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-   -   Proposed wind farm impacts Cobden ALA future (https://www.pprune.org/pacific-general-aviation-questions/602580-proposed-wind-farm-impacts-cobden-ala-future.html)

Paul O'Rourke 30th Nov 2017 22:57

Proposed wind farm impacts Cobden ALA future
 
Alinta Energy has lodged a planning application with the Victorian Government to build 12 wind turbines 180 metres (590’) from ground level to maximum blade tip height.
The closest turbine will be approximately 2.6 kms from the northern end of the Cobden airstrip and just off the centreline. As it is an ALA the turbines do not encroach splays and inner horizontal surfaces are not relevant as the strip is not registered. The issue is compounded due to the fact of rising terrain immediately to the north of the airport in addition to turbine height for both normal and emergency conditions.

In 2013 the Victorian Liberal Government’s aviation development fund granted $200,000 to help seal the strip in addition to $60k (and counting) raised by the community to improve access for air ambulance. My understanding is the Victorian Government have usurped the authority of the Corangamite shire and will handle this themselves. The planning department is now calling for submissions by 22 nd December. With a State election late next year, approval of this development will see expedited development, in my opinion

Does anyone have first hand experience of a wind farm impacting on an ALA and commercial/emergency operators use of such strips? Have there been any successful challenges to the their construction in relation to ALA proximity? If so, what did you do to achieve this?

Planning Application

CASA ADVICE

AVIATION IMPACT REPORT

Flying Binghi 30th Nov 2017 23:33

Probably a search of the Stop These Things web site will offer something of use: https://stopthesethings.com


A quick search of Stop These Things came up with an airport owners win. COPA were involved so may have some advise to offer on the matter:

"...There were also several side parties to the appeal, including the Canadian Owners and Pilots Association..."

https://stopthesethings.com/2017/08/...to-human-life/


Also: "...4 dead as plane crashes at South Dakota wind farm..."

In Oz:"...Whilst on descent to my operating airstrip near Biala NSW, I suddenly experienced severe turbulence at about 500-600ft AGL. The wind at this time had been approx. 5-8 knots from the SE. After landing I ascertained that there was only a slight breeze at ground level. I suspected that the turbulence was caused by the wind turbines at the Gunning Wind Farm but was amazed that the effect could be felt 9kms away..."

https://stopthesethings.com/2014/05/...-south-dakota/






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lo_lyf 1st Dec 2017 02:36

2.6kms. No biggie.

layman 1st Dec 2017 04:53

Flying Binghi

blaming towers 9 kilometres away is a bit of a stretch.

Maximum leeward windbreak effect is usually calculated at 30 times the height of the highest tree (and that is for conifers with around 40-60% density - much denser than 3 rotating blades)

The Gunning towers are 80 metres + 1/2 the rotor (49.5) metres gives effect distance of approximately 3 or so kilometres - well short of the 9 kilometres claimed.

regards
layman

Flying Binghi 1st Dec 2017 05:43


Originally Posted by layman (Post 9974958)
Flying Binghi

blaming towers 9 kilometres away is a bit of a stretch.

Maximum leeward windbreak effect is usually calculated at 30 times the height of the highest tree (and that is for conifers with around 40-60% density - much denser than 3 rotating blades)

The Gunning towers are 80 metres + 1/2 the rotor (49.5) metres gives effect distance of approximately 3 or so kilometres - well short of the 9 kilometres claimed.

I didn't realise trees had rotating branches..:hmm:

Layman, next time yer taking off behind a pax jet is it the wind break effect of the wings that are of concern or is it what comes off the end of the wings ?

For the effect have a look-see at the piccys in this link: https://stopthesethings.com/2014/05/...-south-dakota/





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Connedrod 1st Dec 2017 06:48


Originally Posted by layman (Post 9974958)
Flying Binghi

blaming towers 9 kilometres away is a bit of a stretch.

Maximum leeward windbreak effect is usually calculated at 30 times the height of the highest tree (and that is for conifers with around 40-60% density - much denser than 3 rotating blades)

The Gunning towers are 80 metres + 1/2 the rotor (49.5) metres gives effect distance of approximately 3 or so kilometres - well short of the 9 kilometres claimed.

regards
layman


I guess you havent talked to the local top dresser yet. Clearly you havent flown intowards one yet.

layman 1st Dec 2017 23:31

The 30 times effect from a static windbreak was measured using wind speeds of around 16 knots, not the 5-8 knots in the article. The lower wind speed would further reduce the effect to much less than the 3 kms research has shown.

