5Kw or 30KW?

[Frank S]

 HI all; a newbie to this site.
 I am looking to construct a plan of attack for my proposed semi-retirement home & hobby/ work shop, as yet to be determined where I will relocate so I'm not factoring that part just yet.
First off I have access to acquire a 43m tower made of 3 sections of pipe the top flange is 1.4 m in dia the pipe looks to be 1.2m with a thickness of 14 mm the base pipe is 2 m @ 20 mm thickness OK be that as it may I know I can mount an industrial wind turbine on something like this probably upwards of 30Kw with 25 to 30 meter diameter blades. BUT! After reading 100s of posts I have started wondering if this is the way I want to go. Knowing full well the processes involved in licensing & permitting a grid compatible generator, depending on country of choice or region for location.
  Since I already own a 100 Kw diesel generator and a 30 KW unit, I might be better off thinking of going another route like a couple of 3 to 5 KW turbines or smaller. The workshop will be approximately 700 m2 but more for hobbies than an actual manufacturing facility. The house I am planning will probably be made out of several hi cube shipping containers (I can buy them relatively cheap) and cut or modify to about anything I want.
 SO! Now here is a proposed turbine thought for a design. At first I was thinking about something on the order of a stator @ around 2 meters in diameter with upwards of 420 slots wired with multi layered coils connected in a (get ready for this) 21 phase @a 17.14 deg. Phase then use a long bank of rectifier diodes. Then series parallel to achieve the desired voltage of 48 to 480 DC bear in mind this was going to be a 30 Kw machine, as it would have had about 6 stator packs in line each about 80mm thick and the rotor would have been a 6 stage 1with magnets & 5 with coils.
 I've decided to scrap that Idea for now.  In favor of something more along the lines of the Honeywell ring stator turbine except with external blades up to 6 meters in dia. Possibly 5 or 7 blades I am wanting as near to zero cogging as possible with a 50 rpm cut in 120 rpm cut out.
 And I like the idea of the controlled feathering pitch.
  What do you guys think? Making a laminated stator out of 1 to 40 mm sheet I can do on my CNC plasma machine up to 4 meters in diameter but more realistically I am thinking about 1 meter with 144 slots

[fabricator]

Two things hit me on first glance, the wind zone you pick makes a huge difference, if you pick a bad wind zone, take every cent of that money and buy solar, if you pick a decent wind zone make it a mix of solar and a 10kW Bergy or the smallest Vestas.

[midwoud1]

A 3 Kw DIY windgenerator okay.
There is a lot info on the Forum and the Home Brew Books.
A 30 Kw DIY windgenerator never do that !!
A stator with 2 meter diameter   OMG.
There are windmills of 30 Kw on the market which will work for years.

[Frank S]

Fabricator; I looked up the 10 KW excel S. while searching for the Bergy looks like a viable unit the $ 19K would be in the budget.
 Here is a question that I think I have answered myself. is the primary reason for 90% of all wind turbines having 3 blades due to the turbulence caused by the rotation speeds? creating negative currents similar to prop wash in a helicopter. IF so then  why not go the route of the most powerful helicopter in the world the Russian M26 with 7 blades that spin at a lower RPM than any other chopper.
 This has me thinking the very low RPM large stater dissimilar & off set phase that I am researching may be what I am looking for.
  However like midwoud1 said smaller 3 to 5 kw for DIY especially for a prototype would be 2 things. First it would tell me if I in-fact could do it and second I can build it here in my home hobby-shop. then test it out on the roof top patio without ticking off my Arab neighbors much more than I do on a daily basis anyway.   

[ChrisOlson]

Here is a question that I think I have answered myself. is the primary reason for 90% of all wind turbines having 3 blades due to the turbulence caused by the rotation speeds?

It has more to do with efficiency.  You can achieve within about 2-3% of the efficiency of a three blade rotor with a two blade, but the two blade rotor has to run at higher tip speed ratio to do it.  When you go from three blades to four, you can increase the solidity of the rotor disc at lower tip speed ratio, but you also increase the drag by 33% so the efficiency drops accordingly due to drag coefficient.  Adding more blades yet only keeps increasing drag with no efficiency increases in the airfoil's ability to generate power.

