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Harvesting energy from the wind with low-tech means resulting in driving a small high-tech generator at high RPM.

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Prototype Twentyfold cost reduction Applicable in modern as well as in poor economies Comfort Income Rural

Harvesting wind for local use asks for a complete re-design of what formerly was called a wind turbine. A very simple rotor with primitive sails, attached to a flexible stick should suffice. No danger might come from it being blown over in a storm, it should be easy to adjust to the wind, to upkeep and to repair.

As electricity is generated by moving a magnet very fast and very close along a conductor, the WindDrive harvests the highest speed in its system for this purpose. That is the OUTSIDE of a wheel with sails. A simple rope running along its edge transfers this top speed to the generator mounted somewhere below this wheel.

Additional information

The animated picture shows the components of the WindDrive (click on the picture to enlarge it):

  • The rotor of the WindDrive (color yellow) is constructed much like the frame of an umbrella (as shown), or as a bicycle wheel (later to be described).
    In this rotor sails or wings are mounted. Anything works! Either simple mats woven from grass or high-tech airfoils. At the outer ends of the 'umbrella spokes' forks are mounted. These forks catch and guide a rope that glides into the bottom of the fork, where it can not slip easily. But this rope slips out of the fork when it comes closer to lowest part of the circle in which it runs. Combined, these forks act as a V-groove in a pulley. But there is no need for a V-belt! A simple sisal rope has shown to perform very well in transmitting 100 Watt for months on a test rig.
  • The rope runs over a special pulley (color red) of the generator. The tower is not stiff. It bents and sways as branches do in the wind. So the rope is NOT running with equal tension. To compensate for this, a tensioner may be mounted (detail later to be shown). As the rope does not enter the pulley precisely in the middle, the pulley is build like a jojo, with smooth flanges from which the rope slides to the centre. This centre however is a rubber disk offering more friction to transmit the driving force of the rope to the generator.
  • The rotor, that need not weight very much, turns around a stick, that is part of the WindFollower. The WindFollower (color green) turns where the wind blows it. So it offers the proper direction for the rotor to turn in. The generator is mounted on the same WindFollower, so is the rope tensioner. The WindFollower can easily be lifted off the stick on which it can turn when following the wind. It can be lifted off for upkeep of the rotor with its sails or the all the parts take care for the transmission of the force by the rope drive.
  • The simple stick (color brown) on which the WindFollower can swivel, should be flexible and bent with wind gusts. When the WindRotor should be stuck higher up in the air to catch more wind, then the stick is should get some stays in four or more directions.

  • Internal links

    The WindDrive ask for your imagination ...

    External Links

    • Make your own power FROM SCRATCH!
      We are a group of alternative energy enthusiasts who want to spread the message that It's EASY to make your own power FROM SCRATCH!'s headquarters is located in a remote part of the Northern Colorado mountains, 15 miles past the nearest power pole or phone line. All of our houses and shops run on only solar, wind, water and generator power...not because we are trying to make some sort of political or environmental statement, but because these are the only options available. And we refuse to move to town.
    • Plans and kits for building electric generators with permanent magnets
    • Dutch portal for DIY-wind energy
      About learning the hard way how commercial claims have a large wind content and how to get benefits from a DIY-approach. Many links to information on wind energy in the Dutch language.
    • Send us an email form about any relevant link, that should be added here

    What other people say...

    If you like you can add your own comment

    by tvoivozhd - Sat Dec 06 (2003)
    wind turbines, Hawts, Vawts, lSavonius rotors, low-mass sailwings
    There are innumerable such devices listed in the U.S. and European patent sites.
    A recent good one in the U.S. is the invention of Robert Green. It consists of four sailwings, with opposite pairs connected to each other by a cord to assist in collapse and opening of the parachute wing. They can be stacked like a Savonius for more torque.
    The simple pipe-support is held vertical by four guy-wires. The original model had the pipe-support rotating to transmit power to a ground-level water pump, air pump, etc. Damned dangerous.
    The current model has the power transmitted by a rod inside of the support pipe. Virtue of the thing is that it is dirt cheap, and being low-mass, will produce power in very low wind velocity. Not as efficient as a well-designed wind turbine, but the simplicity, low cost and ease of erection or take-down offsets loss of efficiency for rural pocketbooks.

    You really need a direct drive horizotal wind-turbine for electrical generation, to avoid the energy loss in gearboxes. You might be able to use a low-mass sailwing and a gear-multiplication of some kind with the Green design, by stacking the sails for more torque. It is a drag-device, so it will not rotate at speeds a good permanent magnet generator requires--ergo, the necessity for a power-robbing gearbox.

    by peter broekmeulen - Fri Oct 31 (2003)
    robert green concept
    The difference in winddrive and robert green concept is the way in which the winddrive offers a gear connection because the windwheel is also the big gearwheel and because the big wheel can be with a diameter of 2 mtr and the generator wheel with 10 cm you have a 1:20 distribution. This is probably enough for a standard car generator.

    by Reinder / Demotech - Fri Oct 31 (2003)
    Re: robert green concept
    Peter, please give a link or info on the concept of Robert Green. Regarding the drive-ratio between WindRotor and Generator pulley: a car generator has a far too low efficiency and should not be used. The WindDrive should use a generator that rotates at least at 5000 RPM, With a
  • meter diameter rotor (the diameter on which the sails rotate is smaller!) such a high drive ratio is well possible.
  • by Hans Baarslag - Fri Oct 31 (2003)
    Windmills are normally designed for a windspeed where they work most efficient.One can choose for a lot of blades with low turning speed and alow windspeed that starts them,or a few blades with high turning speed and a higher starting windspeed.A further choice is direct coupling to the grid with a higher efficiency or feeding into a battery.The first choice means maintaining a steady turningspeed because of the frequency of the grid.The second choice limits the quantity of electricity that can be stored and special electricity users or a sophisticated convertor with its inherent loss of overall efficiency.The first observation means one has to know about windspeeds at the place the windmill is planned.Then choices are to be made. Slow windspeeds are more common but higher speeds deliver more.The windspeed after the mill must be appr 70 % of the speed before the windmill as far as I know.How can the winddrive vary in order to adapt at the conditions?The number of sails can vary ofcourse Can they also be made smaller?The diameter of the wheel on the generator can be adapted I suppose Is that a design matter or is it easily changed at a stop?

    by Hans Baarslag - Fri Oct 31 (2003)
    windenergy limiting
    When a windmill is not stopped or turned from the wind in strong winds or gales the electrical devices wil be overloaded and burn out.How do you plan that for the winddrive?

    by peter - Sun Dec 05 (2004)
    more links
    hoi reinder er zijn nog veel meer links naar dit type molen dynamo ik denk dat deze man de initiator is, oorspronkelijk heeft hij voor de engelse ontwikkelingshulp een werkmap gemaakt. wat vind jij van heyt ontwerp groeten peter

    by - Mon Dec 06 (2004)
    wind drive Name
    Simple Aerogenerator Pannirselvam Brasil

    by Hans Baarslag - Sun Dec 04 (2005)
    naam voor winddrive
    Als nederlandse naam stel ik voor: rondzeiler of zeilmolen of zeildrijfwerk. In het engels saildrive, round sailer, enz. Hier zijn dus enige aanknopingspunten voor de zoekmachines. Hans

    by Bert / - Sun Dec 04 (2005)
    Robert Green's "Vertical-axis wind turbine with two-phase sails"
    You can read Robert Green's patent here: It looks very nice but will probably make some noice.

    If you like you can add your own comment

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