JULESBURG #2
1/16/2004 through 11/22/2005
LOCATION DETAILS 
Latitude: 
N 40° 55.1880’ or N 40° 55′ 11″ 
Longitude: 
W 102° 15.3420’ or W 102° 15′ 21″ 
Township: 
11 N 
Range: 
44 W 
Section: 
21 
Elevation (ft.): 
3,795 
DATA DETAILS
January 16, 2004 through November 22, 2005:
The site was located a couple
hundred feet away from the original Julesburg tower. The
tower was instrumented at four levels: 65 ft (20m), 105 ft (32m), 129 ft (39m), and 146 feet (44m). The
tower ws located in a pasture that is situated on a plain above the South Platte River.
The collected data includes the following data fields:
 Wind speed, standard deviation of the wind speed, and data quality flag for an anemometer at 20m height and facing SE
 Wind speed, standard deviation of the wind speed, and data quality flag for an anemometer at 32m height and facing W
 Wind speed, standard deviation of the wind speed, and data quality flag for an anemometer at 39m height and facing W
 Wind speed, standard deviation of the wind speed, and data quality flag for an anemometer at 44m height and facing W
 Wind direction, standard deviation of the wind direction, and data quality flag for a wind vane at 33m height and facing NE
 Wind direction, standard deviation of the wind direction, and data quality flag for a wind vane at 44m height and facing N
 Temperature from a sensor mounted at a height of 2m
All data was collected on data plugs that were sent into the Governor's Energy Office and then to the University of North Dakota for analysis. The data is bad from 9/14/2004 to 11/27/2004. Only a text data file is available for this site. There is also a flag field that indicates any suspect wind speed or wind direction data values. The txt data file, a version of the wind data with blanks whre the flags indicate suspect data, and the UND wind resource summary report are available here:
CSU was chosen as the contractor for the program on September 14, 2007. Using the UND data file, an analysis of the wind resource report was developed using Windographer 1.21. 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:
Highlights of the wind resource analysis at this site are shown below:
Data Properties 
Data Set Starts: 
1/16/2004 11:00 
Data Set Ends: 
11/22/2005 12:00 
Data Set Duration: 
22 months 
Length of Time Step: 
10 minutes 
Elevation (ft.): 
3,795 
Mean air density (kg/m³): 
1.094 
Wind Power Coefficients 
Power Density at 50m: 
397 W/m² 
Wind Power Class: 
3 (Fair) 
Wind Shear Coefficients 
Power Law Exponent: 
0.199 
Surface Roughness: 
0.189 m 
Roughness Class: 
2.53 
Roughness Description: 
Many trees 
Variable 
WS44W 
WS39W 
WS32W 
WS20SE 
Height above ground 
44m (146 ft) 
39 m (129 ft) 
32 m (105 ft) 
20 m (65 ft) 
Mean wind speed (mph) 
16.57 
15.84 
15.56 
14.05 
Median wind speed (mph) 
15.93 
15.23 
14.92 
13.42 
Min wind speed (mph) 
0.68 
0.67 
0.65 
0.58 
Max wind speed (mph) 
57.71 
55.68 
52.86 
50.31 
Mean power density (W/m²) 
379 
327 
313 
232 
Mean energy content (kWh/m²/yr) 
3,318 
2,869 
2,739 
2,032 
Energy pattern factor 
1.7 
1.68 
1.7 
1.71 
Weibull k 
2.271 
2.310 
2.288 
2.276 
Weibull c (mph) 
18.698 
17.879 
17.561 
15.859 
1hr autocorrelation coefficient 
0.83 
0.83 
0.83 
0.83 
Diurnal pattern strength 
0.11 
0.09 
0.09 
0.09 
Hour of peak wind speed 
22 
22 
21 
19 
Mean turbulence intensity 
0.13 
0.13 
0.13 
0.16 
Standard deviation (mph) 
7.71 
7.25 
7.18 
6.51 
Coefficient of variation (%) 
46.6 
45.8 
46.1 
46.3 
Possible records 
97,356 
97,356 
97,356 
97,356 
Valid records 
85,581 
85,915 
86,069 
34,800 
Suspect records 
11,775 
11,441 
11,287 
62,556 
Data completeness (%) 
87.9 
88.2 
88.4 
35.7 
Probability Distribution Function for the 44m W Anemometer
Probability Distribution Function for the 39m W Anemometer
Probability Distribution Function for the 32m W Anemometer
Probability Distribution Function for the 20m SE Anemometer 






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 ExcelR 
6.7 
7.5 
40 
16.13 
10.26 
9.08 
2.9 
25,500 
38.8 
Bergey ExcelS 
6.7 
10 
40 
16.13 
4.09 
3.76 
3.1 
27,600 
31.5 
Bergey XL.1 
2.5 
1 
40 
16.13 
1.19 
12.66 
0.4 
3,800 
43.3 
Southwest Skystream 3.7 
3.7 
1.8 
40 
16.13 
9.31 
0 
0.8 
6,800 
42.8 
Southwest Whisper 500 
4.5 
3 
40 
16.13 
10.12 
10.84 
1.3 
11,800 
45.0 
Northern Power NW 100/20 
20 
100 
37 
15.88 
9.57 
0 
31.0 
271,600 
31.0 
Vestas V47  660 kW 
47 
660 
65 
17.80 
8.25 
0.86 
252.3 
2,210,500 
38.2 
GE 1.5s 
70.5 
1,500 
80.5 
18.61 
11.59 
10.39 
563.1 
4,932,600 
37.5 
Vestas V80  2.0 MW 
80 
2,000 
100 
19.49 
10.89 
5.90 
878.7 
7,697,800 
43.9 
GE 2.5xl 
100 
2,500 
110 
19.89 
7.33 
15.21 
1,218.2 
10,671,400 
48.7 
IMPORTANT: No turbine losses are included in the power, energy, and capacity factor values in the table. Typically, turbine losses can be 520% 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.
