Low output from my ista i-500w 12v turbine Grid Tied

Discussion in 'Connecting to the Grid' started by Dave sweeney, Jul 2, 2013.

  1. I'v got a small 500w 12v AC turbine connected to a 500w GTI. the turbine is 30 feet high in an open area in the west of Ireland. in a 20mph wind the turbine is struggling to produce any where near 100w.
    The wiring is about 5mm thick over about 30 feet run.
    Is there something i'm doing wrong? or have I got some faulty equipment?
    What should I be expecting from the turbine and GTI
    I also have 700w of solar which I am happy with, my experience with the turbine is putting me off them altogether.......can someone please help before I set about it with a large hammer..
     
  2. TomT

    TomT WindyNation Engineer

    Can you please upload a few pictures of the setup?
     
  3. Hi Tom, i'v tried to add some pics but there seems to be a problem, maybe the jpg files are too big
     
  4. Just not loading the pictures..
     
  5. Managed to upload this pic
     

    Attached Files:

  6. Managed to upload these pictures, the electrics are only temporary until I can get the turbine running right
     

    Attached Files:

  7. TomT

    TomT WindyNation Engineer

    What diameter are the blades and do you have a picture of the blades?
     
  8. leamywind1

    leamywind1 WindyNation Engineer

    Hello just chiming in to help out......maybe?
    Your turbine, does it require a 12v source to operate as well as does it need it's controller to work with it all together as one system?
    Most of those types (looks like an Air X-Southwest Wind Power) need a 12v source and its controller to work properly. If so, it may not be made for use with a grid tie inverter at all. The battery and its controller may put the proper load on it where the GTI is not putting the proper load as well as the turbine running at to high of an rpm with just the GTI hooked to it thus only making 100w. I think your best bet is to contact the manufacture to get the proper answer on if your turbine does need a 12v battery to work properly along with what happens if you do not use a 12v battery and its controller.:)
     
  9. Hi, Leamywind1, thanks for your comments, funny you should say about the controller and a battery, when I bought it I remember now the guy said it worked best with its own controller through a battery bank, but still you would have thought that it should still perform better than this through a GTI, after all the GTI needs Volts not amps and the faster the turbine runs the more Volts?.. yes?, I have just checked the turbine this morning and just had a gust of 25mph and the watt meter is reading 121w, we have an average wind speed at the moment of about 10-15mph at this i'm getting between 0-50w. Volts are around 12v and in the gust it goes up to about 15v, even in a wild storm last year the GTI never dumped and the volts never got above 18v, she's spinning like and aircraft prop today!!
    I will see if I can make a video, but I have struggled to upload the 2 pics above so it may be difficult to upload the video but i'll try.
    I'll try and add a link to a youtube video of the same turbine and see what ye all think.

    I'm wanting to go "off grid" I have 700w of solar which is grid tied at the moment which I am fairly happy with (working correct) so would have no problem transferring them to a battery bank, its just the turbine I'm not happy with, I want to have a turbine in the system because we do get winds in Ireland and it would help keep the bank topped up in windy weather, I would like to get a 1000w turbine but am worried it won't work as I want, and it will be a waste of money.

    I also could do with some advise on the size of the battery bank etc, I only have a small 1 bed traditional Irish cottage, my power usage is small, about 6kw/day but with my grid tie it down to about 3kw/day, this in mind I recon if I double the size of my system I should have enough to run the whole cottage.. what's your thoughts?

    Electric bills over here are, as i'm sure the same in the US going up and up and up so I would love to get out of that game altogether.:) Here's a link to the website for the turbine....
    www.istabreeze.co.uk
     
  10. Hi Tom, the blades have a span of about 40"....2" at the tip and about 5" near the hub.
    http://www.youtube.com/watch?v=MrnV4STAQY0 here's a youtube video of the same turbine if it helps
     
  11. I have done a video but struggling to upload it.. what a bummer
     
  12. Now then guys, I've finally managed to upload a video on Youtube, couldn't load it on this site, so anyway here's the link.
    http://www.youtube.com/watch?v=jYyU1vIsAYg
    now before you all say it...the inverter the turbine is connected to had a built in rectifier which I took out and wired straight through as it was faulty so that's why there seems more terminals than their should be.
     
  13. TomT

    TomT WindyNation Engineer

    You have to change it from private.
     
  14. Sorry about that Tom, first time uploading a video, have now made it "public"
     
  15. TomT

    TomT WindyNation Engineer

    By the video the solar is ok. I get just a bit more than half rated power most days. That turbine seems to need more rpm than the blades can give. Also from what you are showing the 10.8-30 volt GTI is really loading it down. So from that the only thing you can do is gear it up or buy something else.
     
