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This website documents the design and construction of a home made wind powered generator or wind turbine.

Drawings    Bench Testing    Mounting    Kits    Courses    Western Cape wind speeds    Moulded blades    First live run    All steel rotors     Electrics    Articles    Home made batteries    Photo Galleries    School events   Europe 2007    Forum    Links

Eskom (utility) power is not sustainable energy, unreliable, pollutes the atmosphere, and in the case of nuclear power, produces dangerous radioactive waste. (Click here to see a summary of Eskom's plans to dispose of nuclear waste safely.) Eskom power is not the only option, however, and since I live in the windiest city in South Africa wind energy was the obvious alternative. Nine months of experimentation later, I had a working permanent magnet generator in my back garden.
 

The generator had to fulfill the following design criteria:

  • An effective source of alternative power, allowing the generation of a portion of the electricty required for the household
  • Constructed using only a drill press and bandsaw (although rotors needed industrial cutting), and avoiding high technology
  • Small and light enough to be picked up and mounted by hand
  • Made from readily available materials
  • Items such as bearings and the shaft should be easily available and low cost
  • Safe: i.e. if something failed or broke damage to property would be minimal
  • Cheap, but sturdy enough to withstand a Northwest gale in Cape Town!
Design of permanent magnet generator
"Very cool site!!
I have it bookmarked..
this is the most
thorough and helpful
site on using the wind
to generate power,
your drawings, pics
and illustrations are
outstanding.. will be
putting this to work
onour homestead.
Thanks so much!!"

naomi
freewebs.com/hopei91
Get your own reviews at

If you have technical questions after reading this site, please please register on the forum and post your questions there. Workshops can be arranged to learn hands-on how to make your own, and events for schools are also available. To receive emails about upcoming courses, enter your name here (or view archive). The next course will be in Cape Town sometime in early 2010.

Various components are available from The Windpower Shop. NEW: For a free online blade geometry calculator, click here.

Bench Testing updated 18 Feb 2009 (forum)
Tests were done on the workbench at speed of 600 rpm, and also with a variable speed motor at various rpm, from about 120rpm to 230rpm. Here are the results, together with graphs and some simple analysis.

Mounting updated 30 Jul 2007 (forum)
It's no use having one ready if you can't get it up there! Here is the relatively simple way how I managed to get a 6 metre pole erected without a winch or assistance. And no need to build a tower, which is often quoted as necessary and the most expensive part of a small wind generating system. Nonsense! Some sites also say mounting on a building is out of the question, due partly to vibration. I think this may be true for wooden buildings (common in North America), but is not true for brick and cement.

Moulded blades updated 18 Feb 2009 (forum)
For an online blade shape calculator, click here

First live run updated 8 Nov 2006 (forum)
Finally after nine months of development, it's up and producing electricity - 240Watts in the gusts! I have read that anyone who claims their wind generator is silent must be lying... well this one IS silent (as verified recently by Popular Mechanics magazine).

All steel rotors updated 4 Dec 2009 (forum)
These rotors are water cut from a DWG file. At first, to keep tool requirements as simple as possible, I tried 1mm steel plate epoxied to plywood disks. They failed spectactularly, so I went for these solid 6mm mild steel rotors...

Rain cover - five part mould updated 16 Jun 2009 (forum)
How to make a five part mould of silicone rubber, and glass fibre and resin.

Electrics - circuits and wiring diagrams updated 16 Jan 2010 (forum)
Generating power is one thing, using it is another... this page shows how to make a switchbox, plans for a controller, simple electronic circuits, as well as 12V/24V lighting with CFL bulbs.

Home made lead acid batteries? updated 13 Aug 2006 (forum)
There seems to be so little information available on doing this, so having read what I could, I have started to experiment with making my own three cell 6V battery, using lead sheet, battery acid, and jam jars...

Stator Test updated 7 Aug 2006 (forum)
Why can't DC current be generated directly by a PM (permanent magnet) generator? This was a (failed) attempt to do just that, by sheilding one leg of the coil, and facing all the magnets the same way...

 

 

Photo Galleries (Back to top)

Here are some photos which show how to go about the various stages of constructing the wind powered generator:

Blades for the turbineLatest balsa blades updated 22 Sep 2008 (forum)
1.5mm balsa with leading/trailing edges. 1000mm long, 100mm wide at root.

Veneer blades updated 15 Dec 2007 (forum)
1mm veneer with leading and trailing edge beading. 1000mm long, 110mm wide at root

Balsa wood blades (forum)
1.5mm balsa sheet with leading and trailing edge beading. 900mm long, 100mm wide at root.

Campsite thumbnailVideo of installation at a campsite
 updated 22 Oct 2008


TV shoot for Free Spirit
 updated 22 Sep 2008
Some photos of the day of shooting for SABC3's Free Spirit.

Bracket version 1 (forum)
This holds the main shaft and stator mounting bolts in place...

Bracket version 2  updated 29 Mar 2007 (forum)
This holds the main shaft and stator mounting bolts in place...

Plywood and steel rotors - 21cm (forum)
The assembled permanent magnet generator showing bearings and shaft5mm marine ply epoxied to 1mm steel plate, 8 magnets on each rotor.

Plywood and steel rotors - 25cm (forum)
5mm marine ply epoxied to 2 x 1mm steel plate, 12 magnets on each rotor.
Under test, these delaminate - the metal is pulled off the plywood by the magnetic force, and the magnets press against the stator. This demonstrated I needed an alternative for the rotor plates

Rain and dust cover updated 28 Oct 2007
Athough the components are theoretically waterproof, it seemed like a good idea to keep rain from getting onto the bearings. So I used some styrene to heat form a top cover, and a slice of a pot plant holder to cover the front bearing - this makes it sloped in a way to direct water forwards and out when the rotors are spinning.

Stator version 5 updated 28 Oct 2007 (forum)
8mm thick, 3 phase, 3 coils per phase, 64 winds per coil,1.0mm diameter wire.


Stator being would from copper winding wireStator version 4 updated 7 Apr 2007 (forum)
8mm thick, 3 phase, 3 coils per phase, 80 winds per coil, 0.8mm diameter wire.

Stator version 3 updated 27 Jul 2006 (forum)
Stator mounted on bracket8mm thick, 3 phase, 3 coils per phase, 60 winds per coil, 1.0mm diameter wire.   Up to 24V, 10 Amps

Stator version 2 (forum)
16mm thick, 3 phase, 3 coils per phase, 80 winds per coil, 0.8mm diameter wire.  12V, 4 AmpsWing turbine blade from large system

Stator version 1 (forum)
16mm thick, 3 phase, 3 coils per phase, 15 winds per coil, 1.6mm diameter wire
6V

Wind energy in Europe, 2007 updated 8 Jul 2007
When travelling in Europe I took note, and photographs of wind power installations I saw...






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