Electric motors convert electrical energy into mechanical energy to drive industrial equipment by means of a rotating shaft. In industry in the province of Alicante, they are used in a wide range of processes, with induction motors being particularly important due to their simplicity, low cost, economy and reliability.
The energy efficiency of an electric motor depends on various factors, including motor efficiency, speed control, proper sizing, power supply quality, loss dissipation, mechanical transmission, maintenance and mechanical efficiency of the driven equipment (pumps, fans, compressors, etc.).
Energy Saving and Efficiency Measures
Use of high-efficiency motors (Savings above 2%)
These motors are manufactured using higher-quality materials and achieve efficiencies above 90%. The European Commission establishes three energy efficiency levels: EFF1 or IE2 (high-efficiency motors), EFF2 or IE1 (improved-efficiency motors) and EFF3 (standard-efficiency motors).
High-efficiency motors consume less energy to deliver the same power output compared to conventional induction motors. Currently, only high-efficiency EFF1 motors are allowed to be marketed.
Installation of variable frequency drives (Savings above 4%)
For the control of pumps and fans, frequency converters or variable frequency drives (VFDs) are used to regulate motor speed by modifying the frequency of the voltage supplied to the motor, allowing it to adapt to load requirements.
In particular, in fluid pumping and ventilation applications where flow rate regulation is required, significant energy savings can be achieved when the required regulation range is relatively wide and operating hours are high.
Motor selection – operating point
Proper motor sizing is essential. Maximum efficiency is achieved between 75% and 85% of the rated load. At lower loads, efficiency decreases significantly, so motor oversizing should be avoided.
