40 mph wind mills??

[jawnn]

What can be done with 40mph winds? Is that just too much?

We have days that are nothing but hard wind. I am thinking that we just need to make a wind mill with the motor we have.

I need to see pictures of medium sized turbines with PVC blades.

[tanner0441]

Hi

Not enough information, but 40MPH winds and PVC blades are not a good combination....

Brian

[dnix71]

My AirX without the electronics and plastic blades has seen gale force winds during T-storms. The peak output recorded was scary. In winds that high you better have some safe place to put the power you are making, or else design the mill to just sit there until the winds get up. 2 mills, one for low wind and one for high wind.

I wouldn't trust pvc to hold up to that for long, though.

[fabricator]

40 mph doesn't mean anything, it all depends on the construction and where it furls, PVC blades are worthless if you are talking about a legitimate machine, there are a lot of blade options these days, use real blades.
If you want a midsize mill that will stand 100 mph winds as a regular diet build any one of Chris Olsons machines.
My 17 footer has seen 80 mph several times, all it does is make mo power.

[Flux]

When I see "motor" and pvc blades I sense the glorified garden ornament on a pole with no form of control or power limiting.

Provided it is small, such a thing works up to about 30mph wind speed. Beyond that the power available rises so quickly that it has to be incredibly small to survive.

The thrust and bending moment on the blades is likely beyond the limits of a bit of pvc pipe and is also likely to be at the limit or beyond of bearing loading and shaft loading of most of the "motors" sold to the unsuspecting for wind power.

As already pointed out is is about at the limit of an uncontrolled thing the size of an Air x with proper blades and at least an automotive styled bearing and shaft.

For pvc I suspect a machine no bigger than 2ft diameter will be the survival limit. If you get long sustained periods of steady 40mph wind it could still be usefully productive but wind is never that simple or accomodating and the 80 mph gust will come.

Survival to 100 mph is possible, even production at thet speed could be possible for some designs, but it will be a fine piece of engineering with power limiting, not a garden ornament made from some bits offered to revolutionise the world on some crazy web site.

Flux

[DamonHD]

Flux: which crazy Web site did you have in mind?  This one?   B^>

Rgds

Damon

PS. Just for giggles, if he's got almost too much wind, might this just possibly be the place to deploy a metal barrel Savonius VAWT or some other inefficient-but-tough design.  Would need a very robust 'motor' though, and one that would work at relatively low revs, or geared.

[Flux]

I wasn't directly implying this site, there are many places trying to flog Amtek motors, treadmill motors and various redundent items at about 1000 times scrap price and suggesting you can run your home from it. They usually try to sell some nice bent tin blades to go with them or the replacvement blades directed at the Air machines and sililar.

I suspect this site may have a lot to answer for regarding the pvc blades.

They may have their place in low wind areas and at least would compare with the bent tin offerings. I only tried once, it took me twice as long as a set of simple wooden blades and the result did work for the dreadfully slow alternator I  had available but if I had run the thing at 36v with simple wooden blades of the same size it would have performed an order of magnitude better.

I agree with you that for very high wind areas a significant tsr becomes embarassing so high solidity or drag machines can have a useful place and shouldn't be ruled out. Still never underestimate the forces involved, they produce tower loadings way beyond a furling HAWt and these forces have to be supported by shafts, bearings and the rest of the structure. Again this involves engineering of a high standard unless the thing is very small.

I see no big issue with a machine producing power in winds of 40 mph. This is well within the working range of a properly furling machine designed for the lower winds. One designed with higher winds in mind could be arranged to give a very good performance in this region and something about 6ft diameter could do something quite spectacular.

Flux

[fabricator]

Mppt makes most of the high wind problems moot anyway.

[electrondady1]

i live at the most southern tip of Georgian bay
about half a klick from the beach.(wasaga beach)
 all day long the wind was blowing hard from the south east.
weather station predicted 80 klm winds.
i wasn't worried 'cause  my drag vertical mills are sheltered from south winds
but some time in the middle of the night the  wind changed direction 180*and started to come off the lake , that's about 300 miles of open water
i woke up at 5.ooam
wind sounded like a freight train
looked out the window, two windmills blown to pieces.
 the ceramic magnet ones i built three years ago.
i fixed one yesterday
today i need to nail on a bunch of shingles that got torn off
oh well.
i'll fix the other one tomorrow

[jawnn]

what we have is a 4800 rpm tread mill motor.. I thought of stepping it up to get some real power to the batteries.

where can I get some good blades? or how to make them?

