Wind Characteristics - Wind Energy: Renewable Energy and the Environment - page 49

3. E. Gilmore. 1987. Wind characteristics northwest Texas region, May 1978-December 1985 . Report

87-1, Alternative Energy Institute, West Texas A&M University.

4. Taehee Han. 2004. Wind shear and wind speed variation analysis for wind farm projects for Texas.

Master's thesis, West Texas A&M University.

5. Katalina Herrera. 2006. Wind direction analysis for Texas. Master's thesis, West Texas A&M

University.

6. Vaughn Nelson and Earl Gilmore. 1974. Potential for wind generated power in Texas . Report NT/8,

Governor's Energy Advisory Council of Texas.

7. I. Van der Hoven. 1957. Power spectrum of horizontal wind speed in the frequency range from 0.0007

to 900 cycles per hour. Journal of Meteorology 14:160.

8. E. D. Eggleston. 1996. Wind speed power spectrum analysis for Bushland, Texas. In Proceedings,

Windpower 1996 , p. 429.

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wind power . Alternative Energy Institute, West Texas A&M University.

QUESTIONS/ACTIVITIES
1. What is the wind power class for your home? In the United States go to the NREL site on
wind data or go to your state map, http://rredc.nrel.gov/wind/pubs/atlas/ . In other countries
try to find wind data values close to your home.
2. Note day and time. Go outside and estimate the wind speed. Now go to the information
channel on your TV and write down that wind speed. If you are far off, what could be the
reason? Going out on a calm day does not count.

PROBLEMS
Use spreadsheet if applicable and available.

1. Calculate the power, in kilowatts, across the following areas for wind speeds of 5, 15, and
25 m/s. Use diameters of 5, 10, 50, and 100 m for the area. Air density 1.0 kg/m 3 .
2. Solar power potential is around 1 kW/m 2 . What wind speed gives the same power
potential?
3. Calculate the factor for the increase in wind speed if the original wind speed was taken
at a height of 10 m. New heights are at 20 and 50 m. Use the power law with an exponent
] 0.14.
4. Calculate the factor for the increase in wind speed if the original wind speed was taken at
a height of 10 m. New heights are at 50 and 100 m. Use the power law with an exponent
] 0.20.
5. Calculate the factor for the increase in wind speed if the original wind speed was taken at
a height of 50 m. New heights are at 80 and 100 m. Use the power law with an exponent
] 0.20.
6. Houston Intercontinental Airport is surrounded by trees (20 m tall). Calculate the factor
for increase in wind speed from 10 to 100 m. Use the ln relationship and an estimated z 0
from Table 3.4 .
7. What is the air density difference between sea level and a height of 3,000 m?
8. In the Great Plains there is a wide temperature difference between summer (100°F) and
winter (-20°F). What is the difference in air density? Assume you are at the same eleva-
tion; average pressure is the same.

For problems with wind speed distributions, remember the wind speed has to be the num-
ber in the middle of the bin. If you use a bin width of 1 m/s, then the numbers have to be
0.5, 1.5, etc. In general, bin widths of 1 m/s are more than adequate. Smaller bin widths
mean more calculations.