A turbine rotor cannot be compared to a helicopter rotor.  With the helicopter they just throw more shaft power at the drag coefficient problem.
--
Chris

[Frank S]

Thanks Chris; as usual I have a tendency to look at things upside down, and allot of times wind up comparing lemons with watermelons  or plates with Frisbee. An ancient Dutch windmill with 4 huge blades would begin to capture wind and grind grain at lower RPMs than a 3 bladed one. Here is where I go off on another tangent. instead of simple curved blades set at a 7 degree outward angle has anyone contemplated or toyed with semi parabolic swept back semi helical and again I'm  maybe confusing the coefficient of wind Resistance to the 800% higher density of water. I am much more inclined to prefer a lower output efficiency with having an extremely low cut in RPM then incorporate inductive resistance VIA  synchronous wound secondary rotor stater. Again philosophy seldom correlates to  design theory or fabrication application.   

[gizmo]

Bulding a machine over 5kw, or even 3kw, is not a task for the beginner. In fact I can bet most of the members here who have build dozens of turbines, including the bigger 15 to 20 foot axials, would not even consider for a moment building something with a 20m ( 66 foot ) diameter. The common axial flux design discussed here just wont scale up that big, even anywhere near it. Once you get over 5kw the engineering changes and its a totaly different ballgame. The forces acting on the turbine change from a few hundred pounds to several tons!

I would suggest you start with a realistic sized machine, like a 6 foot turbine. Then you can use your gained experience to build a bigger machine like the 17 foot turbine you see mentioned here and on the otherpower web site. Once you've built those, you will appreciate why its just not possible to go much bigger.

Glenn

[ChrisOlson]

Glenn is right.  There's the story about the guy who went to a big conference in Texas.  While at the conference he went to the bar in the convention center and got drunk and had to use the bathroom.  She asked where it was.  This lady told him to go down the hall and take a left.  The poor chap staggered down the hall and took a right, which led to the indoor swimming pool.  He walked right into the pool and as he was flopping around in the water all he could think of was Everything is Big in Texas.  So he yelled out, "DON"T FLUSH IT!  I AIN'T DONE YET!"

But even a Texan building a wind turbine needs to acquire two books and read them cover to cover - twice.

http://store.otherpower.com/books/a-wind-turbine-recipe-book-by-hugh-piggott-usa-edition.html

http://store.otherpower.com/books/homebrew-wind-power.html
--
Chris

[fabricator]

If the Bergy 10k is in the budget do yourself a favor and buy it, it is pretty much one of, if not the best commercially built machines on the planet, with years of low maintenance and reliable power,  but DO NOT think this unit could be mounted on any roof.

[neilho]

is the primary reason for 90% of all wind turbines having 3 blades due to the turbulence caused by the rotation speeds?

It has to do with yaw behavior. A two bladed horizontal axis rotor has minimum resistance to yawing when the blades are vertical, and maximum resistance to yawing when the blades are horizontal. When the machine yaws and the rotor is turning, the changes in yaw resistance result in a very fast jerkiness, or vibration whose frequency is twice per rev.. A 3 blade rotor doesn't have that problem.

I would agree that if you just want to use a wind turbine, buy one. If you want to build a wind turbine, be prepared for lots of work, stretched over lots of years.  To quote Mike Bergey, who might be the best developer of small wind turbines on the planet, "It's harder than it looks, and the devil is in the details."

