34 Circular Economy
The Circular economy in action
The financial benefits of improving motor efficiency are generally well understood. However, the environmental advantages are less commonly considered. Chris Callander spoke with Peter Isberg, Digital Lead, Motion, at ABB Sweden, to better understand how following the circular economy’s principles can deliver enhanced financial gains and significant environmental benefits.
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hen considering the challenge of reducing carbon dioxide (CO2) emissions, the role played by motors, and their potential to affect the situation, cannot be ignored. It has been widely reported that motors and electric drivetrains consume around 50% of global electricity, while electricity production accounts for 40% of global CO2 emissions. It is no surprise then that over the last 10 years minimum efficiency performance standards legislation has driven a revolution for electrical motors. Today motors are rated according to their efficiency class. In less than 20 years we have moved from using motors below IE1 to the current position where new motors have to reach a minimum of IE3, with many exceeding this. However, just 10 years ago, the requirement to use motors that met any legislated efficiency classes was voluntary. Because some motors can remain in operation for many years a large number of motors with low-efficiency ratings are still in use today. “I recently analysed a paper mill in Sweden which had an installed base of 1,800 motors,” explained Peter Isberg, Digital Lead, Motion, at ABB Sweden. “Of course, there were IE3 and IE2 motors, but around half of the motors were IE1 or less, particularly among the large quantities of small to medium-sized motors.” The analysis Peter carried out showed that at this single site, upgrading the inefficient motors would have the potential to save a minimum of 9 GWh of electricity per year. Clearly, this would amount to a significant cost saving for the paper mill. Electrical motors and drive systems are estimated to use 33 TWh of Swedish industry’s total annual electrical energy consumption of 51 TWh. Taking the paper mill’s situation a stage further, if all the inefficient motors in Swedish industry were upgraded, and the use of variable speed drives was increased to further maximise their efficiency, Peter believes, conservatively, that the potential energy savings could be more than 4TWh per year. That is more than 8% of Swedish industry’s total annual electricity consumption and enough energy to charge 2.1 million electric cars that travel 12,000km per year each. Alongside the cost savings for industry, this would also result in a notable reduction in CO2 emissions. THE CIRCULAR APPROACH But is replacing large numbers of motors which are still working well contrary to the circular economy’s aspiration to maximise the use of resources? Peter
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says not. “Some 97% of the impact a motor has on its environment comes from the energy used in its lifetime,” added Peter. “So, if you can minimise the energy losses from a motor in use, then the payback in terms of CO2 reduction can be relatively short, considering the initial CO2 debt when manufacturing the motor” In practice, Peter Isberg, Digital Lead, Motion, at ABB Sweden replacing an old 110kW IE1 motor that runs for 8,500 hours per year with a new IE4 equivalent would have a CO2 payback time of around 120 days in the UK*, and this product will last for at least 30 years, so the environmental and cost benefit of replacing inefficient motors is clear. Of course, the extent of the gains will depend on how the motors being replaced are disposed of. There are two choices here. The products can be placed in landfill or placed at the end of the circular loop and used to make new products. Following the circular option and recycling is the better option for the environment, and there are key reasons for this. Take the materials used to make motors as an example. To produce the metals, you have to start by mining oxides which requires large amounts of energy and water. Then converting the oxides into metals also takes large amounts of energy. > 36 “When you compare producing virgin metals with
“Some 97% of the impact a motor has on its environment comes from the energy used in its lifetime.”
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