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Forum Index : Windmills : help me find used 10kw pma motors please
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goldhunter_2 Regular Member  Joined: 10/03/2010 Location: United StatesPosts: 57 |
the largest loose generator I have been able to get a price on 4.5kw there are a few 10kw and bigger available as new complete mills minus the tower but none with sufficient survivable wind speed ratings I did see a some VAWT years ago when I built the other but I have not sen a large unit in person to answer the question in my search for a forum related to wind mills this was the best I had found if you run across that other URL please let me know |
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GreenD88 Senior Member  Joined: 19/05/2009 Location: United StatesPosts: 104 |
I doubt you'll have much luck locating PMA that big, your probably better off if going that big to find a Induction Generator, they can be had pretty cheap. At least alot cheaper than PMA because they don't use the expensive magnets, but they are alot harder to get power out of compared to a PMA. Licensed Master Plumber / EPA 608 Universal License / 410a Safety Certified / Medical Gas Brazer/Installer |
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| goldhunter_2 Regular Member Joined: 10/03/2010 Location: United StatesPosts: 57 |
so given the exact same 10kw generator (not the blade setup) with the exact same rpm's your saying the the VAWT will produce less then half what the HAWT will , how is that possible if the generator produces X amount of power at X amount of RPM's and there both exactly the same? obliviously if one has higher rpms it would produce more but for this comparison they are exactly the same if it spins 200rpm then it should be 200 rpm regardless of the designed unit or at least I would think so |
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Perry Senior Member Joined: 19/11/2009 Location: Posts: 190 |
Your question doesn't really make sense. Take the blades out of it then. You are saying if you put 2 exactly same generators on 2 exactly same poles and spun them at exactly the same rpm then yes, of course they will put out the same. Problem is that at a given wind speed they will not be spinning at the same rpm. For instance, at 10 m/s the HAWT will be spinning at 200 rpm and the VAWT will be spinning at 100 rpm. (those are made up numbers to illustrate the point) Perry |
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| goldhunter_2 Regular Member Joined: 10/03/2010 Location: United StatesPosts: 57 |
yes all the numbers are made up numbers to illustrate this comparison the blade design, weather the unit is gear or not geared etc etc etc are all completely separate issues. maybe to make it easy I should have said test both VAWT & HAWT generator only in shop All I wanted to be sure of is that at say 200rpm both units produced the same amount of power and there was no magical reason I missed form laying the VAWT generator flat instead of standing on end that I lost power output amounts |
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| Perry Senior Member Joined: 19/11/2009 Location: Posts: 190 |
yes, a generator will put out the same mounted vertically or horizontally. nothing gravity dependent in them. Perry |
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| GreenD88 Senior Member Joined: 19/05/2009 Location: United StatesPosts: 104 |
Well you'll have to gear these but on ebay you can find a 10kW Synchronous 1800RPM Generator for $400+Freight. If you have a harbour freight near by they sell Generator heads designed for Gas/Diesel motors 10kW for $299 but 3600RPM. Just a couple options for you since your looking. But I doubt you'll find any Direct Drive PMA that big for the price your thinking of. You could build one but the price is just gonna be outrageous for an Axial Flux that big. From what I've found it costs about $200 just for the magnets for a 1kw Axial Flux. And if you really need 20kw you might be better off building a Vegetable oil Diesel Generator. And asking local restaurants if you can have their waste cooking oil. Licensed Master Plumber / EPA 608 Universal License / 410a Safety Certified / Medical Gas Brazer/Installer |
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| goldhunter_2 Regular Member Joined: 10/03/2010 Location: United StatesPosts: 57 |
a vegetable oil generator would put me back into a huge battery bank plus its better not to put all your eggs in one basket so to speak so I'll keep the vegetable oil for the truck 
really everyone (myself included) wants to find the best price but it is going to cost what it cost weather I buy or build a unit and that is the first fact I came to realize unless I am willing to sacrifice more |
