Calling all engineers: I need you to tell me why an idea won’t work.
Our writer Jim has been investigating grassroots efforts to develop a system for DIY windmills for electrical generation. He built a cardboard model and everything.
Jim’s next step, he says, is to work with PVC materials instead of cardboard, to build something more durable. But, is that necessary? What if there were already systems designed to catch the air just right and turn around and around at high speeds over great lengths of time while attached to electrical power?
Those components DO already exist.
I saw one in my window last night. Watching a box fan that I had set up in the window last week to pump cool air into my house at night, I saw the blades turning around and around – even though the fan was turned off. The same blades that have been designed to push air can in turn be pushed by air.
Furthermore, the aerodynamic blades on these fans are already attached to motors.
Now, I’m no engineer. I’m certainly not an electrician. I, like Jim, am not very handy. However, it seems to me that all across America there are box fans of these types, with blades preformed just right to catch the wind, just right to be retrofitted as windmills.
Instead of using these fans to consume electricity, couldn’t we be adapting them to create electricity?
Would the motors these fans are already attached to be suited for working in reverse, to help transform the mechanical energy of the blades in the wind into electrical energy? What would it take to effect that transformation?
At the very least, couldn’t these round assemblages of fan blades be taken and attached to other motors for electrical generation? Couldn’t we recycle the blades of broken fans, thrown-away fans, for this purpose?
Could this be our generation’s version of swords into plowshares – window fans into windmills?
I don’t have expertise in this matter, so I’m looking for the opinion of people who do. Engineers, explain to me what’s wrong with this idea. What makes it impractical? Why couldn’t it work?
Why is it, if we can have fans to blow the air in every house in America, that we could not have small-scale windmills for electrical generation in every house in America as well?
Hey, check it out over here: scroll down to where it says “Removed from cheap desktop electric fans, these usually have 4 or 6 wide blades, and also work very well”… great!
Yeh, pretty good idea. An electric motor turns electrical energy into rotating motion and will turn rotating motion into electricity. No changes required (Although you’d be well advised to tear out all the wiring inbetween the motor and the plug – there might be diodes to make sure power only goes one way, or resistors/fuses to protect the motor from full mains power – these will just limit your output). I’m no engineer (undergrad physicist though) but the only thing I can see as a problem with this is the tendency for cheaply made electrical goods to be made to break after a year or so. Have a go, see how it works
This is being done everywhere! Just search for ”Box Fan Windmill” (which is how I fiound this page!). You can add permanent magnets to ther armature of the AC motor and its existing coils thereb creating an alternator which generaters AC voltage that is rectified to DC to store in battery system.
Alternately, you can rob the blades and put them on a small stepper motor and have a very reliable, ”instant” low power windmill. I have one of these mounted on a 14′ pole that is capable of generating 15 watts in a 20 mph wind and a maximum 20 watts in higher winds.