Research on wind turbines has suggested keeping aircraft at least '30 blade diameters' from a wind turbines although this was measured at much higher wind speeds (up to 27 knots).

30 blade diameters is still less than 3 kilometres in the case of the Gunning wind farm (40 metre blades + hub diameter)

I haven't flown near them at low level but 9 km away is still a stretch to claim the turbulence was solely from the wind turbines. Over those distances there may have been other effects from the surrounding environment impacting on aircraft (heat turbulence? topology?)

regards
layman

Connedrod 1st Dec 2017 23:57


Originally Posted by layman (Post 9975915)
The 30 times effect from a static windbreak was measured using wind speeds of around 16 knots, not the 5-8 knots in the article. The lower wind speed would further reduce the effect to much less than the 3 kms research has shown.

Research on wind turbines has suggested keeping aircraft at least '30 blade diameters' from a wind turbines although this was measured at much higher wind speeds (up to 27 knots).

30 blade diameters is still less than 3 kilometres in the case of the Gunning wind farm (40 metre blades + hub diameter)

I haven't flown near them at low level but 9 km away is still a stretch to claim the turbulence was solely from the wind turbines. Over those distances there may have been other effects from the surrounding environment impacting on aircraft (heat turbulence? topology?)

regards
layman

Me thinks you forgot to add your dicloser

Written and spoken on behalf of the wind turbine companys recriveing more than $60 Billion from tne australian tax payer.
Ted had turbulence 20km from the turbines. So go ask him, he have livded and flowen in the district since time began.

Flying Binghi 2nd Dec 2017 00:53


Originally Posted by layman (Post 9975915)
The 30 times effect from a static windbreak was measured using wind speeds of around 16 knots, not the 5-8 knots in the article. The lower wind speed would further reduce the effect to much less than the 3 kms research has shown.

Research on wind turbines has suggested keeping aircraft at least '30 blade diameters' from a wind turbines although this was measured at much higher wind speeds (up to 27 knots).

30 blade diameters is still less than 3 kilometres in the case of the Gunning wind farm (40 metre blades + hub diameter)

I haven't flown near them at low level but 9 km away is still a stretch to claim the turbulence was solely from the wind turbines. Over those distances there may have been other effects from the surrounding environment impacting on aircraft (heat turbulence? topology?)...

What research ?

As I have found in the 10 odd years I've been looking into the global warming 'industry' the claims of "research has suggested" just never pan out. So some links to this research please..:)





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jonkster 2nd Dec 2017 02:14

Research I have seen used lidar to measure turbulence from wind turbines in farms located near runways in the UK and (if I recall correctly) indicated potential problems within 5 times the rotor diameter which given the 1.4nm distance probably would be not a big impact on this strip.

Not saying it was definitive or that there might be other research with different conclusions (or I might have read it wrong) but I think in this case my issue would more be the 600' AGL towers within 1.5nm of the strip rather than wind effects.

That height and distance wouldn't make it unusable as a strip but certainly would add a hazard, particularly in poor vis/wx situations and would concern me more than the rotor turbulence.

Connedrod 2nd Dec 2017 03:02

Well if the vic rfs is anything like the nsw rfs the use of this air strip will be of limits for aircraft for the use of fire flighting.
Strips near Gunning Crookwell are now longer able to be used for this reason

Stand by for the divide and conquer of the local community to the have and have nots. Were the have nots stuffer for the sake of the haves

Flying Binghi 2nd Dec 2017 04:07

A link to some research. If the computer models can be believed then there is an up to three mile downwind effect...

"A study from the University of Kansas School of Engineering sheds light on a potential safety hazard that could affect hundreds of airports across the country ... turbines can set up a circular vortex that can roll a plane ... By using advance computational aerodynamics modeling, the KU research team studied the effect of winds from 10-40 miles per hour. They found the higher the wind speed, the farther the turbulence reached – stretching as far as nearly three miles from a single turbine..."

https://www.wind-watch.org/news/2014...ar-wind-farms/






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jonkster 2nd Dec 2017 05:01

FWIW East Midlands Aerodrome in the UK has several wind turbines actually within the aerodrome boundary and closer to the runway than the ones proposed here.

