Disappointed with Wind Turbine

Dave SweeneyDave Sweeney Registered Users Posts: 2
Hi Guys, i'm new to all this...I have 7 x 100w solar panels and a 500w wind turbine all 12v system and all Grid Tied. i'm happy enough with the solar but the wind turbine is disappointing to say the least. I have it about 30 feet in the air in a fairly open situation in the west of Ireland, it starts up great with its 3 blades but I have only ever seen 120w out of it in really strong winds (30-40mph), its connected to a Sun 500 10.8-30v 12v GTI with max 600w, it seams to take a good gust of wind (20mph) for the turbine to reach 10v which is the kick-in voltage of the GTI but soon as it does the GTI loads the turbine and starts to slow it down again, the only time it has the power to overcome the load of the GTI is in storm like conditions.. any thoughts?


  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Disappointed with Wind Turbine

    Welcome to the forum Dave.

    I've moved your inquiry to its own thread for clarity.

    Most of us would not be surprised at your situation as turbines, especially small ones, rarely work well.

    To determine what, if anything, can be done to improve the situation we're going to need some more details such as the make and model of the turbine itself and its published specifications.

    12 Volt GTI's aren't exactly great either, as they rely on some fairly substantial input current to make power (600 Watts / 12 Volts = roughly 50 Amps). The wire distance between the turbine and the GTI could be using up a lot of power as well; 12 Volts doesn't travel very far. For example you'd need 8 AWG just to get it down the 30' tower without too much loss. Wire sizing and distances can be very important, as it does sound as though the moment the GTI starts to put load on the turbine the Voltage drops.
  • BB.BB. Super Moderators, Administrators Posts: 32,212 admin
    Re: Disappointed with Wind Turbine

    This is an ongoing issue with wind systems--Less than expected/predicted output.

    I am not a fan of small wind (in general) because there are few (if any?) off the shelf small wind turbines that can actually perform at rated power. Here are some Wind Links you can read:

    Wind Power Links
    www.otherpower.com (good forum for DIY Wind Power)
    Hugh Piggott - Scoraig Wind Electric site for tons of info (from mike90045)
    Scoraig Wind "Recipe Book" for DYI Turbines (from Chris Olson... From his 4/11/2013 post)
    www.greenpowertalk.org (added from "russ"--Like here but more wind/less solar)
    Small windpower a scam ? Survey says SO
    Truth About Skystream & SWWP
    Windmax HY-2000 2kW Wind Turbine

    So--the two or three problems. First, finding a good quality wind turbine which will survive being on a tower in the sun/wind/rain/ice/vibration for many years (many turbines made the mistake of placing electronics in side the turbine--Both a harsh environment and difficult to service when electronics eventually fail).

    Another is having enough wind at the site... Many turbines will output rated voltage at ~10-12 miles per hour, but will out output any useful current until the winds are >>10-12 mph. Many turbines will produce maximum output at ~25 mph (miserably windy) and many will completely shut down at >30-35 MPH (or even overheat and fail). Power in the wind goes with the cube (raise the speed of the wind to the 3rd power) of wind velocity. Most small turbines cannot generate useful amount of power at low wind speed and at high wind speed they self destruct.

    The last problem is physics... When your turbine is "close to the ground" you do not get smooth (aka laminar) air flow--You get "rolling"/turbulent air which has much less energy in it (can causes Horizontal Axis Wind Turbines to "hunt", and Vertical Axis Wind Turbines have even more issues and are--So far--Next to useless in any installation I have every read about).

    To access laminar flow, your tower needs to be at least 60 feet high and 90+ feet is even better (and at least 30 feet above trees/structures in a 300-500 minimum circle). A good way to see how high your turbine should be is to fly a kite. See how high the kite needs to be before it get in smooth/steady air flow on your property. Most wind maps are at ~125 feet or higher (not sure any wind maps are available at 30 feet).

    Normally, if you do not have "flagging trees" from prevailing winds in your area, you will not have enough wind to make a turbine worth while.

    It turns out that the wind turbine is the "cheap part" of the install. When you add the cost of a tower, concrete, excavation, wiring, dump loads, installation labor, and fees/costs for equipment to access the turbine at the top of a 60-90+ foot tower--Wind is not always a good deal.

    Some folks have chosen to build and erect their own (relatively larger) turbines. And for their places (typically northern latitudes with poor winter sun), they are very happy with the results. If you are forced to buy the turbines and have them installed/maintained--It can be a very expensive proposition to do it "right".

    If you can give us the model/configuration of your wind turbine--Somebody may be able to make some suggestions for improvement (different blades, etc.)...

    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • stephendvstephendv Solar Expert Posts: 1,571 ✭✭
    Re: Disappointed with Wind Turbine

    Hi Dave,

    To get the best performance out of the turbine you should use an inverter with a programmable MPP (Maximum power point) curve. If the "Sun 500" is one of those cheap chinese inverters, then I think it's meant for solar where it will keep hunting for a voltage where it finds the maximum power, which doesn't work well with a turbine. With a proper wind inverter like the mastervolt windmaster or aurora or sma windy boy, you can program in a custom curve that best suits the turbine. Having said that, IMO a 12v "500W" (presumably that's 500W during 12m/s winds?) turbine is not worth the expense of a proper inverter. I'd save the money and keep the installation as is. If you want to invest more in renewable energy then more solar is a much better bet in most places in the world.

    If you did want to get more serious about wind, then a version with a 3m or more diameter starts to produce enough power to make the investment in a proper inverter worthwhile.... if you're in a really windy spot.
  • ChrisOlsonChrisOlson Banned Posts: 1,807 ✭✭
    Re: Disappointed with Wind Turbine
    it seams to take a good gust of wind (20mph) for the turbine to reach 10v

    If it takes 20 mph to get it up to 10V there's probably something wrong with the turbine. That's not normal.

    The other issue is that even though it spins up and the inverter loads the turbine, it slows down right away. That's not normal either. The turbine should at least maintain speed in a constant wind. The turbine needs to be investigated to determine why its voltage output is so low first. And then the matching of its power curve to the load has to be looked at. If the GTI doesn't have the proper MPPT curve for the turbine, it's not going to work anyway.
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