Question

Calculate the power required, to pump 50000 litres of water per minute to a vertical height of 72 m

Answer 1

First convert flow to m^3/s:
50 000 L/min = 50 m^3/min = 50/60 = 0.83333 m^3/s.

Hydraulic power (ideal) = ρ g Q h
= 1000 kg/m^3 × 9.81 m/s^2 × 0.83333 m^3/s × 72 m
= 588600 W ≈ 588.6 kW.

So the theoretical (fluid) power required is about 588.6 kW (≈ 789 hp).
If the pump has efficiency η, required input power = 588.6 kW / η (for example, at 70% efficiency → ≈ 841 kW).