It’s obvious that the motor you use is the most important part of your wind power generator. If you’re new to building a small wind turbines, then you’ll find that this can be one of the most confusing (and controversial) aspects to the process. Motors, generators, alternators, oh my!? You’ll find a lot of words out there that seem to be referring to the same things.
So why's it called a motor?

Many industrial motors make great and very affordable wind generators. In a wind turbine, the motor is used to create electricity. Technically, the “motor” would no longer be called a “motor”; it would be a “generator” or an “alternator.” This article focuses on potential motors that can be purchased online inexpensively as surplus items and can be used to build your own custom wind generator.
Obviously, it’s important you choose an appropriate motor for your generator. Choose the wrong one and you may discover that:
Your wind generator will make no electricity.
Your wind generator will make electricity, but will never reach a voltage high enough to produce usable electricity.
Your wind generator will initially be working, but after a few days or weeks, it overheats and stops working.
But don’t be discouraged. There are hundreds of motors that will produce several hundred or possibly even thousands of Watts of useable energy. And even better, we’ll give some tips on how you can track one down for a reasonable price.

There are three ways that generators make electricity: either by something called induction; by using an exciter; or by using PERMANENT MAGNETS.
Magnets, Magnets, Magnets!
Do-it-yourselfers build wind power generators almost exclusively with Permanent Magnet Motors, because they are widely available, reliable because of the nature of their construction, and start generating electricity at almost any RPM. The ame cannot be said of some of other types of motors.
Inside a permanent magnet motor is a coil of wound copper surrounded by permanent magnets. These motors rotate using electromagnetic induction, which means electricity is supplied to wound copper wire which creates a magnetic field. The magnetic field created by the electricity flowing through the copper wire opposes the permanent magnets in the motor housing. As a result, the copper wire that is attached to the shaft of the motor tries “to push” itself away from the permanent magnets. So your motor starts spinning!
The same reasoning is applied when considering a permanent magnet motor as a generator. Spinning the copper wire by using the energy from the wind in the presence of the magnets creates a voltage difference between the two ends of the copper wire. The difference in voltage causes the electric charges (electrons) to flow in the copper wire, generating electric current.
So you now understand the basic principles of a generator.
So now what should you be looking out for in selecting your motor