Energy-efficient Motors vs VFDs

Too many unexplained terms: What are IE2 and IE3?

This article shows the differences. IE2 is equivalent to what is called high efficiency in the US. IE3 is equivalent to what is called premium efficiency in the US. When running near rated output, the efficiency differences between IE2 and IE3 are very small, such as 95% vs 96%.

VFDs are a separate issue: it does not boil down to "Energy Efficient motors vs VFDs" as the headline tries to suggest.

VFDs are a separate issue: it does not boil down to "Energy Efficient motors vs VFDs" as the headline tries to suggest.

K_Fry, VFDs are not a separate issue here. The whole discussion is on "Energy Efficient motors vs VFDs". I wanted two informations, which are not available in the article - (1) How much difference in efficiency compared to conventional motors? (2) What about part load performance of these high efficiency motors, where VFD makes its usefulness? What way Energy Efficient motors can do the job of VFD, which is meant for improving the part load performance of the connected equipment?

I want to add 3rd one here- (3) What changes in design or materials of construction makes it more efficient?

GA. my all doubts clarified.

This is not a case of either-or. The two technologies can be, and often are, used together.

High efficiency motors will provide an energy/cost saving in all applications. As their use is now mandatory, the drive makers will have to live with the new regulations. Why is Europe leading the way again? The US and Far East should make high efficiency motors mandatory for new installations as well.

VSDs can provide a much larger energy/cost saving in those applications where their use is appropriate. The drive makers know this. This is a case of a headline writer not understanding the technology or the market.

Europe leading the way? That only means it is a green and half though out mess they are leading.

This is a case of a headline writer not understanding the technology or the market.

Correct.

Why is Europe leading the way again?

I am not convinced that they are. High efficiency motors have been used in new installations for a long time in the US, with energy saving being the usual cost justification. Many times, budgets are strictly limited, so it can make more sense (from cost, environmental, and energy usage perspectives) to use a standard efficiency motor with a VFD, than to use a high-efficiency motor without. It depends upon the nature of the installation, and a law that dictates the use of a particular motor does not take into account the engineering of the system required.

The US is developing incentives (cash rebates) for the use of high efficiency motors. This provides a strong motive to update, without imposing a less than optimal engineering solution. (On the other hand, it can be criticized as corporate welfare.)

Overall simple cost analysis will determine if its a truly warranted conversion.

Typical electric motors are in the 80 - 90% efficient range as is so will the 5 - 15% gain in energy efficiency pay for the new motor and related equipment in a reasonable working environments life time?

If the payback time in energy costs saved for the new motor and equipment in its typical working load and run time environment works out to being equal to or greater than the estimated service life of the machine or new equipment then no its not worth the efforts.

Far too often this simple calculation goes unused and a pile of good money goes towards something that serves as no real or practical gain for the customer or company other than 'I'm even greener now' bragging rights.