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| birdhouse Regular Member Joined: 27/01/2009 Location: United StatesPosts: 63 |
i've been following this and fin it very interesting. i don't think anyone here is trying to be negative towards you (goldhunter) but rather looking at your desires realistically. 10Kw is a HUGE number to shoot for. so you want to find a 10 kw pma. mount it to your roof with a HUGE vawt blade system and have it with stand 130mph winds? it is possible if you are a licensed engineer, crane operator, master welder, and aeronatical expert. oh, and have some very deep pockets. nothing is impossible, but it might cost you more than you will ever gain via the "free" power. i think the reason for the HAWT push is lets say you found a 10 Kw pma for cheap somewhere. with your average wind speeds you would generate substantially more electricity from HAWT than a VAWT. depending on the power curve of the pma and losses you may only ever see 8Kw with a HAWT and possible only 5Kw with a VAWT. going big has it's advantages a prop twice as large can produce four times the power (or is it three?). however once you enlarge to a certain point it becomes way harder to keep the whole rig together and SAFE! i'm a contractor and have put a few decks on the roofs of residential homes. generally pretty small decks. the amount of re-inforcing needed is insane. ripping open walls in the first floor to add framing members/metal ties for a deck above the secong floor. the loads you are talking about are pretty hefty! to get a plan stamped for your size and 130mph might require additional footing and LOTS of steel. this is starting to sound like a $250,000 job. it may be cheaper to buy a comercially made 10Kw HAWT with tower to suit. just my $.02 birdhouse i pee more than once before flushing, and don't have to flush at all up at the ranch! |
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GWatPE Senior Member Joined: 01/09/2006 Location: AustraliaPosts: 2127 |
No one is saying to set up a mini wind farm at the moment. BTW, a toy windmill is one that produces no useful work. Any windmill that produces enough electricity to supply the loading is not a toy. The point is that you need to know with some accuracy how much wind energy is available. To say you have an average of this much is no good. I recommend that you at least record, log, the wind, at probably 10 second intervals, with a weather station type calibrated anemometer. Come back after a year with some data, which will include daily wind run, and a daily wind distribution for the whole year. This will cost a few hundred dollars. You can put up a small windmill, and record the power output in a similar way. At the end of a year, do some calcs or have someone evaluate the data. This will probably be the only way you will get an outcome that will be realistic, an guide you for spending the real money. I see you going ahead without a clear picture, and being terribly disappointed when it doesn't work like you had hoped. Put up a small windmill at least, and come back in a year with some recorded power data. To go all the way the first time is likely to cause you grief, and probably cost a lot of the crinkly stuff as well. Gordon. become more energy aware |
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| goldhunter_2 Regular Member Joined: 10/03/2010 Location: United StatesPosts: 57 |
GEatPE, I think you picked up on my sarcastic remarks when perry an I when talking about the small mills since that seems to be everyone's focus as they don't want to talk about the generator it self witch is what I have asked about in this entire post and when I pm'ed you. I was purposely giving general information so I would not have to discuss anything other then the generator unit it self I am already aware my unit my restive requirements and location are different then other peoples and was not asking any questions on those subjects. I did ask for information of uses of 10kw generators other then new mills but they apparently do not exist and wind mills are the only thing they have ever been made for, we where able to briefly start talking about complete mills greenbelt had before you claimed there unbelievable with out any explanation even when I asked witch seemed shallow to me but then again maybe ya'll are in competing commercial markets I don't know but have to assume that is the reason Perry(thanks) did answer my one question once we where both talking about the generator itself that if both generators turn the same RPMs then they will produce the same power |
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| goldhunter_2 Regular Member Joined: 10/03/2010 Location: United StatesPosts: 57 |
