Premium-efficiency motors are normally assumed to cost more because they use more and better copper and iron. Yet analysis of all models on the U.S. market in several common industrial sizes (in this case, 250-hp TEFC NEMA Type B) shows this is untrue. Even though recent efficiency standards have removed the least efficient motors from the market, list price remains tenuously related to efficiency, and careful shopping can reveal a very efficient motor costing the same as or less than a less efficient motor. Since a constantly running motor uses its own capital cost’s worth of electricity every few weeks, and one percentage point’s gain is worth more than $60 present value per horsepower, such smart shopping pays off.
McCoy, Gilbert. 2011. Personal communication with author, March 10. Analysis based on Motormaster+ 4.0, courtesy of Gil McCoy, Washington State University Extension Energy Program.