They are only about 150' AGL though so significantly lower but I think the main issues are how they impact on the aerodrome radar, not turbulence.

Flying Binghi 2nd Dec 2017 07:34


Originally Posted by jonkster (Post 9976021)
FWIW East Midlands Aerodrome in the UK has several wind turbines actually within the aerodrome boundary and closer to the runway than the ones proposed here.

They are only about 150' AGL though so significantly lower but I think the main issues are how they impact on the aerodrome radar, not turbulence.

"...East Midlands Aerodrome in the UK has several wind turbines..."

How many is several ? ...perhaps just two small ones eh..:hmm:

So when yer taxing out behind that little ultralight do you worry about wake turbulence? ..probably not. Though when yer taxi out behind that Airbus wake turbulence is a givin.

I'm still waiting to see a link to the so-called wind power research mentioned by other posters to this thread..:hmm:




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jonkster 2nd Dec 2017 09:13


Originally Posted by Flying Binghi (Post 9976111)
"...East Midlands Aerodrome in the UK has several wind turbines..."

How many is several ? ...perhaps just two small ones eh..:hmm:

quite right - I thought there were 4 but checked and you are right just 2.


Originally Posted by Flying Binghi (Post 9976111)
So when yer taxing out behind that little ultralight do you worry about wake turbulence? ..probably not. Though when yer taxi out behind that Airbus wake turbulence is a givin.

Well, I did say significantly smaller but you are right there are only 2 close to the aerodrome.

The ones at East Midlands are apparently about 150' AGL whilst the ones at Cobden are 600' so 4 times higher. That height would be my concern.

Flying Binghi 4th Dec 2017 02:18


Originally Posted by jonkster (Post 9976186)
quite right - I thought there were 4 but checked and you are right just 2.

Best I can see from a quick Bing search is there were plans to build more wind towers though there were some 'issues'.



Originally Posted by jonkster (Post 9976186)
Well, I did say significantly smaller but you are right there are only 2 close to the aerodrome.

The ones at East Midlands are apparently about 150' AGL whilst the ones at Cobden are 600' so 4 times higher. That height would be my concern.

Each of the three blades on the Midlands towers is not much longer then the wing span of a Cessna 172.
Looking at the approved tower blade diameter of the Cobden site shows each blade would be the equivilant of an entire Boeing 747 wingspan. Any pilot would understand the significant difference in 'wing tip' vortices and down wind sever rotor turbulence potential.






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jonkster 4th Dec 2017 05:17


Originally Posted by Flying Binghi (Post 9977889)
Each of the three blades on the Midlands towers is not much longer then the wing span of a Cessna 172.
Looking at the approved tower blade diameter of the Cobden site shows each blade would be the equivilant of an entire Boeing 747 wingspan. Any pilot would understand the significant difference in 'wing tip' vortices and down wind sever rotor turbulence potential.

.

having made the mistake (once) in my early days of waiving a wake turbulence separation that, giving the conditions at the time and with the wisdom of hindsight was, shall we say, "courageous", I have a passing acquaintance with wing tip vortices. Dumb would probably be a better word.

I have no dog in this fight - I am happy to be shown wrong if turbulence is an issue (I sometimes operate in an area that now has several turbine farms nearby and so if they are an issue I would be keen to know)

As I said I have read at one point research using lidar of operating turbines that indicated the danger of the turbulence from wind turbine rotors dissipates after about 5 diameters. I will try and find a reference to it. I have heard anecdotes of further effects but no hard evidence. I am not saying my recollection is 100% or the research is strictly applicable here but the fact that the siting of the farm at Cobden was not squashed immediately by CASA due to fear of liability makes me think the turbulence issue is likely not a major issue.

(NB I have nothing against anecdotes - they make for investigations but anecdotes by themselves, that may have potentially other reasonable explanations are not concrete evidence).

I think the engineers would have at least some grip on this - they need to site turbines near each other and if they placed turbines inside a region of significant turbulence from other rotors, they would, at best, lose a lot of generation efficiency and at worst increase the wear of the units and likelihood of damage to those downstream.

