applied to all raw data as part of the data validation analysis. The combined data fiiles (with and without the data validation analysis), and the Windographer files (with and without the data validation analysis) are given below:

Current Wind Resource Summary

Highlights of the wind resource at this site from July 3, 2006 through the most recent data are shown below:

Data Properties
Variable
Data Set Starts:
7/3/2006 14:40 MDT
Height above ground (m)
30
Data Set Ends:
7/16/2009 12:20
Mean wind speed (mph)
14.553
Data Set Duration:
3 years
Median wind speed (mph)
13.700
Length of Time Step:
10 minutes
Min wind speed (mph)
0
Elevation (ft.):
6,407
Max wind speed (mph)
68.70
Calm threshold (mph):
0
Mean power density (W/m²)
256
Wind Power Coefficients
Mean energy content (kWh/m²/yr)
2,243
Power Density at 50m:
314 W/m²
Energy pattern factor
1.838
Wind Power Class:
3 (Fair)
Weibull k
2.095
Wind Shear Coefficients
Weibull c (mph)
16.432
Power Law Exponent:
0.121
1-hr autocorrelation coefficient
0.796
Surface Roughness:
0.01 m
Diurnal pattern strength
0.117
Roughness Class:
0.780
Hour of peak wind speed
23
Roughness Description:
Rough Pasture
Mean turbulence intensity
0.1357
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 this to calculate the roughness class and the power law exponent shown above.
Standard deviation (mph)
7.292
Frequency of calms (%)
0.02
Total data elements
479,046
Suspect/missing elements
65,898
Data completeness (%)
86.2

 

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
30
14.55
15.61
5.21
1.9
16,300
24.7
Bergey Excel-S
6.7
10
30
14.55
6.54
2.61
2.0
17,500
20.0
Bergey XL.1
2.5
1
30
14.55
1.90
7.44
0.3
2,400
27.7
Southwest Skystream 3.7
3.7
1.8
30
14.55
13.68
0
0.5
4,300
27.3
Southwest Whisper 500
4.5
3
30
14.55
15.58
6.28
0.9
7,700
29.4
Northern Power NW 100/20
20
100
30
14.55
24.16
0
16.4
144,000
16.4
Vestas V47 - 660 kW
47
660
65
15.98
12.63
0.66
158.4
1,387,800
24.0
GE 1.5s
70.5
1,500
80.5
16.40
16.78
4.93
328.8
2,880,400
21.9
Vestas V80 - 2.0 MW
80
2,000
100
16.84
16.05
2.43
524.8
4,597,100
26.2
GE 2.5xl
100
2,500
110
17.03
11.35
6.00
735.6
6,444,000
29.4

 


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Colorado State University. All Rights Reserved.
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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