Published on May 2nd, 2012 | by Breath on the Wind7
Understanding Wind Turbines and Heating/Cooling: “Eureka!”
Are wind turbines that produce electricity “bad” and contributing to global warming or is it all just hot air? (Hint: the answer has something to do with the air, but not the global climate.)
Our world is warming. Just a little, but it is enough to cause considerable and catastrophic climate changes.
We know that, for anything to warm, there must be a source of energy. Wind turbines produce electricity. That is energy. Couldn’t that be a source?
Archimedes solved one problem by jumping out of a bath and running through the streets naked, exclaiming “Eureka!” (“I have found it” in ancient Greek). We can also understand the wind turbine effect by thinking of being naked in a bath.
Surface Effect and Convection
You draw a bath but it is too hot, so you let it cool a bit and you can just get your feet in. You seem to get used to it and try to put a bit more of yourself under the water, but when you move, the water seems suddenly hot again. The same thing seems to happen with very cold water. Inching into cold water slowly seems okay, but sudden movement brings a new rush of temperature. What you are noticing is called a “surface effect.” The explanation says that the attraction between close molecules has an effect upon how a fluid moves. We know that “convection” (moving fluids: air or water and sometimes small solid particles) is one of the three ways that heat is transferred. So, when you stay still in a bath, a layer of less-moving fluid “insulates” you from what is hotter or cold around you. Moving disturbs that insulating effect as it mixes the water.
At night, the ground surface temperature cools more quickly than the air (there is a lot of cool ground below). The surface effect dictates that the air above the ground will also cool more quickly than air slightly higher. What the wind turbines are doing is creating movement, like your moving in the bathtub. This turbulence overcomes the molecular attraction, the surface effect. The moving air mixes hot with cold and “Eureka!” you have surface temperatures that are more like what is seen in the slightly higher atmosphere. Overall, there is no warming or cooling, as there is effectively no heat energy added by the wind turbines. Only the surface temperatures are warmer. The effect should be a slightly warmer (and possibly dryer) ground.
Rhetoric and the Scientist
This news item has received a lot of press on the web. The original study was released on April 29. Even here on CleanTechnica, we have had Glenn Myers’ original post the next day followed by Susan Kraemer’s. These articles across the web range from attempting to report a paradox to either suggesting wind farms are heating the planet or that they are doing nothing of the kind and scientists should be careful what they say.
Susan warns scientists that they should be very careful in how they word their studies, so they don’t give ammunition to those who advocate against global warming. But wouldn’t this also inject a bias into the study? Perhaps scientists should be concerned with how their study is read, but writing to convince others is not necessarily their field of expertise and maybe we should not be critical of them for not achieving our goals. However, when I look at this and other studies, I begin to think that scientists have taken a page from Hollywood’s playbook and feel that any mention of their study is a good one, no matter what the source, misunderstandings or misapplication. Controversy is at least interest. They may not mind being modern-day “stars.” It is a very short distance between being unbiased and being intentionally vague.
Ultimately, that status and an understanding of such studies is dependent upon us. Eureka!