Need help spec'ing a 100-200watt system

[kihon]

Hi all,

Im playing around with designing a wind turbine to generate between 100-200 watts of electricity - to charge 12v batteries.

The idea is for the design to be manufactured locally in third world countries, where the power requirement is not too high, but the cost must be low.

At the moment, Im trying to decide if it would be better to go for a DC motor, or to make an alternator myself. I would prefer to make it myself, as this would allow the countries which manufacture it to get the manufacturing experience too, however if it is too expensive, then there would be no point.

The first question is does anyone know how much a off the shelf DC motor which is able to generate 100-200 watts cost? (Just to get a rough idea). I have searched for DC motors, but am unable to  work out which of them would be able to generate 100 watts. Any suggestions on what to look for would be very useful.

Second off if I make an alternator with 2 10inch steel discs, with say 12 disc magnets each (NdFeB Disc N38 - Ø22  x 20 (A) Nickel Coated) would that be over kill for 200 watts?

(assume sufficent wind strength and blade size).

Thanks in advance.

[luv2weld]

There are lots of sites out there that explain how to build your own

using small motors. Here is one----

http://www.velacreations.com/chispito.html

Other ideas are stepper motors from computers, printers, etc.

For third world use, maybe you should consider something that

will use parts salvaged from old cars or trucks. They are

not likely to have access to magnet wire or magnets. Probably

not a lot of old computer equipment lying around either.

Maybe consider a pedal generator made from old bicycle parts.

There are several members here that do a great deal of work

for other countries. I'm sure they can help you with more

ideas and point out some of the problems.

DanB and the boys can give you some insight into what they saw.

http://www.blueenergygroup.org/

http://www.fieldlines.com/story/2007/6/5/85322/76409

I know there are others but my brain just will not work

right now to tell me who the posters were.

Ralph

[ZooT]

Yeah.....I was thinking that the magnets and wire might not be easilly available everywhere......by the same token, surplus motors are an "end of the road" solution that would dry up at some point....

[wooferhound]

BT Humble worked a lot in Fiji

http://www.fieldlines.com/?op=search&offset=0&old_count=30&type=diary&section=&s
tring=fiji&search=Search&count=30

[kihon]

thanks for the replies guys, and the links - they are very helpful.

The salvage thing probably wont work too long, because for one thing, stuff only gets thrown away when it is really beyond repair, and as a result salvage parts will be hard to find for more than a few wind turbines.

I am still hoping to go down the manufacture route rather than the motor route, with the hopes of stimulating local manufacturing. I have some contacts who think they can get hold of the magnets there. Im trying out some designs at home to see what will work and what wont, so that we can set up a few projects together with a local university, allowing the students to try out some designs and work out what will work best for them.

My first attempt used a single phase single rotor with 8 neo mags, and 8 coils (150 turns 24 swg). however, it was not a very good design (magnets and coils were fastened on to old CDs!) With PVC blades, I am able to just about get 3v out of it - a lot less than I thought I would get, but I suspect I need a better tower as well.

I decided to move onto a dual rotor design, and have sourced some 10 inch steel discs.  Will try a 12 x 2 magnet design and see how it goes. Will experiment with 12 coil single phase as well as 9 coil 3 phase to see which will get me more power.

Will try keep this updated.

Thanks again.