I really have a lack of knowledge here, what to do next?
books? photos?

Will this book be good enough to figure it all out?
http://scoraigwind.com/books/books.htm

[sean_ork]

what we have is a 4800 rpm tread mill motor.. I thought of stepping it up to get some real power to the batteries.

where can I get some good blades? or how to make them?

I don't know what you think is ''real power'' - kids here makes 200w @12v turbines out of treadmill motors using soil stack PVC ''blades - around 18" long each

no furling but with a supported  bearing before the motor - 10mph = 20w ish

we often see 60 mph+ winds here

[tanner0441]

Hi

If it is a treadmill motor it is most likely DC.  You don't say what voltage the motor is so 4800 RPM is meaningless.

A lot more information is needed before anyone can help you, and you need to read a lot more about basic electrical theory, and the difference between AC and DC, blocking diodes, and the RPM range you expect your turbine to run in.

Brian

[fabricator]

If you want real power build a real mill, and yes, buy Hugh's book and the Dan's book and read them both at least twice, then you will have an idea of why a treadmill motor will never make real power like 3-5 kw.

[tanner0441]

Hi

Here is a list of questions for you...

What voltage system are you looking at, 12,  24,  48?
What height are you thinking of mounting your turbine, and on what sort of mast or pole?
What is your actual measured wind speed? Over a period of time giving a range of conditions.
What trees or buildings do you have around you?
How far are you going to take the power before it gets to the batteries?
What do you expect to be able to do with the power if you get it?  Try not to say space heating or hot water.....

How did you come up with the idea of a wind turbine?

Like fab said build a proper set up. If you really have a good wind site then milk it don't waste it on an electric motor with pipe blades. Remember a motor designed to give 2HP at 240 V will be pulling about 7 to 8 amps, which is all the windings are designed for.  7 to 8 amps at 12 volts is going to be less than 100 watts. Also as well as basic electrical knowledge you need an appreciation of mechanics as well.

You can't feed a DC motor into a transformer, and even if you put the power straight into the battery you have to have a blocking diode or when the wind slows down it will become a motor again and run the battery down. Then you need to be able to stop the thing destroying itself by some means, normally furling. (Turning the blades out of the wind)

There is a world of information on this site, read back through as many posts as your brain will take, you may not learn to build your ultimate turbine but you will learn the questions to ask.

Brian

[Flux]

Can't add much to that, it depends on what you consider real power.

Your treadmill motor will be about 1200W at 240v, assuming you can overload it 100% for wind power that is 2kW at rated voltage. If you run it at 24v then it will do 200W and if you restrict it to 12v then 100W as other have said.

Even for 12v it is probably fast for direct drive under normal conditions but would be ok if you really do have 40mph winds.

For higher voltages you would need gearing and it really is never worth the trouble to gear such a tiny motor.

If you are happy with 100 or so watts then use it, if you want real power then look for something else.

In a 40 mph wind you would get far more out of a car alternator than that motor. These are normally considered totally unsuitable for wind but at 40 mph you should be able to get those fast type Air x blades up to the speed needed for an unmodified car alternator. A large truck alternator with a bit of modification could possibly get some useful power in those winds. Even so a purpose built permanent magnet alternator would be the way to get real power.

Flux

[jawnn]

The dc pm motor is 120volts at 480 rpm and we got it up to 40 watts at pedaling speed.  But putting it directly in to a battery made it very hard to pedal, so I go this idea that maybe we can adjust the torque by adjusting the charge controller?

Please give me a link to both books; I hate trying to get computers to do what I need....I can't even see the screen very well, bad eyes.

The weather people said gusts up to 30 or 40 mph...and we have a lot of gail force winds, across a feild from the south.

Maybe a hundred feet to the batteries? if we mount it low it will be much easier to make the project happen. But it's got to be high enough to clear horses.

I hate groping in the dark for info so I will just have to buy books. But I can't find them on this forum.....

[fabricator]

The best advice I can come up with from the info you provided is don't waste your time, in a 40 mph wind 100 feet away from the batteries twenty feet off the ground you might see a watt or two.

