At a potential hydraulic$-$plant site the

average elevation of the headwater is estimated

at $552\mathrm{.}5m,$ the tailwater elevation at $480m.$

The average annual water flow was determined to

be equal to that volume flowing through a

rectangular channel $9\mathrm{.}15m$ wide with a depth of

$1\mathrm{.}22m$ and an average velocity of $4\mathrm{.}57\frac{m}{sec}.$

Find the annual electrical energy this site can

produce with a water turbine efficiency of $85\%,$

a generator effeciency of $95\%,$ and the loss in

the headworks equal to $3\frac{1}{6}$ of the available head.