Neil

[Frank S]

 Yea, that is pretty much my conclusion as well LOL. while looking up the Bergy I found the Excel S, A grid compatible & connected 10K looks to be around $17 to 20K if it could produce 30% of the kilowatts used in a year  according to the cost per KWH   in Bulgaria @ BGN.081, the break even point would be on the order of 10 years. A higher percentage  would be a shorter payout. That's a doable return if I were to pay cash for it which may be in the budget or may not after the purchase of land and the shipping costs of the move. I can always RE a single room to work completely off of a solar/wind / battery system.
 And yes  I will be purchasing the 2 books you guys mentioned I might as well, I am a sponge for new information. even though the type of turbines you guys seem to be building and using do not resemble anything I am accustomed to, I was thinking more along the lines of a scaled down version of the 10 foot Dia 1200 HP 4300V  150 RPM hammer mill motor I rewound many years ago. it started up on 600v DC then was switched over and brought up to voltage and power gradually I think it may have been built in 1945  and since I by nature live so far outside of the box they will be stretching my carcass over the outside of my coffin. I've rewound a 4.2 KW 400 HZ Onan generator to be a 300 amp welding machine and took a 36 slot Chrysler 100 amp alt once and converted it to a 9 ph 78v alt then a 1 hp 3 ph motor and cut into the coils to get 18 leads the thing ran but like a lot of things it needed something else done to it I lost interest before figuring out what I needed to do.

[wpowokal]

1200 HP 4300V  150 RPM hammer mill motor huff huff trust me I am comming

[bob golding]

as already pointed out. don't  put your hand in your pocket just yet. no point at all trying to calculate returns without doing a  site survey over at least 2 years.
 once you find your site find the wind data from  all the local weather stations in the area over at least 5 years. if the average is below 5m/s it will be marginal on wind alone so have a  mix of solar and wind. if there is a river on the property go for hydro and solar.

nothing like starting small and  getting to know your turbine and how it  performs under different conditions. even a 10 foot turbine in a force 10 gale will surprise you. especially if it doesn't furl as planned.

[Frank S]

Bob I grew up on a farm with a windmill for our well. the tower was only 30 ft and the fan a 10 ft with18 blades  that thing would pump water up to the redwood storage tank even in days when you would swear there was no breeze at all. one year we had a small tornado pass close by I say close it up rooted trees less than 50 feet from the windmill. Never saw what happened to the fan probably landed in the next county. I fabricated another fan mostly from memory after having had to climb the tower to grease the box so many times from age 6 up till the twister when I was 15 it worked almost as well as the 50 year old factory one had.
   Right now I have a folder with wind sunny days cloudy days temperatures  barometric & humidity measures on 20 prospective areas where I am looking in 3 countries that cover the past 5 years. OF course none of that data would be at the exact location mostly just within 20 to 50 KM, nor does it take into account of topography also the studies are limited to 1/4 day periods.IE 00-06/ 06-12 +++ hours. Only Spain has provided me with an average UV count. I have to work out with my company as to whether or not I will be doing a cash out of vested interest @ my 10 year point or allow them to pay out over 5 years and remain a reduced payroll to allow them to use my name as their senior design engineer while consulting VIA  video conferencing. Personally I prefer a cash out even if it is 30% less money 

[SnowGhost]

I suggest buying a 5kw exmork turbine.  Yes, The chinese made stuff can be very variable in quality, but the over all (ie, everything china produces, not just wind turbines) is increasing.  The price is very tough to beat, and that tower will cope with anything you can afford to put on it.

[Frank S]

 Snow ghost; I know well well about the china stuff our factory here is full of manual & CNC equipment some has been in extreme heavy use for 9 years still holds tolerances some less than a year old needs to be cut up and recycled back to them. the key to buying from China is to visit the actual factories where the goods are made, when doing that you can entice them to make top quality products for you. The company I am with is an international trading group it sells everything you can imagine in the industrial and automotive field. Perhaps the next trad expo I attend I will gather info on Solar and wind energy production. Who knows I might even get a 10KW wind unit for free or at MFG cost, if they thought we would be marketing them. Wind gens would never sell here as diesel is too cheap as an alternate source. But since I will be moving from the M.E. to the E.U. If I wind up still a part of the company I could make it a joint venture

[fabricator]

Exmork, hundreds of posts on various forums on hundreds of problems, and little or no technical support from Exmork. Bergy, you will be hard pressed to find any posts on any forums about problems and they have pretty much the gold standard in tech support.
Shipping from Oklahoma to the EU would probably be slightly cheaper than shipping from China.

