Instructables

Can I use an alternator from an old car to generate power from a windmill? ?


richard48722 years ago
We are using basically a belt driven modular gear reduction design utilizing the pulleys sets in our donor vehicle as an example for our wind turbine. We are mounting the alternator on a custom bracket parallel to the prop pulley and using a belt to feed the alternator. We ordered a set of power pulleys like they use for drag racing that allows for more rpm at alternator when the crank is at idle. What we like about the design is when the alternator eventually fails, which it will, instead of having to dismantle the prop assembly, we will simply remove the alternator from its mount, put the power pulley on the new one, and replace it. According to our calculations, when the prop is at 1800 rpm the alternator should be at 3000 rpm + or -. We are having the alternator custom wound out a local armature shop. It should produce 200 amp at 14.4 volts while turning at 3000 rpm. I will try to post pics and results as we proceed.

did your idea work

ummm sry that was for richard4872
wow i hate to be that guy but............ car alternators are one of the best to use for home power just have to know how to use them wind power not so much but you can make a few things work for you like solar hot water heater used as a water turbine all this talk about drill motors and stuff wast of money 200watt motor will not even get you 100watts earth magnets a must for wind low cut in rpm gears forget about it dont even think about them wast more power and time then its worth take a look at this data sheet http://www.epi-eng.com/piston_engine_technology/power_and_torque.htm examples of the amount of power to turn a shaft i would start looking for small PMA devices or if you need help just ask as for solar i say get some but do not waste your money on it if anyone wants to know more just ask i dont want to take up the page on my first post
I am a solar integrator. I have a xantrex charge controller fed by 5kw solar array, a 3k wind turbine, and a grid tie inverter, all backed up by 4 ud 250 ah agm batteries. I haven't paid an electrical bill in almost three years. My local power company reimbursed me $2 a watt on the construction. Plus I now receive credits for the power I feed back into the grid. Because my office is in my home, I was able to apply for the 30% federal reimbursement. All of which more than paid for the parts in my system. As far as return on investment goes . . . I am at 150% and climbing. I don't consider that a waste of money or time.

dear plz let me know your this plan ,i want to develop it plz give me the detail my email is roomi1969@gmail.com

hi, i'm don...very interesting any chance you have a diagram?
and parts list and info of where to locate the parts? if so e-mail it to me please at dbrown0078@live.com
Thanks a lot eother way
hey Phil, I know its been a year since you made this post. Hopefully you get this comment. I am very interested in what you said about the solar hot water turbine. I don't have much knowledge on that.I am NOT extremely new to green energy, but I am no expert. Can you give me a little insight? Or an educational link that I can learn more from. Thanks a lot

Jr
Technically I think it’s possible but still you can gather more information about the same from expert people. You can have a look on various reviews posted by experts. I will personally suggest you http://www.automotix.net/autorepair/askquestions.html here you can ask all your queries and exerts will surely satisfy all your queries.
Oatmotor2 years ago
Look HERE for educated and non-biased insight:
Using an Alternator in Renewable Energy Projects
http://web.media.mit.edu/~nathan/nepal/ghatta/alternator.html

They adapted an alternator for low rpm use in Nepal water turbines and have some very good info on what exactly you need to do to get power from an alternator at the lower rpms necessary for do it yourself apps like wind and water drives. They explain quite well about field coil settings and what it takes to turn an alternator "ON"

The major advantage of an ac alternator(used in gas vehicles vs the dc generator (used in old vehicles and now in treadmills, and varying sizes in many other apps) Is getting the power "out" of the windings. The basic design of the DC "brush" generator requires all output power go thru a "brush-commutator" connection and is practically limited to about 30 amps and requires frequent brush replacement and commutator cleaning. This is why your old treadmill dc motor/generators are usefull to get a taste of power conversion, but are limited by the brushes. AC generator (ALTERNATOR) design eliminates this 30 amp limit by only requiring a very small excitation current to create a magnetic "field" in the rotor(rotating) windings. Power is provided (by auto motor, wind turbine, water turbine, etc)to rotate this "field" inside inside the much heavier "stator"(stationary) windings. This is just the opposite of a DC generator, which must have heavy windings in the spinning portion and heaving brushes to carry the current out. The alternator can provide a heavy current on the "stationory" wound stator, but at the disadvantage of being AC current instead of DC. That's why you have the diodes, they convert the AC to DC.

Unfortunately effieciency is not that great in a small alternator like autos use, about 50%. I don't know, but my guess is the DC brush generator is even less efficient.
The huge AC generators at a coal-fired power plant exceed 95% efficiency. I don't know, but my guess is the old DC generator is even less efficient. I imagine small alternator designs will emerge that are much more efficient, but the REAL advances are taking place on the DC motor/generator front. It won't be long before they are mass-producing some very efficient back-yard generation units based on BRUSHLESS DC generation.
My thoughts for now---tap on to the stator coils BEFORE the diodes for ac power straight to a1500 watt electric heating element for winter use, and leave the regulator/diode system intact. Not only will this provide more flexibility of use, but you have to remember, the alternator ALWAYS requires some "feeder" current, even after it gets up to speed it can only provide this self-sustaining current thru a diode/regulator system. This current MUST be DC, so unless you want to keep providing this DC power from a battery (and it WILL add up) you will need a properly functioning regulator (either internal or external) on your alternator.
nickk5 years ago
It depends on what kind of power you are after. First of all the car alternator is designed to turn at 3000 rpm to generate it's full power, such speeds are impossible with windmills, you will be able to achieve a max of 500 rpm with a windmill that makes you use 1/6 of the full power of the alternator which is not practical unless you are after a couple of watts only. You can benefit from some free heating in your house if you have some spare alternator and a 110v electric heater sitting around, what you do is : open the alternator cover, remove the regulator from inside "the alternator generates AC power" connect a direct wire from the alternator winding to the heater and let it spin ! The alternator will generate AC electricity when it spins which will be transformed to heat by the heater, it will not be a stable source of heat .. but whatever comes for free is always welcomed !!
jjmns73 nickk3 years ago
could you help me with this i would like to turn an alternator to make AC but do not know how hook up the wires.
endolith nickk5 years ago
such speeds are impossible with windmills

