February 25, 2022

The National Electrical Manufacturers Association (NEMA) published NEMA MG 10011-2022 Power Index Calculation Procedure—Standard Rating Methodology for Power Drive Systems and Complete Drive Modules.

This standard discusses the Power Index (PI) for Power Drive Systems (PDS), which can help reduce carbon emissions, enable Smart Manufacturing technologies, and improve system energy savings. The PDS, which is defined as a motor coupled with an electronic adjustable speed drive, provides an unprecedented opportunity to save energy. 

According to Rob Boteler, Chairman of the NEMA Motor and Generator Section’s Energy Management Committee and Government Relations Representative at Nidec Corp., “In my 30-plus years of promoting motor efficiency, there has never been an opportunity to save energy that comes close to the adoption of the PDS replacing mechanical control technologies.”

MG 10011 introduces a Power Index (PI) metric, which allows PDS and drives to be compared for optimal energy savings for end-users. The PI rating balances engineering rigor and broad, data-driven assumptions that can be applied over a wide variety of motor types. This provides an easy-to-use metric similar to a car “city/highway” miles-per-gallon rating.

“The Power Index provides an easy to understand, public-facing description that highlights the energy savings potential of common PDS applications,” said Sarah Widder, Principal for the Emerging Technology Team at Cadeo, a Portland, Ore.-based clean energy consulting firm.

NEMA and the Northwest Energy Efficiency Alliance (NEEA) worked together to develop the Power Index (PI) rating system, providing a streamlined method to evaluate the reduction in power, and associated energy savings, by controlling equipment speed with a PDS.

“This metric will be an important tool for utilities and regulators, who can utilize PI in their incentives programs to encourage the selection of motors and controls that will result in significant energy savings,” said Nicole Dunbar, Codes and Standards Engineer at Northwest Energy Efficiency Alliance, an alliance of more than 140 Northwest utilities and energy efficiency organizations.

“This standard represents an important change in how we think and talk about the potential energy savings from motors and drives,” says Dale Basso, Chair of the NEMA Motors and Generators Section and Motors Manager at WEG Electric Corp. “Power drive systems represent the next big opportunity for industry, utilities, and end-users to acquire energy savings from motor-driven systems,” he said. 

The core audience for MG 10011 is utility companies, energy program administrators, and the U.S. Department of Energy.

NEMA MG 10011-2022 is available on the NEMA website for $84 in hard copy and at no cost as an electronic download.