  16. Thanks for that Tom, Gearing it up would require quite abit of fabricating but I am pretty good when it comes to welding and fabrication so it may be something I could look into, from watching other videos I recon I would need some better blades with more power as there is some drag associated with belts connecting to pulleys etc.

    OR I could just get a better turbine....any recommendations? could do with something that would give me minimum of 100w in 10mph wind, maybe a 1000w unit would be the job.

    As I am ultimately looking to go off grid would my little turbine work better through a controller into a 12v battery bank?

    I've just got hold of some 10mm2 cable today and was thinking of replacing the cable with this to see if that made any difference, trying to make sure I don't have any voltage loss.
     
  17. TomT

    TomT WindyNation Engineer

    I run 6 gauge on mine 3 phase 30 ft. If you gear it up I would go with cogged belts there should be less loss than v-belts. Try for 1-1.5
     
  18. Thanks for that Tom, I brought the turbine down today and did a bench test with the turbine connected to the GTI with just 3" of cable and then tested it with just one length of the 3 core that I was using and there was no difference between them so I have put it back up with just 1 length of the 3 core cable, I tried it with another set of blades that I bought some time ago, 3 blade aluminium wind grabbers , but I don't think they managed to reach the RPM required, so changed them back, i'm sure in a strong wind they would have more power.
    I bought some 10mm2 cable the other day (heavy earth cable) but I haven't used it, like I say, when I did the bench test the difference between direct to GTI and via the 30 ft of 3 core cable was the same.

    The only other thing I would say is that when there is a really strong gust from almost no wind 0-30mph the GTI goes into over volt and lets the turbine spin up over 30volts and then kicks in again when the wind drops.. is this normal? or should the inverter be holding the turbine better.
     
  19. TomT

    TomT WindyNation Engineer

    I have that every time I have a storm. I over volted and burned up a few GTI's before I put the voltage controlled switch on and used it for dump. I also use 2.7 ohm 600 watts worth of resistors. I tried that 5 ohm resistor and the turbine just sped up and the resistor was glowing like a light bulb. I have since changed back to the 2 ohms and it is fine again. It slows it right down even in big gusts. Does not even glow.
     
  20. leamywind1

    leamywind1 WindyNation Engineer

    Hello Dave,
    For your turbine you should test it all out with a battery bank and it's rated controller. Find out what amps you get vs wind speed at 12vdc. Since it is rated for battery charging that may tell the truth faster if it is a good turbine as per the manufacture ratings vs doing it all grid tie at first. That should tell you if you need to replace it asap. If you are considering an off grid system and including a wind turbine that small ro any 500w turbine will only make very small useable power as you can see.
    You may want to look for a turbine that can hit at least 50w in 10MPH wind and maybe two turbines at that.
    Getting a 100w for 10 hrs straight is 1kw of power so you want a turbine that can give you usable power at low winds and those turbines are in the 1kw class and above. From my experience a good 1 kw turbine can do about 50-70w in 12 MPH winds. So, at least two 1kw's are needed or a single 2kw or bigger again if you want decent usable power from wind. Otherwise you can just increase your solar.

    6kw a day......wow that is really low, good for you!! If you are going off grid you will first need to know your sun belt hrs regarding solar energy. That is how long you get the full power for from your system. I am a 4hr in the summer and 2hr in the dead of winter. Next is to size your system to the lowest sunbelt rating. All of this in regard to what you need to produce every day plus back up power. 6kw per day with 700w of solar off grid minus 30% efficiancy factors (est numbers) in a 4 hr sun belt will yeild you about 2kw per day with perfect sun. That should give you an idea on numbers for the array needed to hit 6kw per day. The battery bank needs to be about 36kw for 3 days of back up at a 50% discharge you will get 18kw (6kw per day x 3 days. A 12v battery system to hold that much power would be very large. 1 12v battery at 100amp hrs is 1200 watt hrs or 1.2kw. (.6kw at 50%) You would need 72 of them for a 50% depletion to get 18kw or 6kw for 3 days if there was no sun. At that point you are way better off going to a 24 or 48v system. Higher voltage is always way more efficiant. Again, if you were going off the grid completely. If you feel you need less battery storage then just change the numbers around to meet your needs and/or maybe do a hybrid system. You may also want to go to a higher voltage system altogether depending on how much battery power you want to use.
    (24v x 2amps= 48watts 12v x 2 amps =24watts) high volt is more efficiant!!

    Just my thoughts:)
     
    Dave sweeney likes this.

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