COLORADO ANEMOMETER LOAN PROGRAM
 

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IDALIA: 7/17/2009 to 8/9/2010

LOCATION DETAILS
Latitude:
N 39° 41.980’ or N 39° 41’59"
Longitude:
W 102° 20.354’or W 102°20’21"
Township:
4 S
Range:
44 W
Section:
19
Elevation:
1,127m (4,026 ft.)
Datum:
WGS 84
Tower Type:
Earth Turbines Tilt-Up
Tower Height:
34m (112 ft.)
Vane Offset (deg):
+163°
Direction Basis:
Magnetic North
Mag. Declination:
7° 40' E, changing by 8' W/yr
Symphonie S/N:
309020391
Site No.:
3902

 

CSU ALP Install Team (from left): Derrick Benallie, Todd MacDonald, Daniel Fink, Eric Rasbach, Brian Smith, Morgan Davis, Jake Renquist, and Mike Kostrzewa (taking picture).

DATA DETAILS

July 17, 2009 to August 9, 2010:

The anemometer tower was installed on July 17, 2009 and removed from the site on August 9, 2010. The site was located in a field on the lessee's property just south U.S. Highway 36 about 2.5 miles west of Idalia in Yuma County. The terrain was flat in all directions, with the lessee's home NNW of the tower site. The nearest buildings are about 265 feet away.

Data was collected using three (3) NRG #40C Calibrated Anemometers and one (1) NRG #200P Wind Vane, as follows:

  • Anemometers
    1. 33.8 m (111 feet) heading 253°on an NRG 60" standard boom
    2. 33.8 m (111 feet) heading 352° on an NRG 60" standard boom
    3. 20.0 m (66 feet) heading 290° on an NRG 60" standard boom
  • Wind Vane
    1. 34.7 m (114 feet) heading 250° on an NRG 13" Z-mast with the null point facing toward the tower (with a small offset)

There was also a temperature sensor at a height of 1.8 m (6 feet) on a 6" boom.

All sensors fed into an NRG Symphonie data logger. The certifications for the anemometers are as follows:

NRG #40C Calibrated Anemometers
Anem. No.
1
2
3
Height
33.8 m
33.8 m
20 m
Model No.
1900
1900
1900
Serial No.
179500087836
179500087808
179500087829
Calibration Date
10/31/08 10:44:30 a.m.
10/31/08 5:39:04 a.m.
10/31/08 9:19:47 a.m.
Slope
0.760 m/s per Hz
0.755 m/s per Hz
0.759 m/s per Hz
Offset
0.33 m/s
0.40 m/s
0.35 m/s

The data logger generated wind reports for each day. Using the Symphonie Data Retriever software, each day's data was complied into one large data file. A zipped file that contains all of the NRG data files and a text version of the aggregate data for all days are given below:

Raw Wind Data Files
NRG Data Plug Files
Txt Files
Idalia_3902_NRG_2009_0717_to_2010_0809.zip Idalia_3902_NRG_2009_0717_to_2010_0809.txt

It is important to note that the wind direction data included in these files has already been adjusted for offset at the data logger.

Using this data, an analysis of the wind resource report was developed using Windographer 1.45. For this report, a validation analysis was performed on the data. This data was filtered two ways:

  1. Any wind speed data where the wind speed was less than 1 m/s for 3 hours or more when the temperature was less than 2°C was deleted.
  2. Any wind direction data where the wind direction varied by less than 3 degrees over 3 hours when the temperature was less than 2°C was deleted.

Windographer was then used to add in synthetic data to these intervals with suspect data. During the period considered, there were no intervals of suspect data, so no synthetic data were added.

