E.P. Price, Department of Electrical Engineering, Texas Tech
Users of electric energy, especially in the field of power applications, sooner or later become interested in power factor and methods used in correcting bad power factor conditions. This interest is usually brought about by the bill presented to the user by the power supplier. On this bill the user will observe an energy charge, a demand charge, and a charge or penalty for low power factor. Usually, he can easily understand the energy charge and the demand charge, but he may not understand the power factor charge or penalty. He may not understand what he is being asked to pay for, what benefit, if any, he has received, or what he has done to justify such a penalty. We shall then consider in some detail the meaning of the term "power factor", why the electric supplier makes a charge on the basis of power factor, and what the user can do to eliminate or reduce this charge.