Vertical Axis Wind Turbines

SystemSystem Posts: 2,511 admin
After all the small wind turbine bashing, I wonder if this is really a stupid question, or maybe I'm stupid for even asking.

What is the feeling about VAWT's, and are they worth the money? I get consistant winds (10-20 mph) minimum 300 days a year. Would it be worth investing in a VAWT vs. a HAWT given the noise, and maintenance issues?

Second stupid question: Anyone know quality issues with Chinese manufactured VAWT's? Brand specific would be nice if we don't get in trouble.



  • BB.BB. Super Moderators, Administrators Posts: 32,924 admin
    Re: Vertical Axis Wind Turbines

    That is a tough question...

    The most efficient wind turbines are going to be your HWT (standard 2-3 blades facing the wind). They capture the wind across 100% of the blade swept area.

    VWT on the other hand are probably only able to capture power on roughly 1/2 of the swept area--half the time the "blades" are going down wind, and the other going "back up wind"... So the VWT has to have about twice the frontal area to the wind.

    From what we have seen with all residential sized wind turbines, they have pretty much failed to reach even 50% of their "rated" power output, and many are down in the single digit range.

    I believe you have been reading through the other Wind Threads here--and probably have seen this wind power link (from a pro-wind guy, posted on our host's Wind Power section of their store).

    On the Wind-Works site (first link), the State of Massachusetts is looking to give-up on spending tax/rate payers' moneys on small wind.
    Summary of Findings from the Cadmus Report
    "The average production for the 19 existing small wind turbines highlighted in the progress briefing is less than one-third of the average production projected by installers, with a range of ratios varying from 2 percent to 59 percent of estimated production."

    Bottom Line
    "MTC is now considering program changes to the Small Renewables Initiative that will apply to future small wind projects. MTC expects that these program changes will be announced in late summer, 2008.
    As a result of the information outlined in the following small wind progress briefing, MTC believes that it is in the best interest of the small wind community for MTC to stop accepting applications from new, small wind projects. . . ."

    In the end, if you have a large enough piece of property (away from neighbors and possibly flying wind turbine parts), have the money, and can install either a tilt-up or have your own crane service (or can pay $400 a pop anytime the wind turbine needs "work")... It's your money.

    Pretty much the first question any of us here ask is how long has your turbine been working, how many kWhrs has it generated (over what time), and what is its service history.

    Wind Turbines, done right, are relatively expensive and complex pieces of electro/mechanical equipment hung 30+ feet in the air, subjected to all of the elements, with very little service access...

    And, wind sites are notoriously difficult to predict using standard government wind chart data. Plus, local hills, cliffs, trees, and tower elevation dramatically affect performance too...

    Generally, the recommendation here is to CONSERVE (insulation, energy star appliances, CFL's, turning things off, using alternative fuels where possible), then build out your solar thermal and solar PV/electric systems.

    After you have all of that done, then look into wind as a backup to your solar/generator based systems.

    If you have other needs--say well pumping... Perhaps one of those old style mechanical windmills (with the rods, or even air compressors) you see on old farms might be worth looking into--they are (apparently) still being made.

    Full disclosure--I have never used Wind Power, and have not worked on any wind turbine installations--just based on my readings on the web and my general engineering knowledge.

    If anyone has good experiences with one or more wind vendors--please feel free to post here. I am always interested in learning more.

    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • nigtomdawnigtomdaw Solar Expert Posts: 705 ✭✭
    Re: Vertical Axis Wind Turbines

    I have a 1 kw turbine well down on my todo list after solar! yes its chinese but a hefty substantial unit ( I can only just pick the head up on my own and Im a strong lad)and whilst Im not looking for a lot, I like the idea of power generation from a non solar source. I will install it on a monotower this year. The turbine and mono pole cost me about the same as one of my 200w PV panels I live at the top of a valley and have good winds after two years of living here (didnt now this when I purchased it) but through out my extensive readings over many years on small wind turbines for off gridders home use there are 3 golden rules which seem pretty solid.

    The 3 Golden Rules for Sucessful Windturbine Harvest Are

    1.Location Location, Location if you havent the wind then dont bother!
    2.Swept area of the blades. This determines the energy capture of your unit if it has a small swept area then small power capture. (Seems Logical Captain)
    3. Height Height Height getting your turbine in turbulent free air is a must (a quoted figure of 30 ft above anything within 500 ft comes to memory)

    These are the golden rules and all 3 must be there as a package. See no mention of product yet!

    To address your VAWT question I think the golden rules still apply, Ive seen a wind turbine with a good HAWT reputation look like a absolute duffer because of its location . Not every small Windturbine out there is a pile of junk, Hugh Piggot, proves this time and time again. But people think or dont think on location or turbulance or quality of construction and expect $500 of wind turbine set in a valley behind a mountain will keep the lights shining, yeah and Im teetotal,hic

    I personally think NAWS forum gives small wind a hard time and rightly so on the evidence we seem to see, but remember there are more Small Windturbine manufacturers than SWWP and Chinese Origin , I think Proven of Scotland have a good rep but there are not cheap.

    If you can get the golden rules in place then start thinking about product choice.

    The only silver rule I can offer here is buy a heavey substanial unit like how the Jacobs were constructed, that doesnt rule out a Chinese WT but I agree most of them. You get what you pay for IMHO. Unless its a SWWP unit then you pay lots and get cr.p
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