FAQ—Wind Turbines


  • 1. How much power will a wind turbine produce?

    Several factors determine how much power is produced by a wind turbine:

    • Efficiency of alternator and inverters
    • Swept area of wind turbine blades
    • How high you mount the turbine
    • Wind speed

    The potential for more power increases with the increased efficiency of the alternator motor in combination with the inverter/controller package, a larger swept area of the turbine blades and the increased height of the turbine installation. What many consumers are not aware of is the effect of variable wind speeds on power production. There is an exponential relationship of power available to the wind speed. Consider a hypothetical example where the wind speed doubles from 5m/s and 10m/s. The theoretical power available at 5 m/s is 77 Watts/m² and at 10 m/s is 613 Watts/m². This shows an eight-fold increase in power avaiable at just twice the wind speed. Consider the effect this relationship has when reporting average wind speeds in the following table:

      Example 1 Example 2
    Reading Wind Speed, m/s Power, Watts Wind Speed, m/s Power, Watts
    1 5 77 0 0
    2 5 77 0 0
    3 5 77 0 0
    4 5 77 10 613
    5 5 77 10 613
    6 5 77 10 613


    In both examples, the average wind speed for the 6 readings was 5 m/s. However, in example 1, actual power produced was 462 watts, and in the second example, actual power produced was 1839 watts.

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  • 2. How much do they cost?

    Installation costs for renewable energy systems vary with siting considerations and the complexity of the system design. Rule of thumb costs range from $7 to as much as $15 per installed watt capacity.

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  • 3. What is the standard payback period?

    Each installation site will be unique with variables such as site wind profiles, topography, type of storage, height of the tower, and type and size of wind turbine installed. In addition, return on investment calculations seldom figure in the increasing cost of utility or fuel charges over time. Therefore, any standard payback period would at best be only an estimate.

    So, consider more importantly the life cycle of your installation. Once installed, your utitlity or fuel costs to run a turbine is ZERO.

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  • 4. Can I power my whole house with a wind turbine?

    Many factors will determine your ability to power your whole house:

    • What is the wind resource available at your site?
    • How much power do you consume?
    • Do you utilize a storage medium for low-consumption periods?
    • Does your utitility allow for grid connected net-metering?
    • Are you willing to utilize low power consuming technologies such as LED lighting?

    We all know the wind does not blow all the time. If your goal is to reduce your utility consumption to near zero, we typically recommend a hybrid system combining wind with available solar, geothermal, or hydro.

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  • 5. Can I mount the turbine on my roof?

    The GALE™ vertical axis turbines by Tangarie may be mounted on a roof with some structural considerations and added cost. However, in most cases, this would not be the best option for siting to produce the most power from the available resource. It is best to get the turbine as high as possible, and in a location with the fewest obstructions to the wind to maximize power yield. And more often than not, this would be away from the rooftop, and on a pole.

    The horizontal axis turbines by ReDriven are not mounted on a roof and are typically mounted on a hydraulic steel pole. The ReDriven hydraulic pole is unique in that it allows the turbine to be lowered to the ground for servicing or to better protect the turbine in advance of extreme weather conditions.

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  • 6. What is the warranty?

    All GALE™ turbines by Tangarie are warranted to five years with extended warranty and service coverage available at additional cost.

    All Redriven turbines are warranted to five years.

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  • 7. Are there federal or state wind incentives for my state?

    State and Federal incentives for renewable energy and energy efficiency can be found at DSIRE website.

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  • 8. How much wind potential does my site have?

    General wind classifications for your area can be found at the Department of Energy website. Local meterological stations can also provide wind data for your area. Due to site conditions such as elevation, height of surrounding trees and buildings, you may want a specific wind study for your site. We can provide you with monitoring services for a fee, or you may purchase your own monitoring equipment.

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  • 9. How do I get a permit to install a turbine?

    A building permit will be required to install your wind turbine system. You will need to contact your local building department to determine if they have established regulations for wind turbines. Many departments do not have wind turbine regulations established (this should change in time as wind turbines become more prevalent). Therefore, you may need to apply for a zoning variance at a public hearing with your local planning board. It would be wise to seek the support of your neighbors before the hearing if you are installing in a residential area. Permitting fees could range from a couple hundred dollars to over a thousand dollars depending on where you live. We can provide the support to help you through this process.

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  • 10. Do you have product specifications sheets for the wind turbines?

    You can view and print pdf files for Product Specification Sheets for each size turbine by going to the Vertical Wind page or to the Horizontal Wind page on this website. Or, for additional information on the GALE™ vertical axis wind turbines you may go to the Tangarie website, and on the horizontal axis turbines you may go to the ReDriven website.

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