Wind Characteristics - Wind Energy: Renewable Energy and the Environment - page 50

9. Calculate the wind speed distribution using the Rayleigh distribution for an average wind
speed of 8 m/s. Use 1 m/s bin widths.
10. Calculate the wind speed distribution for a Weibull distribution for c 8 m/s and k 1.7.
Use 1 m/s bin widths.
11. Calculate the wind speed distribution for a Weibull distribution for c 8 m/s and k 3.
12. From Figure 3.13 , what is the percent of the time the wind is 5 m/s or larger?
13. From Figure 3.13, what is the percent of the time the wind is 12 m/s or larger?
14. From a 10 min period, the mean wind speed is 8 m/s and the standard deviation is 1.5 m/s.
What is the turbulence intensity?
15. At the Delaware Mountains wind farm, very high winds with gusts over 60 m/s were
recorded. An average value for 15 min was 40 m/s with a standard deviation of 8 m/s.
What was the turbulence intensity?
Use the following table to calculate answers for problems 16-21. The most convenient way is
to use a spreadsheet.

Bin
j

Speed
m/s

No.
Obs.

1 1 20

2 3 30

3 5 50

4 7 100

5 9 180

6 11 150

7 13 120

8 15 80

9 17 40

10 19 10

16. Calculate the frequency for each class (bin). Remember, sum of f j 1.
17. Calculate the power/area for j 5 bin and j 10 bin.
18. Calculate the average (mean) wind speed.
19. Calculate the wind power potential (power/area).
20. From the mean wind speed of problem 18, calculate the power/area. How will that value
compare (smaller, same, larger) to value in problem 19. Justify your answer.
21. From the answer to problem 18, use the mean wind speed and calculate a Rayleigh distri-
bution for an average wind speed 10.2 m/s. Use Δ v 1 m/s.