Economic Realities and Energy Efficient Polyphase Integral Horsepower Electric Motors

Abstract

Energy efficient polyphase integral horsepower electric motors are currently being vigorously promoted as a profitable method of conserving energy in many industrial and commercial applications. While the goal to be attained is indeed laudable, and must be tenaciously pursued, the economic realities of investment payback on increased efficiency versus cost of change out, power factor, etc. must have a meaningful review before decision making. Actual savings on a discount cash flow basis must be documented. and validity of the claims for the energy efficient motor must be verified.

This paper develops the procedures used by the chemical manufacturing divisions of the Union Carbide Corporation in developing a long range plan for evolution from a motor population of standard efficiency units to one of higher efficiency and increased reliability. It notes statistics publicized by the U.S. Department of Energy, Union Carbide's overall electric equipment efficiency review, their own efficiency testing of sample small electric motors, and a pilot program to determine the number of lightly loaded motors in plant location. It further depicts an economic appraisal on the payback of replacing a standard efficiency motor with a higher efficiency unit and an action plan for purchasing energy efficient motors while simultaneously securing optimization of other parameters.