We assumed a 39% efficiency for this power plant, meaning that for each unit of heat released with the combustion of coal, 0.39 unit is converted to electrical energy. Using an energy balance around the power-generating system of turbines, reheaters, and condensate separators, estimate an energy efficiency defined as 100 × the electrical energy generated (500 MWe) divided by the change in enthalpy of the steam flowing through the power-generating system.