Understanding Wind Power (Wind Generators / turbines)

• Author: DigitalMind
• Filed under: Solar Power and Off-Grid Living, Uncategorized
• Date: Aug 14,2008

What seems like a long time ago, I decided to learn how to create my own power from scratch.  Partially because my little sister lives in an off-grid home, but mostly because it’s just plain cool ! It took a few months of intensive studying, but I figured out Solar Power pretty fast.  At the same time that I started learning how to generate power from the sun, I was learning how to generate power from the wind.  It took me until now to finally understand JUST THE BASICS of this subject enough that I feel confident writing about it and starting to work on my own set of wind turbines.  This article is about the very BASICS of wind power, as I understand it.

How does a wind turbine work ?

Wind turbines operate on a simple principle. The energy in the wind turns two or three propeller-like blades around a rotor. The rotor is connected to the main shaft, which spins a generator to create electricity. Generators (or alternators) are made of really strong magnets that are spun around very quickly next to coils of magnet wire.  The effect of the magnets whizzing by each coil produces an electrical current in the coil.  You connect the coils together in a certain fashion and then it’s like solar power :  you go to a charge controller, which is connected to batteries, then an inverter, then regular house wiring.  (Although if you’re turbine is producing AC electricity, which most are, you need a bridge rectifier to convert it back to DC before going to the charge controller.

Here you can see a video of someone holding a coil of magnet wire that is connected to a light bulb, and then he’s moving a magnet over it quickly with his hands and it’s lighting the bulb ! (Briefly)

That was a great example of how a wind turbine works.  Imagine this happening, but at MUCH higher speeds thank to the wind pushing a series of magnets over a series of coils.  A single spin of the wind turbine would equal what he’s doing during the entire video.

How much power can I expect from a wind turbine ?

This depends entirely on the specifics of that turbine.  They can range from tiny little generators that could pretty much only charge your cell phone, to gigantic turbines that could power a small town.  From what i’ve read, you get the most bang for your buck if you learn to make your own wind turbine.  This is what i’ve been trying to do for over a year now.

About building your own wind turbine :

As far as i’m concerened, the hardest part of all this is the generator or alternator that actually makes the power.  Although i’m finally starting to understand how to build your own alternator from scratch using coils of magnet wire and rare earth magnets, it’s not the only way to do it.  (It is the best way though)

An easier way, would be to use permanent magnet motors.  PM Motors are pretty much the same thing as an alternator.  Usually, you send electricity INTO the motor and it’ll make the motor spin.  However, if you reverse the process and spin the motor by hand (or with a drill or by CONNECTING IT TO propellers and putting it up in the air!)  it will actually GENERATE electricity where you would usually put power IN to make the motor spin.  This is great because if you get your hand on a good PM motor you don’t need to build your own alternator / generator !

IF you had a PM motor, you basically just need to connect the spinning part of the motor to your propellers and you’ve more or less got a wind turbine built ! (Keep in mind, i’m talking only about the very basics here)

Helpful reading materiel about how to build a wind turbine :

Otherpower.Com is one of the best resources on the web as far as alternative energy goes.  They have a great forum with very knowledgable people.

This instructable is pretty well documented and helped me understand the principles a lot.  He built himself a 1000 Watt wind Turbine from scratch for a few hundred dollars! (The equivalent in solar panels would cost atleast $4000 and would take a lot more room)

This site has done lots of experiments with different sized coils and used hard drive magnets to make his generator.  Although the results were not great, this site REALLY helped me a lot to understand how everything comes together.

More to come !

I will be writing much more about wind power, including the different kinds of wind turbines which we haven’t talked about at all in this article.  If you’re interested in Solar Power please stick around and browse this site.  There is lots of information on this subject. Feel free to email me or leave a comment here on techienation if you have any questions.

If you would like to learn how to build your own wind turbine, you NEED to get these detailed books explaining how to do it without spending a lot of money.