Electric motors convert electrical power into mechanical power within a motor‐driven system. Most of the electricity used by an EMSD is consumed by the electric motor itself. Only a very small amount is used to power control functions or other ancillary circuits.
Electric motors and the systems they drive are the single largest electrical end‐use, consuming more than twice as much as lighting, the next largest end‐use. It is estimated that EMDS account for between 43% and 46% of all global electricity consumption.
2.5 times more electricity consumption compared to lighting
Adoption of high-efficiency motor systems would cut global electricity consumption by up to 10%.
The efficiency of a motor is the ratio of mechanical power output to the electrical power input and is typically expressed as a percentage. An energy-efficient motor is simply a motor that uses less energy than a conventional one. It will deliver the same mechanical power output but requires less electrical input power. Energy-efficient motors are manufactured with higher quality materials and techniques, and therefore usually have longer bearing lives, less waste heat output, and less vibration, all of which can increase their reliability and longevity.
In general, we should consider investing in an energy-efficient motor whenever we are purchasing a new or a replacement motor or thinking about repairing an existing motor. Choosing an energy-efficient motor makes sense in the following circumstances:
Payback: The capital cost of an energy-efficient motor can be 15-20% higher than that of a standard-efficiency motor. However, the running costs of a motor are a multiple of the capital cost, and an energy-efficient motor saves money during its entire lifetime. The payback period for an energy-efficient motor will depend on how much it’s used, on the size of the motor load and on the price of electricity. The simple payback of a continuously operated energy-efficient motor can be recovered through energy savings typically in less than 2 years.
