Wind Solar Girl Scout Project

sean30bersean30ber Registered Users Posts: 4
Heres alittle back ground, My daughter is home schooled and is a Girl Scout. She is very eco-consious. I also have been interested in setting up a small wind/solar combination as a test before diving into it head long. This will be a combination school science/Girl Scout and learning for me project. I have two Ametek 38 motors and all donated parts for 20 foot towers and material for the turbine. Ill be building it all from scratch, have plans for the mechanics (donated Power for Patriots Manual). I also have a line on two free Renogy 100w solar panels, donated from a friend. I also have a pretty good location for the towers, and cells will be roof mounted on a garden shed with the towers on both sides so no long cable runs and everything housed in the shed.

Also have a 400w inverter, 4-6v golf cart batteries in good shape. 60amp 3 stage controller 12/24 from Mountain Wind.

Now building the mechanics is the easy part, im handy in the shop. But I am an electrical moron. Are there any links you can provide for setting up a small system. Extreme beginer stuff. Im not even sure I have the right electrical components for this. Lots of reading still to do. Im lucky and most of this stuff was free except the Ameteks and hubs. Generators will go up first and the cells tied in about 2 months when my friend moves and gives me the panels.

I want to make it a good learning experience for my daughter as well as me, so any pointers, hints, directions to good beginner sites would be extremely appreciated. Im not looking for grid tie in stuff. More like off grid. Run a few lights, heat the chicken coop when cold. Little things.

Thanks very much, Sean

Comments

  • BB.BB. Super Moderators, Administrators Posts: 32,800 admin
    Re: Wind Solar Girl Scout Project

    Heating the chicken coop may be a bit much to expect... But we tend not to do too much on wind power here (although, there are folks here with a lot of sucessful experience--so they can answer too)... A couple of links to forums that may help you:

    Wind Power Links
    www.otherpower.com (good forum for DIY Wind Power)
    Hugh Piggott - Scoraig Wind Electric site for tons of info (from mike90045)
    www.greenpowertalk.org (added from "russ"--Like here but more wind/less solar)

    The secret to a successful wind turbine (other than the mechanics of getting the turbine "right") is a tall tower (60-90 feet minimum) in a windy location is critical.

    A 10' tower next the home (or mounted on the roof of a building, will not generate much power and can cause damage/noise issues if attached to a structure.

    Also, keep the turbine away from areas where people congregate/spend time--It is not unheard of for a turbine to shed blades and/or fall from the tower when a bearing or forging fails.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • sean30bersean30ber Registered Users Posts: 4
    Re: Wind Solar Girl Scout Project

    Thanks for the links, It will be a small combined unit with solar. As far as the chicken coop, no biggy. Led lights in the barn and small things to use with it. Like I said more of an ongoing science project with my daughter and a chance to learn for me. I know im not going to get much out of a small system like this, but I have read over and over that the wind/solar combo complement each other well. I dont even know what I could power with this small of a system yet.
  • ggunnggunn Solar Expert Posts: 1,973 ✭✭✭
    Re: Wind Solar Girl Scout Project
    sean30ber wrote: »
    Thanks for the links, It will be a small combined unit with solar. As far as the chicken coop, no biggy. Led lights in the barn and small things to use with it. Like I said more of an ongoing science project with my daughter and a chance to learn for me. I know im not going to get much out of a small system like this, but I have read over and over that the wind/solar combo complement each other well. I dont even know what I could power with this small of a system yet.
    You may or may not get anything from wind, depending on your hardware and location. A lot of the hardware that is being sold does not perform well (if it works at all), and most people overestimate the available wind resource if they try to judge it simply by the way it feels.
  • sean30bersean30ber Registered Users Posts: 4
    Re: Wind Solar Girl Scout Project

    Ok, im not sure its worth it now. Will two 100w solars charge 2 6v batteries for my daughters project here in Arizona. Like I said this is a learning experience for both of us and school for her. The turbines im going to build for the fun of it. Just figured id hook them in with the solar. I know this is small time but is it even worth it for learning. We get a good amount of wind here also along the Superstitions. I havent done any measurements yet and its not consistent but im getting the impression if you dont go big, go home. I thought I was doing a good thing teaching her about renewable energy and the possibilities but im not sinking a ton of money in it for a classroom project. Can I charge anything with two panels. Am I on the wrong forum for advice?
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Wind Solar Girl Scout Project

    What you could expect to get from 200 Watts of solar panel: about 10 to 11 Amps of current maximum, and perhaps 640 to 800 Watt hours.

