As wind-turbine farms expand, research shows they could offer diminishing returns
From the UNIVERSITY OF KANSAS
![Shepherds_Flat_Wind_Farm_2011[1]](https://wattsupwiththat.files.wordpress.com/2015/08/shepherds_flat_wind_farm_20111.jpg?quality=83)
LAWRENCE — Renewable wind energy is experiencing a boom, with more wind turbines popping up across landscapes in the U.S. and abroad. Indeed, wind energy accounted for 3.3 percent of electricity generation in the United States in 2011, according to the U.S. Energy Information Administration. Globally, that number was 2.9 percent for the same year.
But as wind turbines proliferate, researchers at the University of Kansas are looking at how these forests of turbines affect the wind itself. What happens to the wind when a larger number of wind turbines removes more and more of the energy of atmospheric motion?
Atmospheric science professors Nate Brunsell and David Mechem in KU’s Department of Geography are co-authors of a new study just published in the Proceedings of the National Academy of Sciences by an international research group that evaluated the effects of large wind farms on atmospheric flow and its implications for how much renewable energy the turbines can generate.
“Wind turbines generate electricity by removing energy from the wind, so a larger number of wind turbines should result in a slowdown of the winds in the lower atmosphere,” Mechem said.
The researchers quantified this phenomenon in numerical simulations by applying a sophisticated model normally used for weather forecasting to one of the windiest regions of the United States.
The team found that a slowdown effect triggered by wind turbines is substantial for large wind farms and results in proportionally less renewable energy generated for each turbine versus the energy that would be generated from an isolated wind turbine.
While the researchers stress that no current or planned wind farm approaches the size or concentration that would cause the slowdown effect, their results suggest the phenomenon tied to large wind farms needs to be accounted for in future planning of wind energy.
“When just a few wind turbines are installed, each additional turbine results in a similar increase in electricity generated, as you might expect,” Brunsell said.
However, when a substantial number of turbines are installed over a small area, the amount of electricity generated is no longer governed by simple multiplication, according to the researchers.
“Instead, because the turbines extract energy from the wind, additional turbines will each generate less and less electricity,” Mechem said.
The team’s simulations estimate this slowdown effect results in a practical upper limit of 1 megawatt per square kilometer that can be generated — far less than previous estimates not accounting for the effect. Current wind farms are operating well below this generation limit, but the authors found that this slowdown effect needs to be accounted for, particularly when comparing different sources of renewable energy.
The study was published online in the scientific journal Proceedings of the National Academy of Sciences on Aug. 24.
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T-Bone Walker – Call It Stormy
Monday
They call it stormy Monday, but Tuesday’s just as bad
They call it stormy Monday, but Tuesday’s just as bad
Wednesday’s worse, and Thursday’s also sad
Yes the eagle flies on Friday, and Saturday I go out to play
Eagle flies on Friday, and Saturday I go out to play
Sunday I go to church, then I kneel down and pray.
Lord have mercy, Lord have mercy on me.
Lord have mercy, my heart’s in
misery.
Crazy about my baby, yes, send her back to me.
_____
good ol’ wind farm blues, slight return.
It’s like they said; “Let’s just ignore the elephant in the room, and focus on that little ant instead. Whee, look at him go!”
There you have it. All those wind farms on the West coast of North America have created the warm water blob off shore because of continued wind energy depletion. Oh, they didn’t mention the climate part?
Kinda related, but have not heard much about the below for some time.
http://news.mit.edu/2010/climate-wind-0312
The way I see it, next after the Age of Wind comes Fun in Feudal Times followed by The Age of Stone Revisited. I don’t really want to know what comes after that.
My hopes of a flying car in my garage will founder forever, dashed against the rocks of wind technology.
I wonder if wind farms will have effect on down wind rain fall? Take tornados, enough wind farms in Kansas could disturb the formation of tornados which could effect farmers in the Ohio valley. Then again, what do I know, I’m just an old construction worker..
If the earth were not rotating as fast as it does now, the wind would always flow in a north/south direction. Hot air would rise at the equator, flow to the poles, then back again to the equator. It’s the thousand mile air speed due to the earth’s rotation of the rising hot air at the equator , to the zero mph air speed at the cold poles that creates the transverse winds. So, now as we harness these winds, we are slowing the earth’s rotation. We are using up the finite rotational momentum of the earth to simply make cheap energy. We have already passed peak wind, so it’s only downhill from here on. (/sarc.)
Yes, but look how much more efficiently large wind farms can slice and dice endangered birds.
and slice and dice the cash
What about the climatic effects? Reduced evaporation, more rainfall, more thunderstorms, more fog, more extreme highs and lows in temperature the reduction in wind would cause – sounds like climate change could be made real locally by the solution to mitigate it!