I keep trying to stay away form talking about the props/blades but......  ...... you also have to consider with larger HAWT props clearance issues father set backs and you have to be concerned with tip speed as the longer your prop is the slower it needs to spin for example a say 4' dia prop could spin faster then a 7' diameter prop
well I am still looking for one that meets code again the price of a job is all relevant to what you have access to or if you have to source everything out |
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Greenbelt Guru  Joined: 11/01/2009 Location: United StatesPosts: 566 |
I think you picked up on my sarcastic remarks when perry an I when talking about the small mills since that seems to be everyone's focus as they don't want to talk about the generator it self witch is what I have asked about in this entire post The many links I have posted should be adequate to find a means of acquiring a generator of your choice-size, Those Chinese Mill makers will have parts available to service the equipment they sell.There are statements all over the adds, TO E_MAIL or call for any info you desire. But for reasons unknown to me, You continue to bad mouth and reject any and all attempts to make life better for you. Time has proven that I am blind to the Obvious, some of the above may be True? |
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| GWatPE Senior Member Joined: 01/09/2006 Location: AustraliaPosts: 2127 |
Your original request is above, edited a bit. Windspeed of average 11.6mph. This is not enough to go on. For a large installation , and considering the utility requirement of not producing an excess power of 10kW. This alone will be difficult, as chances are that the wind will be blowing hard, when you won't be consuming any, so 2x10kW windmills will exceed that. You want 48 hour battery backup. Even for your house alone this is a separate major project. This will be 10's of thousands of $. You think that $1000 for a 4.5kW PMA is expensive. You have a very big ask, yet you are not prepared to do a little homework, to find out the real wind potential for your site. You think I am shallow for not explaining a comparison between windmills. The wind has energy proportional to the velocity and the cross section. This is not linear as we know with the velocity. For the same cross section and the same velocity, one windmill claims 6 times more generator power output. I think it would be pretty obvious that someone is telling porkies. I wouldn't think it would require any more explanation. I think that you need to reconsider making something youself of this 20kW scale. You should trial building a smaller windmill. You had to ask if all those electrical goods would be suitable for a windmill, so you should not jump in the deep end straight away with a 20kW project, even if you think it wasting time and money to do a trial. I don't think you need my help anymore. Gordon. PS edit: Greenbelt, there is much data published on the net. It is up to the reader to sift through, and determine the accuracy, with comparisons from other established data. become more energy aware |
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| goldhunter_2 Regular Member Joined: 10/03/2010 Location: United StatesPosts: 57 |
in no way where those sarcastic comments I made meant towards you or the mill links you posted (more in reference to things like Air X and similar mills that where insufficient to my needs) The only down fall I had was the wind rating so that was why I had asked for you to PM prices if you sold just the generators, I didn't push any farther since I figured you would get to it when you had a chance and where working some figures up is all. I do appreciate you posting those mills. I didn't bad mouth your unit I asked GWatPE to explain why he did. |
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| goldhunter_2 Regular Member Joined: 10/03/2010 Location: United StatesPosts: 57 |
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| Greenbelt Guru Joined: 11/01/2009 Location: United StatesPosts: 566 |
GWatPE; Exactly, In my opinion that 20 kw mill at 3500 usD is nearly a Gift from the Orient. If it output 1/2 that power in good wind it would still be a very reasonable price, 350 dollars per KW. This price does not include a tower but 20 Cu. yards of concrete with rebar(reinforcement steel rods) and a couple of "I" beam or Channels Section imbeded would make a secure base for mounting at ground level. I would not want 2 1/2-tons mounted 50 feet above my house in a Hurricane or an earthquake. The place for something like this is an open field isolated from the community. Edit; Gordon; Hope you don't mind the 2 posts in one. 
