Power Factor is defined as the ratio of Real Power to Apparent Power, and is equal to the cosine of the phase shift between line current and voltage. When the phase shift is zero, the Power Factor is equal to the ideal condition of one, and is known as ‘unity power factor’. Real Power is the power consumed by customers, while Apparent Power is what a utilities deliver. When PF is equal to 1, the line voltage and current are in phase. When PF is less than 1, utilities will need to deliver more power than what customers really consume, which will result in unnecessary power loss, higher utility bills, and the potential to inject noise onto the power grid.