Given the number of turbines in the US and the much higher aviation density there, surely the FAA would have a handle on this? how many accidents (other than actual collision with the towers by scud runners and ag operators) have there been that can be attributed to turbulence? If it was a significant issue more than say a mile downstream, would it be reasonable to assume the FAA and NTSB would be making noises about it due to actual incidents?

I am not trying to say the turbines location at this site is all rosy from an aviation perspective, I am expressing my opinion (which is of a non-engineer, non expert and with which you are free to argue with :)) that the vertical extent of the turbines would be more likely a hazard to operations at the strip than turbulence.

Like I said - I am not an expert but the above matters make me skeptical of claims turbulence is a hazard that can remain significant distances from the rotors (implied here as a couple of nautical miles) but willing to be convinced with good evidence.

jonkster 4th Dec 2017 05:59

I went looking for the 5 rotor diameter wake turbulence study and found several things.


1. The document I recall I am sure was this one from the University of Liverpool in 2006 "Wind Turbine Wake Encounter Study". Their study used the East Midlands turbines for the Lidar analysis and then used that to check theoretical models of turbulence from the turbines and they make the 5 rotor diameter spacing assessment.
https://www.liverpool.ac.uk/media/li...ine_report.pdf
As FB mentions the East Midlands turbines are not as big as Cobden's proposed ones but it uses that actual measured data to compare with theoretical models of turbulence.

2. The UK CAA then put out a CAP about wind turbines that referenced the above study and they say it is valid for rotors up to 30m but beyond that size there was not enough information to know exactly the effects but that there was ongoing research being done on larger sizes and there is an urgent need for this to be done. They state that as the results about larger turbines become known they would be updating their recommendations.
https://publicapps.caa.co.uk/docs/33...INAL%20Feb.pdf
That was in 2006. I could find no further updates despite the ongoing research they said was being done. It is possible I looked in the wrong place and there may be more recent stuff. Curious though any further research is not easily found. Maybe they decided it wasn't urgent :confused:

3. I found a web page of a consultancy "Pager Power" company that does research on the impacts of turbines on things like radar, navigation and communication etc, that said they have been researching the aviation impacts since 2006 and have flown drones, aircrafts and helicopters close to turbines up to 80m diameters to assess turbulence and have found " In all cases, turbulence thought to be caused by the turbines was apparent, but the size of these effects was considered less than the normal turbulence effects experienced in day to day flying".
They have no published reports on this that I could find though so not sure how much weight to put on that. https://www.pagerpower.com/news/turb...wind-turbines/

All the above is from my quick scanning - I may have missed or misunderstood things so feel free to read the above.

Like I said - I have no dog in this fight but am curious - if there is significant danger from turbulence at long distances (say > 1 nm) it is an issue I would like to know for my own benefit.

Other than anecdotes, is there any verified reputable data on turbulence beyond the immediate location for wind turbines?

Connedrod 4th Dec 2017 19:03

When it comes to wind turbines the word democracy is not prevalent. One large wind turbine farm that devided a community had turbines placed in the wrong locations to the plan. This was taken to the land and eviroment court. Just days before the release of the outcome the turbine company leter dropped that the land and environment court was the last word and had to be accepted. The thought they were goi g to win.
The court told them they lost.
Guess what happened.
The then primere kisten (ill take your money) kaleny, over road the the rueling with a stoke of a pen. Left wing politics at its finest.
Money talks fuk you community.

As for turbalance there plenty around go fly through some if your game and we see what happens. Whats sad is how casa no show on these things are. If you wont prove on how much power these turbine companys have just look at casa.
Remember that $60 billion dollars going off shore in subsidies of your money.

peterc005 4th Dec 2017 22:05


Originally Posted by Flying Binghi (Post 9975941)
What research ?

As I have found in the 10 odd years I've been looking into the global warming 'industry' the claims of "research has suggested" just never pan out. So some links to this research please..:)

.

Ten years of reading crack-pot, crazy conspiracy-theory websites run by people wearing tinfoil hats. Doubt you've ever read a science-based article that contradicted your warped and delusional views.

You regularly invent "statistics" out of thin air and cite whacko websites as credible "sources".

Thirty years of peer-reviewed scientific research, including about 20 Nobel Prizes in Science, have shown man-made climate change is real and a danger to our civilisation.

I like wind farms; more the merrier!


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