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Ever more wind turbines to be erected..

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Ever more wind turbines to be erected..

Old 15th Jun 2014, 05:42
  #41 (permalink)  
 
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I like the alternatives probes illustrated for us - but are they as efficient at bird mincing than the ones currently blighting the landscape? We need to be told!
- well, the sad fact is that actually all kinds of phone masts and TV towers (other communications, too) kill a considerable number of birds, too (saw some numbers in a study a couple of years ago, on paper, therefore no link - sarcastic, I really do store them for my job). Also there are so many so interesting alternatives by now, I'm sure something will be used - better than the towering ones now that are costly and environmentally unfriendly to manufacture. The vertical axis looks interesting (but I'm still only dreaming of my own little one on the roof! One day, maybe...)

Small Wind Turbines - Small Wind Turbine Manufacturers - All Small Wind Turbines.com

the Japanese 'wind lens' sounds interesting as well (not for a household, but) Japanese breakthrough will make wind power cheaper than nuclear | MNN - Mother Nature Network#


P.S btw, hydropower takes its toll on environment, too. In the States hundreds of dams have been demolished and river-life restored Why We Remove Dams | American Rivers
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Old 15th Jun 2014, 06:10
  #42 (permalink)  
 
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The RSPB's merchandising of bird tables has very successfully brought millions of birds into killing range of the domestic cat, another unintended consequence.


All is never as it seems, when the oil tanker Braer ran aground the official final toll of oiled birds was 1300. In the same stormy spell at least 100,000 birds died due to exposure and starvation.
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Old 15th Jun 2014, 08:21
  #43 (permalink)  
 
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One has to admire the French for their determination to avoid total reliance on external energy sources.
If we had continued to invest in nuclear as they have done we'd be in a far better place.
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Old 15th Jun 2014, 08:50
  #44 (permalink)  
 
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I'm with NRWSG - I believe there's a very good case for wind turbines to generate a sizeable proportion of our power needs - but the efficiencies and the style of the current designs, are pretty pathetic.
Propeller-style wind turbines are 19th century stuff. They are terribly inefficient, they kill birds, and they produce undesirable LF noise.
They are extremely limited in windpower applications, in their basically inherent poor design.

Probes is on the mark. The Darrius and Savonius turbine designs are a step forward - but there's another turbine that is a huge step forward again.
This turbine was actually patented by Tesla in 1913, but he couldn't get actual efficiency to match theoretical efficiency, until improved machining and production techniques, and improved materials of the late 20th century, brought the idea to the fore again.

The Tesla turbine is bladeless, is highly efficient, is quiet, and is constructed with a mesh grate on the intake so that birds can't be injured by it. It operates on the boundary layer principles of airflow.
It's a winner in my mind, and it's time the current designs were scrapped and contracts given to companies that will design and produce a viable Tesla wind turbine.

https://www.youtube.com/watch?v=mrnul6ixX90

Here is the prototype Fuller Wind Turbine that utilises the Tesla turbine design.

Bladeless wind turbine inspired by Tesla
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Old 15th Jun 2014, 10:00
  #45 (permalink)  
 
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One has to admire the French for their determination to avoid total reliance on external energy sources.
If we had continued to invest in nuclear as they have done we'd be in a far better place.
Yea I am sort of addicted to those two real time grid websites. The Frogs power demand had dropped off a while back, so their nukes where pumping out a huge percentage more for a while getting exported.
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Old 15th Jun 2014, 10:07
  #46 (permalink)  
 
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So there's wind blowing somewhere all the time. How big a grid is needed to exploit that and how much power gets lost in the long distance transmission?

How much energy can be extracted from the wind before there's an adverse environmental effect? Do we even know? The same question arises with cutting off solar radiation by intercepting it with solar cells.

