Building Your Own Wind Machine

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If don’t have the cash to buy a wind turbine or want the challenge of making your own turbine, you may want to consider building your own wind turbine (Figure 5.11). Building your own wind generator provides invaluable experience.

Directions for how to build a wind machine are available online. At sites like Hugh Piggott’s (scoraigwind.com) or Dan Bartmann’s

Fig. 5.11: This amazingly quiet wind turbine designed and built by the folks from otherpower.com is remarkably reliable and efficient. Other Power sells kits that require some assembly for independent and budget-constrained buyers.

(otherpower.com), you’ll find a listing of other valuable websites and resources.

Homebrew wind turbine master Hugh Piggott’s website sells step-by-step plans for building axial-flux alternator turbines.

There are even a couple of books on the subject: Windpower Workshop by Hugh Piggott and a more recent title, Homebrew Wind Power: A Hands-On Guide to Harnessing the Wind by Other Power’s Dan Bartmann and Dan Fink, which is an extremely well-written and thorough treatise on the subject. Rather than provide a full description of this subject, which would take a chapter or two, maybe even an entire book, we recommend you consult these resources. We also recommend that you sign up for a workshop, for example, through The Evergreen Institute or otherpower.com.

Building a wind generator is not that difficult, if you are mechanically inclined and persistent. You will need a shop and some common hand and power tools. “The hardest part of designing a small
windmill for electricity production is to find a suitable generator,” writes Piggott in Windpower Workshop. “For best performance you’ll need a reliable, low-speed generator that’s pretty efficient in light winds,” he adds. Piggott strongly recommends permanent magnet alternators. “Unfortunately, permanent magnetic alternators are difficult to find.” Piggott lists some sources, among them motorcycle alternators and welders. Unfortunately, each one has a significant downside. See his website and book for more on this and other options.

Car alternators are popular among do-it-yourselfers; however, they require high rpm and are not always very efficient. They also require a lot of electricity to power the electromagnets that create the magnetic field. You’ll also need to rewind the stator coils so they produce electricity at the lower speeds common in wind turbines. This is a big job for those without experience. Most people who’ve tried this route give up in failure.

When building a wind turbine, you’ll also have to design and build blades and install controls. Blades and rotors are particularly tricky. They need to be carefully matched to the generator. Most homemade wind turbines use wooden blades, which must be hand carved.

You will also need to incorporate overspeed controls and a shutdown mechanism. And don’t forget you will need an inverter matched to the turbine. Be wary of cheaply made wind turbines like those with blades fashioned from PVC pipe. Remember, too, that you need to install the turbine on a tower. Tower designs can also be found online. Be careful, however; homemade towers often leave much to be desired. Towers are far more complicated to design than wind
turbines. Your best and safest bet is to buy a new or used tower.