Electric Motors - Leaner, Meaner and Cleaner

IndustryWeek (Alpern) - With new efficiency standards set to go into effect, motors will save power, but also hold the promise for significant savings down the road. By the estimate of the U.S. Energy Department, there are more than 13.5 million electric motors in use in U.S. industrial process operations today. Manufacturing alone spends more than $33 billion to keep those motors running, which accounts for nearly 70% of all electricity used in industry.  Those staggering numbers go a long way toward explaining why innovations in motors and drives have been focused on maximizing power efficiency.

Three years ago, Congress passed the Energy Independence and Security Act of 2007 (EISA), which includes new electrical motor efficiency standards. The legislation updates the 1992 Energy Policy Act (EPAct), which covered low-voltage, general-purpose (Subtype I), three-phase electric motors in the 1-horsepower (hp) to 200-hp range.

EISA raises the minimum energy efficiency requirements of these motors and encompasses Subtype II motors not previously within the EPAct scope, such as close-coupled pump motors, vertical motors and motors from 201 hp to 500 hp, all of which must now be rated to at least NEMA Energy Efficient.

These changes are significant. OEMs will be required to upgrade from a standard efficient motor on machinery they produce to a premium efficient motor. The only motors available on the market after December will meet federal requirements, but cost between 15% and 30% more to purchase.

Those costs, however, can be a bit misleading when viewed over a long period of time. Consider that the lifecycle cost of a typical AC induction motor consists of only 2% for the purchase price and over 97% for the energy used over its life, according to Baldor's Breaux. The added efficiency on premium efficient motors will recover the added cost in six to 12 months, he said, and continue every year afterward over the 15-year to 20-year lifecycle of the motor.