The Windtura 750 is now available - Questions?

Discussion in 'Windtura Generators' started by Minnesota, Nov 30, 2010.

  1. joshua24br

    joshua24br WindyNation Engineer

    Does someone have a link to a site that sells DPST switches that will work with the 3 phase PMA. I have read the link on how to wire them.
    Thank you, Joshua
  2. timber

    timber WindyNation Engineer

  3. timber

    timber WindyNation Engineer

    Hi Joshua,

    To keep some continuity of specific topics, it's probably best to start a new thread under General Questions for something like your question about switches.
    Also, that way, when someone else has the same question in the future it's easy for them to find the answer.
    No offense meant so please don't take it that way ... it's just a suggestion.

  4. mark99

    mark99 WindyNation Engineer

    Joshua, If you can not find the relays locally they are the same relay that Windy Nation sells for their charge controllers. The 40 amp relay. Mark
  5. timber

    timber WindyNation Engineer

    Hi Mark.

    I think Joshua is needing a switch for an electrical brake, not relays ... unless I missed something. (Which is entirely possible)

  6. joshua24br

    joshua24br WindyNation Engineer

    Yes, for electrical brake. I was thinking it was a cheap and positive addition.
  7. timber

    timber WindyNation Engineer

    Yes, and DPDT is the way to go ... I didn't realize that when I purchased my switch which is a 3PDT and a bit more expensive ... although not too bad from Granger's.

    Definitely good to have the brake for raising and lowering if nothing else ... perhaps prior to a storm but better yet for a storm is a way to lock into a furl if possible.

  8. murray2paddles

    murray2paddles WindyNation Engineer

    the furling should be the protection you need in a big storm,, I mentioned to Joshua on his other thread that if you have a furling system when raising or lowering as soon as you leave a vertical ,, gravity will automaticallly furl it for you and the blades will stop spinning.
    The braking might be useful if you had to do some electrical work while the turbine is up and in a wind. BUT best time for that if you have a choice is on a calm day. :lol:
  9. joshua24br

    joshua24br WindyNation Engineer

    Pardon me for not using the correct terminology:

    Question: Does the 750 produce VDC at a lower rpm than the 500? In other words, the preassembeled control panel info states that the input needed "18-29 VDC for 24 volt charge controller". Does the 750 provide this at a lower rpm? I looked over the charts and saw some slight differences of watts output at 16mph, 21mph and 25mph.

    Reasoning: In my Africa application, we have a 24v battery bank and are not producing consistant voltage over 18-28VDC. Therefor our battery bank has never seen a fully charged state. We are micro managing the battery bank daily and need to let it average out over a longer period of time to see if we have enough wind. If we lowered to a 12v battery bank we would be fully charged as we are producing consistant 8-18VDC. The only reason we went with a 24v battery bank was that inverters over 1000w suggested using 24v banks. We bought a 1500w inverter but really only draw less than 300w at any given time.

    Thank you, Joshua
  10. windyguru

    windyguru WindyNation Expert


    The volts to rpm ratio for the 750 and 500 are nearly identical.

    If you are in a low wind area and cannot get over 24 volts, then 12 volts might be a good option for you.

    If you are stuck with your system, and considering everything is in Africa, we might be able to design and build you a voltage doubler. This would roughly double your DC output voltage.

    This would be done as a favor as we do not sell or make these. But we could build you one for free.
  11. Ray5271

    Ray5271 WindyNation Engineer

    Over the course of a year assuming an avg wind speed of 10mph 24/7, what would one expect to see for total power output for the year?

  12. Minnesota

    Minnesota WindyNation Engineer

    The Windtura has a measured coefficient of performance of 0.30 at 10mph, yielding 53 watts.

    Do the math over the course of a year and it comes out 464kWh produced.
  13. windyguru

    windyguru WindyNation Expert

    (365 day/year) x (24 hrs/day) x (53 Watt hours/hour) x (1 kiloWatt hour/1000 Watt hours) =

    464.28 KiloWatt hours or 464 kWh
  14. Minnesota

    Minnesota WindyNation Engineer

    As a follow-up, I do have a good data set collected over 1 full year (2010) on a small turbine to refer to.

    Average wind speed measured over the year using a logger was 10.7mph. Annual measured production charging a battery bank was 295kWh.

    This equals 33.67w average continuous output.

    What is interesting is that the measured power curve using this same year's worth of data shows 22.5w at 10.7mph. But since we know tht actual production was 33.67w then a factor of 1.5x could be applied.

    This suggest we can take the point on a power curve for the average wind for an area, such as 53w at 10mph in your case Ray, and multiply it by 1.5 to get a sustained output; 79.5w. This then projects an annual production of 696kWh is possible. Not bad!!
  15. Minnesota

    Minnesota WindyNation Engineer

    OK, there is also another "general" method that can be used to calculate the annual production strictly based on sweep area. That method yields 590 kWh/yr for a 10mph average wind speed area.

    Take your pick! :D

  16. Greetings, why dosent windynation sell an complete kit? Grid tie inverter w/windtura 750 plug and play? Matched GTI's for a simple install? Thanks, Carl
  17. windyguru

    windyguru WindyNation Expert

    We are considering this option and might offer a grid tie + Windtura 750 combo in the future.
  18. That would be great for us new comers on wind energy. Leamywind1 sent me some know how, really appreciate his help. Thanks to scamsearcher for his input on youtube, "caveat emptor" lot of bad scams out there. Keep me posted on the "kit" gladly wait. Carl
  19. Minnesota

    Minnesota WindyNation Engineer

    I'd like to see a enphase mated to a 750 in some way, perhaps with a buffer battery. I'm surprised Larry has not experimented with this idea.
  20. Greetings, found this posting on youtube:

    Installed a 5KW´╗┐ enphase system about 6 months ago using Mage solar 180 mono panels. I have been back to the site 3 times to replace inverters. I have been less than impressed with Enphase. It has been over 3 months and we have not been compensated for the service calls on their product and the less than stellar output if each inverter. I have only seen a peak output of 130 watts for each 180 watt panel. Thanks, I'll stick with SMA.
    hazeyfla 4 months ago

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