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Really Need Advice Making Micro Wind Farm

Discussion in 'General Electronics Discussion' started by Robmcg, Nov 20, 2016.

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  1. Robmcg

    Robmcg

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    Nov 20, 2016
    A Little About Me - I am a computer repair tech, so I have some very basic understanding of electricity (mostly measuring laptop chargers and dc jacks). I know more about coding than electricity but I own a multi-meter, so there's that. I also am comfortable enough with electricity to wire lights, thermostats and other random simple electronics.

    What I Want To-do - Set Up a small micro wind farm on my balcony of my apartment. I already have idea's of how to make the turbines and wire them together and all that.

    My Location - I am about 50-60 feet above the ground and just above the treetops on the upper side of a hill with lake Erie about 10 miles away. It is always windy on my balcony 10-40mph, I spend a good amount of time out there as I can't smoke in my apartment with my toddler, there is always strong winds except on the very rare days where it is a very subtle breeze.

    My Goals Of This Project - To hopefully generate 1kw consistently (I know wind is not always consistent, I guess I mean average?) over a course of a month and use a grid tie in converter to supplement my energy bills.

    My First Steps - Getting the generator's built and hopefully logging the load data to see how much power I am actually producing and see the high and lows before even hooking it up to my grid.

    My Budget - Low budget project, 100-200 on generators, 100 on random parts for the mills handmade, 200 for grid tie.

    My Questions - I have many so I will put them into a list

    • How much electricity do I need to generate to cover my monthly bill? Here is a picture of my monthly energy usage from my electric company.[​IMG]
    • Will the grid tie in protect from overload to the wall? If not what do I need?
    • Do I need to worry about overloading my grid tie in converter? If so, what I can I do about regulating my volt/amp to it?
    • Would this grid tie in converter work? Ebay Item Link
    • If I want to use 10x 12v DC motors on my wind farm does that mean at max load they would be producing 120v?
    • I was thinking of getting a USB DC Logger to help estimate my loads and such but it doesn't measure the amps, would this even be helpful to me?
    • I really need to better understand what generators I could use for this project that would hit energy production with a 1-2 foot blade per generator.
    • For example would something like this be possible? Ebay Link
    I really need help - I have so many questions but googling my questions more then often just leads to general articles with no real helpful information. I really appreciate any help that anyone can offer.
     
    Last edited: Nov 20, 2016
  2. Bluejets

    Bluejets

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    Oct 5, 2014
    First up, wind generation is iffy at best. If you were to strap one of those 747 size mills to your balcony, then perhaps. 25kwh per day is some serious power generation. Grid connection usually requires quite an amount of supply authority permission and even then, they may or may not allow it. Certainly not with a home- grown system.
     
  3. Robmcg

    Robmcg

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    Nov 20, 2016
    Thanks for replying. 25KW per day is my daily usage, so if I could even generate 500w an hour, I would be able to cut my bill in 1/2.

    I get wind power is not consistent but even if the average throughout the entire day was 8kw that is still substantial to me.

    I am curious how these windmills are rated cause a 25KW wind mill claims to be enough to power a small town http://www.polarisamerica.com/turbines/25kw-wind-turbines/. Is that 25KW a month/week/day/year/hour?

    I feel like what I am trying to generate is not impossible. As for getting approval to do so, I really didn't plan on getting approval, from what I was seeing online, it will just slow the consumption of power on your electric meter, if you are not running an excess of power, which i really can't afford or have room to do.
     
  4. Robmcg

    Robmcg

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    Nov 20, 2016
    If I could find a motor that will produce 50-100w and figuring out how many volts I need to generate to get 500w would make this a lot easier.
     
  5. Robmcg

    Robmcg

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    Nov 20, 2016
  6. Bluejets

    Bluejets

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    Oct 5, 2014
    25kw is the volts * amps. But only at max revs. If you run that for 1 hour you supposedly get 25 *1= 25kwh. However, this is dc which must then be converted to ac and probably at around 75-80% efficiency at best. Note that it has a 12 metre diameter blade and runs at 75rpm. Again quite a mother to hang off your patio. Halving the blade is not half the output. Look at volume as a hint. Could not see any specs of any use in the last link you provided.
     
  7. Robmcg

    Robmcg

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    Nov 20, 2016
    Yeah that is too big again for what I am suggesting. I am proposing taking 5-10 50-100w generators and making a mini windmill for each one. What I really need is to find a electric generator that is capable of making that first, then building & testing it.

    I am thinking of it this way beacuse I am assuming the higher the output the more resistance the generator will have and as I want to make mini blades for it 1ft each ideally giving it a 3ft~ circumference, I definitely need a low resistance generator.

    My biggest hurdle right now is even finding a motor that will output 100w, mostly beacuse I don't know nearly enough about the conversions or formulas or engineering about them to figure that out. Could you suggest one on ebay/online for me?
     
  8. Robmcg

    Robmcg

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    Nov 20, 2016
    Also just FYI, I know wind is iffy, I get it but solar is not even an option where I live. north east Ohio has more cloud cover annually then most of the US. It is cloudy here almost every day. It is one of the reason's the military built so many bases here in WWII as clouds provided basic cover from bomb raids, if they did ever happen.
     