[Bruce S]

Frank S;
Forgive me if I go on a tangent here.
Have you been there since back in the late 80s? say 88 on?
While working at the King Faisal hosp in Riyadh  , I did "spending" money work for the group that sponsored my stay, even flying over to Jeddah to fix everything from old stress test equipment up to teaching them how to operate a concrete dust tester<-? .
I met with a great number of group buying people from just about everywhere!!
Just wondering if you were in any of those groups.
Cheers;
Bruce S

[bob g]

not sure if i missed it or not, but how much power do you really need?

seems like a better start might be an in depth analysis of expected loads, how best to service them, and then determine the size of machine needed?

might well be a substantially smaller machine would serve you very well?

perhaps a small number of smaller machines could do the job? and provide some level of redundancy?

i can't imagine building a 2 meter in diameter rotor, let alone hauling it up a tower, and keep it in service over the long haul... this is to say nothing of the very real concerns i would have with the design and manufacture of a suitable blade set to drive such a monster.

not a first time project in my opinion.

but what do i know, i would be concerned with a 17 footer for a first time build.

fwiw
bob g

[Frank S]

  Bruce the first time I came to the M.E. was in 89 to install some car-stacker Parking machines for some Saudi prince the next time was in 91 when the Sky over Kuwait was so black you needed headlights in the daytime the next time was in  Sept 2002 before the build up for the 2nd gulf war.  Then packed my suit case, a 45ft container with machines and materials and have been here since 3/03
 Bob here is a way to imagine a 2 meter rotor; a 12 inch flat disc magnet rotor/ stator as an exciter circuit  feeding a slip ring pack & the stator  the stator with 160 slots holding 480 coil packs lap wound  coils stagger lap over 4 slots each. The rotor would have 120 slots with 240 coils the rig wired delta/wye/ delta, delta/ wye/ delta. Or some such configuration. The stator wire probably 1.2 mm, 2.3mm & 3.5 mm. The rotor 2mm x20 mm flat strip. The 12 inch rotor to be planetary driven @ 1to 20 ratio main rotor turns 17 to 30 RPM. The secondary coils in the large stator provide eddy current resistance braking.  Primary output to be around 415V @ 50 Hz 3 ph.
  An alternative to this  3 Breezy style 20 HP gear motors on a 3 gear planetary around a single sun gear  either case the turbine whether 3 bladed 20 to 25 meter diameter or12 meter  high torque 36 blade fan style turning @ 17 to 30 RPM.
 All of this is merely pencil on paper & cad drawings at this stage the actual math is still under water.
 OH! and to give a heads up my 1 and only other wind generator that I've built was a 100 AMP Delco 1 wire alt run on a series of sprockets & chains powered by a 8 ft. diameter 15 blade windmill fan from a water well in about 1985 . It would have made a better welding machine than a battery charger if it had been 28v a 25 MPH wind would explode the batteries so I abandoned the idea.
  I great at wasting a lot of time dreaming up stuff but in the end I Often opt to just purchase and let someone else worry about the rest.
 So far I have a folder with 500 files of what other people have done both from the stand point of a backyard tinkerer to Commercial & industrial usage.   

[Frank S]

while drawing up an assembly of the possible stator design that I am thinking of. I started to notice a pattern of coil stacking interference. This got me to thinking ( causing wood to burn uncontrollably) about what an old motor winder had told me a 1000 years ago, well sometimes things seam like a 1000 years LOL. Anyway I remember something about his telling me that to avoid having an off coil at the end of a winding he staggered the open slot count  for each coil pack. It seems like maybe it was 3,5,7 or 3,6,8 or 3,4,5  looks like it is time for me to dig out my old lightening electrical reference  or the Ugly's guide, or the motor wiring for idiots.
  IF I were to prototype an exact scale model of the monstrosity (RUUB-GOLDBERG) contraption I would need to buy a laser torch setup for my CNC cutting machine the plasma torch would not be capable of cutting precise enough segments for laminating to become the stator and rotor. But to do that  I would have to justify the expense by convincing my partners that an increased production of our thin sheet metal cutting division of the business would have a reasonable pay out. Highly unlikely since our 1mm & thinner is less than 5% or our cutting. most is in the 10 to 40 mm range so the plasma works perfect for this.   

