Low power factor is undesirable because it increases the load on a building's electrical system, and utilities sometimes charge customers a penalty for low power factor facilities. Because power factor is lower when a motor is lightly loaded, be sure to choose the right-sized motor. You can also specify a motor with a high power factor, but such models sometimes have lower efficiency. The ultimate selection depends in part on whether a facility is subject to power factor penalty charges. A facility with a significant number of induction motors and a low power factor can solve the problem with premium-efficiency motors that are properly sized.
Induction motors are a mature technology.
Manufacturers continue to make slow improvements in efficiency and performance, but no major changes in the technology are on the horizon. Many of the following selected manufacturers also sell variable-speed motors, which can help to match the motor to variable loads.