I wonder if watermelons actually considered the footprint exchange from dams to windmills. I wonder if watermelons actually considered the footprint damage between dams and the affects of no-dam-controlled floods unleashed into downstream city-dwelling hippy condos.
Watermelons need to be careful what they ask for, they just may get what their asking for.
not enti,rely on topic, but. Bloomberg, (or at least one writer) solidly aligned to the CAGW cult, with regular articles touting how wonderful Energiewiende is going in Germany, we need to copy their example, etc. Well here is a Bloomberg article on a totally different category http://www.bloomberg.com/news/articles/2015-08-31/how-a-mckinsey-analyst-sought-a-fortune-as-a-himalayan-goatherd
Some how this item “… about 25,000 goats froze or starved to death across the region during a bad winter in 2013” was missed by the Global bull warming media machine.
This seems like a good time to review this photo, I consider it one of the most important wind turbine photos ever taken.
http://wermenh.com/wind/images/vattenfall-image_300.jpg
In farming territory, the turbulence downwind of a turbine disrupts the air inversion just above the field. This will reduce the effect of radiational cooling at night and keep the ground temperature higher and evaporate more moisture from the ground.
So turbines should bring warmer and drier conditions.
Thank you for that, Ric, I knew I’d seen it somewhere that wind turbines actually elevate ground temperatures and dry out the land,
The picture makes it look like the turbines increase the albedo of the earth – and hence bring some counterbalancing cooling.
It appears the air passing through the turbines is lower in temperature, causing condensation, the opposite of what you speculate, Generally, removing energy from air cools it, so this is not unexpected.
There is a reduction of pressure over the camber of the wing, which is what makes a wing work. The reduction in pressure cools the air, causing visible condensate.
http://www.boldmethod.com/images/learn-to-fly/weather/contrails/aero-gs.jpg
.
PS This is not a Mach effect. A Mach condensate would be on upper and lower surfaces, and more behind the wing. Wing condensate is more visible on military aircraft, because they tend to pull greater ‘g’.
I don’t think the visible wake is from the pressure effect rafellis is demonstrating. The lowest pressure in the wind turbine photo is just behind the blade, but the lead blade is in the clear. I suspect that the air flow around the rotor level is warmer, moister, and probably supersaturated compared to the the air just above the North Sea water. That air is colder, saturated, and has cloud condensation nuclei from the surface.
Mixing of the two air levels may be the trigger to produce the expanding stream of fog in the turbine wake.
Or something like that, I don’t think I’m completely right myself. Perhaps it’s really low-altitude chemtrails spread to attack the fish. 🙂
Same reason a pressurized can cools when the gas is released, or water drips out of your exhaust pipe. PV/T is constant, or PV =nRT. Reduce the pressure you reduce the temperature, which makes sense because you have fewer molecules colliding.
I wish there was a video of that!
And turbine # 3 seems to be slightly ahead of turbine #2 in lane 2, no look! #1 one is inching up a few rotations followed by using a slight variation in the wind direction and his team mate is getting a clear path…
oh no The one behind T3 is slowing down… and now T 4 in lane 4 seems to be speeding up by 10 kms at it’s tips but his team mate behind has lost sight of him . this is getting exiting…..we are getting up to 0.0003 watts!!!!
And now a break for our sponsor… Here is AL GORE!!!!
wow … fast shutter = stopped blades flat and downstream turbines are directly inline of turbulent flow, that can’t be good for output, but might be damaging to machinery
The photo has been used to suggest a more random placement would give a smoother response to changing wind direction.
Yeah, blade tips cutting through turbulent flow at nearly 200mph is not the design point!
@ur momisugly ric, that picture should remind us all of the one the warmistas use . You know the cooling tower one?
These murderous machines come at a terrible cost in loss of wildlife and are an affront to the land.
http://i.telegraph.co.uk/multimedia/archive/01596/red-kite_1596489a.jpg
“A red kite killed by colliding with a turbine in Spain, where up to a million birds a year may be dying in this way.”
Oh, but cats kill birds.
That’s the Green response- cats kill birds. That makes it all okay then, right?
Oh, and windows. Windows kill birds, so if the cats didn’t get them, they’d die anyway. So everybody that owns a cat or a window is responsible. All is well.
Dear jorgekafkazar, Really? are you serious? seriously?
Cats do not, I repeat, do not kill eagles or any other raptor type bird.
That statement is right out of the wind lobby handbook.
EJ, Ej, Ej… didn’t you catch his mock- serious tone? Assume the sarcasm and all is well.
