Chapter 2 - Energy, Energy Transfer, and General Energy Analysis - Problems - Page 102: 2-66

$W_{e}=323.27kW$

First we calculate the flow of mass: $m=\rho Q=\rho VA=1.25\frac{kg}{m^3}*7\frac{m}{s}*\frac{\pi*(80m)^2}{4}=43982.3\frac{kg}{s}$ Here we are working with kinetic energy: $W_{k}=\frac{1}{2}mV^2=\frac{1}{2}*43982.3\frac{kg}{s}*(7\frac{m}{s})^2=1077.57kW$ Then the actual electric power generation is: $W_{e}=0.3W_{k}=0.3*1077.57kW=323.27kW$