How to Build a Wind Generator at Home: Choosing a Motor
This page focuses on choosing a motor for your DIY wind turbine. If you are looking for how-to-build-a-wind-generator instructions, head over to my How to Make a Wind Turbine at Home page.
If you’ve come across this page while looking for commercially made wind generator plans, check out my Review Wind Generator Plans page.
If you have come here looking for information about how to choose a good motor for your DIY wind turbine, please continue on.
The first thing you need to know when looking for a motor is that wind turbines do not crank out thousands of RPMs like cars do. On average, a basic DIY wind turbine will hum along at about 500 RPMs. This means that many generators, such as the alternator in your car, do not make good wind turbine motors.
When building a wind generator at home, the best motor is one that produces the HIGHEST amount of voltage at the LOWEST RPMs. Let’s take a look at some figuers.
First of all, you’ll want to find a motor that produces at least 1 volt for ever 25 RPMs and can handle 10 or so amps. Why? Well, you’ll most likely being charging 12 Volt batteries, which means you’ll want to be producing about 14 or so volts, plus you’ll need a little extra juice to make up for inefficiencies.
So, if you have a wind generator that spins at roughly 500 RPMs, and you have a motor that produces 1 volt for every 25 RPMs, you’ll have a wind generator that produces, more or less, 20 volts.
How do you see if a motor meets these guidelines? Check it’s rated VDC and it maximum RPMs. Then divide the max RPMs by the VDC.
For example, say you find a motor that is rated at 120 VDC and has a maximum of 5000 RPMs. You would just divide 5000 by 120, which would give you 1 volt for every 41.7 RPMs. Have you found a good motor for your DIY wind generator? No, 1 volt for each 41.7 RPMs is not going to cut it. Keep looking!
Let’s take a look at a couple more examples. By far, the most popular DIY wind generator motors are made by Ametec. Not all models are suitable for wind generators, though. We’ll look at a good one and a bad one.
First, the bad one:
The first motor we’ll look at is the Ametec 37 VDC. This motor is rated at 37 VDC and has a maximum RPM speed of 2100. Using our arithmetic, we can see that this motor produces 1 volt for every 56.8 revolutions. This, as you know, is not going to do the job.
Warning: Just because this motor is totally unsuitable for a DIY wind generator, that doesn’t mean people on eBay won’t be touting it as the “power producing motor that’s going to get you off the grid and on the road to energy independence!” …or some other nonsense. No matter what people say, do your own math and make sure the motor is suitable for your project.
A Good Ametec Motor!
If you are going to make a wind generator at home, you want to find an Ametec 99! This motor is rated at 99 VDC and has a maximum rate of 535 RPMs, meaning it produces 1 volt for every 5.4 revolutions. That’s nice! Unfortunately, you are not the only one who has learned how to build a wind generator at home, and those who have come before you have snapped these motors up! If you find one grab it!
Fortunately for you, though, you have read the above information and are now armed with enough knowledge to go out and find a suitable motor for your wind generator.
Now let’s switch gears a little bit. To generate electricity with your completed project, you’ll obviously need some wind. Before building, be sure that you have a suitable location, one with plenty of unobstructed wind.
To figure this out, get a hold of a wind atlas that describes your area. Or, if you are more serious, for example, if you are planning to go off the grid, then you should invest in a wind meter and measure the wind conditions on your property. Finally, you also have the option of hiring a professional wind assessor.
Next, decide where you will mount your wind generator. Modern generators are very lightweight, and many people simply mount them on their rooftops. This is an acceptable location, but you should keep in mind that the higher up your generator is, the more smooth, reliable wind you’ll get, and the more power you’ll be able to create.
For best results, I recommend you build a tower that holds your generator 30 feet above any nearby structures. Wherever you put your generator, make sure it’s safely inaccessible to any pets or children that may be around.
When it comes to making your generator, you have two good options. If you want a more in-depth DIY project, simply buy a set of plans that explain how to build a wind generator at home. In this case, you’ll be doing all of your own shopping, fabricating, and assembling. If that sounds fun to you, have at it!
If that seems a bit complicated, on the other hand, you have the option of buying a wind generator kit. In this case, you’ll get prefabricated parts that you just have to assemble. A good kit will include a generating unit, a tail assembly, gears for the generator, a set of blades, and the wires and cables needed to hook the unit up to a battery pack.
In regards to wiring, this is one area where I take off my DIY hat and hire a professional. Wiring is serious business, and unless you have significant experience with it, you may also want to contact an electrician. Also, some people with large generators sell electricity back to their power companies. If you plan to do this, you’ll have to meet certain guidelines, which are best met by a professional electrician.
Windmills have been around for hundreds of years. You’ve probably seen the beautifully designed structures built in places like Denmark and Holland. While modern-day generators are not quite so picturesque, they are far more functional and practical as electricity producing devices.
They are also regaining their mainstream popularity, as people today are looking for ways to produce electricity with renewable sources that don’t pollute the environment. If this sounds good to you, learn how to build a wind generator at home and enjoy your new home improvement project.