An Intermittent Wind Powered Generator
Picture above shows: At one point above ground, natural wind does not always blow at same speed and towards one precise direction. In fact, wind blows intermittently. At one moment, wind speed is high, the next moment the wind speed is slow down. Sometimes wind speed changes violently. Directions of wind is also not precise, it changes from time to time. This is intermittent wind.
Normal wind generators prefer to work in continuously wind and in one direction. In order to make normal wind generators work more efficient, most of generators installed some kind of devices to reduce effects of intermittent wind, such as: install a tail, place blades at high place...
Unlike normal wind generators, This generator is powered by natural intermittent wind.
As pictures above show. A kite-like object (1) to catch wind power is at one end of a wire (8), a weighted object (3) at other end of wire (8). When wind (4) blows very slowly, or wind direction is suddenly changed, kite-like object (1) caught less wind force. Weight (force of gravity) of object (3) is greater than wind force on kite-like object (1), object (3) will go down and drag kite-like object (1) back, see arrow (5). When wind speed is high, wind (4) pushes kite-like object (1) towards windís direction hardly, wind force on object (1) is greater than force of gravity on object (3) and pulls object (3) up.
As nature windís speed and direction change from time to time, the object (3) will go up and down repeatedly. This kind of up and down movement can be used to power an electricity generator or other appliances, such as water pump...
Force of gravity on object (3) can be adjusted by changing its weight. Shape, size and material of kite-like object (1) also can be changed in order to decide how much wind force can be caught. In other words, wind force caught by kite-like object (1) is depending on its design.
Before this intermittent wind powered generator starts to work, there is a balance between force of gravity on object (3) and wind force on object (1). If shape, size and material of kite-like object (1) are decided, in order to get the balance, weight of object (3) should be adjusted. If the weight of object (3) is fixed, then design of object (1) should be changed to get the balance. Intermittent wind force on object (1) often breaks the balance from time to time and cause repeatedly up and down movement of object (3).
Advantage of this generator is: It is very simple, also cheaper to be made. No expensive blades and other contral system are needed.
Disadventage of this generator is: Power output is also intermittent (not continuously).
We built a small version of test model of this generator on my window at a secound floor room. In this test model, the weighted object (3) is replaced by a magnet. The magent will moving inside a coil. The object (1) is replaced by a toy kite. It looks like working from time to time.
This intermittent wind power generator works based on three elements:
1. Speed and direction of natural wind change from time to time. The wind force caught kite-like object (1) also changed form time to time.
2. How much wind force can be caught by kite-like object (1) is depending on its shape, size and material. Some design of object (1) may catch more wind power, other design of object (1) may catch less wind power. If size of kite is larger, lower speed wind is needed to pull the weight object (3) up. Shape of kite-like object (1) is also very important: We tried plactic shoping bags, balloon... and found strange shape of kite may help to break the balance easily.
3. Force of gravity on object (3). The weight of object (3) can be adjusted, for example add another magnet or attract some metal items on magnet.
A toy kite bought from £1 shop.
A short video on Youtube shows some working moments of this test model. Here
But there are many questions to be answered about this generator:
(1) What will happen, if this intermittent wind powered generator is in much large scale?
(2) What kind shape, size and materail of the kite-like object (1) are the best? Specially in very larger scale? Biger size may work better in low wind speed weather, but may too big in strong wind weather?
(3) What will happen if more magnets and more coils in this system?
(4) Can this system be used to pump water from low level to high level?
Other people think about this idea:
From Lee (25 April 2008) (USA)
That's an interesting idea. I wonder what the most fluttery form in the wind would be. I can imagine a wall made from piping with a bunch of these things .... If the flutter parts were all different colors it would be pretty to watch too like a great big animated wall of flowers! Also you might want to mount the coils on back of the feed tube itself and use a small light spring to pull the magnet back instead of gravity.... it would take up less space and give a more reliable movement I think.
Jeanna (25 April 2008) (country unkown)
I will make one. what about a sail on a mast with a couple of lines?
Ben (24 April 2008) (UK)
There is not that much power to be harnessed with this design
einsteinian (28 April 2008) (Youtube)
Hi, I like the idea/concept. I noticed something watching it and wanted to suggest another version. I noticed that the kite likes to stay floating which causes the magnet to spend most of the time in a holding pattern either in or out. I also noticed stronger and tighter pulling force on the tube than the string. My thought, connect kite-tube-magnet like @---o firm, then place magnet end into coil. let me know if you want more info to try it, anyways nice project/video.
**** Reply to this message: Yes, this system is working intermittently. I think we can change the design of kite-like object, to make the kite much easy to un-balance in blowing wind. The shape of the kite I am thinking, is like a big disc, with a wire in center. This kind of shape is very un-even. But I did not test it yet. Regards
From Makezine Blog Editor (28 April 2008) (USA)
This is a fairly inexpensive way to generate power from intermittent wind. This isn't going to power your computer, but it is an interesting concept. I would like to see hundreds of these used to generate power at a more usable level.
me2000r (29 Apr 2008) (Youtube)
One could provide some means of varying the counterweight based on average wind speed, in order to more accurately 'balance' the wind-catching device and the counterweight based on current wind conditions. This should make the system more efficient. Also, consider using a balloon-shape for the wind catcher.
Jonathan (30 April 2008) (UK)
I will put a link to it from my flutter gen page
if its ok with you: http://www.creative-science.org.uk/sharp_flutter.html
I think it would be a great project for someone who lives high up, say
in a tower block. I have tried using a plastic bags as a wind sock
like you have and it worked but I think I never had enough wind really.
sturgeon333 (01 May 2008) (Youtube)
If you add a spring you might make it more efficient. Once the kite pulls the string out fully no more energy is being captured. With a spring you could store some extra energy that gives the magnet a stronger rebound when the wind slows.
Designed by Mr Q Gang
My other ideas:
A Half Bicycle
A car can run on two wheels with a centre of gravity movement system
Make a waterproof outdoor light from recycle water bottle