  9. davenn

    davenn Moderator

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    Sep 5, 2009
    a car alternator will easily produce 100W ... easily produce more than that
     
  10. Bluejets

    Bluejets

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    Oct 5, 2014
    True...however most car alternators run at about 55% efficiency and need revs to work.
    Fine to say they produce a fair amount at just over idle, but one must remember they are driven at a much higher speed than the engine.
    I'd say about 3000rpm should get one somewhere near 3/4 output.
    A 3 ft diameter blade will not get you there let alone one at 3 ft circumference.
    However, we are not talking small power requirements here. The op is looking at getting (initially 25Kwh) now 12Kwh per day.
     
  11. Robmcg

    Robmcg

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    Nov 20, 2016
    I am open to idea's guys. I am here for help, I came here after one of my random internet searches brought me to this site for other windmill results.

    I really don't know anything about what is possible but I feel like if I could find the generator I need I could build a system that would work. Or at least experiment with. Alternator's run around 100-150 around here, so that really isn't the type of money I would want to commit to 1 part of the experiment.

    How many watt's would an alternator produce at max load? If anyone know's, just for reference, I am sure I won't get it there.

    I've only replaced my alternator a couple times in my car. Isn't the physical resistance on turning those pretty tight? If it turns very easily, I may be able to make something out of one (maybe some gear ratio's could achieve hitting that rpm. I just know beacuse of my blade limitations they are not going to have enough force to spin an object without at least a push start, which would obviously render the entire idea pretty worthless.
     
  12. Robmcg

    Robmcg

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    Nov 20, 2016
    Your 55% efficiency remark stuck a nerve with me, I familiar with energy efficiency from computer power supplies. What types of electrical generators are the most energy efficient (fyi please don't mention some prototype that is well beyond my means)? That may be a start to the right path :)
     
  13. davenn

    davenn Moderator

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    yeah well that is unlikely to happen on his"micro" system huh
    it time to be realistic and start experimenting with other possibilities
     
  14. Bluejets

    Bluejets

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    Oct 5, 2014
    Brushless are more efficient but I still don't think it will be anywhere near enough for your needs and outlay.

    I really believe if you want to go down the wind power road then cost would not be the issue only outcome in the fact that one might believe they are saving the planet. Trouble is there are many calculations to consider if you think "dust to dust".

    Still, nothing wrong with grabbing an old alternator or 2 from a wrecking yard and give it a go.
    Also saw somwhere on the net where a bloke made blades from plastic downpipe ( stormwater pipe)
     
  15. Robmcg

    Robmcg

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    Nov 20, 2016
    I'm not looking into this to save the planet. Yeah that needs to happen and I am all for it but I bought a Prius knowing full well that the damage they do the environment by mining the battery materials outweighs any positive effect they will have in their lifetime.

    The biggest issue I have is I hate seeing things wasted, as I stand out on my balcony to smoke everyday and get blown around by the wind as a 6'0ft 250pd man, I can't help but think that this heavy wind has to be able to spin some turbines.

    Also I am hoping to one day live off the grid with my family and this is a great learning experiment of what is possible before hand.

    What do you think about driving an alternator with a chain link drive with the main gear on the wind mill being almost as big as the blade and the gear on the alternator being the size of a 1/2 dollar? Figure that would be 30-40:1. As i wrote this I already thought of the added wind resistance but the gear could just be cut out with 3 pegs matching behind the blades and a 1/2" trim on the outer rim.

    So how much voltage do I need to get out of my alternator to get 100w? Alternators are DC right?
     
  16. Alec_t

    Alec_t

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    Jul 7, 2015
    This will guide you as to how much power you can generate :
    WindPower.JPG
    Note that the use of several small generators will be less efficient than using one big one.
     
  17. Robmcg

    Robmcg

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    Nov 20, 2016
    So check this out ebay item what i dont get it is what happens if this overspins to 300v? does everything in my house just explode and catch fire? a bit drastic to get my point across.
     
  18. Robmcg

    Robmcg

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    Nov 20, 2016
    Thank you and I understand that but I'm trying to figure out what is possible with my confined space I have.

    What I don't get about your image formula (although ty for more information), is that really doesn't account for what generator is being used? That has to drastically affect that equation, right?!
     
  19. Alec_t

    Alec_t

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    Jul 7, 2015
    Indeed it does. The formula merely gives you the power available in the wind itself. You have to multiply that by the overall collection-efficiency factor of the turbine, taking into account blade inefficiency, friction, mechanical-to-electric conversion, AC/DC conversion etc. I'd be surprised if a small turbine (say 1ft diameter rotor) could achieve more than 25% efficiency.
     
  20. Robmcg

    Robmcg

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    Nov 20, 2016
    So with my availible area, I was thinking I could fit a 5-6 foot vertical windmill in that space easier. Also would it be more efficient to use a AC generator over DC? Knowing I want to connect it to a grid tie.

    I feel like vertical windmill's are not nearly as popular, I could only imagine they aren't nearly as efficient, I could only guess, not having blade gravity to assist with spin and being much smaller in general as something to do with that?
     
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