The summary report, the combined data files (with and without the data quality analysis), and the Windographer files (with and without the data quality analysis) are given below:

Final Wind Resource Summary

The anemometer tower was removed from the site on August 9, 2010. Highlights of the wind resource at this site for the entire monitoring period are shown below:

Data Properties
Data Set Starts:
7/17/2009 18:10 MST
Data Set Ends:
8/9/2010 10:50
Data Set Duration:
13 months
Length of Time Step:
10 minutes
Elevation:
1,127m (4,026 ft.)
Mean air density (kg/m³):
1.087
Wind Power Coefficients
Power Density at 50m:
355 W/m²
Wind Power Class:
3 (Fair)
Wind Shear Coefficients
Power Law Exponent:
0.241
Surface Roughness:
0.408 m
Roughness Class:
3.17
Roughness Description:
Forest

 

Variable
Height above ground
A: 33.8m (111 ft.)
B: 33.8m (111 ft.)
20m (66 ft.)
10-min. Mean wind speed (m/s)
6.526
6.549
5.761
10-min Median wind speed (m/s)
6.220
6.330
5.480
10-min Min. wind speed (m/s)
0.282
0.282
0.238
10-min Max wind speed (m/s)
24.730
24.860
22.460
10-min Standard deviation (m/s)
3.090
3.022
2.729
Weibull k
2.191
2.264
2.197
Weibull c (m/s)
7.347
7.380
6.494
Mean power density (W/m²)
266
262
184
Mean energy content (kWh/m²/yr)
2,332
2,297
1,616
Energy pattern factor
1.762
1.716
1.781
Possible records
55,828
55.,828
55,828
Valid records
54,693
54,777
54,761
Missing records
1,135
1,051
1,067
Data recovery rate (%)
97.97
98.12
98.09
1-hr autocorrelation coefficient
0.855
0.850
0.846
Diurnal pattern strength
0.029
0.036
0.052
Hour of peak wind speed
21
21
15
Mean turbulence intensity
0.1276
0.1240
0.1442

 

Vertical Wind Shear, Height (m) vs Mean Wind Speed (m/s)

 

Wind Frequency Rose at 33.8 meters

 

Daily Wind Speed Profile, Hourly Mean Wind Speed (m/s) vs. Hour of the Day

 

Seasonal Wind Speed Profile, Monthly Mean Wind Speed (m/s) vs. Month

 

Seasonal Probability Distribution Function at 33.8m - Sensor A: Frequency (%) vs. Wind Speed

 

Seasonal Probability Distribution Function at 33.8m - Sensor B: Frequency (%) vs. Wind Speed

 

=

Seasonal Probability Distribution Function at 20m: Frequency (%) vs. Wind Speed

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. 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
m/s
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
33.8 6.53 11.71 4.98 2.3 19,900 30.3
Bergey Excel-S
6.7
10
33.8 6.53 5.59 2.83 2.5 21,500 24.5
Bergey XL.1
2.5
1
33.8 6.53 2.15 7.35 0.3 3,000 34.0
Southwest Skystream 3.7
3.7
1.8
33.8 6.53 10.73 0 0.6 5,500 35.0
Southwest Whisper 500
4.5
3
33.8 6.53 11.61 6.19 1.1 9,600 36.5
Northern Power NW 100/21
20
100
37 6.68 10.35 0 26.8 234,400 26.8
Vestas V47 - 660 kW
47
660
65 7.71 9.18 1.33 234.0 2,050,300 35.5
GE 1.5s
70.5
1,500
80.5 8.16 12.06 9.76 531.6 4,656,800 35.4
Vestas V80 - 2.0 MW
80
2,000
100 8.66 11.42 7.03 856.9 7,506,200 42.8
GE 2.5xl
100
2,500
110 8.90 8.32 15.77 1194.4 10,463,000 47.8

IMPORTANT: No turbine losses are included in the power, energy, and capacity factor values in the table. Typically, turbine losses can be 5-20% to account for maintenance downtime, icing/soiling and losses from other turbines in a wind farm. Users wanting to be conservative in the performance projections should multiply the power, energy, and capacity values by (1- % losses) to account for these losses.


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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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