[birdhouse]

http://www.amazon.com/Homebrew-Wind-Power-Dan-Bartmann/dp/0981920101/ref=sr_1_4?ie=UTF8&qid=1356653590&sr=8-4&keywords=hugh+piggott

there's one of the books^^^

100' is a long ways for a hobby mill!  especially at 12v.  i'm sure you could see more than a watt or two with decently thick copper wire runs, but the wire alone would cost WAY more than the mill build.  so you spend well over a hundred bucks on wire, and maybe get 10-75 watts out of it... 

is that worth it to you? 

at the same time, if you plan on just learning from this first one, then the wire and tower could be used for the next build, assuming you make the tower strong enough for the next anticipated size of mill. 

if you're going to bury the wires runs, i'd use larger than anticipated conduit so you can add to, or use larger wiring in the future. 

adam

[sean_ork]

The best advice I can come up with from the info you provided is don't waste your time, in a 40 mph wind 100 feet away from the batteries twenty feet off the ground you might see a watt or two.

I have a ''toy'' treadmill motor, that was rescued from the bin, mounted on a 6' pole out in the field - connected to a large 12v battery at the end of 150m of 6mm cable - at 40mph I see over 100 watts from it into the battery

and it's been out there doing that for nearly 2 years, and it has soil stack PVC blades

[fabricator]

The best advice I can come up with from the info you provided is don't waste your time, in a 40 mph wind 100 feet away from the batteries twenty feet off the ground you might see a watt or two.

I have a ''toy'' treadmill motor, that was rescued from the bin, mounted on a 6' pole out in the field - connected to a large 12v battery at the end of 150m of 6mm cable - at 40mph I see over 100 watts from it into the battery

and it's been out there doing that for nearly 2 years, and it has soil stack PVC blades

So, unless you live in a very windy area you haven't even come close to paying off the cable or the battery.

[sean_ork]

So, unless you live in a very windy area you haven't even come close to paying off the cable or the battery.

we don't all sit down with a calculator before doing everything, ''paying off'' doesn't figure

the point I was making is that a certain amount of very useful power can be achieved, certainly a lot lot more than the 2 watts you guessed at

[jawnn]

ok we can move a battery to the wind turbine.  My land lord wants to throw something together right now, and hang the effenciency, but I want to build something that works. so I get to do the research, and plan for next winter.

How about vertical wherly gogs? seems like it would be easyer to build, but not as effecient.

Our solor pannels do not work in the winter here , so anything is needed.

Is this book better than the other one? Homebrew Wind Power Dan Bartmann

well maybe easyer to get.

[jawnn]

Is there a cataloge of parts? motors, blades ,plans, kits?

I build a bicycle last year, from scratch, it took a long time to design it, and a few summer months to build it.

 So I think I can build some kind of wind energy machine, if I can raise the money and information.

[tanner0441]

How much solar do you have?
You still haven't said what you want to do with the power?

120V at 450 RPM is open circuit connect it through a diode to a battery and spin it at 450 RPM measure how many amps you are getting into the battery. Your wind speed 40MPH gusts, gusts don't last long you need to measure the wind speed at your location, not a general weather report.

If you think I am anti plastic blades I have had a bad experience with them. I built a mill with three 2 ft blades giving me just over 4 ft of span. I cut the blades carefully and glued the pieces I cut off to the back of the blades and spent ages shaping them into a proper airfoil shape and balancing. Then one windy night they took a hit from a branch blown from a neighbours tree and shattered. The bits were bedded into things far enough that if it had been a person it could have killed them.

As for calculators. The questions being asked. ie. How much power will a 4800 RPM motor generate? How did we come up with the answers? Sat for a minute or two with a calculator.

An other questions often asked on here is...... I have done this.... why doesn't it work?

Read the books, do the sums, and make notes.  Then if you have a problem you will have enough information to understand the explanations.

If your only going to mount the turbine at 20ft or so, then read up on ground effect turbulance.

Brian.

[fabricator]

The books suggested in the thread would all show you exactly step by step how to build a complete turbine.

