Interesting Wind Power Concept

[orogenicman]

This is a very interesting concept. Just thought I would post this here to see what others think of it:

http://news.discovery.com/tech/wind-powe...lades.html

[ib.me.ub]

Any concept that draws on environmentally friendly resources is a good idea in my book! If it works.

[Autumnlicious]

I was under the impression that piezoelectrics weren't very efficient. And carbon fiber is still a new technology.

However, it will work well for areas with chaotic winds. But high wind locations, usually where most wind farms are, are consistent, or so I thought. The chaotic motion of enough densely packed 'hairs' of these things might make it tenable too.

Looks like the surface of a giant ear drum.

I'd prefer these if one can get greater or equal to power out of these things compared to a wind farm of the same square footage.

[Anomalocaris]

Several things about this idea seems wrong to me:

1. The stalk generators will not be frictionless as the article claims because there will be hysteresis loss in the carbon fiber resin composite tubes with each sway.

2. The stalks can't be packed very close like article suggests because the stalks can hit each other as they sway.

3. It not clear if the much larger numbers of thrashing stalks required to generate the same power as 3 big wind turbine blades would really be safer to birds

4. These stalks can only generate power when the wind speed or velocity is continuously varying. If the wind holds stead, hysteresis loss will quickly damp out the swaying and the stalks will simply stayed bent over, thus stop generating any power. So these stalk generators can not product highly reliable power. Conventional wind turbine can produce highly reliable power if wind holds steady. Highly reliable power is disproportionally valuable from green perspective because they reduce the need to run normal gas fired power plant at highly inefficient regime to provide regulation service to damp out fluncturations in wind power.

5. These stalk generators seems to have no provision to regulate their outputs like conventional wind turbine with variable pitch turbine blades can, so they impose additional polluting regulation service requirement on the power grid.

6. They will not be quite like the article claims. They will produce wind noises as they sway just like wind turbine blades would as rotate.

7. There seems to be no way to keep these stalks swaying excessively in very high wind except by building them excessively strong for normal operation. Normal wind turbine can simply feather their turbine blades to eliminate effects of very high wind. They same problem also arises when there is need to stop the stalks swaying to perform maintenance. Turbine can be stopped by simply feathering the blades. The stalks can't be stopped unless the wind stops.

[ib.me.ub]

The article actually talks about friction loss associated with more mechanical systems, not the system being frictionless.

[orogenicman]

Several things about this idea seems wrong to me:

1. The stalk generators will not be frictionless as the article claims because there will be hysteresis loss in the carbon fiber resin composite tubes with each sway.

2. The stalks can't be packed very close like article suggests because the stalks can hit each other as they sway.

3. It not clear if the much larger numbers of thrashing stalks required to generate the same power as 3 big wind turbine blades would really be safer to birds

4. These stalks can only generate power when the wind speed or velocity is continuously varying. If the wind holds stead, hysteresis loss will quickly damp out the swaying and the stalks will simply stayed bent over, thus stop generating any power. So these stalk generators can not product highly reliable power. Conventional wind turbine can produce highly reliable power if wind holds steady. Highly reliable power is disproportionally valuable from green perspective because they reduce the need to run normal gas fired power plant at highly inefficient regime to provide regulation service to damp out fluncturations in wind power.

5. These stalk generators seems to have no provision to regulate their outputs like conventional wind turbine with variable pitch turbine blades can, so they impose additional polluting regulation service requirement on the power grid.

6. They will not be quite like the article claims. They will produce wind noises as they sway just like wind turbine blades would as rotate.

7. There seems to be no way to keep these stalks swaying excessively in very high wind except by building them excessively strong for normal operation. Normal wind turbine can simply feather their turbine blades to eliminate effects of very high wind. They same problem also arises when there is need to stop the stalks swaying to perform maintenance. Turbine can be stopped by simply feathering the blades. The stalks can't be stopped unless the wind stops.

1) I think Scotty addressed this one.

2) Why would it be a problem for these stalks to come into contact with each other?

3) One would think that these stalks would be more natural to birds than wind generators, since, except for the fact that they don't have branches, they look a bit like trees.

