There is a scientific law called electromagnetic induction, which basically states that an electric current is manufactured when any sort of electric conductor moves through a magnetic field. On the basis of this law, all sorts of generators have been built. Examples of different generators are the massive turbines at the Hoover Dam, for instance. How this works is the falling water from the dam provides the mechanical energy need to turn those huge turbines, and there are billions of tons of water that flow through the dam every day! This mechanical energy is turned into electrical energy, and provides a large portion of the southwest of the United States with their electric power.
From a purely scientific standpoint, what happens is that electrons in the atoms move by a magnetic field. These moving electrons provide the basis of electric power. It’s that old saying, “for every action there is a reaction”. Based upon this fact, all sorts of generators have been made, harnessing the power necessary that we all use in our modern, technological lives. There are generators that are in our cars, called alternators, which take the energy from the automobile’s engine and turns it into electrical energy that powers the windows, stores enough charge in the car’s batteries so it can start in the morning, and allows the stereo to blast out tunes! It’s a wonderful invention, and one that would be awfully difficult to live without!
Other examples of electric generators are the wind turbines that take the power of the wind, which is mechanical energy turning the blades of the windmill, and turn them into electrical energy via the generator. This energy is then fed into the power grid through high-transmission lines, for example, and delivered right into our homes. This is called the “green power” that is ubiquitous today. Wind turbines use the natural force of the wind to create electrical energy. Other electric generators take the power of human force and then convert that mechanical energy into electrical energy. A good example of this are those hand-cranked emergency radios and flashlights that are on the market. Extremely handy when severe weather such as hurricanes or tornadoes hit, they don’t need to be plugged in to the wall socket, or even need batteries! All one has to do is crank the handle, and this mechanical energy will provide the power necessary to listen to the weather forecast, or the light needed to find the car keys.
Electric generators are essential to our modern lives, and provide the electric power necessary to run our machines and computers, even when the main power is knocked out.