Repair for high-voltage electric motors energy efficiency vs resource use?

Electric motors in the industry represent 69% of the industrial electricity consumption in Europe. Even if few in number, high voltage (HV) motors represent a significant share of this consumption due to their more intensive use and high output power. Two main HV motor technologies exist: induction motors (IM) and synchronous motors (SM), of which the latter are more energy efficient. Improving energy efficiency as well as use extension by maintenance, repair or remanufacturing have been identified as relevant circular economy strategies for improving the environmental performance of such active and durable products. However, the assessments performed focus on small- and medium-size electronic products, leaving out bigger products that are more durable and more energy consuming such as HV motors. Those motors are often used until failure, which frequently occurs in stator windings, and which could be repaired by rewinding at the expense of a slight decrease in efficiency. However, other use extension strategies such as reuse and remanufacturing are hindered by the customization of HV motors to their specific use. Finding an appropriate set-up for a second use is difficult for such motors and it is therefore performed seldom. The aim of this study is to compare the life-cycle environmental impact of lifetime extension by repair for the two motor technologies in comparison to their replacement