The Race for Efficiency
The Race for Efficiency
Today’s high-efficiency motor market is racing ahead of legislation — and the rest of us need to catch up.
Over the past few decades, energy efficiency in motors has become an ever- increasing concern for OEMs and manufacturers alike. With multiple energy bills mandating higher efficiency across ever-broader spectrums of motors, including the most recent Small Motor Rule by the Department of Energy, efficiency has become an essential consideration when choosing a new motor.
But industry is outpacing legislation. While recent mandates have expanded the range of motors that must meet IE3 efficiency standards (or, as we call them in America, premium motors), they haven’t upped the efficiency rating itself. Motor manufacturers, meanwhile, have continued to push the standard, creating IE4 and even IE5 models, the latter of which haven’t even been officially defined, much less regulated. Even without a legislative push, the race to produce increasingly impressive “super-premium” motors has only gotten more intense.
“It’s more competition,” Dan Jones, president of Incremotion Associates, said. “[It’s] ‘I’ve got a better motor than yours.’”
At first glance, the decision to push beyond the mandated IE3s could be considered a dubious one. End users aren’t currently required to replace old and inefficient motors — they just have to upgrade if they get a new one, and companies aren’t under any mandatory compulsion to go super-premium like they are to pick up an IE3. Businesses looking to squeak by with the bare minimum will likely choose IE3 motors, which could last 15 years on average. That leaves a fairly small market for more advanced motors.
Compounding the issue is that, as efficiency goes up, so do the costs of development. Pushing a motor from the IE3 to the IE4 category requires a significant spike in cost compared to going from IE2 to 3. Normally, in order to improve the efficiency of a motor, manufacturers just add a little copper and iron, but that method doesn’t quite cut it to reach IE4. The two ways manufacturers have found of pushing a motor’s efficiency to IE4 levels is to either use a rotor entirely made of copper or to utilize permanent magnets. Either option is vastly more expensive than the typical aluminum cast motor. And as the cost of production exponentially rises, the margin of improvement between each tier of motors goes down.