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
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APPLICATION INFORMATION

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

WIND TURBINE RESOURCES

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LA JUNTA - 11/30/2012 to 3/25/2016

LOCATION DETAILS
Latitude:
N 37° 52.992’ or N 37° 52’ 59.52"
Longitude:
W 103° 41.80’ or W 103° 41’ 48.0"
Survey Meridian:
Colorado, Sixth Principal Meridian
Township:
25 S
Range:
56 W
Section:
8
Elevation:
1,332 m (4,370 ft)
Datum:
WGS 84
Tower Type:
Earth Turbines Tilt-Up
Tower Height:
34 m (112 ft)
Vane Offset (deg):
+65° (built into raw data)
Direction Basis:
Magnetic North
Mag. Declination:
7.8963° changing by -0.1308°/yr
Symphonie S/N:
309020086
Site No.:
3741

CSU ALP Install Team: Joel Moritz, Torres Neuhoff, Chad Paulson, and Mike Kostrzewa

DATA DETAILS

November 30, 2012 through March 25, 2016:

The anemometer tower was installed on November 30, 2012. The site is located in Otero County in a field near ranch buildings north of U.S. Highway 350 about 10 miles SW of La Junta. The terrain is a rough pasture, with good access to the wind from all directions. The land rises slightly to the west and north. Ranch buildings are located about 275 feet NNE of the site, with corrals located just adjacent and east of the site

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

  • Anemometers
    1. 34 m (111 feet) on an NRG 60" standard boom
    2. 34 m (111 feet) on an NRG 60" standard boom
    3. 20 m (65.6 feet) on an NRG 60" standard boom
  • Wind Vane
    1. 35 m (114.8 feet) bearing 245 deg on an NRG 60" standard boom with the null point facing toward the tower

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

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

NRG #40C Calibrated Anemometers
Anem. No.
1
2
3
Height
34 m
34 m
20 m
Model No.
1900
1900
1900
Serial No.
1795-00183416
1795-00164536
1795-00183414
Calibration Date
9/28/11 at 16:58:34
11/24/10 13:23
9/28/11 at 16:36:58
Slope
0.763 m/s per Hz
0.758 m/s per Hz
0.764 m/s per Hz
Offset
0.37 m/s
0.40 m/s
0.39 m/s

The data logger generates wind reports for each day. Using the Symphonie Data Retriever software, each day's data is complied into one large data file. A zipped file that contains the NRG data files for all days are given below:

Raw Wind Data Files
NRG Data Plug Files
La_Junta_3741_2012_1130_to_2016_0325.zip

It is important to note that these are the raw files include the offsets for the wind vanes so no compensation is required.

Experienced users may also wish to download the site file used to process the raw data with the Symphonie Data Retriever software. You can find the site file here.

From the collected data, an analysis of the wind resource report was developed for entire data collection period using Windographer 3.3.10. Since the data set contains data for two or more wind speed sensors at different heights above the ground, Windographer considered the wind shear relationship between different wind speed sensors to extrapolate the data to different heights. A best fit using the power law profile was chosen to extrapolate the data.

Using this data, an analysis of the wind resource report was developed and the data was flagged for icing in two ways:

  1. Any wind speed data (from any anemometer) where the wind speed was less than 0.5 m/s at a temperature less than 0 degC for 3 hours or more was flagged and ignored when calculating the wind resource statistics.
  2. Any wind direction data where the wind direction varied by less than 3 degrees at a temperature less than 0 degC for 3 hours or more was flagged and ignored when calculating the wind resource statistics.

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

Interim Wind Resource Summary

Highlights of the wind resource to date at this site are shown below:

Data Properties
Data Set Starts:
11/30/2012 15:20 MST
Data Set Ends:
3/25/2016 09:00
Data Set Duration:
3.3 years
Length of Time Step:
10 minutes
Elevation:
1,332 m (4,370 ft)
Mean air density (kg/m2):
1.061
Wind Power Coefficients
Power Density at 50m:
204 W/m2
Wind Power Class:
2 (Marginal)
Wind Shear Coefficients
Power Law Exponent:
0.176
Surface Roughness:
0.0873 m
Roughness Class:
1.89
Roughness Description:
Agricultural land with some houses and 8 metre tall sheltering hedgerows with a distance of approx. 1,250 - 500 metres.

 

Variable
Height above ground
A: 34m (111.5 ft.)
B: 34m (111.5 ft.)
20m (65.2 ft.)
10-min. Mean wind speed (m/s)
5.292 5.315 4.829
10-min Median wind speed (m/s)
4.85 4.86 4.39
10-min Standard deviation (m/s)
3.021 2.975 2.735
10-min Min. wind speed (m/s)
0.37 0.40 0.39
10-min Max wind speed (m/s)
26.64 26.11 24.46
Weibull k
1.821 1.871 1.853
Weibull c (m/s)
5.954 5.994 5.444
Mean power density (W/m2)
169 167 129
Mean energy content (kWh/m2/yr)
1,482 1,465 1,131
Mean turbulence intensity
2.173 2.122 2.187
Energy pattern factor
0.17 0.16 0.18
Possible records
174,346 174,346 174,346
Valid records
165,095 165,345 165,462
Missing records
9,251 9,001 8,884
Data recovery rate (%)
94.7 94.8 94.9

 

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

 

Wind Frequency Rose at 34 meters

 

Wind Energy Rose at 34 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

 

Probability Distribution Function at 34m - Sensor A: Frequency (%) vs. Wind Speed

 

Probability Distribution Function at 34m - Sensor B: Frequency (%) vs. Wind Speed

 

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.

Keep in mind too that listing a particular turbine doesn't imply an endorsement - not does it imply that installing a particular turbine model is feasible or recommended for a particular site. For consistency, the larger turbines are included even at sites that where they may not be practical so that one can compare the relative production of different sites.

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
%
Southwest AIR X - 45 ft tower
1.5
0.4
13.7 4.51 40.1 0.0 0 155 4.4
Bergey XL.1 - 100 ft tower
2.5
1.0
30.0 5.18 3.6 3.7 0.2 1,900 21.2
Southwest Skystream 3.7 - 45 foot tower
3.7
1.8
13.7 4.51 30.6 3.4 0.3 2,600 16.3
Southwest Whisper 500 - 42 ft tower
4.5
3.0
12.8 4.46 33.9 1.9 0.5 4,400 16.7
Endurance S-250 - 100 ft tower
5.5
5.0
30.0 5.18 38.8 0.0 0.7 6,100 14.0
Bergey Excel-R - 100 ft tower
6.7
7.5
30.0 5.18 26.2 2.6 1.4 12,200 18.5
Bergey Excel-S - 100 ft tower
6.7
10.0
30.0 5.18 12.2 1.4 1.5 13,300 15.2
Endurance E-3120 - 100 ft tower
19.2
55.0
30.0 5.18 23.9 0.0 12.5 109,400 22.7
Northern Power 100-21 - 121 ft tower
21.0
100
37.0 5.40 10.5 0.0 17.4 152,800 17.5
GE 1.5-77 - 213 ft tower
77
1,500
65.0 6.10 21.9 1.9 379.4 3,323,800 25.3
Vestas V100 - 262 ft tower
100
2,000
80.0 6.41 20.0 1.2 649.6 5,690,900 32.5

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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2008 Mechanical Engineering,
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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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