For me to better understand wind turbine technology I have attached a graph which indicates the wind speed distributions for two sites, A and B, where the mean wind speeds are 5.0 m s-1 and 8.0 m s-1 respectively.
a).Use the graph (attached) as a separate document to estimate the percentage of the year during which the wind speed lies in each of the following ranges, at each site.
• i.0 - 4 m s-1
• ii.5 - 16 m s-1
• iii.> 16 m s-1
b) Comment briefly on the suitability of each site for a wind turbine with a cut-in wind speed of 4 m s1 and a shut-down wind speed of 16 m s-1.
Wind and speed graph attached as file, shows Wind speed distributions for sites A and B
Note: The bars in graph show the number of hours for which the wind speed lies within each band of speeds. For example, at site A, the speed is normally at 1 m s-1 for about 530 hours a year, and at site B it is in this range for just over 200 hours per year
a) First we use the graph to estimate the percent of the year during which the wind speed lies in each of the given ranges at each site. Now, since the wind speed is given in terms of annual hours we have to do the calculations in terms of hours. The total hours in a year are 8760.
i.0 - 4 m s-1
Site A, Hours in the range: 4130, Percentage of year: (4130/8760) X 100 = 47.15%
Site B, Hours in the range: 1890, Percentage of year: (1890/8760) X 100 = 21.58%
ii. 5-16 m ...
This posting gives you a step-by-step explanation of percentage of year during which a wind turbine operates. The response also contains the sources used.