[fabricator]

Hey! At least spell my heroes name right! Rube Goldberg.

[Frank S]

OK, since this thread is about 5 or 30KW so far I had been concentrating my attention on the prospects & design of the larger unit which is ultimately unrealistic I know this, here are a few of the reasons I came up with a design of 160 slots in a laminated stator that would be 150mm thick with an internal diameter of 1.8 meters it would have had 480 coils of 2mm diameter wire 300 turns each wired up as 80 poles 3Ph this should have meant that @ 75 RPM it would produce 50 HZ the amount of voltage & current would be dependent on the number/size & excitation voltage of coils in the rotor this probably could be achieved with a pancake magnet stator rotor assembly but at such low RPM that would have to be geared up to run 3 or 4 times the turbine speed easy enough to accomplish be scavenging a planet gear set out of any old Chrysler automatic transmission
 END OF monster thoughts until actual move has happened.

 Now on to the more realistic 5KW
  Looking at 100s of you guy's machines I have seen some intriguing designs as well as configurations. 
  the realistic questions are about to start. I have already answered 100s of them by reading most posts of dozens of threads and I have a folder of 500 PDF files dn/loaded from several sites
   First off; I am seeing rotors made out of disc brake rotors and mild steel even 1 out of aluminum and 1 of wood. almost all have the magnets glued to the surface instead of embedded  Does anyone have any real stats about the variations of flux density of surface versus embedded?
   what about a single stator between 2 rotors versus single rotor magnets on both sides between 2 stators
  Has anyone ever done a stack pack of 2-3 or more rotor/stator assemblies on a single shaft
 Do any of you know of anyone having ever done a 2-3or 4 pack assembly as planets geared to a sun gear or sprocket-ed , say like use a 90 tooth center sprocket with 3 packs with 30 tooth mounted @120 degrees to one another This wouldn't have to be chain it could be timing belt.
  I was just thinking about the realm of this aspect connecting 3 smaller say 12 to 14 inch units in parallel
 Possibly even mount  a 4th wired up differently to serve as over-speed and dump control.
 Time to do more searching because every question I think of means I need to read 100 more pages

[ChrisOlson]

  Has anyone ever done a stack pack of 2-3 or more rotor/stator assemblies on a single shaft
 Do any of you know of anyone having ever done a 2-3or 4 pack assembly as planets geared to a sun gear or sprocket-ed , say like use a 90 tooth center sprocket with 3 packs with 30 tooth mounted @120 degrees to one another This wouldn't have to be chain it could be timing belt.

Ferrite magnet generator on one of my 3.8 meter turbines:



All the turbines I've built over the past 2-3 years have an oil bath chaincase style transmission.  This is a 3.2 meter machine that develops 2. 5 kW @ 28 mph.  It runs at 40-150 volts.  The transmission is a .400 ratio and the generator runs at 1,200 rpm at rated power.



--
Chris

[Frank S]

Thanks Chris

[midwoud1]

Hi Frank.

The best thing to do , Make your own windgenerator according to the Home Brew Books.
Or with ferrite rotor discs and transmission and MPPT tracking. ( Forum )
Experienced mechanical engineers like Chris , Fabricator ,Sparweb ,Birdhouse ect. have good results with it.
Methanolcat is making a big size with a gearbox.
The Diy generator design is a lot different compared to electric motors .
Iron core-stators have a cogging problem in our generators.
An extra power generator : A 10 Kw Bergey as Fabricator mentioned.
In my opinion a battery-bank is better than grid-tie ( a never get back system )
Where do you want to settle in Eu. in the future ?