I was told that in New Zealand, where they have a geothermal power station, the number of geysers around Rotorua and their height and eruption frequency have decreased over the years.....so it seems that extracting energy from nature has its drawbacks even if we don't yet know what they are.
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Old 15th Jun 2014, 10:23
  #47 (permalink)  
 
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So there's wind blowing somewhere all the time. How big a grid is needed to exploit that and how much power gets lost in the long distance transmission?
But radeng, that's the whole point of a transmission system ... to move power over large distances in an efficient manner. Also, this new grid may be largely offshore, so not as intrusive as the normal tower line structures. I'm not saying that wind is by any means the whole answer, but we have the technology now to make it a worthwhile part.
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Old 15th Jun 2014, 10:26
  #48 (permalink)  
 
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Back in the late 70's I remember seeing work that was being done at Edinburgh University on wave power, and a number of different types of device to derive electricity from the bobbing up and down action. There seemed to be a lot of work going on at the time, but it all went quiet in the 80's. It would be interesting to see why it was not progressed.
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Old 15th Jun 2014, 10:29
  #49 (permalink)  
 
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There ISN'T wind blowing somewhere all the time! Remember the winter of 1962/3? Massive area of high pressure over the UK for months. That brought clear skies which in winter led to many weeks of temperatures way below zero, And of course there was no wind anywhere under the wide influence of the high pressure system.

Thankfully we had coal back then, and first-generation nuclear power was just dawning.

Politicians love windmills as the Daily Mail reader sees these only too visible monstrosities and thinks 'oh goody, the gov is doing something about impending power shortages'. In fact it's doing stuff all.

We need reliable core power - nuclear power - and we need it NOW! (So we should have started building it at least 10 years ago!). And we need to keep all the coal fired stations on line (no silly biomass) until nuclear replacements are in place.
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Old 15th Jun 2014, 10:31
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Propeller-style wind turbines are 19th century stuff. They are terribly inefficient, they kill birds, and they produce undesirable LF noise.
They are extremely limited in windpower applications, in their basically inherent poor design.
Onetrack, If you check out some of the most modern large turbines, from say Enercon or Vestas you'll find that they are extremely efficient and quiet, especially the Enercon machines which have blade tip winglets and no gearboxes. An unfortunate aspect of the overall strategy in the UK has been the siting of large numbers of turbines in relatively low wind areas.
Contrary to belief there's an extensive grid network well up into the Scottish Highlands, a legacy of the hydro electric developments of the 1950's. Annual productivity of 50-60% of rated power is common in these areas. If development had been more market driven rather than driven by financial inducements these remote areas would have seen many more turbines as the low wind and usually densely populated sites would not have been viable.
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Old 15th Jun 2014, 11:08
  #51 (permalink)  
 
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Shaggy Sheep Driver; tilting at windmills can be the new national sport...
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Old 15th Jun 2014, 11:15
  #52 (permalink)  
 
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"An unfortunate aspect of the overall strategy in the UK has been the siting of large numbers of turbines in relatively low wind areas."

Which everyone has to pay for for years to come and no one will hold the greenies responsible because "as long as it's clean and green" is all they care about, regardless of whether it is cost effective.

Most subsidies are now being cut to the bone or totally abolished here in Aus, especially if it has anything to do with Carbon, Wind and Solar because too much has been ripped off the Gov't in the past and someone has at last said enough is enough.

Not 100% sure I agree with it but that is what happens in the long run if you pull the wool over peoples eyes.
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Old 15th Jun 2014, 11:15
  #53 (permalink)  
 
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Vertical Axis machines have been experimented with for a number of years now, but there are a number of practical problems and they are not as efficient as Horizontal axis machines of the same size. Think about it the blades travel through the air flow in different directions which causes interference and vibration.
This has also been proved by taking power curves for the various types of machines using standard measurements which include wind speeds, atmospheric pressure, temperature and Humidity by an internationally agreed methodology.

As for the Tesla machines it would be interesting to see a properly accredited power curve measurements taken for the system to confirm the claims made for them.

If you want to blame any body for the lack of development in nuclear energy in the UK Blame Maggie Thatcher*, when the old supply networks were sold off the new companies looked at Nuclear realised that there was a lot of hidden costs which had been borne by the MOD and went for Gas generation which gave quick large returns on any investment for the short term which was the ethos at that time. EDF is still part owned by the French Government. Market forces at work again.

