Where does the power to turn a wind generator actually come from? When we extract 735 mega watts of power using the wind what effect is this having on the global wind patterns? This is of little consequence now but is anyone investigating large scale implications?
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The sun's energy, causing eddy currents as well as major density re-distributions, drives air flow. Density also affected by humidity of course.

You can get a pretty good idea of how turbines great local eddy currents and reduce ground level energy by looking at their nominal layout spacing. Any closer and the efficiency effects are noticed. A good analogy can also be made to wind break tree plantings. The immediate effect, just down wind of a turbine or wind farm is to cause particulates (soil particles) to settle out. Out on the Great Plains, it can argued, a row of wind turbines is a soil conservation device (but devoid of any wildlife habitat value).

The really high turbnies, which reach upper level air flows, would not have any direct effect on aolian erosion/dpeosition. However, as upper layer air flows induce ground-level eddy currents and drive the air we are in contact with, your question may have some importance. Meteorological models may be able to provide some answers.

I suggest California challenge Texas to a "green race". That would be awesome, to see which state can get the greenest within, say, two years.

They would probably effect the wind as much as sky scrapers. Kinda like pissing in to the ocean.

This is pretty cool. I wrote a post on this about a month ago. They're both on the edge of the solar and wind race...

Jetson Green Texas vs. California Story

John, without built in handicaps, Texas would win that race...it has more land and waaaay more wind.

There's some controversy over a Texas wind farm to be situated off the Gulf Coast. Here's an NPR story about it. The problem: It's right smack in the middle of a very important migratory flight path for birds.

The skyscraper analogy occured to me early on and, yes it is the same thing but by accident and not design. A building will disturb the wind flow and certainly extract some power from the flow to the extent that the building is moved by the wind. A wind generator, however, is put into a given wind stream for the express purpose of extracting energy from the wind flow and turning it into electricity. Yes, it may be "like pissing into the ocean" now but what about the future? The energy that is being taken from the thermal forces that make our weather may start to cause changes we will not be pleased with..there is no free lunch when it comes to energy. I'm not trying to be a doomsday guy here but a little prognostication might be in order.

Mike
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Urban "Micro-climates" are known to occur from adsorption of incoming solar radiation on pavement and buildings, interrupting normal energy flows, which is to say that micro-climates are the norm over large metro areas. Adding solar panels to the city may contribute to this, but would certainly not dominate the effect if put on roofs. Likewise, extensive areas of wind farms may create microclimates, slowing down average wind velocities over large areas of landscape, as would a forest or cityscape. If we use the urban example as an analogy, it seems a small price ot pay.

This is pretty cool. I wrote a post on this about a month ago. They're both on the edge of the solar and wind race...

Yes, but California started with a huge lead in wind. At one point in the early 1980s, it had more than 80% of the world's installed wind generating capacity. Now its share is below 4% and continuing to decline.

Talk about missed opportunities . . .

Regards,
Thomas O. Gray
American Wind Energy Association
www.awea.org
www.ifnotwind.org

As Enoch stated there are couple of proposed projects under possible development on the major migratory path of about 60% of the North America's birds, the Galveston area project and one about 80 miles north of Brownsville, TX. The project in south TX may have some backing from the City of Houston which is considering switching to 100% wind power and would be a major financial stakeholder in the project.

As for the bird kills, it is troubling, but I can't guess the number of bird kills it might cause due to the facts that the larger turbines have slower blade speeds and the average migrating bird travels around 3000 ft up. The Galveston site would most likely be the most problematic since it is a major stop over location for the birds.

Wind farms, tidal power + plugin Hybrids = Energy security and environmental sanity.

Great article!

I'm ill informed on the subject, but who's behind the wind farm development in Texas? Seems like a great financial opportunity, and I wonder if that's as much or more of a motivation than the "green" aspects.

Here’s a link to some information regarding the City of Houston's wind power plan in Kenedy County, TX. I believe the proposed location is off-shore the north tip of South Padre Island
http://www.bizjournals.com/houston/stories/2006/05/15/story2.html

There has been some controversy over the Mayor's connections to the head of the wind company, but since the initial news story there has been little information on how things are progressing

Wind power has consequences too; these turbines kill birds and bats. See http://batcon.org/home/index.asp?idPage=55&idSubPage=26

I agree with Jilted that the large scale effects would be inconsequential; I also believe that highly localized effects are possible, but I do not think they would be worrying. Urban centers have large tall buildings which are densely packed. The wind effects are more severe on a localized level in a city than in a wind farm, yet nobody proposes eliminating urban centers. Just the thought of doing so to eliminate wind effects would be ridiculed.