Right.
At least if your position is anti-wind generation.
If it is evaluating pros and cons, then looking at actual data should be preferrable to playing the emotion card.
Isn’t this what we say some in climate science are doing?
All of the pro- wind power rhetoric needs to pass a simple test… stop the subsidies for 5 years and see how many wind plants get built. None of the extant wind projects would pay for themselves without heavy subsidies and forced higher utility rates to the consumer.
Alan,
I was not offering an opinion on wind generation per se. Whenever the topic comes up one can count on people bringing up the avian and bat kills and the hypocrisy of environmentalists on that score. Seeing as we operate some rather significant commercial wind generation facilities, I checked to find out what actual data we have on the subject. Reality, at least in the PNW, seems rather far removed from the stories which are frequently mentioned.
Knowing that, I am simply cautioning folks to base their criticisms on well founded points, with the huge numbers of bird deaths being most likely from projections and models which may have the same capacity for accuracy as GCM’s.
Sorry Alan, I did not catch that. My apologies to both of you then, guess I’ll assume more sarcasm next time.
As wind direction varies, quite often turbines are in the wind shadows of those upwind of them. In addition, the downwind turbines actually pile up the wind as it turns them and affects the wind upstream. No mention of the changes in environment of the land under these turbines. With slower wind, it gets hotter down there and moisture can be cooked out of the soil. Crops and animals will suffer.
Is it really necessary to build a gigantic windmill to efficiently extract energy from the wind? Perhaps someone should sponsor a contest for other designs that would be less ornicidal and/or butt ugly.
Here’s one that just occurred to me:
How about something like a wind sock with a tunable aperture which cold be used to direct the flow of wind so that it resonates a leaf spring (a “reed”) with a magnet attached to it? The magnet could be situated so that it vibrates inside a solenoid, producing an A/C voltage which could be stepped up to provide incremental torque to a more traditional rotor-and-stator dynamo?
I realize it would take hundreds of these little “clarinets” to equal the power of one large mill, but on the other hand they have the advantage of operating over a broad range of wind speeds and are totally indifferent to wind direction. Furthermore, they can be manufactured out of synthetic fabric and a few off-the-shelf electrical components, making their mass production dirt cheap. They also do not pose any danger to the wildlife.
You pretty much need a giant turbine:
1) The “swept area” is directly proportional to the energy you can work with.
2) Wind speed increases with height, especially close to the ground. The higher you get the less wind shear is present (the wind speed at the top vs bottom of the rotor) and that reduces blade flex and infrasound production.
Here’s one novel idea people are exploring. It kinda sucks relative to the points above, but might be interesting in some applications.
http://www.technologyreview.com/news/537721/bladeless-wind-turbines-may-offer-more-form-than-function/
Several such whacky wind turbine designs are unveiled every year.
So far, no such innovative idea has out-performed the standard horizontal axis fan on a mast concept.
As explained here:
http://www.gizmag.com/dodgy-wind-turbines/27876/
The authors report playing around with a “sophisticated model.”
That gives a warm and fuzzy feeling! Try an ‘Images’ search using the phrase.
Seriously, recall Strunk and White’s classic: “Omit needless words.”
As far as Im concerned, file this one under… well, duh
The change to wind patterns will also…
-wait for it-
…change the climate
The entire nonsensical process reminds me of the “save the whales” campaign. Turns out saving the whales results in more predictors. More predictors then results in the loss of more creatures on the bottom of the food chain – who would have thunk it!
Anyway, off to picket for the raising of taxes to save the poor Steller Sea Lions, whose population decline is a total mystery to us.
We lose a little on each transaction… but we’ll make it up in volume.
“What happens to the wind when a larger number of wind turbines removes more and more of the energy of atmospheric motion?”…… I would add, in the case of the offshore wind farms, what’s happening with the oceans when their watter is stirred by those turbines and by other “facilities”? I think that this is also a subject we need to analyse, since oceans are the most powerful force on Earth that influence climate. Well, it seems that those wind farms play a significant role in climate change: http://climate-ocean.com/2015/K/k-.pdf. I’m really interested in your oppinions. Thank you, Anthony, for drawing the attention to this subject!
And if we put millions of wind turbines floating in the middle of the Atlantic and Pacific oceans this will kill the winds from hurricanes and typhoons. Of course they would be used to generate hydrogen fuel…
I have not read all the comments, but make 3 points.
First, the windfarms already constructed have been already taken the best siting, ie., that which is most windy and/or most conveniently placed for supply needs & coupling to the grid. This means that the windfarms already will be the most efficient/productive, and there will inevitably be decreasing returns on future installation.
