Question $2$

$($a$)$ The mean wind speed at the site of a wind turbine is $5\mathrm{.}8\frac{m}{s}.$ The turbine produces XXXX of electricity annually and has a capacity factor of $38\%.$ If the rated wind speed of the turbine is $9\frac{m}{s}$ calculate the proportion of the turbine's electrical output that is produced during times when the wind speed at the site is between $10$ and $11\frac{m}{s}.$

$[6$ marks$]$

$($b$)$ Explain why a horizontal axis wind turbine should be oriented such that its swept area is perpendicular to the direction of the incoming wind. $[6$ marks$]$

$($c$)$ Describe the differences in the construction and operation of impoundment versus pumped storage hydroelectric power plants. $[8$ marks$]$