Twenty years ago I designed and built my own wind generator
. In fact I built 11 of them. I used a Ford 100 amp alternator
as my starting point. Next I used a mechanical engineer
to help me with the mechanical design so the unit was completely enclosed and not subjected to the saltwater environment
I took my mechanical drawings to Marlboro Foundry in Massachusetts
to have a pattern made by a pattern maker so I could have the foundry make aluminum
castings. The castings consisted of two identical pieces which I machined in my basement to accommodate the stationary armature along with the rotating field. Other pieces that I fabricated including a base which was sandwiched between the alternator
proper and a 2" aluminum
pipe that contained half of the slip ring assembly that I designed.
My field used a neodymium iron boron permanent magnet whose flux density was about 12 killogauss, the highest flux available in a permanent magnet at that time. I stumbled with the magnet, could not get it built here in this country without spending big bucks. I found a company in China
who made them exactly to my very tight mechanical specification. That magnet looked like a donut. I was mounted between the pole pieces of the old electromagnet field which was scrapped. Note, the pole pieces required machining which I was able to get done on my basement lathe by my Son who is a machinist.
I worried about the armature!!!! The typical auto alternator is designed for high RPMs and slow RPMs I know would cause magnetic saturation in the armature's metal. So I redesigned the armature for a lighter gage wire and had them rewound in a shop somewhere in NY.
Many more details but skipping ahead, I studied propeller
design so I could make my own. I had special tooling made for my 5HP wood shaper in my basement. I wanted the cutters to remove most of the unneeded wood stock which it did. Then I build a jig so I could cut the propeller
down to where it should be using a router. Afterwards, it still required a lot of sanding
using a belt sander.
The propeller ended up being 4 blades, 5' in design. The reason for a large blade is captured wind energy is equal to 1/2( d*A*S^3) where d is air density, A is the blade swing area and S is the wind speed.
My machine developed about 12 amperes with winds just over 15 knots. Even with the redesigned armature, I could see core
saturation occurring at low RPMs when I rotated the shaft on my lathe while looking at the armature waveforms with a scope
I planned to market this thing!!!! FEAR OF LIABILITY stopped me from manufacturing them.
So you want to build your own windgenerator!!! GUYS, think what is involved to do right before you do anything.