For example, as of this writing Wikipedia's definition is: "PF equals the absolute value of the cosine of the phase angle between the voltage and the current."

A Simple Explanation Should Start Like This: In a typical AC electric circuit, there is a delay between when the voltage pushes the electrons and when they actually begin to flow (the electrical current). Power Factor is a single number that defines both, how much of a delay there is and, more importantly, what percentage of the current is actually doing work. Thats Not So Bad!

This lesson is a series of simple and clear steps that explains:

-what causes that delay?
-what is affected by it?
-what can be done about it?
-should something be done about it?

You can read textbooks until you are blue in the face and never understand this.

This lesson explains in small steps so you don't miss any details. After dedicating about 30-45 minutes to it, you'll understand:

-the Terminology associated with PF
-the PF Triangle
-about PF Correction Capacitors
-what a Lagging PF is
-and the Economics of PF (economics would refer to energy savings, reactive demand penalties from the Utility, and equipment capacity issues...transformer capacity, cable capacity, etc.).