Following on from the rumour that the plans for the siting 181 wind turbines on the Isle of Lewis are to be rejected due to environmental concerns, offshore wind farms have come under attack for the UK’s Ministry of Defence on the grounds that turbines interfere with its radar.
The story was reported in The Times newspaper: Wind farms ‘a threat to national security’
“The MoD has lodged last-minute objections to at least four onshore wind farms in the line of sight of its stations on the east coast because they make it impossible to spot aircraft, The Times has learnt. The same objections are likely to apply to wind turbines in the North Sea, part of the massive renewable energy project announced by John Hutton, the Energy Secretary, barely two months ago. They would be directly in line with the three principal radar defence stations, Brizlee Wood, Saxton Wold and Trimingham on the Northumberland, Yorkshire and Norfolk coasts.
Giving evidence to a planning inquiry last October, a senior MoD expert said that the turbines create a hole in radar coverage so that aircraft flying overhead are not detectable. In written evidence, Squadron Leader Chris Breedon said: “This obscuration occurs regardless of the height of the aircraft, of the radar and of the turbine.” He described the discovery as alarming.”
So it seems that whether wind farms are sited onshore or offshore, they will face strong objections.
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Jennifer Marohasy BSc PhD is a critical thinker with expertise in the scientific method.
Perhaps the MoD should research it a bit more thoroughly.
http://www.awea.org/pubs/factsheets/060602_Wind_Turbines_and%20_Radar_Fact_Sheet.pdf
“British solutions to wind turbines and radar
Studies in the United Kingdom and elsewhere show that while wind turbines can cause “clutter” on radars, there are engineering solutions that can be implemented or should be explored further. In the UK, the Ministry of Defense registered concerns on many wind projects, but in November 2005, Wing Commander Nicky Loveday said, “We have been learning about things that we thought were a major problem for us. We have had to step away and say: actually it really isn’t a problem for the air defence community” (Windpower Monthly, November 2005).
A June 2003 study from the British Department of Trade and Industry (DTI) concluded that there are hardware and software mitigation efforts that can be implemented to reduce or eliminate the effects of wind turbines on radars. These solutions include adding radars, adding filters to the radar software, or altering the layout of a wind project. These solutions vary in cost based on the site-specific situation.”
Apart from the fact that most wind turbine blades are composite and provide very little radar returns surely the British aerospace industry can filter the completely predictable rotating wind turbine blades with a simple doppler filter. There is a huge difference between the rotating blades of wind turbine and a low flying jet.
This is also not a new story:
http://www.guardian.co.uk/science/2004/mar/04/thisweekssciencequestions2
“Software fixes that help radar systems filter out signals from wind farms have been developed, though these work better with offshore wind farms surrounded by lots of flat sea. Another option is to redesign the turbines and the way they are arranged so they better blend in with terrain.
The military research company Qinetiq is using stealth bomber technology to build turbine blades that don’t show up on radar screens. “We’re looking to change the properties of parts of the material structure to reduce the amount of reflection,” says Andy Beck, a radar expert with Qinetiq. Making the turbine blades from different layers the right thickness can bounce back signals that neatly cancel out the arriving pings. And honeycomb-style foam can absorb enough of the incoming radar energy to send very little back.
Qinetiq hopes to build its first stealth turbine blades later this year, which are expected to cost 10-20% more than standard.”
And finally some actual science rather that renewable power catastrophe crap:
http://www.bwea.org/aviation/radar.html
“This study has focused on the development and validation of a computer model that can be used to predict the radar reflection characteristics (Radar Cross Section, which is measured in square metres and is normally presented on a logarithmic scale) of wind turbines and understand the complex interaction between radar energy and turbines. The scope of the model includes:
* The affects of the radar propagation over the terrain between the radar and the wind farm;
* The dynamic radar scattering from the wind turbines;
* The signal processing in the radar;
* Display of results via a simulated radar display.
The model was validated through a full–scale trial, using a QinetiQ mobile radar system to collect data for a single operational wind turbine at Swaffham in Norfolk. The model was then used to perform a detailed sensitivity analysis and to compile a list of the key factors influencing the radar signature of wind turbines.