KarlJ Has a 0.7 - 1.0 KW mill Custom built and pretty nice at a cost of $1,500.00 Goldhunter2 If you're still listening? According to the spec's on the China mill its power is rated at 10 m/s wind speed. this is about 22.3 miles per hr. Your average wind speed 11.6 mph. is 5.2 m/s and though it looks like you have 1/2 the power , You don't. Where the reference formula came from. EDIT,> The numbers below are not a true analysis of the power output at the given wind speed, it would be less. I worked this out as a ratio of power to a ratio of wind and it does not apply when rotor speed causes a voltage and frequency drop in the light wind.< end edit. The wind pressure on the blades is 0.344 pound square foot of blade area. at 11.6 MPH. a hair over 1/3 pound. At the rated wind speed of 10 meters per second. (22.3 MPH.) The pressure on the blades is 1.27 pounds square foot. dividing 1.27 by 1/3, or 0.34 = 3.74 so minus the original .34 the force is 2.74 times more So dividing 20 kw output by 3.74 = 5.34 KW, this is the output at your wind speed average. You would need a 60 KW turbine to come near your 20 KW goal with your average wind. Most likely a 30 kw machine would serve you with a large battery bank to store night time energy. EDIT; There are a few people on this forum who have windmills, windmill related parts or total packages for sale. I am Not one of them and have no monetary interest in who buys what. all the most senior people here are what I call decent and honorable. another uncommon thing on this forum is They are Smart, as in well informed. This is all I have, May there be no storms in your future. Time has proven that I am blind to the Obvious, some of the above may be True? |
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Downwind Guru Joined: 09/09/2009 Location: AustraliaPosts: 2333 |
Mate!!!! I cannot remember the the last time someone got offered this much good advice in a single thread and you still whine about no one will answer you question. It is either we dont know or can see big problems with what you would like to do and have tried to offer advice to what we think to be a better option. Why we bother i dont know!! as you are hell bent on your own approach. The realistic answer is to get your power usage back to a realistic level a home wind generator can handle. You have your head in the clouds of what is realistic and what is not. Some that has given advice to you have been involved in wind energy for decades and know their stuff but you refuse to listen, as they dont give the answers you want to hear. They have been a little more polite then me, but the facts remain the same. As for your spare bits.......I have access to 6-7 delco alternator for both car and marine, also have 4-5 heavy duty starters, a 2 hp ac motor , a used washing machine and dryer , a old Coleman power-mate 4000 watt generator .......can I use any of these for my wind turbines? The answer is yes....But would anyone bother ...the answer is NO. None of the junk will make a good generator and would not be worth the effort of doing so. Then whats the point in telling you that, as you have expressed you think a delco alternator will make a good mill with a so called kit........It wont.. but it will work.....poorly!! This thread reminds me of a Texan that wanted to use push bike parts and aerplane props to build a wind mill that he belivied to be a good design and when many here tried to tell him it was not a good design he got the sh*ts on and left because he never got the answers he wanted to hear. I hope you are a little more smarter than he and at least listen to some of the advice given. I would like you to prove us all wrong and put up a monster Vawt with outstanding results, But there is to many people here with good knowledge for us all to be wrong. Pete. Sometimes it just works |
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| goldhunter_2 Regular Member Joined: 10/03/2010 Location: United StatesPosts: 57 |
greenbelt, ok I misunderstood I I thought you where a dealer for those mills downwind, I think you should re-read all my post as I never implied the delco alternator and or kits would make a "good" windmill "have tried to offer advice to what we think to be a better option." requested help is always usefully unfortunately what someone else thinks is a better option is strongly based on there location and situations by human nature. "The realistic answer is to get your power usage back to a realistic level a home wind generator can handle. " again with the power usages as I said before my usage is modest for me but far different for someone on the other side of the world but again was not the topic of this thread
"Some that has given advice to you have been involved in wind energy for decades and know their stuff but you refuse to listen, as they dont give the answers you want to hear. They have been a little more polite then me, but the facts remain the same. " I don't think I have ever disagreed that there are very knowledgeable people on here unfortunately that may be part of the problem as much more is read into a question and offering two much information clouding the issue and avoiding the original topic. if the discussion had went to building a AXFX or this is something that has a PMA in it or this company sells new PMA generators it would have given relevant info |
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| KarlJ Guru Joined: 19/05/2008 Location: AustraliaPosts: 1178 |
OK. I've read this thread -as fast as it has been advancing, i think its time to take a breath. I myself think a VAWT is a beautiful piece of kit and worth a look. Now -some fundamentals I have picked up from VAWT's. - they need support both ends thus it makes sense to mount a generator at each end as its simple to do so. 10KW VAWT is going to need a capture area of about 100m2, this is going to be an engineering challenge that is insurmountable on this forum I would think Luck favours the well prepared |
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