WIND ENERGY SYSTEMS - Cd3wd

Chapter 2—Wind Characteristics 2–67
16. The yearly mean speeds for Dodge City for the years 1948 through 1973 are 13.50,
12.15, 11.54, 12.41, 12.77, 14.04, 13.68, 13.34, 13.12, 13.23, 12.42, 13.41, 13.71, 11.05,
9.93, 11.06, 12.29, 11.31, 11.48, 11.40, 11.37, 10.48, 11.04, 11.22, 10.65, and 11.44 knots.
(a) Find the mean ū and the standard deviation σ.
(b) Find the 90 % confidence interval for ū, using the actual standard deviation. How
many years are outside this confidence interval?
(c) Discuss the accuracy of using just the last year and a 50 percentile standard deviation
to estimate the long term mean.
17. Find the equation for Wichita wind speeds versus Dodge City wind speeds for the data in
Table 2.6. What is the correlation coefficient r? (Note: This requires a hand calculator
with linear regression capability or access to a computer.)
References
[1] ANSI Standard A58.1-1982, Minimum Design Loads for Buildings and other Structures,
American National Standards Institute, Inc., 1982.
[2] Burr, I. W.: Applied Statistical Methods, Academic Press, New York, 1974.
[3] Climatography of the United States, Series 82: Decennial Census of the United States
Climate, “Summary of Hourly Observations, 1951-1960” (Table B).
[4] Cole, F. W.: Introduction to Meteorology, Wiley, New York, 1970.
[5] Corotis, R. B.: Stochastic Modeling of Site Wind Characteristics, ERDA Report
RLO/2342-77/2, September 1977.
[6] Corotis, R. B., A. B. Sigl, and J. Klein: “Probability Models of Wind Velocity Magnitude
and Persistence,” Solar Energy, Vol. 20, No. 6, 1978, pp. 483-493.
[7] Corotis, R. B.: Statistic Models for Wind Characteristics at Potential Wind Energy Conversion
Sites, DOE Report DOE/ET/20283-1, January 1979.
[8] Donn, W. L.: Meteorology, McGraw-Hill, New York, 1965.
[9] Elliott, D. L.: Synthesis of National Wind Energy Assessments, Pacific Northwest Laboratory,
Richland, Wash., Report NTIS BNWL-2220 WIND-5, 1977.
[10] Golding, E.: The Generation of Electricity by Wind Power, Halsted Press, New York,
1976.
[11] Gumbel, E. J., Statistics of Extremes, Columbia University Press, New York, 1958.
Wind Energy Systems by Dr. Gary L. Johnson November 20, 2001