wind turbines and changing regional weather patterns



Are Wind Turbines Creating Changes in Regional Weather Patterns?

(UPDATE! The best article to date that addresses the possibility that large scale wind farms can impact rainfall. Click here for article at

Are wind turbines impeding the progress of fronts across Texas?

Does the recent construction of the world's largest wind farm in west Texas have any influence on nearby weather and the recent record-setting drought in south Texas?

by Carl Caton, San Antonio
August 17, 2009

I must say that I've always loved the idea of windmills. Growing up in the dry, parched plains of West Texas, one thing you could always count on was wind. And not just any old wind but a dry, preheated, industrial sized wind. Daily. In my mind, if a windmill could do anything, it could turn a negative into a positive. A windmill could turn that constant, irritating desert wind into a vending machine for electricity.

And although I've since moved to a place that has less wind and more trees, I've been delighted to see windmills popping up all over west Texas. They're as plentiful as new weeds in a freshly tilled garden. In fact, west Texas boasts some sort of world record for windmills. And new revenue for county government. And royalty checks for landowners. And....

As I mentioned, we moved further south to San Antonio about twenty years ago. It was a more beautiful place with lush landscaping and centuries old live oak trees giving wonderful shade. San Antonio doesn't get that hot desert, Pacific wind like west Texas. Instead we get a predominately southeastern breeze that blows in from the Gulf of Mexico.

Another difference in the weather in San Antonio involves precipitation. We typically get much more rain in San Antonio, to the tune of around thirty inches. Much of our rainfall comes from a weather process called "frontal precipitation". In this process, a front of dry cold air pushes down from the north and collides with warm, moist air moving up from the south. When this "collision" happens, we get those blessed rains that makes our world look beautiful.

Our "rainy months" in San Antonio have typically been May and September. That's when the cold fronts and warm air collide at just the right location above the Alamo. Lately, however, we're not getting those rains in May or September. In fact, we're getting very little rain whatsoever. Depending upon how you measure things, we're in one of the worst droughts ever recorded in our area. Literally, hundred year-old trees are dying.

This extended drought has found me searching for a reason for such an unusual weather event. One thought that has crossed my mind is wondering if the windmills are changing our weather patterns. Let me share with you why. Whether you believe in "the butterfly effect" or not, we've all become painfully aware that tiny changes in weather patterns in one area can have profound effects in others. After all, isn't that what the climate change debate is all about: "What happens if the earth's average temperature rises a fraction of a degree?" Most climate change advocates profess that tiny changes can set off massive, cataclysmic, weather events.

With that thought in mind, let me ask you this question: Do windmills create changes in regional weather patterns? Or better yet, if you build the world's largest wind generating farm in one area, will it have ANY effect on weather in the surrounding area? Well, you might say, it may not change MUCH. But the basis of every fundamentalist, climate change advocate is that TINY changes in our atmosphere can create enormous changes the weather worldwide.

Back to my discussion on south Texas weather. San Antonio can be hot, in fact, miserably hot in the summer. Usually in late August, I start watching the national weather map, longing to see the evidence of a cold front heading to our area. In fact, I'm a little compulsive about this. With sweat pouring down my brow, I check the national weather map. "Yea, the cold front has made it to Oklahoma!" Then the next day, I'll say, "Oh boy, the cold front has made it on down to west Texas!" I'll start checking more often as it moves further south through San Angelo, then Brady, and into Blanco. The closer it gets, the more excited I get. And finally, hopefully it will push into San Antonio and I'll stand out on the porch of our house and just soak in the cool air. It's heaven on earth - a welcome respite from the summer blast furnace.

One thing I've noticed lately as I've practiced my odd form of entertainment is that, very often, those blessed cold air masses don't..... quite..... make.... it.... to.... San Antonio. What a disappointment! Interestingly, San Antonio is at this unique location when it comes to weather. We are at the very edge of where cold fronts travel. Now, don't get me wrong, there are plenty of those Herculean size cold fronts that blast across North America, come charging through San Antonio like a freight train and continue the march right down to the Gulf coast and beyond. I'm not really speaking about these most powerful fronts. I'm talking about those many, many cold fronts that have just enough energy to almost.... almost.... almost make it to San Antonio. Kind of like the little train that is puffing along saying, "I think I can, I think I can". Think about that particular cold front, the one that has "just enough" energy to "just barely" make it to San Antonio in order to create frontal precipitation.

