Saturday, February 14, 2015

Staying the Course to a More Efficient Future

A few days ago, I posted a link on Linkedin to a recent IEEE article on U.S. electricity demand ( ).  Domestic electricity per capita has been flat since 2007. Much of this is attributed to energy efficiency efforts, including legislation that raised the bar on acceptable, minimum efficiency levels, including minimum efficiency of the largest consumer of electricity in America; electric motors.

The International Electrotechnical Commission (IEC), an international, non-government, consensus based standards  organization founded in 1906, has established four levels of motor efficiency to date.

Level IE1 was pretty much the worldwide de-facto standard for motors operating under 690V around 1990. In 1992, the U.S led the way by adopting IE2, effective in 1997. Followed, albeit slowly, by the rest of the world. By 2013 most of the world had adopted IE2.

Almost everyone in the U.S. is aware that legislation in 2007 raised electric lighting efficiency standards, ushering in the era of CFC and LED lighting, but few know that the same legislation raised the bar again on electric motor efficiency, to the IE3 level, effective in 2010. This time the world was quicker to follow. By 2017 the IE3 minimum efficiency standard will be the law of the land for new motors manufactured almost worldwide.

At the moment, there is no legislation in process anywhere in the world to implement IE4. At least not yet. But there it sits as the "holy grail" of motor efficiency. Many OEM's that use IE2 motors in their products aren't waiting for legislation. In the pump, compressor or HVAC worlds IE4 provides a significant competitive advantage over the IE2 motors they now have to design out. As long as they have to pull out a white sheet of paper, they might as well go IE4 if they can.

But IE4 technology can be expensive. Induction motor technology alone can't get there without adding electronic drives, and not every induction motor can be driven by an electronic drive. Permanent magnet technologies also need drives and have the hidden variable cost and long supply chain of rare earth magnets. Switch reluctance technology is so different from conventional motor and drive manufacturing that a new manufacturing infrastructure must be built to provide them in volume, and they can be noisy.

At the Motor and Drive 2015 conference in Orlando in January, we at Digital Power Engineering introduced another solution. A technology that takes a motor configuration that's been around for 120 years and is the electric motor of choice above 400 HP, and makes it practical at low HP as a motor that exceeds IE4 efficiency, has no magnets, requires no drive for single speed operation and is compatible with contemporary motor manufacturing. If you or anyone you know uses a motor above 200 watts in their product, they may already know about the need to shift to IE3. Have them drop me an email at and let's start the conversation about an accessible IE4 solution that can provide them a significant competitive advantage.

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