The power factor of a system describes the efficiency with which electrical power is converted into useful work output. It is the ratio of real power (measured in kilowatts, kW) used to do work to the apparent power (measured in kilovolt-amperes, kVA) supplied to the circuit.
The power factor can range from -1 to 1:
- A power factor of 1 (or 100%) indicates that all the power is being effectively converted into work.
- A power factor less than 1 indicates inefficiency, where some power is wasted in the form of reactive power.