Now, for that cold front that has "just barely enough" energy to make it to our area, what happens when that same cold front runs into the worlds largest array of windmills. Think about how much energy every one of those windmills can generate. Every ounce of energy the wind generator removes is one less ounce of energy that will move the cold front further south, right? And what if that "wall" of windmills stands in front of a cold air mass that "just barely" has enough reserve energy to make it to San Antonio? Might the cold front run out of steam "just before" it makes it to San Antonio? As climate changes advocates remind us, "even tiny little changes in weather can have profound impacts in other areas of our climate". Earth's global weather function is all interrelated, right? In the same vein, can even tiny changes in weather caused by a massive wall of windmills, cause even a tiny change in weather nearby? I would think that a thinking person would say yes. How much? I don't really know. 

Before I move on, let me share with you a few conversations I've had with professional meteorologists. As I've tried to articulate this harebrained observation to professionals, both responded with the idea that these cold air masses are very "thick". They've shared that these cold fronts are so massive and so high that they would easily move over my supposed "wall of windmills". I agree. The point I'm making is this: if there is a cold front that's moving down across the continent and it has "just enough" (that's the key point: "just enough") energy to make it to San Antonio, and if that air mass is just barely going to make it to San Antonio, if that cold air mass is just large enough to project that it would normally make it to San Antonio - then if that air masses runs into a wind farm, is it possible, even in theory, to "not quite" make it to San Antonio? 

I can't understand in my little pea brain how this couldn't be true. And you might agree with me, saying, "OK, in theory you're right that in just the right situation, it's possible that the tiny effect the windmills have on weather could change the impact of that cold front. But it really won't have a significant effect, otherwise". Ok, let's go with that for a minute. But what if we're talking about an area like San Antonio, that seems to be just at a critical location in its latitude that the average, run of the mill cold front typically does "just barely" make it there?

Let me share this with you a different way. If you studied the historical movements of cold air masses in North America and if you compiled all that data and created some conclusions of how far those fronts typically move, I think in such case, you would discover that cold fronts move a certain distance "on average". And at each point along that line, as measured by latitude, there is a certain probability that a certain number of cold fronts would impact that area. I really think you could prove this statistically. Now with that data in hand, if you then build a massive array of wind turbines that extract huge amounts of energy from that statistically proven body of cold front "data", do you think there would be a change? I don't think you could say no. I think you might say that it wouldn't be "much". Would it change the statistical probability of how far cold fronts travel by a few feet, a few miles, or a hundred miles? I don't think you could say there would be NO change at all. I don't think you can intelligently say that hundreds or thousands of massive wind turbines, carefully arranged over hundreds of miles, lying directly in the path of predominant wind patterns, would result in zero change to weather. 

Another interesting thought to consider was proposed by a professional meteorologist I spoke with. He didn't think the windmill farms would be much of a "wall" as I see them. He thinks the cold air masses are so high that those pesky little wind turbines would prove to be of little interference. Sounds good. But he went on to say that the windmills might cause some sort of "stumbling effect" where the upper air might be drawn downward as the slower air moved through the turbines. If that theory was true, then could it be that there would truly be some slowing of the air mass as it tumbles, falls, goes through some chaotic "reorganization" before it moves on? I think if you were in a laboratory, driving air through a wind tunnel and stuck a little wall in the bottom of the wind tunnel, you would create some chaotic turbulence that would indeed slow the wind. But what do I know?