As for wind generators killing birds, this is false. TH has already run stories stating this. It is one of those 'eco-myths'. As for bats, I think it reasonable to assume bats might be killed. Their nighttime 'echo´ navigation may be ´confused´ by the blades and generator. This is a guess as I have not read much into this subject.

The argument that wind turbines are bad because they kill birds and bats is ridiculous. House cats kill millions of birds every year and no one complains about that. Think big picture people- energy independence/reduced pollution is worth the sacrifice of a small amount of birds.In the long run more birds will be saved by having a cleaner environment.

Could somebody give up a comparative analysis of Germany and USA use and development of wind power? It seems like the germans are way ahead of us in that field and many people here in USA do not have a remote idea of how thing are develop in the other side of the pond
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There was a rush to develop the best wind sites in Germany starting in the late 90's. At this point I suspect the easy pickings are over and they are facing a lack of offshore opportunities and thus must go "up." The cultural context is significant. Because sprawl is less prevalent in Germay (development planning encouraged) the prospects for landscape infringements could be reduced.

If anybody is interested to know why investing in wind is a good idea. Check out the link below.

"Even if only ~20% of this power could be captured, it could satisfy 100% of the world's energy demand for all purposes ... Several practical barriers need to be overcome to fully realize this potential"

I guess the "practical barriers" are Bush, ExxonMobil, et. al.

http://www.stanford.edu/group/efmh/winds/global_winds.html

The argument that wind turbines are bad because they kill birds and bats is ridiculous. House cats kill millions of birds every year and no one complains about that. Think big picture people- energy independence/reduced pollution is worth the sacrifice of a small amount of birds.In the long run more birds will be saved by having a cleaner environment.

I absolutely agree. Having said that, it's clear that there are a few locations where wind farms can cause problems for specific species of birds, usually raptors (birds of prey--hawks, eagles, etc.). Wind companies do typically survey sites for potential problems before building, and that practice should continue.

Regards,
Thomas O. Gray
American Wind Energy Association
www.awea.org
www.ifnotwind.org

As for wind generators killing birds, this is false. TH has already run stories stating this. It is one of those 'eco-myths'. As for bats, I think it reasonable to assume bats might be killed. Their nighttime 'echo´ navigation may be ´confused´ by the blades and generator. This is a guess as I have not read much into this subject.

On birds, not really false--it's just that at the vast majority of wind sites, the numbers are so small that they are tiny in the overall picture of human-related avian mortality.

On bats, there are a number of theories, but no answers yet. My personal theory is simply that there isn't anything in nature like a wind turbine and so bats don't recognize them as a threat. A link is provided above to more info at the Bat Conservation International (batcon.org) site. BCI, the American Wind Energy Association, the National Renewable Energy Laboratory and the U.S. Fish & Wildlife Service are supporting a joint research effort to reduce bat kills. At the moment, work is focused on (1) finding a sonic deterrent that will keep bats away from the turbines and (2) trying to find out whether there is a way to predict in advance which wind sites will be problematic. While at least a few bats are killed at every wind farm, wind facilities in the Appalachian Mountains appear to have much higher levels than those elsewhere, except for one site in Alberta.

Regards,
Thomas O. Gray
American Wind Energy Association
www.awea.org
www.ifnotwind.org

"Even if only ~20% of this power could be captured, it could satisfy 100% of the world's energy demand for all purposes ... Several practical barriers need to be overcome to fully realize this potential"

The potential of wind power to contribute to world energy supply is huge. For more information, see the Plugging the Gap report.

Regards,
Tom

"I guess the "practical barriers" are Bush, ExxonMobil, et. al."

I wouldn't say bush is a barrier, he in fact started the wind revival in the USA by bringing about the wind boom in Texas. Now everyone else is following and california looks like they are building more again finally. State competition is the best thing. Now that Bush is president he's doing more talking than doing but part of being president is selling your soul to the big oil I guess.

"I guess the "practical barriers" are Bush, ExxonMobil, et. al."

I wouldn't say bush is a barrier, he in fact started the wind revival in the USA by bringing about the wind boom in Texas. Now everyone else is following and california looks like they are building more again finally. State competition is the best thing. Now that Bush is president he's doing more talking than doing but part of being president is selling your soul to the big oil I guess.

I wouldn't say bush is a barrier, he in fact started the wind revival in the USA by bringing about the wind boom in Texas.

Yes, Bush is a real hero. I bet you photoshop pictures of him with a cape on his back and that codpiece he wore from his flightsuit stunt.

How many households can 1 wind miller provide energy for? I live in central
Texas. Don't see very many wind mills here. We have plenty of wind.