A hydroelectric generating plant is supplied from a reservoir of capacity 3.6 × 106 m3 at a head of 100 m. Find the total energy available in kWh if the overall efficiency is 75%.
A hydroelectric generating plant is supplied from a reservoir of capacity 3.6 × 106 m3 at a head of 100 m. Find the total energy available in kWh if the overall efficiency is 75%.
Right Answer is:
735750
SOLUTION
Given
overall efficiency = 75%
Reservoir capacity (V) = 3.6 × 106 m3
Water Head (h) = 100 m
Now to calculate the potential energy, we know that
Density of water = 997 kg/m3
g = 9.8 m/s2
Potential energy = E = mgh
E = D × V × g × h (∵ mass = density × Volume)
Put all these in formula of potential energy, we get
E = (D × V) × 9.8 × 100
E = 997 × 3.6 × 106 × 9.8 × 100
E = 3517416 × 106 J
E = (3517416 / 3600) x 103 kWh
E = 977060 kWh
Hence, total output energy can be calculated as
E’ = 977060 x 0.75
∴ E’ ≈ 732795 Wh ≈ 732.7 kWh