While I'm rambling on here with all this anecdotal evidence, let me share another last, interesting tidbit. Texas weather is very unpredictable and we've gone through these drought cycles long before the advent of the wind farms. But, this drought we're experiencing in south Texas has generally been getting worse, and worse, and worse. I think it's worth at least considering that we've been building more, and more, and more windmills directly above us, directly in the path of cold fronts that might, barely, just barely, just barely make it to our area - that in such case - it might change our rainfall here even in a tiny, tiny, way... or maybe a whole lot.

We have to be careful about what we want to believe. I love "green energy". We all love green energy but we have to be careful that we don't become "anchored" in our idea of "good energy" and "bad energy". When we do this, we become predisposed to wanting a certain type of energy to do well and another type of energy usage to be reduced. It's easy to make villains of traditional energy - those "evil" oil companies. But we must be careful to understand that all energy sources have positive and negative attributes. Cause and effect is a reality. And more than ever, we should be more careful about understanding the long range impact of any energy source... even if we like it. I'm a believer in alternative energy but we should be careful about mixing religion and science.

I've read elsewhere that scientists reject the idea that windmills create global climate change. That could be true. Let me be clear: I'm talking about regional changes in weather, not global climate change. The question I'm asking is, will hundreds or thousands of windmills in west Texas reduce our annual rainfall totals in south Texas? And if so, how would it then translate into lower lake levels, underground water, and river flows in an area that is already at the "breaking point" with water constraints? Will it have any effect on the lives of people living in the seventh largest city in the U.S.? Will it be a "tipping point" in having adequate water supplies in San Antonio? Too many environmentalists are knee deep in "the cause". Too many academics are trying to create formulas. Too many scientists can't think of anything but "global". I'm thinking about my eighty year old neighbor who is walking across her yard carrying water in a bucket in order to be in compliance with city watering restrictions.

Now, should we even consider the ramblings of a west Texas clod like me who really knows very little about weather? Maybe not. All this weather talk leaves my head spinning round and round. But being we're in the "go green" mode where we're thinking about spending a massive part of our country's wealth, borrowing billions of dollars, mortgaging our children's future in order that we might change the earth's temperature, just maybe, by a tiny fraction of one degree in order to avoid an uncertain change in our weather future - then in that frame of mind - maybe we should consider if those great beacons of "alternative energy" are actually as green as they claim to be. 

I'm not sure I like windmills as much as I thought.



Point: We must develop wind energy because it's one of our few options. And it creates jobs! And it makes me feel good!

Answer: Before we spent 100 years building our entire energy complex around petroleum, wouldn't it have been wise to do a little forward thinking about the effects of its use? Should we not be a little more forward thinking about the effects of wind energy before we pour billions into the development of this new energy source? Cause and effect is a reality. Let's explore.

Point: Our most recent drought conditions result from a lack of rain in seasons not characterized by frontal precipitation.

Answer: Correct. My point is that this drought has been one of slow progression. I'm not saying that we never get frontal precipitation, I'm saying that we're "missing" those chances of frontal precipitation more often. And as the tally of missed rains chances builds year over year, the soil becomes dryer deeper and deeper down. My greatest fear is this:

We're not in a drought - in fact - our weather might be permanently changed to a condition of twenty inches of average annual rainfall, not thirty. For a region that is at the bitter threshold of running out of water resources, an area where hundred year old native oak trees are dying, that would be devastating. For professional meteorologists, this is all academic. For those living in south Texas who watch their eighty year old neighbors carry water in buckets to water their lawn, it's a frightening possible reality. We've got skin in the game. 

Point: It has been suggested by a professional meteorologist that if the wind turbines were to decrease rainfall in the area, it would happen in the general locale of the wind farm.

Answer: It seems that these powerful fronts would still have enough power in reserve to push through the wind farm but would slow to some degree several hundred miles beyond the wind farm such as in south Texas.

Point: It has been suggested by a professional meteorologist that these frontal air masses are so tall and strong that the wind turbines are but a tiny hindrance to the path of air.

Answer: Agreed, but would the wind farm might create a "stumbling effect" where some of the energy from the front would "collapse" to the ground just beyond the wind farm and thus create enough disruption to have any effect on how far the weather system would travel beyond?

