Compulsory electric motor efficiency regulation to reduce electricity use

3rd November 2023 By: Schalk Burger - Creamer Media Senior Deputy Editor

The new proposed compulsory specification for efficiency requirements of electric motors will see South Africa's electric motor efficiency regulations lifted to International Electrotechnical Commission (IEC) IE3 minimum efficiency standards, and a cost-benefit analysis shows a payback period of less than one year, project development and consulting firm Unlimited Energy Resources director Dr Theo Covary tells Engineering News.

The National Regulator for Compulsory Specifications has gazetted the proposed compulsory specification for efficiency requirements of electric motors (VC 9113) for comment. The regulation specifies that electric motors with power ratings from 0.75 kW to 375 kW must have a minimum efficiency class of IE3, as specified in the South African National Standards/IEC 60034-30-1 standard.

"International studies show that 96.7% of the total cost of an electric motor is the electricity it uses, while 1% of the costs are associated with repair and maintenance and 2.3% with capital costs," says Covary.

The impact of introducing IE3 minimum energy performance standards (MEPS) for electric motors in South Africa will be significant, with savings in the order of 840 GWh/y for 0.75 kW to 300 kW electric motors.

The payback periods for transitioning to more energy efficient motors range from 0.28 years for the 0.75 kW motors to 0.87 years for the 300 kW motors. IE3 MEPS will lead to energy savings of 10 219 GWh from 2023 to 2033.

Further, the environmental impact of these MEPS will be significant owing to the high emission factor of South Africa's electricity of 0.9488, and which is associated with high levels of nitrous oxide and sulphur oxides.

Additionally, 1.1-billion litres of water a year will be saved if the country's electric motors are of IE3 standard, Covary notes.

Meanwhile, the manufacturing impact will be limited as electric motors are imported. The trade impact is also minimal, although it should be managed through awareness and communication, he points out.

"Electric motors are the workhorses of modern industry, accounting for 45% to 50% of global energy consumption. Owing to their omnipresence, international best practise is to regulate electric motor efficiency through MEPS.

"South Africa's economy was built on energy-intensive industries, including mining, chemicals, iron and steel, and the context is ideal for regulating the energy efficiency of electric motors.

"But South Africa does not have such legislation and no regulation means the benefits of energy efficiency are not being exploited," he says.

The majority of South African electric motor sales are in the lower energy performance categories. However, a lifecycle cost analysis proved that the cost of owning a motor throughout its operational life was more important than the initial purchase price, emphasising the urgency of communicating this information to industries and buyers of electric motors.

"The research found that the design life target of premium brands is as high as 20 years. There are currently thousands of motors in operation, which have been bought in the past 5 to 15 years and will still be in use for the following 5 to 15 years.

"Inefficient electric motors make local manufacturers and industries less competitive, owing to increased operational costs, especially given the high electricity tariff increases the economy has endured from 2007, which increased by 753% compared with total inflation of 134% over this period."

Experience in other sectors has also shown that deeper consumer understanding of the long-term cost and savings implications of greater energy efficiency accelerates the penetration of more efficient apparatus into the market.

"The lack of available information around electric motor efficiency is, therefore, a primary impediment in South Africa. To address this, international best practise uses energy label programmes based on regulated MEPS, which are supported by academic research and awareness campaigns," Covary says.

Most countries have more than 20 years of experience in MEPS, energy labels, communication campaigns and energy saving analysis, besides others.

"South Africa, as a new entrant, has the opportunity to leverage from this global experience, which has generated significant research, best practise experience and insight," he adds.

Meanwhile, it is important to note that total system efficiency, and not only the efficiency of the motor, is the ultimate goal of energy efficiency standards.

"An electric motor converts electrical energy into mechanical energy, which is then used to complete tasks for industrial, commercial, residential and personal needs, such as driving fans, pumps, machine tools, household appliances, pool pumps and even electric wristwatches.

"Thus, while electric motors are a key component of a system, they can serve no function on their own. Therefore, it is not the sole contributor to a system's functionality, efficiency and overall performance. The US Department of Energy identifies three categories to improve system efficiency, namely power quality, motor and transmission efficiency and monitoring and maintenance.

"This strongly highlights the importance of a system-based approach to maximising energy savings, and also aligns with the South African experience," he notes.

However, the US National Electrical Manufacturers Association has indicated that, while system efficiency is beneficial, it is difficult to regulate. This view was also confirmed by local industry experts, hence the importance of introducing electric motor MEPS, says Covary.

Meanwhile, standards and labelling programmes do not seek to regulate the pre-used market, and governments typically make use of energy labels, awareness programmes and swop-out incentive programmes to accelerate the transition.

However, these are generally a function of available resources and it must be accepted that this process must be managed, and that it takes time for older and inefficient stock to work its way out through natural attrition.

"Purchasing decisions, particularly in distressed economic periods, are primarily price-driven, but, especially for electric motors, this thinking is particularly unwise because electric motor-driven systems cost far more to operate over their lifetime than the initial cost of purchase," he says.

He adds that South Africa is also likely to migrate to IE4 level efficiency requirements from 2030.