NOTE: An update has been added below, using the press release that came out today after the news stories yesterday.
While ironic that something designed to reduce CO2 emissions (and presumably warming)is actually producing warming around it, this isn’t really any big surprise. Orchardists and vineyard operators in California have been using motor driven wind turbines to elevate local temperatures to save crops from frost for over half a century. What is different here is the scale of nighttime warming, large enough to be visible on MODIS satellite imagery thanks to large scale wind farms.
Dr. Roger Pielke Sr. and associates have been doing research along these lines for quite some time, and has this summary on some recent research.
From Louise Gray in the Telegraph:
Wind farms can cause climate change, according to new research, that shows for the first time the new technology is already pushing up temperatures.
Usually at night the air closer to the ground becomes colder when the sun goes down and the earth cools. But on huge wind farms the motion of the turbines mixes the air higher in the atmosphere that is warmer, pushing up the overall temperature.
Satellite data over a large area in Texas, that is now covered by four of the world’s largest wind farms, found that over a decade the local temperature went up by almost 1C as more turbines are built. This could have long term effects on wildlife living in the immediate areas of larger wind farms. It could also affect regional weather patterns as warmer areas affect the formation of cloud and even wind speeds.
Full story here:
Here’s the paper:
Zhou, Liming, Yuhong Tian, Somnath Baidya Roy, Chris Thorncroft, Lance F. Bosart and Yuanlong Hu 2012: Impacts of wind farms on land surface temperature. Nature Climate Chnage. doi:10.1038/nclimate1505
And the abstract (bold mine):
The wind industry in the United States has experienced a remarkably rapid expansion of capacity in recent years and this fast growth is expected to continue in the future. While converting wind’s kinetic energy into electricity, wind turbines modify surface–atmosphere exchanges and the transfer of energy, momentum, mass and moisture within the atmosphere. These changes, if spatially large enough, may have noticeable impacts on local to regional weather and climate.
Here we present observational evidence for such impacts based on analyses of satellite data for the period of 2003–2011 over a region in west-central Texas, where four of the world’s largest wind farms are located. Our results show a significant warming trend of up to 0.72 °C per decade, particularly at night-time, over wind farms relative to nearby non-wind-farm regions. We attribute this warming primarily to wind farms as its spatial pattern and magnitude couples very well with the geographic distribution of wind turbines.
h/t to WUWT reader Andrew Kissling
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UPDATE: 4/30/12:30PM PST The press release came out this morning, including this image:
Temperature Differences near Wind Farms
This graph shows the night-time land surface temperature differences near wind farms between 2010 and 2013. Credit: Liming Zhou et al., Nature Climate Change
Here’s the PR:
Scientists find night-warming effect over large wind farms in Texas
Wind turbines interact with atmospheric boundary layer near the surface
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  IMAGE:Wind farms are numerous in parts of Texas; scientists report new results on their effects.Click here for more information. |
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Large wind farms in certain areas in the United States appear to affect local land surface temperatures, according to a paper published today in the journal Nature Climate Change.
The study, led by Liming Zhou, an atmospheric scientist at the State University of New York- (SUNY) Albany, provides insights about the possible effects of wind farms.
The results could be important for developing efficient adaptation and management strategies to ensure long-term sustainability of wind power.
“This study indicates that land surface temperatures have warmed in the vicinity of large wind farms in west-central Texas, especially at night,” says Anjuli Bamzai, program director in the National Science Foundation’s (NSF) Division of Atmospheric and Geospace Sciences, which funded the research.
“The observations and analyses are for a relatively short period, but raise important issues that deserve attention as we move toward an era of rapid growth in wind farms in our quest for alternate energy sources.”
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 IMAGE:This graph shows the night-time land surface temperature differences near wind farms between 2010 and 2013.Click here for more information. |
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Considerable research has linked the carbon dioxide produced by burning fossil fuels with rising global temperatures.
Consequently, many nations are moving toward cleaner sources of renewable energy such as wind turbines. Generating wind power creates no emissions, uses no water and is likely “green.”
“We need to better understand the system with observations, and better describe and model the complex processes involved, to predict how wind farms may affect future weather and climate,” said Zhou.
There have been a growing number of studies of wind farm effects on weather and climate, primarily using numerical models due to the lack of observations over wind farms.
