P o w e r F a c t o r (power factor)
The AC voltage used in daily life is constantly changing in voltage, ideally In the following, voltage and current are called in-phase, and P F = 1. Can make the most of the wire Transmission efficiency. In this case, all the power used by the electrical equipment is called active power. 

The maximum current of the appliance is instantaneously earlier or later than the instant of the maximum voltage of the power grid.
Will reduce the efficiency of the wire. Due to its non-synchronization, the internal resistance of the wire causes additional
Power loss, the power lost in this part is called no power.

Therefore, we generally want to make the electrical equipment

as much as possible The highest voltage is synchronized.

The closer the P F is to 1, the more synchronized the wire loss

is The more environmentally friendly.