Well, Draug, they COULD cause turbulence, by interacting with the wind that was already there.

I'll agree with you that this is pretty dumb, though.

Could, maybe. But they make it sound like the turbines are engines turning like a plane's propeller.

It means that someone is going to get funding to do more research. People still debate global warming for some reason and we have tons more data than they have for their small area over only 8 years. The issue is really the adage I hear from my professors: "data cannot prove you correct," especially with such a small data set

Ok, so manmade climate change is a big issue these days.

How, you might ask, do windfarms contribute to warming??

Well turbulence caused by wind farms will mean lower wind speeds and higher temperautres. One question, is this a problem?

That really depends. The first thing about higher temperature is more energy is radiated - out into space and also down torwards the earth bouncing off the surface.

My initial conclusion is that higher temp, localised around a wind farm, is a good thing. Total energy will be lower, thus average temperatures will be lowered, thus extreme weather conditions (which require high energy concentrations) will be rarer.

However this global assessment ignores the local impact; the study only shows higher temperatures at night. And our understanding of what that means is fairly limited (or at least mine is)

But wait, i hear you say, if higher temperatures are good - then global warming is lots of higher temp thus better!

Alas that logic is flawed. Higher local temperatures without adding any energy to a system means lower temperatures somewhere else. This warming effect takes energy out of the wind - exactly what wind farms are designed to do, they take the energy and convert some of it to heat and some of it to electricity.

I'd guess the local warming effect is much smaller than urbanisation's warming effect. And is likely negligible... But more study is warrented.

And yes, the turbines could cause heating, i think it sounded like it was the tower and not the turbines, but that's not clear... Still interesting study, the headline is batshit crazy BAD journalism!

"But more study is warrented."

I wouldn't even give a dime of public money to studying this. No doubt vast numbers of human activities could be analyzed for their warming / cooling effects, and tons of the resulting studies could get into science headlines, precisely because warming and cooling are such trendy topics right now.

What I really love was how they jumped to the conclussion it was the windfarms and didn't even look to other possible differences. Like, what kind of ground cover is there? Windfarms have nothing but fields beneath them (at least in Indiana) but the areas (again in Indiana) around them may have woods or cities/towns. Guess what? Cement and grass/soil have different effects on the ambient temperature. And that is just *one* possibility.

Yeah, this "study" was all about getting a research grant.

Draug, is turbelence not a random motion of the air, while wind can be high speed coherent motion.

Reducing that average wind velocity and increasing the turbulence - in my mind at least - means a minor heating effect, plausible if not threatening, imho - though i admit my fluid dynamics is fairly weak, general and qualatative (ie i wouldn't be able to suggest any interesting shapes, but the general trends seem fine)

I don't see what wind speed has to do with temperature. If it's 90 degrees outside a thermometer will read 90 degrees regardless of the wind temperature.

Ok smeck, i'll grant your position. When i say further study is needed, i don't mean at the expense of important things. And i do think this is pretty poor reporting.

And draug, i'd have thought the turbulence caused by trees woupd be a bigger impact than the cement/soil differences... And are totally the same sorts of systems as wind farm tower or urban buildings - so useful for comparison

Coldsoup yes. But if you can reduce that wind speed, the energy HAS to go somewhere.

Generate electricty and you can use it to heat up your thermometer.

All energy generation is less than 100% effecient at converting the input to output and the loss is always to heat (i think)

OK, ora, cool.

But as for cement/soil, I do think it's a pretty huge difference. I believe I read somewhere something on the order of one degree average over the year, though I could be completely misremembering.

Let's see... Energy is pulled out of the air by reducing wind speed ever so slightly. So remove energy, reduce temperature. Not all the energy is 100% converted, so slight loss of that energy back into the environment. Yet somehow the temperature goes up, meaning the environment gained more energy than it gave up to the windmill to begin with?

What am I missing here?

Wind speed does not directly correlate with temperature.

For an ideal gas, the temp does vary with the average particle velocity. But for a large scale phenominum (sp?) like wind there is a distribution around the mean particle velocity... Does that make sense?

I would have thought that the people writing this article would have realized how silly this really is... thermodynamics is at work, Mr. Watson. If large wind farms didn't generate some degree of heat, we would have a perpetual motion machine.

On a lighter note, I bet coal-fired plants have a pretty decent warming effect on the local climate too. Nuclear too... Funny how that works.

@Draugnar I think it's possible because what's occurring is mechanical energy (air moving) is being converted into electrical potential energy, and some is lost as heat in the process. But I'm by no means an expert on the subject, it's just what I'm seeing as the cause.

@G1 while that is the case, i don't think it is the warming effect they are talking about.

I'm imaginig a steady stream of air (wind) with average velocity of 50 m/s being broken up by the turbine blades and continuing at 49.8 m/s with some of that loss going directly to turbulence which increases the distribution around that average velocity - which equates to a higher temp - (noticably it does this even without any electrical component... It is just the mechanical effect and the turbulence it causes)

What's the issue then? I would imagine that something like a forest would do this plenty on its own, and far more prolifically than a wind farm...

Of course wind farms increase the temperature around them! Nobody is going to debate that. They're not giant air conditioners for the Earth...

I didn't read the paper but nothing the scientists were quoted as saying seems that absurd. Nobody made any claims about GLOBAL warming.

No yonni, but why is it news unless it is 'green tech not as green as we thiught! May cause global warming'

Either misleading to those who think it implies global warming, or barely news. And in either case poor journalism.

Poor journalism for sure. But what can you expect?

Professionalism from professionals? It's not what i might expect from some random webdip thread, but from scientific america???

Global warming causes the ice in my drink to melt.

Tear them down and build a coal power plant. At least then there's no guesswork with its contribution to climate change.

Yes emacs, without global warming all of your icecube would remain solid for years to come...