The price to buy a wind mill to generate electricity is outrageous.

>>928162
using a windmill to generate electricity is going about it all wrong op
you should be using a wind turbine to generate electricity.

if you wanna connect the blades directly to the alternator, it wont work coz the rotational speed is too low. you'd have to rewire the alternator to compensate. however if you have a windmill, then presumably you can use gears or belts to obtain the necessary speed, so it could work unaltered.

>>928162
Because they're low production volume items and a car alternator that is made in the millions still costs like $300.

http://www.canadiantire.ca/en/pdp/coleman-400w-12v-land-and-marine-wind-turbine-0740213p.html#.VpL8Lb8jxpk

Just because you can put together a system from scrap doesn't mean the company building a commercial product can too.

>>928184
Thanks for not answering the question. Fool.
Can OP connect a
>wind turbine
to a car altinator to generate electricity?
Fucking grammar police.

car alternators are poor for windmills. They need high rpms to generate power. You can increase the speed via belts and pulleys but at a power loss. Also every time it shuts off because of the regulator it will over speed and basically explode. Most off grid windmills are direct connect to the batteries with excess power being dumped from the batteries into a resistor or water heater. The only way i could see it working is one of those large water moving windmills with 14+ blades. The more blades the more torque and wind it collects but it also reduces overall speed so it may control it and keep it from over speeding. You can convert an alternator to a pma which is much more suited for it.

>>928162
You need to excite the inner stator to produce a magnetic field when the thing starts rotating.
Not using magnets would mean the alternator would pull some current, about a few amps to be ready for rotation. So when the wind isn't blowing you would have a drag on the power.
However you can make a convoluted rotation sensor and excite the center coil and turn on the regulator when the mill reaches a certain rotation speed putting out a small voltage with a tiny magnet in there.
You can use a set of permanent neodymium magnets in the center glued with epoxy. Machine slots in the original metal of the stator. Then you could use the center coil rotation to track speed and make an electric brake circuit to prevent over speed.

Generally it's simpler to get a use exercise running track DC motor or a DC motor from a large lift truck and just spin it at the right rpm range.

>>928221
Who cares about the 10% loss of efficiency when you are getting several KW of power free from the wind and it goes up by the cube of the wind speed?
Surely there are more parts to fiddle with, but belts last 10-15 years without breaking, It's the bearings and waterproofing the sucker is the hard part over all. Put the whole contraption in a box, take the diodes out, run the AC power down a large extension cord for distance(saving efficiency using HV AC instead of DC). Then rectify it for DC going into your charge controller. Also, you can run the suckers in parallel with the right wiring and diodes before going into the charge controller.

>>928210
You can pick up alternator cores cheap at the junkyard and refurbish them with new bearings and pull the diodes out for AC transmission for distance.
The GM ones are easier and cheap by the dozen. Even craiglist ones are damn near free.

>>928184
/diy/ never fails to disappoint.

Well before you do anything it would help if you carried out a wind power site assessment to see if it's actually worth the cost to install a wind turbine.

To do this you put an anemometer up on a pole and measure wind speed for a year. For better results use a bunch of anemometers at different heights

In general small wind turbines do not make sense:
http://www.lowtechmagazine.com/2009/04/small-windmills-test-results.html

Field excitation would be an issue. Installing magnets on the armature and modifying the existing circuitry...

>>928754
And how do you plan on maintaining the 700 odd RPM the alternator needs to even do anything?

Think the speed your engine idles at. That is the minimum speed you'll need tog get from the wind.

If alternators were viable, people would not go to the effort of gutting and rewiring fisher and paykel motors..

There are countless YouTube videos about how to do exactly this.

Personally, I think I would go with a dual conular sail or helix design. Blades have a lot of drawbacks.

You can also build your own 3-phase generator instead of using a car alternator; some videos show you how to do this with coil wire and spent brake rotors. This has the advantage that you can set up a higher voltage value, which means less amperage for the same power, better distance power efficiency, and not having to use expensive thick ass cables.

>>928825

Gear/pulleys

Often you find the alternators pulley is smaller than the crank pulley.

Then given the size of the wind turbine you can get some serious leverage meaning overdriven to fuck.

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At this stage in the game you would almost have to just build your own. I was thinking a vertical one like pic related, as they would be much easier to build and maintain. Something similair to this would be easily made at home. The fins could be made of either pvc or aluminum, pvc being the lighter or less dense but aluminum being easier to shape/mold.

I found this file and it would have a lot of info to help, now you just have to write up rough plans and price it out. I know i probably will

http://www.rpc.com.au/pdf/wind4.pdf

There is a whole writeup that I saw somewhere on how to do this with a repurposed washing machine motor. I think my girlfriend saw it on pinterest or one of those other retarded sites?

What makes OP think the generator/alternator is the expensive component in a wind turbine?

And what is the obsession with charging 12 volt batteries anyway?

DIY is slowly becoming cancer.

>>928162
>Why cant I hook up an altinator from a car to a wind mill to charge a battery?
Because you don't know what you are doing.
Car alternators need power to start with, plus they have to much sticktion and have to be rotated too fast for a small windmill to be ble to spin them.

The usual way to build a DIY windmill is to use your own magnets and coil windings. This results in an "air-core" dynamo. The coils are stationary and the magnets are spun (they are glued to the windmill's rotor hub).
Air-core means the generating efficiency is lower, but it also means there's no cogging, so the windmill can spin in very light winds.
Finally, this way is very simple and durable; it lasts a long time and only has 2 bearings that wear out and need to be replaced.

Also the blades are composite or wood.... Any kind of thin metal tends to fatigue and crack & break; especially aluminum. Even if you can weld it or rivet it perfectly. Lots of people have tried it and seen it fail. Composite or wood is much lighter and still lasts way longer.