The following are some of the results generated by the project:
* The design of the tower and nacelle should have the smallest Radar Cross Section (RCS) as possible. The RCS of these components can be effectively reduced though careful shaping and choice of construction materials;
* Large turbines do not necessarily lead to large RCS (i.e. tower height does not greatly affect RCS);
* Blade RCS returns can only be effectively controlled though the use of absorbing materials;
* Spacing of wind turbines within a wind farm needs to be considered in the context of the radar cross range/down range resolutions.
* Spacing the turbines such that only one turbine can appear in any range cell has advantages in identifying the wind farm, filtering out the turbines and in tracking aircraft over the farm area;
* Single wind turbines do not create a significant ‘radar shadow’. Any shadow region is only dark to a distance of a few hundred metres behind the turbine. Beyond this there is some reduction of the radar power, and a time-variation, but these will not prevent detection except possibly for very small targets.
This study complements the recently the completed study by AMS which looked at the feasibility of modifying radars to remove the effects caused by wind turbines (report number W/14/00623/REP).”
Which is good as all the modern wind turbines are variable speed which have much smaller nacelles and only have composite blades that can easily shaped to avoid radar returns.
Finally the pilots of attacking aircraft are incredibly adept as using terrain to mask their approach. Is anyone suggesting that we level all the hills and mountains to enhance radar effectiveness?
Good stuff Ender. The squadron leader does say, “This obscuration occurs regardless of the height of the aircraft, of the radar and of the turbine.”
More on wind farms here from 4th February:
http://tpa.typepad.com/research/2008/02/the-human-cost.html
Paul – “Good stuff Ender. The squadron leader does say, “This obscuration occurs regardless of the height of the aircraft, of the radar and of the turbine.””
My guess is that the radars in question are older and perhaps should have been pensioned off ages ago. If wind turbines are a problem then migratory birds would be just as bad and the MoD can’t object to them:
http://www.bwea.org/pdf/Wind-Turbines-and-Radar-Operational-Experience-and-Mitigation-Measures.pdf
“A new Northrop-Grumman ASR-9 primary surveillance radar became operational at Palm Springs in January 2001. This replaced an ASR-8 which had suffered considerable problems due to clutter from the many wind turbines in the Palm Springs area. Wind turbine clutter had led to limitation of radar service to aircraft in the areas around the wind turbines.
The ASR-9 was the first radar to use MTD technology, providing a vast increase in performance over MTI radars. The ASR-9 at Palm Springs has modifications applied which originated from FAA engineering research to deal with radar clutter from migratory birds in the San Francisco area. The modifications in the Palm Springs radar include dynamic clutter mapping and six Doppler filters, providing much enhanced sensitivity to moving clutter at different velocities. Air traffic controllers at Palm Springs are now able to
vector traffic across the wind turbines without any detrimental effect on radar performance since the turbines no longer appear on the radar screen. No
limitation of radar service is required.”
Instead of relying on a second quote of what someone said maybe, I looked at the research. Perhaps you should read the link that I provided.
Additionally if these radars are able to be compromised by a few wind turbines then this should be a bigger cause for concern. Do you imagine that an attacking enemy plane would cruise in at an easy to spot height on it’s own? No it would be part of a modern strike package that would include powerful jammers, chaff and decoys. If these radars cannot handle a few wind turbines then an aggressive attacker with modern countermeasures would be able to take them out before the radar operators had finished their first cup of tea.
I really think you should be worrying about the state of Britain’s radar system rather than the siting of wind turbines.
I guess the MoD are making it up simply because they don’t like wind farms?
“Qinetiq hopes to build its first stealth turbine blades later this year, which are expected to cost 10-20% more than standard.”
Great – Makes ’em even less economically viable. No worries – the public will just have to pay more via high electricity prices or taxes or both.
Since Al Gore and his supporters claim that global warming is the greatest threat to mankind, rather than mankind against itself, they should be protesting that wind turbins are more important in their war against mankind, I mean global warming, than in the mankinds wars against mankind, I mean like real people. Got it? In other words, global warming trumps military and terrorist attacks.
Good point Woody. Does Global Warming also trump other environmental concerns like danger to migrating birds?
