Glossary · Automation fundamentals, platforms and components
Efficiency (energy conversion)
Also known as: Energy conversion efficiency
German: Wirkungsgrad
In engineering, efficiency is the ratio of useful output power or energy to input power or energy of a device or system, usually given as a percentage or a value between 0 and 1.
- Automation components
In one sentence
Efficiency is the ratio of useful output power to input power of a device such as a motor, drive or power supply, usually given in percent.
Example
A motor with 92 % efficiency converts 92 % of its electrical input into mechanical power; the remaining 8 % becomes heat.
How it applies
- Engineering: Efficiency determines energy consumption and heat losses; for motors, IEC 60034-30-1 defines efficiency classes (IE codes).
- Operation: Efficiency depends on the operating point; many devices are less efficient at partial load.
- Documentation: Data sheets should state the conditions under which an efficiency value applies, such as load, voltage and temperature. Heat losses derived from efficiency feed into cabinet cooling design; see Heat dissipation.
- Maintenance: Worn bearings, misalignment or clogged filters reduce the efficiency of motors, pumps and fans over time and increase energy costs.
Efficiency vs. energy efficiency
Efficiency (Wirkungsgrad) is a physical ratio for a single device. Energy efficiency is the broader goal of achieving a result with less energy, which also includes operating strategies, standby modes and process design.