    Will that recharge 220 Amp hours @ 12 Volts? Yes, but slowly. At its best it would just barely make the recommended 5% minimum charge rate for those batteries. Now, if the loads do not draw when the batteries charge all will be well.

    As a school project there really is no fail. :D Even showing the shortcomings of solar and/or wind is a valid experiment; you just have to present it right.

    Small scale wind usually does not work; not enough wind, not a good enough install, and poor quality turbine equipment all lead to failure and disappointment. That too can be a valid demonstration. Or even showing how much power you get from the panels vs. how much you get from the turbine.

    So would be showing the costs and economy of scale. All these things have to be taken in context.

    The #1 thing, whether off-grid, grid-tied, or grid-only, is conservation. Small solar power systems can work, as long as you don't expect them to supply amounts of power they're not capable of. A typical home would use 25 kW hours per day, and as such would require a very large solar set-up to supply such power. By contrast my off-grid cabin uses 1/10 that. Adjusting your lifestyle to suit the limitations is a lesson in itself. A lot of people in the world still live without any electricity; something our "electric everything" society has difficulty comprehending.
  • BB.BB. Super Moderators, Administrators Posts: 32,800 admin
    Re: Wind Solar Girl Scout Project

    For the wind turbine--The other links I suggested should be of help. Figuring out the blade profile vs RPM needed to drive the motor...

    From a quick search, the Ametek 38 motors do not appear to output much current... So you may be limited 1.5 amps or so:


    Ametek 37VDC
    Also known as
    Ametek 36VDC & 38VDC

    NO GOOD
    • Nominal voltage 37 VDC
    • 12/24 VDC
    • No load amps 0.35
    • Shaft 5/8" diameter. x 2.0" long
    • 4" diameter. x 4 7/8" long
    • 2100 RPM @ 37 VDC
    • Weight. 8 lbs.



    It seem that the most current version floating around of the Ametek 36 VDC motor has the same voltage to rpm ratio as the Ametek 30, but it does NOT have the output like the Ametek 30 has. It will work, but only as a trickle charger. (around 1 to 1.5 amps expected).

    Although, this link suggests 3 - 5 amps are possible??? Possibly there are different versions of the Ametek 38s.

    And here are some more tips:

    http://www.tlgwindpower.com/tips.htm

    I am not sure--Do you have/plan on 2x 100 watt "12 volt" panels? (really panel Vmp~17.5-18,6 volts typically)

    For a simple/fast(er) charging system, you can pick around 10% rate of charge for the battery bank (5-13% typical rate of charge rule of thumb for a off grid system using the battery's 20 Hour discharge rate):
    • 200 watt array * 1/14.5 volts charging * 0.77 panel+charger derating * 1/0.10 rate of charge = 106 AH @ 12 volt battery bank

    Assuming a minimum of 4 hours of "noon time equivalent sun" in early spring/late fall:
    • 200 watt array * 0.52 system derating * 4 hours of sun = 416 Watt*Hours per day of AC power (if you use a small DC to AC inverter)
    • 200 watt array * 0.61 system derating * 4 hours of sun * 1/12.5 VDC = 39 AH @ 12.5 volts per day (DC loads)

    Certainly can run (for example) a laptop computer for something like 10 hours per day pretty easily (and much more in the summer).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • sean30bersean30ber Registered Users Posts: 4
    Re: Wind Solar Girl Scout Project

    Awsome. Thats what i was looking for. Ive been weighing making 2 of my own panels after installing the two I get. Again for educational purposes but I see 100w 12v panels are a dime a dozen. If I end up using 4 panels 12v 100w each what size charger controller would I need. Would I have to go larger than the 60amp 3 stage. For our project I cant see going more than 4 panels and the two small, free tower, wind turbines. Correction on the Ameteks. They are 50vdc. Im still reading alot. Your right, the more I read about the small wind the more I read its not what its cracked up to be. Should be fun project for use to do together though. Quality time is a commodity.
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Wind Solar Girl Scout Project

    You've got two things to consider with the charge controller: if used only for solar, it will go between the panels and the battery and need to handle the combined current of all the panels. In this case four panels probably be around 20 Amps, possibly a bit more. If you want to include wind, then there must be a controller for that. This would be in a diversion configuration where "excess" power to the battery is "syphoned off" to a dump load. Wind turbines always need to have a load available to them to prevent over-speed. In such a case you can either use one controller for solar and another for wind, or one controller for both (functioning only as a diversion controller). Again, the controller has to be able to handle the maximum current from whatever charge source it is regulating.

    You could make your own 100 Watt panel, then test its performance against a commercial unit of the same size. If you do, don't forget to keep track of how many hours you put in to building it, as cost analysis is an important consideration too. :D
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