Paul – “I guess the MoD are making it up simply because they don’t like wind farms?”
I guess they are desperately hoping that no-one will notice that their air defence radars are so easily jammed. I mean where did all the defence money go?
This hypothetical headline and story would not make good reading:
“MoD incompetence threatens national security
The MoD, having failed to upgrade critical air defence radars with the latest technology, now find something as simple as a spinning wind turbine can render attacking planes invisible”
But of course it is the wind turbines fault.
Mark – “Great – Makes ’em even less economically viable. No worries – the public will just have to pay more via high electricity prices or taxes or both.”
Not really as only the ones that are in the direct line of site of the radar will need them.
Max – “Good point Woody. Does Global Warming also trump other environmental concerns like danger to migrating birds?”
Absolutely not – there are plenty of places where wind farms can be situated where there are no migratory birds. BTW have you ever protested about tall glass buildings or mobile phone towers being built in the path of migratory birds? It is amazing how people can suddenly be so interested in saving birds when wind farms are mentioned when previously they cared bugger all about them.
Ender, here’s another headline for you.
GW scam to cost even more.
As well as the ridiculus 16 billion to be spent on cluttering the sea with inefficient wind mills, their instillation will cause another 16 billion to be spent on upgrading the perfectly adequate defence radar system.
Hasbeen – “their instillation will cause another 16 billion to be spent on upgrading the perfectly adequate defence radar system.”
Yes the one that is jammed by wind turbines. I guess Britain will just have to ask any nations that are considering attacking the coast of Britain not to use jamming so that some taxpayers money can be saved.
“Not really as only the ones that are in the direct line of site of the radar will need them.”
Um, wouldn’t that be just about every offshore wind turbine? Didn’t know the enemy plans to only attack using a limited set of routes.
“Yes the one that is jammed by wind turbines. I guess Britain will just have to ask any nations that are considering attacking the coast of Britain not to use jamming so that some taxpayers money can be saved.”
C’or! It’s the enemy attacking in a formation of wind turbines. They’re going to chop us to bits!
Yes yes – with military spending about 88 times climate science and the US having “saved” Iraq by precipitating the death of up to 1,000,000 Iraqis.
Good call Woody. We all feel much safer now.
Luke, more Americans died on 9-11 from terrorists than throughout time to global warming. We choose to make our priorities right.
Woody – “Luke, more Americans died on 9-11 from terrorists than throughout time to global warming. We choose to make our priorities right.”
And free speech and privacy are completely overrated.
Luke
I think you are totally out of line with your “US having “saved” Iraq by precipitating the death of up to 1,000,000 Iraqis.” comment.
An absolutely riddiculous statement. The US is not responsible. Full stop. It is the believers in Ender’s “And free speech and privacy are compeletely overrated” philosophy that (for whatever reason) are brainwashed to think that killing innocent people going about their own business in extremely difficult circumstances will achieve “peace on earth” … or whatever.
Honestly – comments like these from people who I consider relatively educated and intelligent make me despair.
Hello Arnost – Hello – don’t think it may have precipitated a little chaos. Just a tad – are you that much of a “true patriot” – and all the way with LBJ? Come on ! The adventure has precipitated total chaos.
Objectives not achieved and I think it’s an insult to us as allies having to assist them in such behaviour.
So this blog is having a little ruse post about windmills and “future” bombers when we have reckless military adventurism on a massive scale based on false pretences with more terrorists than ever created and prime suspect not apprehended. Billions of dollars expended to give Iraq that pock-marked well machine-gunned look. Very chic. Nobody here gives 2 hoots about that but we can get all hot and steamed up over some “threat” of windmills. Sheeesh !! No hypocrisy here.
Arnost – “It is the believers in Ender’s “And free speech and privacy are compeletely overrated” philosophy that (for whatever reason) are brainwashed to think that killing innocent people going about their own business in extremely difficult circumstances will achieve “peace on earth” … or whatever.”
No it is the restriction on free speech and privacy that have been enacted in the name of the GWOT that is the problem. Such freedoms once given up are very hard to get back. We can only hope when reason again reasserts itself and we lose this irrational fear of terrorism that the Patriot Act and similar draconian laws in my country will be repealed and never rise again.