On October 18, 2010, the U.S. Department of Energy (DOE) held a public meeting to discuss new minimum efficiency performance standards (MEPS) for electric motors currently under consideration by DOE. Neal Elliott, Associate Director for Research at ACEEE, delivered a statement on behalf of the National Electrical Manufacturers Association (NEMA) and a group of efficiency advocates led by the Appliance Standards Awareness Project (ASAP).  Before discussing Dr. Elliott's statement, here is a brief synopsis of the 20-year history of motor standards at DOE.

The Energy Policy Act of 1992 (EPAct) provided a definition of electric motors and directed the DOE to enact MEPS.  The standards applied to certain electric motors between 1 and 200 horsepower, and were based on the “energy efficiency” level specified in NEMA's MG-1 standard (equivalent to the current levels in Table 12-11).  In the Energy Independence and Security Act of 2007, DOE was directed to enhance those standards.  Most of the motors covered by EPAct were required to meet higher standards, defined by NEMA MG-1 Table 12-12.  Additionally, certain larger motors from 200-500 HP were brought up to the Table 12-11 level. (For more on history of motor MEPS, see ACEEE’s 2007 report.)

ACEEE, ASAP, and NEMA, along with associated organizations, have been meeting over the past several months to discuss ways to expand the scope of covered motors to a consistent level that would increase energy savings while addressing enforcement challenges. Dr. Elliott's statement, which can be read in full here, discusses the major issues involved and a path forward agreed to by the stakeholder groups listed above. The direction laid out in this statement recommends expanding scope of coverage at the MG-1 Table 12-12 level, rather than seeking to raise efficiency beyond this level, which could have unintended negative consequences.

The consensus agreement being sought would expand the types of poly-phase integral horsepower motors covered by MEPS, and bring (nearly) all of them up to the NEMA 12-12 level.  This approach has several advantages.  

• First of all, most U.S. motor manufacturers already sell motors that meet this standard. Thus, it would not be an undue burden requiring new engineering designs and production equipment.  
• Second, the efficiency improvement from bringing an uncovered motor up to the 12-12 level is much greater than increasing the efficiency of a covered motor from the 12-12 level to the next highest reasonable efficiency level.  
• Third, covering almost all electric motors from 1 to 500 hp at the same level, with limited, defined exceptions, makes enforcement much easier.    This last point applies to motors coming in from overseas, and closes several loopholes such as making small changes to the motor design to make it an un-covered motor. 
• Last, but certainly not least, is the often overlooked issue of motor purchasing decisions.  When end-users have a failed motor, they can either replace it with a new (and likely more efficient) model, or they can have it repaired.  The decision to replace or repair comes down to an economic decision.  Larger motors are often cheaper to repair, while smaller motors are cheaper to replace.  The technologies required to increase induction motor efficiencies beyond MG-1 Table 12-12 raise the first cost of the motor (even though the life cycle cost can be lower), and can raise compatibility issues in some applications.  These factors have the tendency to shift the motor decision to repair, which leads to a greater number of older, less efficient motors remaining in the marketplace, and could have the unintended effect of actually raising the total energy use from motors, instead of decreasing it.  However, raising the standards to a level that is already being achieved by motor manufacturers will mitigate those cost increases.  

ACEEE looks forward to continuing to work with DOE, motor manufacturers, and the energy efficiency community to achieve the best available energy efficiency in motors and motor systems.