4) My understanding is that any movement would create electricity. I just find it unlikely that any location where they could be installed would have such utterly constant wind velocity that you envision. Perhaps it could actually be located in more places than typical wind farms because constant wind velocity would not be a requirement.

5) Huh?

6) I can imagine that they would produce some kind of noise, most likely a whistling or swoshing noise, a bit like wind blowing through trees, but not as loud because they have no leaves. I don't see it as being a problem in areas where wind farms are typically located.

7) It appears to me that the design indicates that the only maintenance would be at the base of the stalk. If there is a problem with the stalk itself, I would think that the only thing you could do would be to replace it. As far as maintenance in excsssive wind conditions, you would simply not work on them under such extreme conditions. I doubt if even wind farms are worked on in extreme wind conditions.

I think most of these issues could be worked out once a demonstration project is designed and built. It is an interesting concept, but I admit that I don't understand all of the issues that could arise with such a system, the biggest one for me, of course, being whether or not it could generate enough electricity to make it worth the effort and expense. Thanks for posting your thoughts on the subject.

[Anomalocaris]

1) I think Scotty addressed this one.

2) Why would it be a problem for these stalks to come into contact with each other?

3) One would think that these stalks would be more natural to birds than wind generators, since, except for the fact that they don't have branches, they look a bit like trees.

4) My understanding is that any movement would create electricity. I just find it unlikely that any location where they could be installed would have such utterly constant wind velocity that you envision. Perhaps it could actually be located in more places than typical wind farms because constant wind velocity would not be a requirement.

5) Huh?

6) I can imagine that they would produce some kind of noise, most likely a whistling or swoshing noise, a bit like wind blowing through trees, but not as loud because they have no leaves. I don't see it as being a problem in areas where wind farms are typically located.

7) It appears to me that the design indicates that the only maintenance would be at the base of the stalk. If there is a problem with the stalk itself, I would think that the only thing you could do would be to replace it. As far as maintenance in excsssive wind conditions, you would simply not work on them under such extreme conditions. I doubt if even wind farms are worked on in extreme wind conditions.

I think most of these issues could be worked out once a demonstration project is designed and built. It is an interesting concept, but I admit that I don't understand all of the issues that could arise with such a system, the biggest one for me, of course, being whether or not it could generate enough electricity to make it worth the effort and expense. Thanks for posting your thoughts on the subject.

1. The fact that system is not fundamentally frictionless means there will be wear and tear, and it's not clear how the hysteresis loss will impact its mechanical efficiency.

2. Even mild contacts between swaying stalks will impart local loads and stresses near points of contact much higher than the stalks would experience as part of normal swaying, and will also create complex oscillation modes and frequencies throughout the length of the stalk not normally to be expected in normal swaying. Carbon fiber in matrix structures are not particular tough under impact load. So possibility of contact will require the stalks be made much more robust, heavy, and thus more costly and inefficient than otherwise.

3. I am not sure if a dense field of comparatively very thin, swaying stalks will appear to birds to be something for which they would have appropriate instincts.

4. The point is a supposedly green generating resource that can not produce a reasonably constant output over time scale of a 5 or 10 minutes is not very green. The power grid can't just take any power. It must take power offered, along with power services required to ensure grid reliability in voltage and frequency. This means if it were to take power from a source that fluncturates quickly, like this stalk field, It must also simultaneously take rapidly centrally controllable power, called regulation service, to damp out short term fluctuations in the green resource. Fast response units capable of providing good regulation service tends to thermally inefficient, and providing this regulation service would further require that they run in an suboptimal part of their output range. So the green generation that can't maintain reasonably constant output must then account for the emissions of the regulating thermal resources they require to provide useful power to the grid. When that is factored in, the fluctuation in output in a green renewable resource would indeed be quite costly in both non-renewable fuel and ghg emissions.

5. There is no way to independently modulate the output of the stalk field to provide smoother power output like one could conventional wind turbines with variable pitch blades.

6. Wind turbines are not loud, but people complain about their noises anyway.

7. The point is stalk fields can't be worked on even in a light wind because there is no provision to fix a stalk and prevent it moving. Wind turbines can feather their blades and lock their shafts.