As numerical models are computationally intensive and have uncertainties in simulating regional and local weather and climate, said Zhou, remote sensing is likely the most efficient and effective way to study wind farm effects over larger spatial and longer temporal scales.
To understand the potential impact of wind farms on local weather and climate, Zhou’s team analyzed satellite-derived land surface temperatures from regions around large wind farms in Texas for the period 2003-2011.
The researchers found a night-time warming effect over wind farms of up to 0.72 degrees Celsius per decade over the nine-year-period in which data were collected.
Because the spatial pattern of warming mirrors the geographic distribution of wind turbines, the scientists attribute the warming primarily to wind farms.
The year-to-year land surface temperature over wind farms shows a persistent upward trend from 2003 to 2011, consistent with the increasing number of operational wind turbines with time.
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 IMAGE:Wind farms dot the horizon in Lubbock County and other Texas areas.Click here for more information. |
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“This warming effect is most likely caused by the turbulence in turbine wakes acting like fans to pull down warmer near-surface air from higher altitudes at night,” said Somnath Baidya Roy of the University of Illinois at Urbana-Champaign, a co-author of the paper.
While the warming effect reported is local and small compared to the strong background year-to-year land surface temperature variation, the authors believe that this work draws attention to an important scientific issue that requires further investigation.
“The estimated warming trends only apply to the study region and to the study period, and thus should not be interpolated into other regions, globally or over longer periods,” Zhou said. “For a given wind farm, once there are no new wind turbines added, the warming effect may reach a stable level.”
The study represents a first step in exploring the potential of using satellite data to quantify the possible effects of the development of big wind farms on weather and climate, said Chris Thorncroft of SUNY-Albany, a co-author of the paper.
“We’re expanding this approach to other wind farms,” said Thorncroft, “and building models to understand the physical processes and mechanisms driving the interactions of wind turbines and the atmosphere boundary layer near the surface.”
Other authors of the paper include Lance Bosart at SUNY-Albany, Yuhong Tian of NOAA, and Yuanlong Hu at Terra-Gen Power LLC in San Diego, Calif.
Any climate effect that is not related specifically to the products of burning fossil fuels can be safely ignored, rationalized or overlooked.
The flow of taxpayer funds into the pockets of the crony bureaucrats, politicians and financial interests who perpetuate these scams is especially to be overlooked and never considered when it is time to vote.
Actually I think the biggest atmospheric temperature effect is not waste heat from the turbines. It’s more likely there is a huge effect in the way the surface gets rid of KE. Texas is dry! The surface has trouble shedding energy by conduction down through the dry soil. It also has trouble conducting to the atmosphere in calm conditions since (calm) air is a wonderful insulator.
During the day the surface gets very hot from incoming shortwave and the best way for it to equilibrate in calm conditions is radiataing long wave. If you create a lot of turbulence in the boundary layer you change the proportion of energy lost from strongly radiated (and lost to the lower atmosphere) to strongly conductive to the lower atmosphere.
At night the same turbulence increases the amount of energy that can be transferred by conduction from the surface to the lower atmosphere. Instead of a weak surface boundary mixing you get mixing all the way up to the height of the blades and beyond, several hundred feet.
The law of unintended consequences.
ROM says:
April 30, 2012 at 3:07 am
A lot of people decry anecdotal evidence, but I’ve found that good anecdotal evidence can lead to Aha! moments or at least further understanding of a phenomenon at hand (or expose the fact that there’s a phenomenon at hand). This is a great story, I’ll be repeating it!
You didn’t say what the stars looked like, I will assume “glorious.”
Clearly, you found the height of the air inversion. Radiational cooling chilled the ground, that chilled the air which chilled air right above it, and eventually you should have had a thin layer of cold ground air next to air that hadn’t cooled down or had enough mixing to stay warm.
I’m sure the windchill factor swamped things, but when you were in the howling gale level, could you tell the air was warmer?
The link to Pielke’s blog has a link to http://pielkeclimatesci.wordpress.com/2007/07/02/in-the-dark-of-the-night-%e2%80%93-the-problem-with-the-diurnal-temperature-range-and-climate-change-by-richard-t-mcnider/ “examines the behavior of the stable nocturnal boundary layer (SNBL)” and includes:
There’s a bit of a dilemma here, and exposed in the main focus of the new article. Nighttime ground level temperatures are vitally important to ground level life (like to all the New England gardens that may have suffered a freeze last night). However, they’re utterly useless to measure the heat content of the atmosphere. However^2, radiational cooling is still important as a measure of how much CO2 is retarding nighttime radiation. However^3, water vapor confounds those measurements.
