Comparative life cycle assessment of induction machines made with copper‐cage or aluminium‐cage rotors

Abstract

This paper deals with Life Cycle Assessment (LCA) of induction machines and try to determine whether a coppercage rotor is better than an aluminium-cage one, for a given using time and considering the global environmental footprint. The paper focuses on induction motors directly connected to the power grid, without electronic converters. The LCA takes into account the materials extraction, the machine construction, the use and the end of life for several criteria. In the first part, a copper conductor is compared to an aluminium one and results are discussed considering the part of recycled material in the rotor manufacturing process. In a second part, two machines with the same efficiency are compared. The environmental impacts differences are discussed. In the third part, two machines of the same sizes, but with a different rotor, are compared considering various usage times. The lower losses of the copper-rotor machine yield a significant advantage for the efficiency but the gains are smaller when the global life cycle is considered.

Induction motors with copper rotor: a new opportunity for increasing motor efficiency

“…The payback period was calculated and was considered adequate for values less than four years. The useful life was set low for this type of motor (10 years) [29], [30] due to the environmental conditions in which the motor works. The following were considered: the cost of the maximum demand kW, the load factor, efficiency factor, the operating time, the discount rate, and the income tax rate.…”

Influence of Equivalent Circuit Resistances on Operating Parameters on Three-Phase Induction Motors with Powers up to 50 kW

“…As this economic assessment is very sensitive to the number of hours of annual motor operation, Figure 19 shows the evolution of the payback according to the number of hours/year, considering a duty cycle of 45% of hours at full load, 35% of hours at 3/4 of full load and 20% of hours at 1/2 of full load [22]. Although these results have not been evaluated in this study, they would allow an analysis of the environmental impact derived from the measures adopted, with reference to the materials used and the associated energy savings, through the study of the life cycle of modified motors compared to initial motors [23,24].…”

Remanufacturing a Synchronous Reluctance Machine with Aluminum Winding: An Open Benchmark Problem for FEM Analysis

“…When comparing the carbon footprint of final copper products made in the United States consumption mix (3217 kg/ton), as well as of the wrought aluminium made in the North American consumption mix (primary + secondary + scrap: 9871 kg/ton) and the cast aluminium made the North American consumption mix (1284 kg/ton)-when based on greenhouse gas emissions, regulated emissions, and the energy use in transportation (GREET) model [25]-it can be deducted that the environmental impact heavily depends on the input material and the end product. Nevertheless, it has been found that, through a comparison of the life cycle assessment of induction machines made with copper cage or aluminium cage rotors, the environmental impacts of construction and end-of-life copper cage rotors are worse than that of an aluminium ones [26]. In the automotive sector, the exceptionally high relevance impact categories for production and use phases are also human toxicity and ecotoxicity [27], where aluminium provides more favourable results [28].…”