Recent Comment
Share
Urban turbines are no simple matter. To really pull a good amount of power from the wind, it helps to have a turbine with a fairly large diameter, and to have a big turbine, you need a big plot of land.
Unfortunately, most of us just don't have huge...tracts of land. The solution, however, may soon be within reach with the help of modular wind turbines. While other small wind turbines we've featured have decreased the footprint considerably, these modular turbines can fit just about anywhere, be arranged into any shape, and can pull power from the air even in very low-wind environments. Wind speeds as slow as 2 m/s will start the juice flowing.
The miniturbines are already for sale, but it looks to me like mass production could easily bring down the price considerably (from $150 for 8 miniturbines.) But even now, only one square meter of miniturbines will produce 131 kw/yr in a 5 m/s wind environment. Most houses, though will be able to find quite a bit more than 1 square meter, and in higher wind areas, these little guys could easily shave hundreds off home energy bils with a truly simple and elegant design that won't even disturb the neighbors.
Via: Inhabitat
Hits: 10890
Comments (9)
Subscribe to this comment's feed
written by monotonehell, April 02, 2007
Two questions if anyone knows:
1. How much noise do these little gems make?
2. In the picture they seem to be linked by cogs. Does this mean that there will be differential torque power losses as each tries to work against the other if there's a speed difference across the chain?
1. How much noise do these little gems make?
2. In the picture they seem to be linked by cogs. Does this mean that there will be differential torque power losses as each tries to work against the other if there's a speed difference across the chain?
-
- +0
-
-
written by Hank, April 03, 2007
MTH -
I can only guess that there will be power loss if the power isn't even across the whole chain. I'm not too familiar with the physics of it, but there must be some good reason why they've linked them all together.
Second, all wind turbines make some noise, but these would likely make more, unless the cogs fit perfectly. I doubt they would. That would be another drawback to the system.
I can only guess that there will be power loss if the power isn't even across the whole chain. I'm not too familiar with the physics of it, but there must be some good reason why they've linked them all together.
Second, all wind turbines make some noise, but these would likely make more, unless the cogs fit perfectly. I doubt they would. That would be another drawback to the system.
-
- +0
-
-
written by Kris, April 04, 2007
MTH-
In the absence of frictional forces due to the turbines' axes and cog interfaces, the absolute value of the torques from each turbine would add cumulatively. Thus, in terms of total usable torque, wind power would only be `lost' if it were to attempt to blow one turbine from one side and another from the other side (due to the behaviour of the cogs). Since a gust of wind would usually only approach the turbine array from one side (on this scale), this shouldn't be an issue. i.e. (neglecting frictional forces from the axes and cogs) due to the configuration of the cogs and assuming the wind approaches from only one side of the array, there is no issue with individual turbines countering the torque of the others.
Hope this helps...
Kris
In the absence of frictional forces due to the turbines' axes and cog interfaces, the absolute value of the torques from each turbine would add cumulatively. Thus, in terms of total usable torque, wind power would only be `lost' if it were to attempt to blow one turbine from one side and another from the other side (due to the behaviour of the cogs). Since a gust of wind would usually only approach the turbine array from one side (on this scale), this shouldn't be an issue. i.e. (neglecting frictional forces from the axes and cogs) due to the configuration of the cogs and assuming the wind approaches from only one side of the array, there is no issue with individual turbines countering the torque of the others.
Hope this helps...
Kris
-
- +0
-
-
written by talamaska, April 04, 2007
that isn't true. I think the mini-turbines are placed checkmately in opposite direction. the blades are turned in different direction so when the wind blows it will power all the turbines but half of it will turn in opposite direction.can u dig it?
-
- +0
-
-
written by monotonehell, April 04, 2007
@Hank & Kris: The reason I worried about the loss is that this kind of thing and the whole wind dynamics of buildings and urban areas do set up a lot of micro-turbulence.
