What is the Power Output and Efficiency of a Coal-Burning Power Plant?

[planke]

Homework Statement

At a coal-burning power plant a steam turbine is operated with a power output of 491 MW. The thermal efficiency of the power plant is 39.0%.
(a) At what rate is heat discarded to the environment by this power plant?
______ GW

(b) At what rate must heat be supplied to the power plant by burning coal?
______ GW

Homework Equations

e = W/Qh = Qh-Qc / Qh

The Attempt at a Solution

I don't know how to approach this problem. Is there some equation for power to use for thermodynamics?

Thanks!

 

[rock.freak667]

The Attempt at a Solution

I don't know how to approach this problem. Is there some equation for power to use for thermodynamics?

Thanks!

Start with the definition of efficiency η.

Remember power is nothing but the rate of change of energy. (1 W = 1 J/s)

 

[planke]

I think this problem should be really straightforward, but I am still having trouble understanding how to solve it.

 

[rock.freak667]

I think this problem should be really straightforward, but I am still having trouble understanding how to solve it.

In your relevant equations you posted

e=W/Q_h

So what is Q_h ?