To minimise energy use, and to ensure that pumps are correctly matched to the duty expected pumps, and pumping stations should be regularly tested.

In water supply application, which are usually fitted with centrifugal pumps, individual large pumps should be 70 - 80% efficient. They should be individually tested to ensure they are in the appropriate range, and replaced or prepared as appropriate.

Pumping stations should also be tested collectively, because where pumps can run in combination to meet a given demand, it is often possible for very inefficient combination of pumps to occur. For example. it is perfectly possible to have a large and a small pump operating in parallel, with the smaller pump not delivering any water, but merely consuming energy. See Pump station manager

Pumps are readily tested by fitting a flow meter, measuring the pressure difference between inlet and outlet, and measuring the power consumed.

Another method is thermodynamic pump testing

Thermodynamic pump testing

Thermodynamic pump testing is a form of pump testing where only the temperature rise and power consumed need to be measured to find the efficiency of a pump. This is measured by means of temperature and pressure probes fitted to tapping points on the pump’s inlet and outlet...

where only the temperature rise and power consumed need be measured.