Second, wind is contributing about 3% to the energy mix, but given future targets for renewables, and taking into account the point made above, there needs to be say a 20 to 25 times expansion just to bring wind to about 50% contribution to the energy production mix. So we are not talking about just a small increase in the amount of these installations.
Third, to date, windfarms have not resulted in the meaningful reduction of CO2 emissions because of the need for backup generation provided by fossil fuel generators. These back up generators are either run at 100% output with energy drawn off as and when wind is not producing. or they are idle but run in ramp up/ramp down mode being ramped up when wind is not producing, and ramped down when it is. The first method of back up produces 100% the CO2 that would be produced by the generator even if no windfarm had ever been built. The second, is akin to driving one’s car in urban conditions rather than freeway/mtorway driving. Although wind on average is such that windfarms can produce about 23 to 265 of their nameplate capacity, this does not result in a corresponding 23 to 26% reduction in CO2 since fossil fuel generators produce almost as much CO2 when used in ramp up/ramp down mode when compared to the amount of CO2 they would have produced if left to run at steady state providing 100% conventional output.
Windfarms fail on their primary criteria, ie., they do not result in the meaningful reduction of CO2. They are certainly inefficient and fail to produce reliable energy always on tap as needed, so fail on an engineering perspective.
When this sc*m falls, the biggest fallout will come from the fact that renewable energy has been extremely expensive and never resulted in the meaningful reduction of CO2 in view of the need for conventionally powered fossil fuel generated backup which backup was required (and known to be so) due to the vagrancies of the wind (and/or the fact that the sun does not shine at night and in mid to high latitudes is not particularly strong and does not coincide with peak demand, ie., long winter evenings/nights). This is obvious to any 14 year schoolchild so should be obvious to politicians. Every windfarm application should be accompanied with a report as to the amount of CO2 emissions that the windfarm will save on a yearly basis during its expected lifetime (this should include the CO2 used in its construction and coupling to the grid and backup generation), and what effect that reduction in CO2 is expected to achieve in reducing temperatures going forward.
PS. I am not suggesting that it is necessary to take steps to reduce CO2 emissions, but merely pointing out that renewables fail on their prime objective, ie., to significantly reduce the CO2 that is produced in energy production.
“Windfarms fail on their primary criteria, ie., they do not result in the meaningful reduction of CO2.” But they do job of killing a lot of birds and bats as our politicians and the Audubon Society looks the other way.
Their primary criteria is to produce energy. They are easier and less expensive to install and interconnect than Nuclear, Gas, and Coal. You can still use the land they are sited on for other purposes. They don’t generate waste like Coal and Nuclear. They don’t create weaponizable material like Nuclear. They don’t require fuel like Coal Gas and Nuclear. And per Stanford University windfarms can be used for baseload electricity to the grid.
Remarkable! You have managed to create an entry propagandizing wind turbines such that each and every sentence is wrong!
Dead wrong. The only purpose is to create immediate tax and energy credits and construction profits for their (democrat) political donors snd overseas factories, the unions who put them up and who sip them here for tax credits and deductions. At 16 – 19% production factors, they will wear out from no maintenance (because none is budgeted nor required by the tax credits!) before their 7-9 parts rotor, blade and bearing lifetime expires. Crane, parts, repair time and manpower rental expenses alone to replace a bearing are more than a year’s production of electricity.
False. For a field of generators covering 200 – 400 acres, you need tens of miles of high-voltage copper and towers, then a controllers network (remote operated!) and transformer AND a very-high voltage transmission line back to the nearest substation transformer yard and ITS connections. All that for 20 1.5 MWatt “generators” that (on average) produce an irregular output of 16% x 20 x 1.5 MWatts (that equals an unreliable “average” power of only 4.8 MWatts, by the way.) Or you can build a combined cycle 480 Megawatt GT on 20 acres in 1 year with one road with ONE transformer yard connecting to the same grid to generate reliable energy 60 x 60 x 24 x 365 days a year. Paying taxes and generating electricity, rather than USING taxes to generate profits for the politicians’ companies.
And pollute the general area with hundreds of miles of ugly monsters. And require hundreds of tons of roads, concrete, electric towers and transformers that are wasted – except for the tax money they send to their owners chosen political parties.
They waste every pound of insulation, copper, concrete, rock, asphalt, steel, gravel, and rare earth metal extracted from open unregulated pits in China and every Watt of energy wasted building and shipping and installing them. Worse, they deliver (on average) on 1/6 of they REQUIRE to be built – and a guaranteed loss immediately of 83% of their installed mass and its support infrastructure. Plus the pollution left overseas killing people.