...Gears?
http://rpmgt.org/order.html Goto this website, purchase the SSG kit. Put the fit together exactly as told and use it to restore Lead Acid Batteries. I pulled an old car battery out of the muck in my backyard, the date indicated it was 14 years old. I 'energized the battery repeatedly after draining it between energizing's. After 12 times this battery now holds 14.4 volts. The advantage is, this device energizes/charges the battery with COLD energy, NO HEAT! ALL other chargers use heat and after a short time, they ALL do more damage than good. Now I am restoring all minds of lead acid batteries! I have a small enterprise going on restoring batteries for people who have computer UPS, Battery UPS use lead acid batteries and I make five bucks for every battery I restore, some UPS use TWO batteries and I can do upto eight batteries all at once and still collect five bucks for each one! Best of all the SSG is SELF POWERED! Plug-in a 'run' battery 9fully charged and eight batteries on the other side including a new battery for the next run. switch the 'run' battery for every run and the batteries never go dead!
Yes.  When the alternator is turning, apply some DC to the field coils and you'll get output.  Using the regulator from the car will give a steady 12V output.  Building a custom regulator will provide more voltage.  Here's a few examples: images.google.com/images
Car alternators require a high rpm to produce power and that is done in a car with a belt and pulley.

It is possible to do that using belts and pulleys on a wind turbine but overcoming the friction and torque of an alternator would require super high winds that make it unfeasible.

Any DC permanent magnet motor can be used as a wind turbine generator as long as you get enough wind to turn the turbine.

Old stepper and treadmill motors are used and you can buy low watt permanent magnet motors fro specialty motor shops.

I have built them out of small rc style motors but they do not hold up well and tend to burn out quickly.

You can see my small 125 watt turbine and solar system here for ideas:

http://www.youtube.com/solarcabin




cabin.jpg
Kiteman5 years ago
Simple answer: yes.

Complications: what sort of windmill? How are you connecting the windmill to the alternator? How are you going to control the current? What sort of batteries are you going to charge?...

All of these problems have been solved in a range of Instructables.
snotty Kiteman5 years ago
The other simple answer: not really. From what I've seen around the net over the years, most people find it easier to use a stepper motor or even build their own system from scratch. However, some people have retrofitted car alternators with rare earth magnets for similar applications. I don't remember if anyone did this for a wind turbine though. I'm making a mini turbine out of bamboo and a VCR at this very moment.
Bamboo turbine first assembly (it works!).jpg
snotty snotty5 years ago
PS: sorry If I sound like a naysayer. I'm not trying to be :) Wind power is awesome for so many reasons. Keep on trying!!
OSIM5 years ago
the old "hot rod" alternator was single wire 'perm. mag but doesn't make power till 1700 rpms then its quite powerful, but weight is 12 lbs. I just wasted a month trying to make one work for me. A new rebuild is 80+ bucks, now trash.
kadris35 years ago
an alternator would be great for an old used lawn mower motor. u need a battery or you get no output. you can fine tune the device by varying the field. if you can find a generator, it will produce electricity without a battery needed for the field. dc motors have long been used as well. it depends on that which you are trying to do, and how much power you need. good luck.
I have had success with using the parts from an alternator, particularly the coils and bar magnets, as raw materials in creating generators. I think attempting to drive the alternator directly is a bit of an uphill struggle. Its engineered to be driven by a high power, high torque engine.
jungleflyer5 years ago
The bit about needing 3000 rpm is wrong. Most alternators will put out the Maximum at speeds lower than that. The average alternator puts out 35+ amps at 2,000 rpm. Speeds as low as 800 rpm can give 5 amp output. To "gear up" using pullies is no big deal.
ramonc1235 years ago
why go threw the problems when u can buy one from windbluepower.com for $250 bucks and um this is a diy web
ncblu5 years ago
you can but it is going to be a bit of a job, you will need to re-wind the stator coils to cut in at a lower rpm ( but you may have trouble getting that rpm to begin with) you will be giving up some power by doing so and at best you may be able to charge car batteries and run an inverter off that. check around the internet. to get 110 volts ou would need to remove the regulator and crank it up to around 8000 rpm and then that presents a whole new set of problems that need addressing.
you will need a car battery and a regulator to vary the voltage and currant output also the battery powers the field coils.
pyper5 years ago
You would need a battery to power the exciter (name?) winding of the alternator, and you would need to play about with regards to rpm / power and match that to the speed and torque of your windmill. I would suggest that a large DC motor would be a better alternative, such as one from a treadmill, or large cordless drill (expensive!) Alternatively generators don't seem that hard to build, I've seen several people build them out of rare earth magnets / windings set in resin, I'm sure there is an instructable for something similar on here.