In the pump industry, much our work involves two extremely simple, yet efficient machines – – the centrifugal pump and the AC induction motor. The centrifugal pump converts mechanical energy into hydraulic (flow, velocity, and pressure) energy and the AC motor converts electrical energy into mechanical energy. Many medium and larger centrifugals offer efficiencies of 75-90% and even smaller ones usually fall into the 50-70% range. Large AC motors, on the other hand, can approach an efficiency of 97% and any motor, five hp and above, can be designed to break the 90% barrier.
The importance of pump efficiency is entirely related to the use of energy. As the cost of electricity and other energy sources continue to rise, it just makes good sense that we use it as efficiently as possible. Whenever possible, we should select the most efficient pump available as it will usually justify its, potentially higher, first cost during its useful life.