Well, your democrats are deliberately making sure the terrorists are supplied directly with enriched pure uranium and the rockets and missiles to deliver it towards the homes of their enemies, so “terrorists” are not so very likely to even WANT to get a useless mix of waste radioactive spoils from US power plant reactor fuels, are they? Plus, your democrat-led fears won’t even let US (who WOULD process them correctly!) to recycle US uranium fuels that WOULD greatly increase future supplies!
Every wind turbine requires a running reserve be available 60 x 60 x 24 x 365, or kept on standby for the same period at startup rates that destroy the steel forgings and welded exhausts from constant but irregular starting and stopping. A 100 million dollar machine that should run 48 months straight is cracked through in 7 – 14 months.
And unicorn horns were reported by scientific consensus to be able to transmute metals. How many government-paid scientists can you buy for 92 billions a year? And your scientific consensus claimed the moon’s craters were volcanic, and completely rejected plate tectonics for dozens of years ….
I have to agree with RACookPE1978. My wife and I drove across the country last month, both ways, and on different roads. We observed hundreds upon hundreds of giant windmills, as far as the eye could see.
That was just on the roads we traveled. Presumably, there are more windmills for hundreds of miles in any direction. They really do ruin the landscape.
The sole reason for all those monstrosities is government subsidies. If not for the huge tax breaks, those windmills would not exist, at least not the ones used for generating electricity.
If a technology cannot be supported by a market-based demand, then it is ipso facto inefficient. It is no different in principle from paying people to dig 10’X10’X10′ holes in the ground, and then paying them to move those holes fifty feet away. Windmills are make-work that benefits a few, at the expense of everyone else.
And they’re as ugly as sin.
+++ dbstealey and RACookPE1978
We will impart more of the wind energy onto the earth and depending upon where the majority of turbines are, could make the earth spin faster/slower – we’re doomed
Should be easy enough to calculate. Just take the kwh being produced by the windelec (turbine) at the front of the array, and compare it with the kwh being produced by the windelec (turbine) at the back of the array.
Not exactly rocket science. Where do they get these guys from?
http://www.energydigital.com/public/uploads/large/large_article_im3209_offshore_wind_UK.jpg
Why does that pic remind me of Arlington? Maybe it’s a pic of the ‘Alarmington Cemetery’ – where alarmists bury their models.
LOL
It illustrates that the priority is to build wind turbines; not to extract the maximum amount of energy.
A return to laminar flow after a flow disruption is 10 to 20 characteristic diameters (in a pipe). Any Engineer who’s studied fluid mechanics since the 1920’s should be able to tell you that. Those towers look like they’re spaced at 5 to 7 “blade disc” diameters. Of course spacing at 10 compared to 7 approximately doubles area and connection costs. And offshore wind is already around double the cost (based on _nameplate_ capacity) compared to land-based.
It’s difficult to imagine, but CAGW is on the cusp of disconfirmation given almost 20 years without a global warming trend.
In just 5 years, it will be a quarter of a century, with the chance of 25+ year FALLING global temp trend developing by the early 2020’s from: PDO cool cycle, AMO cool cycle and the weakest solar cycle since the Mauder Minimum all kick in at the same time….
Eventually, all these wind farms will be dismantled and these bird-killers will just be a footnote in the history books.
CAGW will be looked at as a silly period of human history when the world went collectively insane from the effects of government propaganda and failed statist ideologies….
We’re getting tantalizing close… CAGW apologists will try to Karl2015 (now a verb) as much as possible, but any additional shenanigans from the alarmists will eventually be legally actionable under fraud and misappropriation of public fund laws…
The alarmists are running out of excuses, options, money and time.
Taxpayers just aren’t buying what they’re trying to sell, as poll numbers so clearly indicate.
About 2or 3 years ago there was a considerable concern in the UK about the latest form of arboreal , fungal , disease to affect the country ,affecting ash trees . Since it seemed that the disease was spreading across from Europe by wind action , I wondered what affect the turbulence created by assembles of wind turbines might have on the spread of the disease and overlaid disease concentrations on top of wind farm maps . I convinced myself (but probably because I was already biassed against wind farms ) that there was a coincidence and actually posted a comment about it to the Telegraph (in the days when you did not have to pay them to comment).
There was one reply that pointed out that in Denmark the incidence of fungal tree disease was extremely high and also coincided with the greatest concentration of wind turbines in Europe (at that time).
In a country so vast as the US this is not likely to be a problem even if there was the possibility of a link , but in small confined countries like England might this not be worth someone investigating , especially as Oaks, Chestnuts , and Ash appear to joining the Elm in extinction from our country hedgerows.
(And yes I do appreciate that global warming is also a possible factor).