The upper generator room at Hoover dam. Generators as far as the eye can see - 17 in all. This power plant has the ability to generate 2 billion watts. Over the course of a year it can produce as much as 17 billion kilowatt-hours if running continuously, but typical production per year is only about half that.

This is a cutaway picture of the kind of generator typically found in an automobile. It is usually called an alternator. The shiny triangular part in the middle is the pole face of an electromaget. The electricity is generated in the coils wrapped around the black and blue cores. The shaft is turned by the engine, causing the magnetic poles to move past the coils, thus changing the flux through the coil. Obviously, with probably 12 magnetic poles and perhaps 24 coils it is a little more sophisticated than the demonstration generators we use in class.