Question

A hydroelectric reservoir can supply water continuously at a rate of 100 m³/s. The head is 75 m. The theoretical power that can be developed is (in MW).

1. 73.5
2. 65.7
3. 68.5
4. 70.8

Answer 1

Correct Answer - Option 1 : 73.5

Concept:

• Hydropower plants capture the energy of falling water to generate electricity.
• A turbine converts the potential energy of falling water into mechanical energy and the generator converts the mechanical energy from the turbine into electrical energy.

The power equation for a hydropower plant is

P = ρQgh

Where,

P = power generated (W), ρ = density of water (kg/m3), Q = volumetric flow rate of water (m3/s), h = head height (m)

Calculation:

Given:

Q = 100 m3/s, h = 75 m

P = ρQgh = 1000 × 100 × 9.81 × 75 = 73.5 × 10⁶ = 73.5 MW