[Frank S]

Unless you have extensive mechanical design experience you are far better off listening to the advice given here and even if you are an accomplished machine designer the knowledge posted in these forum threads are invaluable. Almost anything you can think of has been tried in one shape form or fashion or another numerous times by others currently posting or by several who no longer show up very often if at all.
 One thing that is advisable is to search these forum threads for which ever motor or generator type you are contemplating then read upon the various methods of implementation and designs and study the outputs this will help you decide which design you would want to use for the amount of energy produced versus money spent.
 I am currently on revision 30 of design #12 By the time I relocate to some where that I can actually put my designs or one of the tried and proven home brew machines to use I will have settled on 3 possibly 4 designs and know within a few watts or volts what the expected output should be before even spending a dime on a build But that is just me not everyone can or are willing take the same approach to things that I do
I am by nature a steel guy this does not mean that I am anti to any material for blade construction in any way, but when I look at all possibilities for blades it boils down to some very simple choices either go super exotic in blade design construction or go for a wooden design.
 For me it would not be much of a factor I often use wood for component modeling to send for sand casting a part this involves carving and sanding.
 Some think that making blades out of PVC pipe is easier than carving them from a wood blank. Or simply buying a set of plastic blades for the smaller turbines instead of attempting to carve their own.
  with just a little attention to the articles in the home brew books a set of wood blades can be made fairly painlessly and without any high tech equipment

[birdhouse]

i say build it with a wooden two blader.  just get a clear chunk of 2x4 and carve a blade.  there have been a few threads lately with near the same motor.  4800 rom has come up a few times, and i have yet to see the results. 

if your landlord is into it, then go for it. 

here's some good reading for you.  also, youtube.com has some great videos on blade carving...  just watch a few...

http://www.scoraigwind.com/pirate%20oldies/Hugh%20Piggott%20Axial-flow%20PMG%20wind%20turbine%20May%202003.pdf

adam

[jawnn]

Ok I ordered some books threw interlibrary loan. Home brew power and Wind turbine workshop and one other not on your lists.

Hope they have something easy to build  we don't have much money.

Does anyone use timing belts or bicycle chain to gear up the motors?

Looks like we will have to build several machines.
We have only enough solar to pump water on these dark dark days. Hope we get sun tomorrow; my own small batteries are down to 10 volts.

My land lord sends me AC then I turn it back to DC into small batteries. I run LED lights, but they run CFLs and other absurd things, like an oven that uses propane but needs too much AC to keep the safety valve on. That needs to be dumped, and replaced with wood stove. We both have stopped using refrigerators.

Too bad we can't just get a water pumping wind mill, it would save so much power that we may not need an electric wind turbine.

How thick were the PVC blades that shattered? Would ABS be stronger?

[tanner0441]

You really haven't read many threads on here. Not too far back on this topic (wind) Chris Olsen posted photographs of a complete build using a chain and sprockets to gear up the speed of a turbine. Remember though gearing up has mechanical losses, and if you only have a 100W wind no amount of gearing up will give any more.

There is a formula for calculating shaft power from wind speed and blade diameter.

The advice to carve a single twin blade set up is good twin blades are the fastest but put a lot of gyroscopic forces on your turbine bearings, when it yaws, which is reduced when you go to three blades. Carved wood blades are lift blades, pipe blades are drag blades and as such are far less efficient.

You need to sit down and calculate your total electrical requirement, lighting load, water pump, oven solenoid, (though I would be surprised if that is more than 10 to 15W)  then you will know how much power you need to generate and how big a battery you need to give you a buffer in times of no wind, and too little wind to charge your battery is no wind, the fact your turbine is turning means nothing.

Brian

[birdhouse]

10v is REALLY low for your batts!  sulfation has probably already set in if this is a regular excercise.  i wouldn't expect them to last all that long with this type of abuse. 

pvc, abs, ect...  these are less than ideal blade materials.  sure you can spend many hours shaping a "pipe" blade to perfection, but it's still a pipe blade.  have you ever heard the saying "you can't polish a turd"?  same idea.

do you own a hand saw, hammer, chisel, block plane, and some sand paper? 

i think folks get discouraged when they hear "carving" a blade.  many here "butcher" their blades into shape.  chainsaws and angle grinders with flap wheels can make the "carving go much quicker!  even with simple hand tools, a two blader out of a 2x4 could be easily be made in an afternoon! 

once you read your books this will make more sense. 

you need very high rpms to get that motor to work.  i have many doubts that a pipe blade set is going to get you there. 

adam

[jawnn]

I don't know how power the solar produces; I keep forgetting to ask my land lord.

For now I am going to work on pedal power and read the three books I ordered through our library.

Gotta top off my three 18 ah batteries every day and get some aerobic exercise, still 40lbs over weight. Not good for someone with a enough heart disease to have a heart attack 1.5 years ago.