Thursday, November 10, 2011

How I home-built an electricity producing Wind turbine


Part 1 Step 1.
The Generator.

I reduced the project to just five little systems.
If attacked one at a time, the project didn't seem too terribly difficult.
I decided to start with the generator. My online research showed that a lot of people were building their own generators. That seemed a bit too complicated, at least for a first effort ?? This depends on your time, resources, and determination.

So how much did all this cost to build? Well, I saved all the receipts for everything I bought related to this project.

PartOriginCost



Motor/GeneratorEbay$26.00
Misc. pipe fittingsHomecenter Store$41.49
Pipe for bladesHomecenter Store$12.84
Misc hardwareHomecenter Store$8.00
ConduitHomecenter Store$19.95
Wood & AluminumScrap Pile$0.00
Power CableOld extension cord$0.00
Rope & TurnbucklesHomecenter Store$18.47
Electronic PartsAlready on hand$0.00
RelayAuto Parts Store$13.87
BatteryBorrowed from my UPS  $0.00
InverterAlready on hand$0.00
PaintAlready on hand$0.00



Total
$140.62

Not too bad. I doubt I could buy a commercially made turbine with a comparable power output, plus a commercially made charge controller, plus a commercially made tower for less than $750-$1000.
Future modifications and enhancements I would like to make to the system include:
  • Mount the electronics in a weather-proof enclosure.
  • Add meters to monitor battery voltage and charge/discharge current.
  • Add a tachometer so I know how fast it is spinning.
  • Add more batteries to increase reserve storage capacity.
  • Add a second wind turbine or solar panels to increase power production.
  • Get a higher Wattage inverter.
  • Some method to automatically furl or brake the unit in high winds.
  • A concrete foundation for the tower.
  • A taller tower with steel stakes and steel guy wires.

Others were using surplus permanent magnet DC motors as generators in their projects. This looked like a simpler way to go. So I began looking into what motors were best for the job.
A lot of people seemed to like to use old computer tape drive motors (surplus relics from the days when computers had big reel to reel tape drives)

The best apparently are a couple of models of motor made by Ametek. The best motor made by Ametek is a 99 volt DC motor that works great as a generator. Unfortunately, they are almost impossible to locate these days. There are a lot of other Ametek motors around though. A couple of their other models make decent generators and can still be found on places like Ebay.

This web site talks about the virtues and vices of various Ametek motors when used as generators.

http://www.tlgwindpower.com/ametek.htm

There are probably lots of other brands and models of permanent magnet DC motors available that will work well as generators. Permanent magnet DC motors work as generators, but they weren't designed to be generators. So they aren't great generators. Some types of motor are a lot worse than others. When used as generators, motors generally have to be driven far faster than their rated speed to produce anything near their rated voltage. So what you are looking for is a motor that is rated for high DC voltage, low rpms and high current. Steer away from low voltage and/or high rpm motors. You want a motor that will put out over 12 Volts at a fairly low rpm, and a useful level of current. So a motor rated for say 325 rpm at 30 Volts when used as a generator, could be expected to produce 12+ volts at some reasonably low rpm. On the other hand, a motor rated at 7200 rpm at 24 volts probably won't produce 12+ volts as a generator until it is spinning many thousands of rpm, which is way too fast for a wind turbine. So shop for motors accordingly.


I managed to score one of the good 30 volt Ametek motors off of Ebay for only $26. They don't go that cheap these days. People are catching on to the fact that they make great wind generators. Other brands will work, so don't fret about the price Ameteks are going for. Shop wisely. Anyway, The motor I got was in good shape and worked great. Even just giving the shaft a quick turn with my fingers would light a 12 volt bulb quite brightly. I gave it a real test by chucking it up in my drill press and connecting it to a dummy load. It works great as a generator, putting out easily a couple hundred Watts with this setup. I knew then that if I could make a decent set of blades to drive it, it would produce plenty of power.

So Blades and a hub to connect them to were the next order of business. More online research ensued. A lot of people made their own blades by carving them out of wood. That looked like an outrageous amount of work to me. I found that other people were making blades by cutting sections out of PVC pipe and shaping them into airfoils. That looked a lot more promising to me. This web site tells you how to make a set of blades for a small wind turbine using PVC pipe.





It Doesn’t!  I can show you how to Go Green and live a more Sustainable Life and Actually Save Money too .!!!


Finally a Support System for Those Who Want to
Go Green on a Budge
! 

Most of these modifications won't be made until I am living on the site permanently, or semi-permanently. One modification I am going to work on completing in the next few months before my next trip out there is the weather-proof enclosure and probably adding the meters.
As the project evolves in the future, I'll post updates here.

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