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BLACK FOREST - 9/25/2010 to 9/29/2011

LOCATION DETAILS
Latitude:
N 39° 0.563’ or N 39° 0’ 33.78"
Longitude:
W 104° 41.738’ or W 104° 41’ 44.28"
Survey Meridian:
Colorado, Sixth Principal Meridian
Township:
12 S
Range:
65 W
Section:
17
Elevation:
7,485 feet (2,281.4 m)
Datum:
WGS 84
Tower Type:
NRG Tilt-Up
Tower Height:
20 m (65.6 feet)
Vane Offset (deg):
+78°
Direction Basis:
Magnetic North
Mag. Declination:
8° 48' E, changing by 7' W/yr
Wind Explorer S/N:
1241
Site No.:
3904

DATA DETAILS

September 25, 2010 to September 29, 2011:

The anemometer tower was installed on September 25, 2010 and removed on September 29, 2011. The site was SE of the intersection of Shoup Road and Black Forest Road near the town of Black Forest. The tower was located in a clearing with 30-40 foot tall trees about 180 feet to the north and about 225 feet to the south of the tower. The wind tends to blow east-west in the direction of the clearing.

All data was collected using an NRG #40 Calibrated Anemometer and NRG #200 Wind Vane mounted on a tilt-up tower located at a height of 20m. The certification for the anemometer is as follows:

NRG #40C Calibrated Anemometer
Model No.
1900
Serial No.
179500152534
Calibration Date
4/30/2010 4:28:35 p.m.
Slope
0.755 m/s per Hz
Offset
0.42 m/s

This equipment fed into an NRG Wind Explorer data logger. All data plugs were sent to the Colorado ALP at Colorado State University 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
Highest
2 sec
Gust
mph
Gust
Date/Time
Black_Forest_3904_2010_0925_1117.A10 Black_Forest_3904_2010_0925_1117.txt
51
10/25/2010 2:06
Black_Forest_3904_2010_1117_0123.A10 Black_Forest_3904_2010_1117_0123.txt
50
12/20/2010 8:07
Black_Forest_3904_2011_0124_0410.A11 Black_Forest_3904_2011_0124_0410.txt
53
3/11/2011 4:42
Black_Forest_3904_2011_0410_0610.A11 Black_Forest_3904_2011_0410_0610.txt
47
4/22/2011 14:12
41
9/3/2011 8:29

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.

Using this data, an analysis of the wind resource report was developed using Windographer 1.49. For this data an offset of +78° was applied to the wind vane data. 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 mph for 6 hours or more was deleted.
  2. Any wind direction data where the wind direction varied by less than 3 degrees over 6 hours was deleted

Windographer was then used to add in synthetic data to these intervals with suspect data. A summary report, the combined data files (with and without the validation analysis), and the Windographer files (with and without the validation analysis) are given below:

Final Wind Resource Summary

Highlights of the final wind resource assessment at this site are shown below:

Data Properties
Variable
Data Set Starts:
9/25/2010 13:30 MDT
Height above ground (m)
20
Data Set Ends:
9/29/2011 16:30
10-min. mean wind speed (mph)
5.829
Data Set Duration:
1 year
10-min median wind speed (mph)
5.160
Length of Time Step:
10 minutes
10-min min. wind speed (mph)
0.310
Elevation:
7,485 ft (2,281.4 m)
10-min max wind speed (mph)
29.76
Mean air density (kg/m³):
0.979
10-min standard deviation (mph)
4.003
Wind Power Coefficients
Weibull k
1.496
Power Density at 50m:
45 W/m²
Weibull c (mph)
6.4701
Wind Power Class:
1 (Poor)
Mean power density (W/m²)
24
Wind Shear Coefficients
Mean energy content (kWh/m²/yr)
207
Power Law Exponent:
0.177
Mean turbulence intensity
0.392
Surface Roughness:
0.10 m
Energy pattern factor
2.733
Roughness Class:
2.00
1-hr autocorrelation coefficient
0.781
Roughness Description:
Few trees
Diurnal pattern strength
0.393
Note: The wind power density and wind power class at 50m are projections of the data from 20m. A surface roughness of 0.1 meters was assumed for this projection. This is the surface roughness for terrain with a few trees. This value was then used this to calculate the roughness class and the power law exponent shown above.
Hour of peak wind speed
15
Total data elements
159,381
Missing data elements
733
Data recovery rate (%)
99.5

 

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

 

Vertical Wind Shear, Height (m) vs Mean Wind Speed (mph)

 

Wind Frequency Rose at 20 meters

 

Wind Energy Rose at 20 meters

 

Daily Wind Speed Profile at 20m, Hourly Mean Wind Speed (mph) vs. Hour of the Day

 

Seasonal Wind Speed Profile at 20m, Monthly Mean Wind Speed (mph) vs. Month

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
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
5.83
67.7
0.02
0.2
1,800
2.7
Bergey Excel-S
6.7
10
20
5.83
46.7
0.00
0.3
2,200
2.5
Bergey XL.1
2.5
1
20
5.83
25.0
0.03
0.0
300
3.8
Southwest Skystream 3.7
3.7
1.8
20
5.83
63.3
0.00
0.1
700
4.2
Southwest Whisper 500
4.5
3
20
5.83
67.7
0.02
0.1
1,100
4.3
Northern Power NW 100/21
21
100
37
6.30
58.9
0.00
3.4
30,100
3.4
Vestas V47 - 660 kW
47
660
65
6.76
58.5
0.00
20.7
181,700
3.1
GE 1.5s
70.5
1,500
80.5
6.95
66.4
0.02
34.9
306,000
2.3
Vestas V80 - 2.0 MW
80
2,000
100
7.14
64.6
0.00
77.3
677,000
3.9
GE 2.5xl
100
2,500
110
7.22
55.7
0.03
112.6
986,400
4.5

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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