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

MOFFAT - 6/24/2005 through 7/25/2006

LOCATION DETAILS
Latitude:
N 38 ° 0.001 ’ or N 38° 00′ 00″
Longitude:
W 105° 54.42’ or W 105° 54′ 26″
Township:
43 N
Range:
10 E
Section:
6
Elevation (ft.):
7,561
Tower Type:
NRG Tilt-Up
Tower Height:
20 m (65.6 ft)
Vane Offset (deg):
+195° (See below)
Direction Basis:
Unknown
Site Number:
0664
Wind Explorer S/N:
0664

DATA DETAILS

June 14, 2005 through July 25, 2006:

The anemometer tower was installed on June 14, 2005. The site was located in the town of Moffat, which is in the San Luis Valley. The valley runs from north to south. The tower was installed in the city park. Trees and buildings in the area impacted the winds measured at the site.

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
Moffat_0664_2005_0812_1001.A05 Moffat_0664_2005_0812_1001.txt
Moffat_0664_2005_1001_1110.A05 Moffat_0664_2005_1001_1110.txt
Moffat_0664_2005_1110_1215.A05 Moffat_0664_2005_1110_1215.txt
Moffat_0664_2005_1215_0117.A05 Moffat_0664_2005_1215_0117.txt
Moffat_0664_2006_0117_0228.A06 Moffat_0664_2006_0117_0228.txt
Moffat_0664_2006_0228_0329.A06 Moffat_0664_2006_0228_0329.txt
Moffat_0664_2006_0329_0509.A06 Moffat_0664_2006_0329_0509.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.

Note that the wind direction sensor was not functioning correctly during the entire measurement period.

For this data, UND applied an offset of +195° 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 +195° 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 July 25, 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:
6/14/2005 11:20
Height above ground (m)
20
Data Set Ends:
7/25/2006 10:00
Mean wind speed (mph)
8.69
Data Set Duration:
13 months
Median wind speed (mph)
7.01
Length of Time Step:
10 minutes
Min wind speed (mph)
0.00
Elevation (ft.):
7,561
Max wind speed (mph)
46.05
Calm threshold (mph):
0
Mean power density (W/m²)
100
Wind Power Coefficients
Mean energy content (kWh/m²/yr)
880
Power Density at 50m:
142 W/m²
Energy pattern factor
3.515
Wind Power Class:
1 (Poor)
Weibull k
1.312
Wind Shear Coefficients
Weibull c (mph)
9.45
Power Law Exponent:
0.126
1-hr autocorrelation coefficient
0.747
Surface Roughness:
0.01 m
Diurnal pattern strength
0.413
Roughness Class:
0.78
Hour of peak wind speed
17
Roughness Description:
Rough pasture
Mean turbulence intensity
0.317
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)
6.83
Coefficient of variation (%)
78.6
Frequency of calms (%)
1.07
Possible records
58,456
Valid records
56,502
Missing records
1,954
Data recovery rate (%)
96.7

 

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
8.69
51.84
2.38
0.76
6,600
10.1
Bergey Excel-S
6.7
10
20
8.69
33.99
1.09
0.84
7,400
8.4
Bergey XL.1
2.5
1
20
8.69
16.80
3.11
0.12
1,000
11.8
Southwest Skystream 3.7
3.7
1.8
20
8.69
47.29
0
0.21
1,800
11.4
Southwest Whisper 500
4.5
3
20
8.69
51.84
2.78
0.38
3,300
12.5
Northern Power NW 100/20
20
100
25
8.96
60.84
0
6.95
60,900
7.0
Vestas V47 - 660 kW
47
660
65
10.25
43.06
0.27
74.6
653,400
11.3
GE 1.5s
70.5
1,500
80.5
10.56
49.62
3.04
155
1,357,100
10.3
Vestas V80 - 2.0 MW
80
2,000
100
10.88
48.10
1.56
254
2,222,700
12.7
GE 2.5xl
100
2,500
110
11.03
40.20
3.85
354
3,099,500
14.2

 


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.