Wind Turbine Search

willeertwilleert Posts: 4Registered Users
I don't know much about wind turbines however I do live off grid with a PV system which I designed and installed myself. I have been asked as a favor to offer advice on the replacement of a wind turbine that failed so now I am learning something about wind. The turbine was a 400W unit located 520 feet from a 24V battery system. It actually looked to me like an inexpensive cheap not very good piece of equipment. I don't understand how it ever worked given the distance the power had to travel from the turbine to the batteries - maybe it didn't. I have been looking for a 1KW or smaller turbine that will produce a sufficient voltage to transmit the distance early on its power curve. The control for charging would be located at the batteries. I can't think of any other way to make this system work. PV seems much easier than wind.

Any ideas on equipment or what to do? I would think transmitting power longer distances is common with wind but  do not find turbines that seem to produce the voltage to do this with a low voltage drop. Maybe the turbine is just too small?

Thanks for any replies

Will

Comments

  • JoshKJoshK Posts: 232Solar Expert ✭✭
    You can build it to generate any voltage you want.  The higher the voltage, the better it travels.
  • willeertwilleert Posts: 4Registered Users
    Hi Josh,

    Thanks for the reply. I don't want to build a turbine. I am attempting to source a smaller turbine that produces sufficient voltage to transmit the 520 feet at a reasonably low output. From what I can learn wind turbine output voltage increases as the turbine speeds up. I don't know and can't find a smaller turbine that produces a high enough voltage to go the distance. Many of the smaller turbines I can find do not post their manuals or specs on the web so that they can be studied. I am hoping someone on the forum knows of or has experience with transmitting a 1Kw or smaller wind turbine output 520'.

    Will
  • JoshKJoshK Posts: 232Solar Expert ✭✭
    Well if you have a 1kW turbine, and send 60v @ 16.666A a distance of 520'... 
    Using a 3/8" Aluminum wire, you would get 57.9v @ 16.666A at the other end.  That's 0.965kW.

    I figured that out with the help of this:
    http://www.rapidtables.com/calc/wire/voltage-drop-calculator.htm
  • BB.BB. Posts: 27,681Super Moderators admin
    You are correct... It is very hard to find a quality/small wind turbine. This is one case where build it yourself guys are probably (in general) better than buying commercial. However, the costs, tower, footings, wiring, controllers, are still expensive and easy to damage with high winds, lightning, icing, etc.

    IF you can find a "higher voltage" wind turbine (48 volts or a bit higher) and then use a MPPT (maximum power point tracking) charge controller--These have an internal buck type switching power supply that can take high voltage/low current from the turbine and efficiently down convert to the low voltage/high current needed to charge the battery bank. It is even possible that a 24 volt turbine will actually run at a higher voltage on an MPPT controller and give you better output to the battery bank.

    Of course, you will need to install a second "dump controller" on the battery to get rid of excess charging current (high winds, full battery). If you have the MPPT controller turn off--The horizontal axis wind turbine types can over speed in high wind and self destruct.

    Midnite makes a nice MPPT+Wind Controller+Dump setup (not cheap). And there are some other MPPT controllers that can work with wind--But I am not the right guy to ask about that. My personal opinion would be to install more solar panels and use a backup genset--Unless you folks really want to spend the time and money on wind--just because you want too.

    http://www.solar-electric.com/inverters-controllers-accessories/chco/misoclchco.html

    -Bill

    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Dave AngeliniDave Angelini Posts: 3,874Solar Expert ✭✭✭✭
    I am with you Bill !  But, if the OP lives in a place that does not do well with winter sun the Bergey is a very good choice.  I have used them and they are a solid company that will be there if you need them.
    "we go where power lines don't" Sierra Mountains near Mariposa/Yosemite CA
     http://members.sti.net/offgridsolar/
    E-mail [email protected]

  • willeertwilleert Posts: 4Registered Users
    Thanks for the comments. I have been imagining a system such as BB put forward. A higher voltage wind turbine at the tower and a MPPT controller at the batteries. A dump / diversion controller would then also be needed to dispose of the extra power when it is available. I use a pair of Classic 150s for my offgrid PV system and an arduino based diversion control to optimize its production. The existing system that had the turbine fail has 6 AWG copper -2 wires + ground already buried in the ground between the tower and the batteries. This is a real limitation for trying to find a turbine that will work. That is why I am looking for a higher voltage output turbine. I have read the Bergy manual now and it looks like a very nice unit - made by people who know what they are doing and who are producing a safe and reliable product. Unfortunately it is a three phase unit which with the wire already in the ground means it would not work without adding wires.

    So....Might there be a single phase turbine that produces 48V + at reasonable output? I have been looking for a while but am not finding. I did find the Soma in Australia:

    http://www.energymatters.com.au/soma-120volt-1000w-wind-generator-p-737.html

    This is the type of turbine I think could work for my friend - given the existing system parameters. It would be nice to find something similiar in North America however and that is what I am not finding.

    Thanks

    Will
  • BB.BB. Posts: 27,681Super Moderators admin
    Three phase rectifier at the base of the tower? Then two wire the rest of the way.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • JohannJohann Posts: 240Solar Expert ✭✭✭
    If you use a AC wind generator you could use a step-up transformer at the tower to send high voltage power a longer distance but you will lose some power in a transformer.


  • JoshKJoshK Posts: 232Solar Expert ✭✭
    edited March 2016 #10
    You will lose some in the transformer, but you will probably lose more in the wire if your voltage is not high.
  • willeertwilleert Posts: 4Registered Users
    Thanks for all the comments. I really like the Bergy system and would recommend that to my friend with the three phase rectifier. I don't think he will want to spend the money required to get a good system that will work but we shall see....

    Thanks again for all the thought and sharing of knowledge.

    Will
  • Dave AngeliniDave Angelini Posts: 3,874Solar Expert ✭✭✭✭
    edited March 2016 #12
    You are welcome! The reason Bergey is so good is it is not a matter of if you will need them, it is a matter of when.
    Wind gear needs maintenance.
    Cheap equipment in wind/water energy is a waste of time and money.
    "we go where power lines don't" Sierra Mountains near Mariposa/Yosemite CA
     http://members.sti.net/offgridsolar/
    E-mail [email protected]

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