* Didn't the Tories start the subsidies on wind to try and catch the Green vote!
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Old 15th Jun 2014, 11:38
  #54 (permalink)  
 
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thanks, onetrack, very interesting! (the noise, though... )

And
it seems that extracting energy from nature has its drawbacks even if we don't yet know what they are.
sure, everything has its drawbacks.

as for the underwater devices - most tend to influence sediment, and if it starts to settle in wrong places, it won't do.
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Old 15th Jun 2014, 22:59
  #55 (permalink)  
 
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I don't see how better design for a single stage can get you past Betz's rule and present day turbines get to within 80 or so percent of that. There are a couple of stability questions that need to be answered though. Requiring that wind power, if available, be purchased first makes investment in conventional power less attractive. Another problem is that present generators are not synchronous machines. If more than 20% or so of nameplate capacity connected to a grid is derived from induction machines, like present day wind turbines, the grid becomes unstable and will shut down, probably damaging expensive machinery on the way.

As an aside, I have read that the University of Delaware has proposed siting large wind farms in such a way as to mitigate or eliminate the effects of hurricanes. If that be true, what are the existing farms already doing to the weather??

After an excellent landing etc...
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Old 15th Jun 2014, 23:06
  #56 (permalink)  
 
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"Requiring that wind power, if available, be purchased first makes investment in conventional power less attractive."

That is wrong for a start. Why should wind get a free run.

How about Wind Turbines are not built until the economic case for them is proven instead of it all done by subsidies ?

How much do some of these Wind generating companies get paid without actually producing anything ?
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Old 16th Jun 2014, 02:38
  #57 (permalink)  
 
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Ogre - Wave energy R&D is ongoing, and the research is all about trying to find the most viable and most efficient system. A trial WE unit has just been installed and is about ready to be commissioned, at Garden Island Naval Base, just off the cost of Perth, Western Australia. It looks promising.

CETO Commercial Scale Unit Overview

I have to agree with little cloud - subsidies are largely poorly structured, and market-driven systems are the way to go.
However, subsidies do play a part in getting new systems established and encouraging R&D - provided those subsidies are limited, they're properly targetted, and they're not just used as a constant source of funding to keep companies in business, that would otherwise fail.
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Old 16th Jun 2014, 02:55
  #58 (permalink)  
 
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R&D should be totally separate from any subsidies, if any subsidies are needed at all.
R&D can be written off in Aus by companies.

Why should Wind, Solar power etc get subsidies when other companies don't ?
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Old 16th Jun 2014, 04:10
  #59 (permalink)  
 
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Onetrack.
Fascinating video of that Tesla turbine running.

I don't quite see how it would replace a wind turbine though?

I can certainly see how it could replace a turbocharger, or a compressor in a jet engine very successfully, it's a brilliant idea.

How would you get all that air mass that turns a conventional wind turbine, to go down the inlet of the tesla?
The second vid seems to suggest it's not a problem, but could you explain please?
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Old 16th Jun 2014, 05:05
  #60 (permalink)  
 
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Atomkraft:
How would you get all that air mass that turns a conventional wind turbine, to go down the inlet of the tesla?
Well, I can't tell you, and I guess that's why the Tesla turbine is still being studied and experimented with. Obviously, how to get adequate wind pressure guided onto the turbine discs needs to be explored further. Perhaps funnelling it, would assist.

The simple and obvious technique is to build a much larger version of Fullers prototype, which would provide a far larger output. Personally, I would consider adding an exhaust tube to his Tesla wind turbine, at right angles to wind flow - to add a venturi effect, which would assist in speeding up air flow through the turbine. Fuller is an aviation man, he does understand airflow!

Tesla didn't invent his turbine with wind in mind. However, the design lends itself to usage in positions such as geothermal steam turbines, where the Tesla turbine can take full advantage of the pressure of either steam or just hot artesian water under pressure.
There's a lot of research yet to be done, but I'm sure someone will find a way to improve wind turbines so they perform at greater efficiencies than they do now.
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