Plastic generally isn't very strong and is too heavy (hint: PVC pipe sux)

See here-
http://www.reuk.co.uk/DIY-2kW-Wind-Turbine.htm

Also do a "normal" windmill, not a VAWT or any of that oddball stuff. The normal kind of windmill (3-blades) works best overall; it's why the BIG power-generating windmills are built the way they are.

>>928162
You need a pwm regulator to regulate the magnetic field strength of the rotor, otherwise if it goes self excited, it starts to have too much resistance and the wind turbine stops. Especially when the rpm and torque do not match what alternator is working with in a car.

So it is not trivial and requires measurements and experiments.

If you read the specs of alternators, it is usually 12 volts and 40 amps, which is 84 watts of electric energy.

>>929041

"Normal" windmills may be simple and effective, they also make noise (never mount to the roof of your home), cast flickering shadows (sucks if you or a neighbor are epileptic), and fling deadly ice chunks in or after bad weather.

That is why I think vertical shaft designs are better.

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>>928802
I can see these from my house.
I'm guessing there is plenty of wind.

>>929018
>And what is the obsession with charging 12 volt batteries anyway?
Probably because 12 volt lead acid batteries are the most common rechargable battery in the world?
naw that cant be it.

>>929332
But if you put say 4 in series for a 48v system, you can get a lot more usable power up to your inverter.

The only real reason to use a 12v system is if you are just powering mobile or automotive appliances.

>>929365

12V dc is a good compromise since car batteries and car accessories like relays are plentiful and cheap. the danger of going higher than 12V is that you get flash-overs that destroy equipment. campers that run at 24V, for example, have many more equipment breakdowns.

>>929332
>>929365
>>929372

>Oh wow I have this strong desire to want to go and buy car batteries.

If we're posting about it on the internet, the likelihood of needing to reply on anything battery powered is slim, because already your phone line is providing constant power, albeit low.

>>929308
There may not necessarily be enough wind for a small turbine to make sense. Especially if you live around a bunch of trees amd other clutter.

And again see this link, for the most part small wind turbines do not make sense:
http://www.lowtechmagazine.com/2009/04/small-windmills-test-results.html

>>929372
I've never heard of a 24 volt camper having a fire, 24 volt campers are rare enough to begin with, usually custom since the part selection is really low. 24 volts or 30-32 volts at peak is still really low voltage. What people fuck up with windmills is voltage drop. Lets say you have a small windmill that puts out 500 watts at 30 mph (rated wind speeds on windmills is 25 mph, expect a lot less at 10) thats over 40 amps. The tower needs to be a MINIMUM of 30 feet to avoid turbulent ground wind. Even with the building at the bast thats at least 40 feet of wire. You would need like 2-3 AWG to keep it under 5%. Thats expensive thick wire which leads to mechanical issues. It needs to be flexible and you need to be able to detach it once and a while for the wires to uncoil. A less turbulent wind site helps but ultimately it will twist. slip rings wont last in the weather and cold. Small windmills are only viable if you have a three phase windmill, it 24 volts or higher or its a really short run at 12 volts with thick wires. 48 volts is when you get into real output territory. Gets expensive though, pretty much everything runs on inverters at that point. Windmills should only be used in a home power system as a supplement.

Hello, I know this isn't /r/ but does anyone have any good info links for a REALLY small size school project wind turbine. I'm thinking like 20-40watt. Just enough to power a lamp

>>928825
With permanent magnets installed in the alternator, it will still put out an AC voltage at low rpm. The trick is to install a zener diode and direct that low voltage ac(without diodes in alternator) to a step up transformer.
Once the voltage is high enough from the output of the alternator, switch to dump it to the charge controller or batteries for charging.

As far as maintaining rpms, use a VAWT with large scoops to direct wind into the blades.
Also you could use the windmill to pump water to a tank, then discharge it to a water turbine for high rpms on an alternator/generator.

>>929989
A minimum of 30 feet? try a VAWT on a simple pole 6-10 feet to avoid roof wind or just set it out in the field. Got a farm of these turning right now.
Use #0 to -#2 stranded welding cable, cheaper by the foot than trying to buy more expensive boutique wire.
Again, ignore the meager cost of replacement, and slight loss , use carbon/metallized carbon brushes on your slip rings. Cheap at rewind shops or online.

Yes, only as a supplement power unless you live on the coast or East Texas/Oklahoma.

>>930023

VAWTs don't need to rotate around into the wind, that solves the slip ring and twisting of cables.
Kinda overcomes the loss in efficiency with less maintenance cost of parts.
Magnetically levitate the bearings with a slab of bismuth to repel against the air core's neodynium magnets.

>>929129
12 * 40 = 840
Most alternators start at 55A and cheap Delco ones are rated up to 105 amps without modification. Even at 60% duty cycle that is 750 watts.
Losing about 20% for belts/pulleys, wire and electrical leprechaun circuits is still 600W or so.

>>928834
http://www.lowtechmagazine.com/2013/03/the-mechanical-transmission-of-power-3-wire-ropes.html

>>928834
http://www.notechmagazine.com/2011/09/continuously-variable-bicycle-gear-hub.html

>>930023
can you link the VAWT, I only see HAWT online and the few VAWTS i see are under 150 output. I know they handle lower to the ground wind/turbulence better but i never saw one with serous output unless it was some pie in the sky 15000 dollar cad drawing that doesnt exist.

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>>930273

There's two Helix VAWT's that I know of just in the seacoast region NH, so, may be a bit expensive but they do exist and are proven... the companies that build them however (Helix Wind and its private successor Venger Wind) have up and evaporated, so I think you're good to go to copy the design for your own use.

>>929999
Just hand wind a few coils and a some magnets in a disk turned by a simple propeller. Use LEDs for low power example. Under a watt.