Another Observation: It appears that very little research has been conducted on the cause and effect relationship between regional weather patterns and wind turbines. Most researchers and scientists think globally. That's important, but the point of my article is really about how the people of San Antonio could be impacted by a permanent reduction in annual rainfall. It's very important to consider that San Antonio lies at the very edge of the "Great American Desert". Tiny changes in regional weather could have a profound impact on our way of life given we live at the very "tipping point" of becoming part of that American desert. Another important consideration is that San Antonio has just experienced an unprecedented surge in population growth. Our water resources are under strain as never before. The city is desperately searching for new resources. And so, not only do we need every possible water resource we can find, we couldn't possibly consider the ramifications of actually being in a permanent, era of declining rainfall. That being said, it is crucial that we understand the realities of how our weather patterns will be effected before someone invests many more billions of dollars in a massive, expanding array of wind turbines.

More reading:



"So far, a number of energy companies, especially in the United States and Europe, have made the choice [of using wind turbines] without knowing much about small-scale and large-scale climate impacts."

"Unaddressed, the severity of the local weather impact induced by large wind farms would fall somewhere between the environmental costs of deforestation and global warming, Baidya Roy said."

"Now researchers are looking at another potential “unintended consequence” – the likelihood that collectively, groups of large wind farms in one region could alter weather patterns downwind of the turbines in another region."
  Christian Science Monitor

"Wind farms may have an impact on local weather patterns. As environmental engineers have discovered, wind farm propellers create a lot of turbulence in their wake, mixing air up and down with effects that can be detected for miles." 
Science Daily

"With a new power source comes an impact to our environment. Roy says, "Large wind farms can significantly affect local meteorology." He studied these massive machines and believes wind farms can actually impact our weather because wind turns the blades of the turbine around a rotor, which helps generate electricity the blades create a lot of turbulence in the wake." 
Science Dail

"Large groups of power-generating windmills could have a small influence on a region's climate. All large wind turbines disrupt natural airflow to extract energy from wind." Science Daily

"Results from climate modeling studies by myself and others suggest that large-scale use of wind power can alter local and global climate."
David Keith
University of Calgary

"Researchers are investigating the potential for large wind farms in one region to alter weather patterns in another region downwind."
Washington Post

“as the technology ramps up, so hopefully we don’t get into really surprising consequences before we have a chance to realize what they might be.” Daniel Kirk-Davidoff

"But a team of researchers from the University of Maryland have found that large-scale use of wind turbines as a power source may have an impact on our environment directly opposite that which they purport to minimize: Climate change." Meteorology News

"Slowing wind speeds by 5 or 6 miles per hour – while it sounds negligible, could have significant impacts on the large-scale atmospheric flow and yield consequences we do not yet understand." Meteorology News

"Researchers are investigating the potential for large wind farms in one region to alter weather patterns in another region downwind. Specifically, the turning of the windmill propellers creates considerable turbulence, which mixes air up and down." 
China Economic Review

"A forecast for a hotter, drier Earth could result if we build too many wind power generating plants throughout the world." Energy Saving Research

"But important questions remain: Could large wind farms, whipping up the air with massive whirling blades, alter local weather conditions?" Energy Daily

"Extracting energy from wind changes regional air currents, which can in turn affect how the nearby ocean circulates, according to Goran Brostrom of the Norwegian Meteorological Institute in Oslo." Discovery News MSNBC

"Meneveau pointed out that dense clusters of wind turbines also could affect nearby temperatures and humidity levels, and cumulatively, perhaps, alter local weather conditions." 
Science Centric

"That being so, it’s logical to assume a massive windmill deployment could at least alter regional weather patterns.

Prinn emphasizes he’s not against wind power or any other renewable energy technology. He simply thinks it’s essential to explore how any of the proposed technologies might affect us."
MIT Spectrum

"How might the good people of San Antonio be impacted by a PERMANENT reduction in annual rainfall?"
Carl Caton

wind turbines and changing regional weather patterns

(c) 2009 Caton Family

wind turbines and changing regional weather patterns