Answer:
The highest efficiency is 34.28%
Solution:
As per the question:
Power generated, P = 1 GW = [tex]1\times 10^{9} W[/tex]
Temperature of the super heated steam, T = 458 K
Temperature of the water flowing in the river, T' = [tex]28^{\circ}C[/tex] = 301 K
Now,
(a) The efficiency can be given by utilizing the Carnot efficiency:
[tex]\eta_{C} = 1 - \frac{T'}{T} = 1 - \frac{301}{458} = 1 - 0.6572 = 0.3428[/tex]
%[tex]\eta = 0.3428\times 100 = 34.28[/tex]%