COLORADO ANEMOMETER LOAN PROGRAM
 

PROGRAM INFORMATION

Frequently Asked Questions
Colorado Wind Resource Maps
ALP Sites and Data
Small Wind Electric Systems: A Colorado Consumer's Guide
Small Wind Applications Guide Video
Professional Anemometry
Donations

APPLICATION INFORMATION

Program Goals
Selection Criteria
Lessee Responsibilities
Site Layout and Anchors
Tower Safety
Data Plug Replacement
Ideal Sites
Online Application
 

WIND TURBINE RESOURCES

Zoning
Equipment Information and Dealers
Financing
Links

ABOUT US

Current Personnel
Student Positions
Contact Us

CRAIG - 7/26/2005 through 12/12/2006

LOCATION DETAILS
Latitude:
N 40° 31.4832’ or N 40° 31′ 29″
Longitude:
W 107° 35.7270’ or W 107° 35′ 44″
Township:
7 N
Range:
91 W
Section:
34
Elevation (ft.):
6,470
Tower Type:
NRG Tilt-Up
Tower Height:
20 m (65.6 ft)
Vane Offset (deg):
+260°
Direction Basis:
Unknown
Site Number:
0662
Wind Explorer S/N:
0750

DATA DETAILS

July 26, 2005 through December 12, 2006:

The anemometer tower was installed on July 26, 2005. The site was located approximately 2.6 miles west-northwest of the town of Craig. The tower was located on the south side of a large hill. The Yampa River Valley lies south of the site. The hill likely impacted winds from the north, but the tower had good exposure to winds from the south. The vegetation around the site was predominately grass and sagebrush.

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
Craig_0662_2005_0726_0810.A05 Craig_0662_2005_0726_0810.txt
Craig_0662_2005_0810_0929.A05 Craig_0662_2005_0810_0929.txt
Craig_0662_2005_0929_1106.A05 Craig_0662_2005_0929_1106.txt
Craig_0662_2005_1106_1211.A05 Craig_0662_2005_1106_1211.txt
Craig_0662_2005_1211_0121.A05 Craig_0662_2005_1211_0121.txt
Craig_0662_2006_0121_0212.A06 Craig_0662_2006_0121_0212.txt
Craig_0662_2006_0212_0416.A06 Craig_0662_2006_0212_0416.txt
Craig_0662_2006_0416_0514.A06 Craig_0662_2006_0416_0514.txt
Craig_0662_2006_0514_0723.A06 Craig_0662_2006_0514_0723.txt
Craig_0662_2006_0723_0831.A06 Craig_0662_2006_0723_0831.txt
Craig_0662_2006_0831_1105.A06 Craig_0662_2006_0831_1105.txt
Craig_0662_2006_1105_1212.A06 Craig_0662_2006_1105_1212.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 +260° to the wind vane data. 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 +260° was already applied by UND 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 December 12, 2006. Highlights of the wind resource at this site for the entire data collection period using the Windographer are shown below:

Data Properties
Variable
Data Set Starts:
7/26/2005 15:30
Height above ground (m)
20
Data Set Ends:
12/12/2006 15:10
Mean wind speed (mph)
9.43
Data Set Duration:
17 months
Median wind speed (mph)
8.31
Length of Time Step:
10 minutes
Min wind speed (mph)
0.00
Elevation (ft.):
6,470
Max wind speed (mph)
51.97
Calm threshold (mph):
0
Mean power density (W/m²)
109
Wind Power Coefficients
Mean energy content (kWh/m²/yr)
956
Power Density at 50m:
154 W/m²
Energy pattern factor
2.885
Wind Power Class:
1 (Poor)
Weibull k
1.491
Wind Shear Coefficients
Weibull c (mph)
10.44
Power Law Exponent:
0.126
1-hr autocorrelation coefficient
0.732
Surface Roughness:
0.01 m
Diurnal pattern strength
0.282
Roughness Class:
0.78
Hour of peak wind speed
16
Roughness Description:
Rough pasture
Mean turbulence intensity
0.235
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 terrain of rough pasture. This value was then used this to calculate the roughness class and the power law exponent shown above.
Standard deviation (mph)
6.52
Coefficient of variation (%)
69.2
Frequency of calms (%)
1.47
Possible records
72,574
Valid records
71,561
Missing records
1,013
Data recovery rate (%)
98.6

 

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
9.43
41.21
2.18
0.80
7,000
10.6
Bergey Excel-S
6.7
10
20
9.43
24.17
1.12
0.90
7,900
9.0
Bergey XL.1
2.5
1
20
9.43
10.89
3.07
0.13
1,100
12.5
Southwest Skystream 3.7
3.7
1.8
20
9.43
37.16
0
0.23
2,000
12.6
Southwest Whisper 500
4.5
3
20
9.43
41.20
2.64
0.41
3,600
13.7
Northern Power NW 100/20
20
100
25
9.73
52.58
0
7.34
64,300
7.3
Vestas V47 - 660 kW
47
660
65
11.13
32.08
0.46
80
700,700
12.1
GE 1.5s
70.5
1,500
80.5
11.46
38.83
3.09
162
1,419,500
10.8
Vestas V80 - 2.0 MW
80
2,000
100
11.82
37.17
1.71
274
2,401,000
13.7
GE 2.5xl
100
2,500
110
11.98
30.21
3.70
384
3,362,600
15.4

 


For more information Contact Us!

 



Disclaimer | Equal Opportunity | Contact CSU
© 2008 Mechanical Engineering,
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
This page is Javascript enabled. Turn on Javascript to view.