An 800-MW electric power plant has an efficiency of 30%.It loses its waste heat in large cooling towers.Approximately how much waste heat (in MJ)is discharged to the atmosphere per second?

Question

Quizplus · Accepted Answer

Efficiency of the power plant = 30%
Therefore, Power Output = Efficiency x Power Input
Power Output = 0.30 x 800 MW = 240 MW
The waste heat generated = Power Input - Power Output
Waste heat = 800 MW - 240 MW = 560 MW
To convert MW to MJ/s, we multiply by 3600
Waste heat in MJ/s = 560 MW x 3600 s = 2016000 MJ/h or 2016000/3600 = 560 MJ/s
Therefore, approximately 1.9 x 10^3 MJ or 1 900 MJ of waste heat is discharged to the atmosphere per second.

An 800-MW Electric Power Plant Has an Efficiency of 30