Suffice it to say, as long as it still gets frigging cold at night in the high, dry deserts of the world, things aren’t as bad as some people make it out to be.
I’ve run a bit far afield, but thank you for your great anecdote!
WFHI Wind Farm Heat Island effect?
“The sorry lessons of green-power subsidies”
“A recent study, co-authored by Fraser Institute energy economist Gerry Angevine, found that Ontario residents will pay an average of $285-million more for electricity each year for the next 20 years as a result of subsidies to renewable energy companies. ”
http://www.theglobeandmail.com/report-on-business/the-sorry-lessons-of-green-power-subsidies/article2417284/
E.M.Smith says:
April 30, 2012 at 3:48 am
It’s the typical reflectance, err, albedo, that’s 18%. Even new snow manages to absorb some 10% of sunlight. I could see dark solar panels reflecting about a third of the light of average terrain, absorbing an extra 12%, so only and extra 120 watts.
During the daytime, any extra convection will help limit the increase in the high temperature, but I bet there are interesting nighttime effects with really great radiators positioned a few meters above the ground.
What the hell are those above talking about? This is about turbine blades mixing warm and cool air at ground level. Nothing to do with windmill blades heating the atmosphere by friction. For F’s Sake!
ROTFLMAO,
Quick have GISS place all their thermometers next to wind mill farms and really develop that hockey stick.
Don’t you just love it when a plan comes together?
So, wind farms caused the drought in Texas?
/sarc
Once again, dollars spent on researching “duh” because CO2 correlated warming just isn’t behaving like their darling anymore.
Just wait, the next thing will be that warmer temperatures cause sweating.
****
P. Solar says:
April 30, 2012 at 1:22 am
Nuclear power plants warm the local rivers and this may legitimately be called an effect on the local environment , it is not “climate change”.
*****
Only for “once thru” cooling systems, which I doubt have been built for decades. Modern cooling systems are “closed” systems, reusing the same cooling water over & over. No river water warming.
All the wind farms are warming the earth; that we know.
Electricity gained? There is not much to show.
The green power decree
Heats the earth one degree.
Its Quixotic pursuit has now reached a new low.
> Michael Bergeron (@zerg539) says: Lets save the world from warming by making it warmer!!!!
The effect isn’t global.
> Rob Schneider says: Is this not caused by the basic thermo effect of heat being created whenever there is a conversion of one type of energy to another?
No, its caused by mixed down air from higher up.
> eljay says: This is both tragic & funny
Only if you don’t think.
> wayne says:… They create turbulence breaking the smooth surface skin laminar flow which increases soil evaporation.
Don’t believe you. See above.
> Andrew says:… what extentthe observed effects impact maximum (daytime) temperature readings
Unlikely. I think this relies on their being a temperature inversion, which is almost always at night. And in light winds, too, come to think of it.
> teh same effect is also observed in grape-growing regions which use horizontal windmills (ie. helicopters) to mix air in order to elevate ground temperatures.
Again, only on cold nights (to avoid frost).
> Mark says:… Richard Black has (albeit with huge caveats) covered this at the BBC http://www.bbc.co.uk/news/science-environment-17871300
Yes, and Balck has got it right: the key bit you’ve all missed is “The scientists believe the effect is caused by turbines bringing relatively warm air down to ground level.”
Black has some more useful comments; its a bit of a shame whoever wrote this post didn’t read him first, it would have avoided a lot of confusion. For example:
“Recognising that this could wrongly be interpreted as suggesting the local temperature will continue to rise, lead researcher Liming Zhou cautioned: “The estimated warming trend only applies to the study region and to the study period, and thus should not be extrapolated linearly into other regions or over longer periods.”
and
“At night, air above ground level tends to be warmer than the ground. Dr Zhou and his colleagues believe the turbine blades are simply stirring up the air, mixing warm and cold, and bringing some of the warmth down to ground level.
“The result in the paper looks pretty solid to me,” commented Prof Steven Sherwood from the Climate Change Research Centre at the University of New South Wales in Australia.
