Power, efficiency, and Heat?

Question

An electrical generating plant operates at a boiler temperature of 220C and exhausts the unused hear into a nearby river at 19C. If the generating plant has a power output of 800MegaWatts and if the actual efficiency is 3/4 of the theoretical efficiency, how much heat per second must be delivered to the boiler?

Answer 1

What is this, your math homework?

Answer 2

Theoretical efficiency    n_t = 1 - TL/Th

n = 1 - (19+273)/(220+273)  = 40.7%

Actual efficiency  n_a =  .75 * n_t = 30.5%

Efficiency n = Qout/Qin

.305 = 800MW /  Qin

Qin  = 2616 MW

This is my approach.