A small home-built generator working

KevinbKevinb Solar Expert Posts: 26
Hi Guys,
I've been playing around with DC wind generators a little and decided to try a little harder this time. I found a 3 phase alternator on ebay and bought some cheap aluminum blades (also ebay.) I picked up a couple of deep cycle marine batteries today to start playing around with it. Here are a couple of pictures, showing it charging a little over 8A in what I'd consider pretty typical wind when it's blowing where I live in Flagstaff. I originally designed this mount for an Ametek 99VDC motor, and it furls by tilting backwards, although I haven't seen it furl yet today (not strong enough wind.) It's only 10 feet up in the air so the wind is a little gusty, but I'm relatively happy with the initial testing. I think if I make a new hub to spread the blades out more and possibly do some trimming on them to increase the speed, it may be good for charging at 24 volts. I need to get an anemometer and start doing some real testing and logging. I have a much bigger alternator on order that I hope will be good for about a 10 foot rotor, and will put it up 30 feet or so. Before that I'll rig up a truck mount and get more serious about the blade design to get good power and figure out the required furling. At least this is a start :D

Comments

  • BB.BB. Super Moderators Posts: 26,969 admin
    Re: A small home-built generator working

    Nice looking little unit... I would focus on the blade roots were they mount to the hub... Anything you can do to spread loads and forces to prevent concentrated bending/vibration will help the blades last longer.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • KevinbKevinb Solar Expert Posts: 26
    Re: A small home-built generator working

    Okay I got some 1/4" thick 304 stainless and had a local shop waterjet this new hub for me, and used some more 1/4" 304 on the back and 1/8" aluminum on the front to reinforce things. It's pretty windy today at my place (as it usually is) although the weather service says it's currently 6MPH wind in Flagstaff. Spreading the blades apart seemed to have helped quite a bit. I'm averaging about 10A today, and have to keep my stereo running along with about 200 watts of lights to keep from over-charging the batteries. Yesterday's wind was about the same. The first picture shows the new hub design, and the second picture shows it charging with 17.2A at 13.6 V. The wind was fairly strong, but still a typical windy day here with no storm. Right after I took that picture a wind gust made it go over 20A (I don't know how high because my amp meter blanked out.) I looked up at the generator and it was furling (tilting back) so that seems to work about right. I wasn't watching the volt meter at that point, but the battery voltage got high enough that my Trace inverter went into protection mode. So now it's time to get a load diverter, and start testing with the batteries hooked up at 24V. I really need an Anemometer too.
  • mike95490mike95490 Solar Expert Posts: 7,358 ✭✭✭✭
    Re: A small home-built generator working

    Why not get a switch to "short" out the wind gen output, manually or when reaching float? Shorted output should stop the blades, and save bearing life too?
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

  • KevinbKevinb Solar Expert Posts: 26
    Re: A small home-built generator working
    mike90045 wrote: »
    Why not get a switch to "short" out the wind gen output, manually or when reaching float? Shorted output should stop the blades, and save bearing life too?

    I think that most people use a combination of a load diverter to switch the power to something else useful like a heater so the power isn't just wasted when the batteries are full, and also a "kill" switch to short the 3 phases together if a storm is coming. Here's an example of a diverter- http://www.survivalunlimited.com/windpower/diverloadctrlr.htm

    Shorting the wires out when the generator is making lots of power can cause bad things to happen...
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