South Africa should join its peers in adopting a minimum efficiency performance standard (MEPS) for electric motors, says Zest WEG Group rotating machines manager Fanie Steyn.

An MEPS is a specification that effectively limits the maximum amount of energy that may be used by a product in performing a specified task.

The application of an MEPS for electric motors will result in the phasing out of the least efficient electric motor classes by setting a minimum standard for the efficiency of motors imported and sold in South Africa.

South Africa’s energy use in its expansive mining industry is high and the implementation of an MEPS for electric motors can potentially be a “low-hanging” fruit to significantly reduce the strain on the country’s national electricity grid.

This will benefit the bottom line of the energy-intensive mining sector, which is a significant user of electric motors.

“The electric motor makes the mine work. All the pumps, fans, mills and compressors in the mine are driven by electric motors,” he says.

While there have been discussions for an MEPS for South Africa, it has not gained sufficient traction, with Zest WEG Group working to champion the adoption of the premium IE3 electric motors as a replacement for the less efficient IE1 motors.

Many South African large corporates are transitioning to using the premium IE3 voluntarily; however, there is a need to cement the standards to ensure that the full benefits are gleaned across the board.

For more than two decades, many countries have started implementing and labelling MEPS schemes to improve the efficiency of the motors installed in each country.

With electric motors accounting for an estimated 30% of global electricity consumption, it is significant that more than 42 countries already have MEPS in place, Steyn tells Mining Weekly.

This includes 28 European countries, as well as South Africa’s Brics – Brazil, Russia, India and China – counterparts.

Energy efficiency is the “easiest, cheapest and best way” of realising immediate significant savings on motor driven systems, despite a 15% premium.

South Africa imports about 280 000 electric motors a year, some 150 000 of which are low efficiency motors rated at IE1 level as standard.

The conversion from a standard efficiency IE1 motor to a premium efficiency IE3 motor can translate into energy savings of between 2.1% and 12.4%.

“If the 150 000 low-voltage motors entering the country were IE3 rated instead of IE1, the national grid could be relieved of about 195-million kilowatt hours a year.

“Over five years, we can save three-billion kilowatt hours – the equivalent of a small power station,” says Steyn.

The reduction in energy use will, in turn, reduce running costs and significantly reduce carbon dioxide emissions, and the slight differential capital cost is quickly recouped through lower operating costs.

“Of course, the transition will take a few years, as all motors have to be replaced by new ones. “The suggestion is to start right now by aligning the minimum energy efficiency level of the three-phase motors with IE3, in line with other countries, for all three phase motors of between 0.75 kW and 375 kW,” he says.