New household wind turbine, VERY cool!?

Question

Those who have read my Q/A before know that my husband works on the commercial wind turbines. You also know that we eventually plan to build our home totally off grid.

My husband is always doing research on homeowner sized wind turbines.

This is one my husband just learned about. It's pretty darn cool! Basically it works a lot like the electric bullet trains. This allows the turbine to spin MUCH faster than most can withstand, because there is no friction due to the magnets!

Here's the link:

http://www.treehugger.com/files/2007/01/magwind_vertica.php

Comments on this new wind turbine?

Answer 1

Amazing looking bit of kit. Thanks for letting us know about it. Sure my husband will have some questions, will edit if he does. Thanks

Answer 2

In response to  engineer's comments:

It looks like a sophisticated Savonius rotor.  I concur.

These rotors are not very efficient (they operate by drag, not lift) and they are both small and down low in relatively slow-moving air.  They may look cool but they will not generate much energy.  ~~My comment on this starts thus:  what on this earth does LIFT have to do with a wind turbine????  MY background is aviation, lift is what allows an airplane or helicopter to fly, not turn a rotor on a wind turbine.  There are 4 main factors in Aviation: Lift, Thrust, Drag, and Weight.  Since we are not lifting anything off of the ground, weight is a moot point, as is lift.  Thrust is what propels the plane, be it from a propeller or from a jet engine.  Drag is the airplane's  resistance to the wind.  Thrust must overcome drag, and lift must overcome weight.  Everyone with me?  Excellent!

  Wind force is what turns a rotor on a wind turbine, be it a conventional horizontal axis wind generator, or a non conventional "s-rotor" vertical style.  

Commercial scale wind generator manufacturers have not introduced a vertical turbine yet for one main reason.  First some background information.  Homeowner scale turbines can produce DC (Direct Current...what a car makes for example) power, commercial scale generators must produce AC (Alternating Current...house power).  In the US, this power must be 60 HZ (Hertz, also referred to as 60 Cycle.)  This is the frequency.  By way of comparison, part of Japan is on 50 cycle, as are parts of Europe...if not all, on this I am unclear.  Airplanes use 400 cycle power.  Frequency is dependent on how fast you are spinning the generator to a large extent.  Each manufacturer has their own system for keeping the power going out to the "grid" at 60 cycle...be it regulating the speed of the generator or "cleaning up" the power before it leaves the turbine.  

Here is the reason: S-rotors are very hard to regulate the rotational speed on according to the engineers I have spoken to that have worked on these projects, as well as the few articles I have read on them.  This makes them CURRENTLY impractical to use for utility scale wind generation.

HOWEVER...

Since homeowner systems can be used to generate DC current, this problem does not apply.  Your car's alternator does not care if your engine is turning 500 Revolutions Per Minute (RPM) or 12,000 RPM.  (note: other than Top Fuel Dragsters and some motorcycles, most engines will get nowhere near 12,000 RPM)  So, the output off of this vertical style rotor can be used in a small scale system.  

According to the information on the website, their cut-in speed, (the speed it starts to produce power) is under 5 MPH wind speed, most commercial machines do not start to produce power until wind is at least 12 MPH.  The really interesting thing about it is that they are using magnetic levitation to cut friction by a large amount.

Commercial Scale wind turbines shut down at windspeeds of 50-75 MPH depending on the brand.  These guys are claiming that it will run and hold together at over 100 MPH.  That is pretty impressive.  

I would really like to speak to someone that has used one..I am curious.  For those of you that read this far, Yes, I am Garnet's Husband!  <W.E.G.>    

A note to Engineer:  Please try to keep your terminology straight, when people use the wrong terminology, it really makes them look...well, let us go with "Not so Bright."

Hope this helps some folks,

D_Offio

Answer 3

You are a gem of information regarding alternative energy Bohemian Garnet.  Since I'm no expert on what the specifications quoted on the website actually mean as to power production, can you give more information to answer the comments of  "Engineer"?

Answer 4

whoa thats cool

Answer 5

It looks like a sophisticated Savonius rotor.

These rotors are not very efficient (they operate by drag, not lift) and they are both small and down low in relatively slow-moving air.  They may look cool but they will not generate much energy.