Wind turbines extract kinetic energy from the air around them, and since less energy makes for weaker winds,
turbines do indeed make it less windy. Technically speaking, the climate zone right behind a turbine (or behind all the turbines on a wind farm) experiences what's called a "wind speed vacuum," or a "momentum deficit." In other words, the air slows down.
The effect has implications for wind-farm efficiency. Upwind turbines in a densely packed farm may weaken the breeze before it reaches the downwind ones. It could even have a more general impact. If wind farms were constructed on a truly massive scale, their cumulative momentum deficit could conceivably alter wind speeds on a global scale (though how winds would change is complex—they'd likely slow in places and speed up in others).
Wind farms can also affect the local temperature. According to Somnath Baidya Roy, an atmospheric scientist at the University of Illinois, as a breeze passes over a wind farm, the turbines create an atmospheric wake where wind speeds drop and turbulence increases. The rotors spawn a set of eddies that mix air from above with air from below. The eddies can lift cool air and sink warm air or vice-versa. That turbulence could raise or lower local temperatures. In a paper published in 2012, one group of researchers studied areas over several wind farms in Texas and found that local surface temperatures had risen by a small but significant amount.
http://www.popsci.com/science/article/2013-05/fyi-do-wind-farms-make-it-less-windy
“We found that when wind turbines are present,
they slow down the outer rotation winds of a hurricane,” Jacobson said. “This feeds back to decrease wave height, which reduces movement of air toward the center of the hurricane, increasing the central pressure, which in turn slows the winds of the entire hurricane and dissipates it faster.”
The researchers found that 78,286 large wind turbines arrayed off the coast of New Orleans would have dropped Hurricane Katrina’s wind speeds by 81 miles per hour, and reduced storm surge by up to 71 percent. Covering most of the Gulf Coast with wind turbines (meaning over half a million individual turbines) slowed down a modeled Katrina even more (wind speeds by 90 mph and storm surge by 79 percent). The same area covered by half as many turbines would still cut storm surge by 63 percent. Hurricane Isaac would have lost up to 60 percent of its storm surge and 57 mph of wind speed. Their model of Hurricane Sandy found that 112,014 offshore turbines would cut wind speed by 80 mph and drop storm surge by 21 percent.
The purpose of a wind turbine is to transmit kinetic energy from wind into electrical energy used to power homes and businesses. The wind that comes out the backside of a wind farm has less energy than it did when it entered the array. And a recent study found that wind farms, even on a huge scale, do not affect the climate as some have claimed. And Archer and Jacobson said in 2012 that 4 million turbines spread around the world could generate half the world’s energy needs without interfering with atmospheric circulation too much.
http://thinkprogress.org/climate/2014/02/26/3332521/offshore-wind-turbines-slow-hurricanes/
Joe Barton is an idiot for many reasons. But not because of this. The energy comes from somewhere, which reduces the energy somewhere else. There are consequences to everything.
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