Development in crane hoisting motors has proceeded gradually over the past decades. A recent study shows possibilities to reduce carbon footprints by modifying material use and dimensions in motors, and by taking the actual purpose of the motors into closer consideration.
In the EU alone, motors account for 40% of all energy consumption. Energy efficiency in motors has become more relevant during the last ten years because of changes in energy legislations not only in the EU, but also in the USA and China.
A study on the energy efficiency of hoisting motors led by Anna-Kaisa Repo, Senior Research Engineer at Konecranes, concentrates on determining the life-span energy consumption of an intermittent-duty (S3) type hoisting motor. Repo presents her view of the big picture of improving the energy efficiency of motors in Europe.
“On the EU level the biggest benefits in improving energy efficiency lie in motors from 1 kW up to 50 kW because these types of cage-induction motors are plentiful in industrial locations.”
Repo’s concentration on the matter of energy efficiency wasn’t prompted by the situation in the EU, but by her active involvement in developing environmental product declarations for Konecranes equipment. One of the key sections in these declarations is environmental impact, which includes carbon footprint. This provoked a logical starting point for the study.
The right motor for the right purpose
A key aspect in designing motors, which is also related to energy efficiency, has to do with taking the actual task and purpose of the machine into account. One of the starting points behind Repo’s study was to balance the energy consumption of a product’s manufacturing phase with its lifetime consumption.
“If we talk about a typical continuously operated motor, such as an S1 motor in an air conditioning system for example, where the running time can be as much as 6,000 hours per year, the impact of manufacturing on total energy consumption is relatively low. But then, when we look at intermittent-duty motors in cranes, the impact can increase starkly. Manufacturing becomes more relevant because the operational energy consumption is low due to lower usage hours and dominating partial-load operation,” Repo explains.
Anna-Kaisa Repo, Senior Research Engineer, Konecranes
- Anna-Kaisa Repo has been a member of the Konecranes Research team since 2009.
- Her current tasks include leading research projects related to electric motors and drives, energy efficiency, and energy storage and participating in the work to standardize motors.