Rgds. - Frans -

[Frank S]

Franz; right now it is a toss up between Romania, Bulgaria & Spain OF one of the first then probably along 1 of the rivers or near to one. Like the Danube I have spotted a 200 hector plot on the Romanian side where  I could set up a fish farm and  build my factory I design and build freight elevators in the 3 to 100 ton range, also build attachments for lathes , mills & roll forming machines. Back in the 70s/80s  I used to build oilfield drilling rigs and oil field equipment then moved on to rebuilding Heavy haul transport trailers and Caterpillar equipment. I started building elevators in the 90s I have built more than 100 here in Kuwait along with a lot of steel structures for half a dozen countries here in the M.E. Right now in 1 of my bed rooms I have a hobby shop where I am rebuilding an older Harrison CNC/ Manual lathe and a Clarkston tool & cutter grinder . At work I have 3 mechanical engineer students who I am attempting to teach them how to think for themselves instead of relying on my experiences all of the time they've all got a Baylor's or above and not 1 of them posses an IQ of 90 I don't think. We have a total of 20 engineers in our company.

  Hence is the reason I like this board, I finally found a group who know more about a few things than I do. Even if a lot of it is on a much smaller scale than would suit my purpose, there is a wealth of information gathered from several years of trial & error

[midwoud1]

Hi Frank.
I see a lot of good ideas . Make your house of shipping containers. Hurricane and earthquake  proof. A container is a good module to make your own idea house.
 Another collegue on the forum , is working on it too.
In the 70's and 80's I was working on oilrigs ,mainly in the Northsea ( Penrod drilling ..Hunt brothers ) They had many rigs that time ,very big busines. Than they bought a silvermine and the world silver-stock . In a couple of years the market collapsed . Penrod bankrupt.
For us no problem , we worked for the other companies too.
We did well-test and installing and improving the flare system.
There also was Mac Dermott with a derrick-barge DB 102   with 2 cranes 7000 tons each to lift complete production platforms.

Now I  make  windgenerators with variable blades ... controlled by a microcontroller .
It's working succesful , never overspeed ,no overload on the mast.
Save parking during storm.
Making your own electricity that feels very good. Making coffee with windpower etc.

A new design will be soon on Youtube.

Rgds  - Frans -

[Frank S]

Well I guess that unless either of these books are on some bookstore shelf somewhere in Europe I will not be getting either of then very soon .
http://store.otherpower.com/books/a-wind-turbine-recipe-book-by-hugh-piggott-usa-edition.html

http://store.otherpower.com/books/homebrew-wind-power.html

 There are 2 things in this world that I do not do #1 buy anything off of Ebay that I cannot physically touch before buying
#2 buy anything that must be mailed except select items by contract courier IE DHL I haven't used the US postal service since 1988 and the postal service over here is even less reliable not to mention the company only checks their mail once in a blue moon. So I guess I wait until I visit Europe  this summer then see about having one sent to a hotel where ever  I decide to stay for a month

[fabricator]

No matter how long an expat lives in a new country he will always be a the foreign guy.

[Frank S]

No matter how long an expat lives in a new country he will always be a the foreign guy.

Fab;  I have enough Cherokee, Comanche, Swiss, German, & Irish in my blood to make me the foreign guy anywhere on this planet. I accept Texas as my home country because I was born there, that makes me a foreign guy anywhere else in the US

[fabricator]

Texas sure as hell aint as foreign as Romania, life is pretty cheap in some of those countries especially the life of a non native.

[Frank S]

Texas sure as hell aint as foreign as Romania, life is pretty cheap in some of those countries especially the life of a non native.

I'll just have to remember to speak mostly German  since Romanians speak a form of Italian Spanish mix or English I'l be able to understand a lot of what they say but hopefully they won't be able to understand me.

Here is one of my renditions of a wind generator just a little larger than norm for here



 I have no Idea yet as how much I should be able to expect out of it each coil slot is 10mm x17mm x8mm about the same size as would be found on a 50 HP motor but more of them
 what yo see here is about 700 lbs without copper or blades
 it won't be easy to build a scaled down model so I will just finish my research in the design or that or 3 others I am drawing and try to machine the major stuff before we hopefully move next year
 since I lost my box years ago I am even drawing one with coaxial counter rotating turbines the stator would be rotated opposite of the rotor  like I said no box and out of meds