What Calculations must be considered when building a Windmill

[student]

I need to know all the calculations that must be considered before building a WInd gen. Any websites that will be helpful are most appreciated. Thanks. Remember, I am a student with no experience in this at all so as simple as possible will be great. I have a deadline to meet. Thanks again. Please add all the formulas also.

[windstuffnow]

 http://www.otherpower.com

http://www.windstuffnow.com

;o)

[devoncloud]

Wow, you got a lot of work to do then, How soon is your deadline?  Ok, first some matterials you will need (to get started)...  Also please keep in mind that these are just suggestions, you can use other devises for everything I am putting in here, it is just that these are pretty cheap and easy to find.

1. Neo magnets.  See wondermagnet.com.
   
2. a car hub (see pull it yourself junkyard for best deal)
   
3. The rotor to the same hub, possibly two rotors depending on if you are going to make your design a dual rotor hub or a single rotor with laminations.(see pull it yourself junkyard for best deal).  If you have access to a machine shop(you will probably need access to one of these anyway) you can have some rotors cut out of 1/4 inch steel plates.  
   
4. Magnet wire (you will have to know the size you need, so for that you will need to know how to do the calculations, and I do not have the time to show you all the formulas, sorry.  Search the site, they are all over the place but you can find them.(See electrical supply or magnet wire company)
   
5.  angle iron or some other metal to make your frame out of (see metal shop or construction site for scraps)
   
6. Plywood to make your moulds in (see your hardware store)
   
8. Resin(see your hardware store)
   
9. Wood to make your blades (see hardware store)
   
10.  saws, chisels, sanding devises to make your blades (also see your hardware store)
    
11.  Wire.. Thick wire (well insulated as well) is needed to run your electricity from your wind generator to your batteries.  (See electrical supply)
    
12. Bridge rectifiers (see electical supply)
    
13. Knowledge (see self)
    
14. Hard work  (see self)
    
15. Time  (see self)
    
16. Brains  (see self hopefully)
    
17. Tools  (see friends or self)
    
18. TOWER (pre-made, several thousand bucks, make it yourself a couple hundred)(see hardware store or search the net)
    
19. ability to take the fact that you may fail (see self)
    
20. MONEY..... as you can see, after purchasing all this, (which is not all you need, you still need a tail for instance)you are looking at spending four or five hundred bux just on your generator, not including Tower, unless you are lucky and can get allot of this crap for free.
    
    

Are you sure you want to take this on if you have a deadline?  You might want to think this out some more buddy.

Devon

[MickS]

Well said

Mick

[finnsawyer]

STU-DENT: n.  A person who is engaged in studying something.  Hmm?  Are you looking for a free ride?  Everything you need you can find by studying the posts on this board.  However, wishing to help direct your energies, I suggest you get a book on Aerodynamics such as "The Illustrated Guide To Aerodynamics" by H. C. "Skip" Smith.  Its a good read, doesn't involve calculus, and will give you a good grounding on the behavior of air foils.  You can find equations there for lift and drag.  Good luck!    

[student]

I am not looking to get a free ride. Thank you for the book sugesstiion. I have other classes and have this project as one of them. I figured I could get some quick advice since I have 5 other classes to study for and that is why I posted the question that way. Your advice has been taking well and will look for the book. Thank you.

[student]

Thank you windstuffnow. I will check the second site.

[student]

devoncloud,

  Thanks alot for all the advice. i am very sure I want to take this on. Its my engineering design project. Its funny though I have a budget of $200 and have to stay within those limits. I have to ac induction motors that I got for free and a friend said he was going to give me a PM alternator for free which will be great. Also I have got some scrap metal from school that we will be using as the base. I have 5 other classes I am taking and that is why I was asking for all the advice I could get because some of the sites are not consistent with their formulas. Anyways THANK YOU VERY MUCH for all the help. I will start going through your list and check it against mine.

[Flux]

Try also Windpower Workshop by Hugh Piggott and Wind Power for home and business by Paul Gipe, between them they cover most things.

Flux

[devoncloud]

hugh's matterial is very good.  As a matter of fact, you may want to purchase his latest plans for building a wind generator, as his plans are very detailed and will take alot of the guess work out of your project.  

Here is his Hugh's website which will get you started on building your own PM alt:

http://homepages.enterprise.net/hugh0piggott/

I do not know how much power you will need for your grade, but induction motors as a rule are "SO SO" for power output.  Making a PM alternator from scrathch usually works much better, but given you have time constraints, I guess the best route for you is the quickest one.  I have no experience with the induction motors, but there are plenty of people on this forum that do and their are postings concerning how to use these all over the place on this site.  

Also, I hope you are good at working with power tools, and know your way around a machine shop or at least know someone who does and is willing to put as much time into this project as you are.

