# Pumping Water - Energy Cost Calculator

## The energy costs of pumping water

The energy cost per hour for pumping water can be calculated in imperial units as

C = 0.746 Q h c / (3960 μ_{p}μ_{m}) (1)

where

C = cost per hour (USD/hour, EUR/hour, ...)

Q = volume flow (US gpm)

h = differential head (ft)

c = cost rate per kWh (USD/kWh, EUR/kWh, ....)

μ_{p}= pump efficiency (0 - 1)

μ_{m}= motor efficiency (0 - 1)

Alternative calculation in metric units

*C = q ρ g h c / (3.6 10^{6} μ_{p} μ_{m}) *

* = q p c / (3.6 10 ^{6} μ_{p} μ_{m}) (2)*

*where*

_{}q = volume flow (m^{3}/h)

*ρ* = density (1000 kg/m^{3})

*h = differential head, height (m)*

*g = acceleration of gravity (9.81 m/s ^{2})*

### Example - Pumping Energy Cost

*10 US gpm* is lifted *10 ft*. The electricity cost is *0.1 USD/kWh* and the pump and motor efficiency *90% (0.9)*. The cost per hour can be calculated as

*C = 0.746 (10 US gpm) (10 ft) (0.1 USD/kWh) / (3960 0.9 0.9) *

* = 0.002 USD/hour*

### Pumping Energy Cost Calculator

Q - Volume flow (US gpm)

h - head (ft)

c - cost rate per kWh(USD/kWh, EUR/kWh, ....)

μ_{p}= pump efficiency

μ_{m}= motor efficiency

*1 US gpm = 0.227 m3/h**1 ft = 0.305 m*