Drives and Controls Magazine
More efficient motors ‘could cut global electricity use by 7%’
Published:  01 November, 2016

Global electricity consumption could be cut by around 7% by using more efficient electric motors and related systems, according to the Energy Research Centre of the Netherlands (ECN). The Centre has calculated that such measures could save more than 1,350TWh of electricity and would mean that 17% less coal-fired generating capacity would be needed, avoiding the need to build around 200 new power plants and saving around $375bn in the process.

According to ECN, 45% of the world’s electricity is used for electric motors and pumps, ventilation and compressor systems – often using outdated and inefficient motors and systems.

“We were as surprised as everyone else to discover that such a large proportion of global electricity consumption can be attributed to electric motors,” says ECN researcher, Jeffrey Sipma. “More than 2.5 times as much electricity is used for electric motors and electrically-driven systems than for lighting. There is a huge potential here for cost-effective and technically relatively simple energy-saving measures.”

ECN suggests that substantial savings can be achieved using relatively simple measures, such as replacing older, inefficient IE0 or IE1 motors by more modern and efficient IE3 or IE4 machines. Significant savings could also be achieved by installing VSDs (variable-speed drives) on pumps, compressors and ventilation systems, reducing consumption by 15–40%. Depending on the process being powered, this could also increase production capacity.

More savings could be made by repairing leaks, implementing motor management systems, replacing pumps or ventilators, or making various other technical and organisational improvements. The actual energy savings vary depending on the application, but ECN expects average reductions of 20% for industrial systems and 15% for services.

Over the past two years, ECN has been helping the Indonesian government to develop an action plan to move to more efficient motors and systems in industry. The country still uses many IE0 and IE1 motors, often imported cheaply from China. ECN says that Indonesia could save around 23TWh of energy a year if major industrial and commercial users adopted more efficient practices. This would save Indonesian industry $1.5bn, and the government would be able to use $1bn of energy subsidies elsewhere.

Moreover, says ECN, Indonesia could scrap half of the new coal-fired power plants that it has planned – representing an investment of $11bn – and would be able to meet a large part of its climate change obligations. “This is a win-win situation for everyone, and the cost savings are many times greater than the investment required to implement this energy programme,” says Sipma.

Already, one pharmaceutical company in Indonesia has cut the electricity consumed by its cooling water systems by 49%, generating annual cost savings of $80,000 and repaying the investment within two years. Elsewhere, a petrochemical company installed 34 VSDs and cut its electricity consumption by 28%, resulting in a five-month payback. And a textiles factory reduced its electricity consumption by 59% by installing 15 VSDs on ventilation systems, recouping its investment in just over a year.