Devon

[student]

Flux,

     I just wanted to say Thank you.

[student]

Devon,

    I do agree. From what I read a homebrew PM alternator is the best. Unfortunately I have not done any machining before and do not want to try and will mess it up because I do not have that much money for it. I had a post on the very first day I stumbled on the site to actually buy an old PM alternator so maybe I could reverse engineer it and build mine. So far the response has not been that bad. Thanks for the link.

About how much power, I am suppose to charge a 12 volt car battery to power a greenhouse. I really want to get this project off the ground but I feel like I do not know enough to start. Anyway thanks for your advice. I am very grateful.

[devoncloud]

Using the induction motor will probably require some machining as well student.  In order to get it to charge a battery sufficiantly, you will probably be needing a lathe to shave the shaft down in order to fit some neo magnets on there.  This will require some machining skills.

Devon

[devoncloud]

Oh, and I guess this should be mentioned as well student.... depending on where you are located, you may not have enough wind for your project.... unless you go 100 feet or more in the air.  I would hate to see you go through all this time and trouble to find you cannot charge your battery because your wind generator does not spin.   I forget the website, but there is a site that gives you the average wind measurements in your area.  You will want to find this site and see if you have enough wind there.  I doubt you will have the money, time, experience, and OK from your school to set up a 150 foot tower, even if it is just a pole with guide wires.  You have to understand the physics involved with such a tower.  the wind will be forcing your wind generator to the side putting and extreme amount of force on your tower.  We are talking several hundreds of pounds of pressure (if not thousands).  The higher the tower, the more stress that your tower will be under.  This could be dangerous stuff if you do not do it right.  

You may want to look into solar as a substitute or possibly a combination of the two.  If you have a stream (especially one that is comming off of a hill) you may want to think about a hydro generator..... they produce 24/7, and if you build pressure by bringing water from a higher elevation down to a lower one with pipes (that also decrease in size a bit as you get lower), you can produce a really good amount of power. You can get them spinning very well and even gear them up to get induction motors to spin even faster, which is a good thing.

You could make a project out of the solar panels as well.  You can buy several single cells and make your own solar panel (saves money and shows you have some skills for your teacher to see that he can still grade you on instead of the wind generator).

And, after you are all through with this, do not forget you will need a charge controller and possibly a charge dump.  When your battery is full, you need something there to stop the batteries from overcharging so you still have a greenhouse left so your teacher can give you students lighting projects to do .

Devon

[Gary D]

  In addition to Deavons thoughts, even if your teacher gave the ok to do this project, the school board may shoot it down due to legal liability issues. Make darned sure your hard work isn't going to be "trashed" becouse of a teacher oversight. Spinning blades can be lethal, and blades that come off a rotor at 1000 plus rpm can do property damage as well. If an inverter is used to jump voltage up to household voltage, an inspection may be required for safety reasons (especially if water is used nearby).

   Much to research, but I hope you're project can fly! It could help teach many students and parents about renewable energy options.  Gary D.

[nothing to lose]

Ya, what everyone else has said, but I did not notice what kind of school you are a student of. If High School oh boy..  If collage they do lots of stuff!!

Anyway, look over otherpower.com they have some good gennies and lots of pics of the parts and such.

 You might want to take a short cut and build whats reffered to as a garbo gen. Take a garbage disposel type motor, machine down the armature, epoxy on some magnets, mount some blades (4' dia I think) and mount to post. Connect to a Diode to convert the AC to DC and connect the DC to a deepcycle battery and hope for wind!

 More to it than that, but sort of the basics. I think jerry would have much more info on this. Probably the fastest and cheapest way to get something flying that will produce useable power.

 You also need to prevent over charging the battery when it is full. Something about a Shunt relay I think on otherpower.com where one of the guys switches power over to a heating element. You don't want to just disconnect the power from the gennie because then it will free spin, you want to keep a load on it and the reason for the relay and heater.

Not sure what Jerries actual username is. Maybe a search for garbogen will get results.

[finnsawyer]

It looks like he's on the college level.  If so, the $200 budget is chicken feed.  He obviously can't do much with it.  He may have to settle for a part of the project.

[Gary D]

  First, my apologies to Devon... sorry for the misspelling of your name. Second, being unsure of the grade level, I thought some thoughts were in order. If in High School, oh boy really is in order, thus my comments.

  If in tech school, or College, 200 bucks isn't extremely out of the question if: the school uses co-op power- many times a co-op will donate a pole, erect it on site, and possibly even have spare entrance cable laying around. They could also ensure the electrical safety of the system. Co-op's occasionally do projects based on need in the community for free. Wall mart or a battery wharehouse could supply the batteries for free if approached properly. Just a few thoughts... results vary...  Gary D.