“Daytime temperatures do not appear to be affected. This makes sense, (and) this same strategy is commonly used by fruit growers who fly helicopters over their orchards to combat early morning frosts.”
Hoho
This paper refers to local land temperature change not global climate change. Come on now, you guys are smarter than that!
The law of conservation of energy would be the place to start thinking about this stuff. Heat on earth comes from the sun. The heat generated by burning fossil fuels (let alone heat stirred up by wind farms) is insignificant compared to solar heating and the heat trapping effect of GHGs. This is very basic stuff.
Tony Mach says:
April 30, 2012 at 12:18 am
That’s a good point, I don’t know the answer. (Which means I shouldn’t be wasting everyone’s time with a reply!)
UHI effects are generally blamed on heat storage in bricks, concrete, and pavement being released at night. That by itself may be enough to delay or prevent the formation of an inversion. However, it sometimes doesn’t take a very tall building to be above the rural inversion level, so I think you have a very good point.
While there are places with very thin inversions (e.g. ROM’s great story from running a seeder late at night), large valleys can make for inversions deep enough to cover tall buildings.
The morning I left Carnegie-Mellon University and Pittsburgh PA in August 1974, I drove east on the Penn-Lincoln “Parkway” and climbed out of valley, I took a last look at Pittsburgh in my rear-view mirror. It was about 1000, and the inversion was just breaking up, made visible by the brown cloud lifting above the city.
I missed CMU and its ARPAnet access, I didn’t miss Pittsburgh’s steel mills and coke plants.
Not only can you increase the incidence of Texas wild fires but you can fan the flames and blow them all the way to Nebraska and New Mexico – you are blowing in more oxygen as well as kinetic energy.
Anthony, looks like you will have to add another column for your site surveyors. Check for local windfarms.
Nick Stokes and EM Smith,
Aren’t you failing to distinguish between heat and energy? I can’t remember enough about quantisation of energy within and between atoms, but I’m sure Boltzmann has something to say about it. Since friction with air absolutely generates heat, and turbulence creates eddies and vortices which will increase the residence time of the air in that area, I could see a wind-farm could potentially result in the release of energy (heat) in the vicinity of the farm that would have been released or transferred in other forms of energy transfer (not necessarily heat) elsewhere had the wind farm not been there. How much and whether it’s significant (compared to stirring up 30m of air depth) I know not.
wmconnolley says:
April 30, 2012 at 6:03 am
While Wayne may not have worded things quite right, exactly how is the air inversion broken up without turbulence? Clearly, ground heating is out, as is vacuuming out the inversion. Seems to me turbulence to break up or prevent the boundary layer and the laminar flow above it is close enough. Once you replace cold, still ground level air with warmer nighttime wind, you’re going to mess up dew formation and allow nighttime evaporation.
Please go into more detail.
Ric Werme says:> UHI effects are generally blamed on heat storage in bricks, concrete, and pavement being released at night…
Not really, no. http://en.wikipedia.org/wiki/Urban_heat_island#Causes
Mr. Connolly, I didn’t miss it. We have motor-driven wind turbines in orchards along Hwy 11 for the purpose of mixing warmer air with cold frost-producing air in order to keep fragile fruit from frost damage. No farmer I know would extrapolate that practice to say that “the climate is affected” because of it. They are fully aware of the local mixing affect. In these parts, that’s a “duh” piece of information.
My complaint centers on the money used to produce this already known “revelation”. I’ve a better way to spend research money. Just ask a farmer.
But then “weall ur red-nek flat erthrs ta the likes a’yu”.
Ah, according to Richard Black’s story for the BBC it is all OK as the warming only happens at night! What next? Maybe they will find that onshore the vibrations are setting off earth tremors, or offshore confusing marine wildlife!
Wind farms might be good at reducing overall fuel consumption but they are by no means fuel replacements, still got to have something for when the wind, either doesn’t blow or blows too hard….
@wmconnolley quoting approvingly Zhou: “The estimated warming trend only applies to the study region and to the study period, and thus should not be extrapolated linearly into other regions or over longer periods.”
This is your version of science? Then go tell all the model makers they are out of business because observations must not be extrapolated to the world at large. Every study that estimated empty grid cells from neighboring cells is fatally flawed.
If the sun rose in the east this morning and every morning in your living memory, don’t count on it happening tomorrow because you’d be committing the sin of extrapolation.