So now I'm conflicted. Talking it through; If A is moving more slowly than B then the result will be a maximum of the slower one, A. So what's the point of having them all linked in this fixed way if the accumulative effect results in no extra work done? Or am I getting my knickers in a knot?
@talamaska: Yes I realise that each alternate unit's fins are reversed so that one drives its mate clockwise then counter-clockwise. I'm talking about losses in the system by relative differential speeds between the units.
So now I'm conflicted. Talking it through; If A is moving more slowly than B then the result will be a maximum of the slower one, A. So what's the point of having them all linked in this fixed way if the accumulative effect results in no extra work done? Or am I getting my knickers in a knot?
@talamaska: Yes I realise that each alternate unit's fins are reversed so that one drives its mate clockwise then counter-clockwise. I'm talking about losses in the system by relative differential speeds between the units.
-
- +0
-
-
written by Kris, April 05, 2007
Monotonehell,
I see what you mean a little more clearly now, but my above explanation still holds. The point is that the turbines have to move at the SAME rate because they are connected as such (and have the same diameter). The speed at which they all will rotate is determined by the cumulative torque provided by the combined turbines.
So I think your question is best answered by the first point: that all turbines must rotate at the same rate because of the way they are connected. The second point explains what will happen in a differential wind profile.
Is this any better than my first attempt?
Talamaska - Cheers for the observation :) I hadn't noticed that the orientations are mirrored for adjoining turbines (even though they HAVE to be that way for the thing to work :p ).
So in the end, I think this design is really quite elegant. The only real `losses' will come from the axial friction, moment of inertia of each turbine (which will be pretty small as they are apparently plastic), the friction between the cogs, the orientation of the array to the direction of wind approach (for each turbine if you want to consider micro-currents), and the efficiency of each turbine in converting the supplied air pressure to torque.
I see what you mean a little more clearly now, but my above explanation still holds. The point is that the turbines have to move at the SAME rate because they are connected as such (and have the same diameter). The speed at which they all will rotate is determined by the cumulative torque provided by the combined turbines.
So I think your question is best answered by the first point: that all turbines must rotate at the same rate because of the way they are connected. The second point explains what will happen in a differential wind profile.
Is this any better than my first attempt?
Talamaska - Cheers for the observation :) I hadn't noticed that the orientations are mirrored for adjoining turbines (even though they HAVE to be that way for the thing to work :p ).
So in the end, I think this design is really quite elegant. The only real `losses' will come from the axial friction, moment of inertia of each turbine (which will be pretty small as they are apparently plastic), the friction between the cogs, the orientation of the array to the direction of wind approach (for each turbine if you want to consider micro-currents), and the efficiency of each turbine in converting the supplied air pressure to torque.
-
- +0
-
-
written by Adrian Akau, May 13, 2007
The first problem is that the voltage on each turbine is low and most grid tie inverters work best at about 200-500 VDC range. Even if the voltage from the turbines were in series, if the micro turbines were spinning at different rpm's, the voltages would be different and the slowest spinning turbine would limit the power of the faster moving ones.
The second problem is that postage from Hong Kong is $300 for a set of 20. I wrote to this company and that is what I was told. Howver, even if 100 micro turbines were orderd, the postage would still be about the same.
The third problem is that they are relativly fixed devices. They would most likely be best used as battery chargers or taken along on camping trips to supply emergency power.
This e-mail address is being protected from spambots. You need JavaScript enabled to view it
The second problem is that postage from Hong Kong is $300 for a set of 20. I wrote to this company and that is what I was told. Howver, even if 100 micro turbines were orderd, the postage would still be about the same.
The third problem is that they are relativly fixed devices. They would most likely be best used as battery chargers or taken along on camping trips to supply emergency power.
This e-mail address is being protected from spambots. You need JavaScript enabled to view it
-
- +0
-
-
Write comment
| < Prev | Next > |
|---|
What are they being made of at present?
P.S. I love the Python reference in the second para. ;)