Inductive loads, like the motors and transformers, can produce reactive power with the delayed current wave in relation to the voltage. Capacitive loads, such as banks of capacitors or buried electric cables, can produce reactive power with current advanced in relation to the voltage. The power factor is based on the dimensionless number that varies between zero and one. If the power factor equals zero, the energy flow will be completely reactive, and the stored energy will be returned to the source in each cycle.
In a short form, the power factor can be considered delayed or advanced in order to identify the phase angle signal between the electric current and voltage waves that are produced. The specific power factor is determined by the type of load connected to the electrical system, which can be resistive, inductive or capacitive. If a load is resistive, it will be connected to the system, causing the current and voltage to change polarity in phase, requiring that the power factor is unitary, so that the electric energy can circulate in the same direction through the system in each cycle.