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"Motor
efficiency in the U.S.: the next step"
With
trilingual summary
The August featured article will be posted next
month.
The 1992 Energy Policy Act (EPACT), first federal
legislation to set minimum efficiency levels for standard polyphase a-c motors
1-200 hp, recognized that still higher efficiencies would probably become
readily available and directed the Department of Energy to encourage their
development. That led to establishment of the NEMA Premium line of motors in
2002.
Energy conservation advocates, such as the
Consortium for Energy Efficiency (CEE) and the American Council for an
Energy-Efficient Economy (ACEEE), actively promoted user acceptance of the
"Premium" product. Its higher price, however, resulted in limited market share.
Conservationists were also frustrated by EPACT's narrow scope, which left out
eight-pole motors, all ratings above 200 hp, and a number of mechanical
offshoots of standard horizontal designs, such as close-coupled pump motors.
A step forward in 2005 was passage of a second
Energy Policy Act, stipulating that NEMA Premium motors were to be the "product
of choice" in federal procurement. But again, that market was limited.
Finally, after many months of Congressional
deliberation, the Energy Independence and Security Act became law in December
2007. Although public attention was drawn primarily to provisions dealing with
automotive fuel economy and renewable fuel production, the 2007 Act considerably
broadened the regulation of motor efficiency. Its requirements, to become
effective at the end of 2010, include:
- Energy efficient (EPACT) performance is now
mandatory for many motors formerly exempt, including eight-pole ratings (for
which NEMA had defined higher efficiencies but the 1992 law had not);
U-frame designs; and NEMA Design C.
- For those ratings within the EPACT scope,
the 2007 legislation raises the required efficiencies to NEMA Premium levels
(which have not been defined for 8-pole designs or for NEMA Design C).
Meanwhile, CEE recommends that electric utilities
and governmental energy agencies develop or enhance incentive programs to
encourage wider use of NEMA Premium (or better) low-voltage motors still outside
legislative jurisdiction, in ratings from 250 through 500 hp. According to the
Department of Energy's own 1998 market assessment, motors above 200 hp (3/4 of
them in the 250-500 hp range) make up only 1% of the market but account for 45%
of energy usage.
Can efficiencies continue to escalate, whatever
the incentive? The ACEEE doubts it. Certainly each incremental increase tends to
be smaller than the last, and at higher cost.
From "Motor
efficiency in the U.S.: the next step,"
to be published in the
Electrical Apparatus August 2008 issue. Visit our online webstore to
order
copies. © 2008
Barks Publications, Inc. All Rights Reserved.
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