Saturday 2 October 2010

Would you believe if I say Wind Mills can have adverse effects on climate..??

I personally believe that whenever human being tries to intervene in any of natural process is due for major disaster. May it be then drilling earth for natural resources, obstacle to wind, building construction in sea? 

Today, many of us understand the effect of carbon emissions on climate and believe solution of that could be something like Wind energy, solar energy etc. which we believe generate energy without any climate change impact. All in all, the whole world is desperately trying to seek the substitute energy resources to avoid end of the world. 

In this process, did we all ever notice that how much extra precautionary we need to be here before choosing any particular energy source? Yes, we need to think very carefully about these things on long term basis. Recently, I come across one of the research from MIT where Dr. Prin (TEPCO Professor of Atmospheric Science) and Wang (Principal Research Analysts) who have made strong argument that Wind energy is not completely safe and can have adverse effect on climate in long run when U.S. Department of Energy is planning to account 20% of nation’s electricity supply by wind power in 2030. Although, AWEA (American Wind Energy Association) estimates currently only 2% of electricity is generated from wind turbines. 

Currently, 6% of the world’s total energy comes from nuclear reactors; while fossil fuels, a major contributor to global warming, provide approximately 85 percent, according to IEA (International Energy Agency). At the same time, in above pictures we can see that others* (includes Geothermal, Wind & Solar energy) is only 0.7% of total energy which is very much minimal.  Although, this proportion is expected to grow in coming years as people are betting heavily on Wind energy as it’s cheaper as well than other such resources. 

Prinn cautioned against interpreting the study as an argument against wind power, urging that it be used to guide future research that explores the downsides of large-scale wind power before significant resources are invested to build vast wind farms. “We’re not pessimistic about wind,” he said. “We haven’t absolutely proven this effect, and we’d rather see that people do further research.”

But a new MIT analysis about wind power says that millions of wind turbines would need to be installed across vast stretches of land and ocean to generate wind power to reach expected global scale. Such a massive deployment could indeed impact the climate as well as wind, they found, though not necessarily with the desired outcome.

In their land analysis, they simulated the effects of wind farms by using data about how objects similar to turbines, such as buildings, hills and clumps of trees, affect surface “roughness,” or friction that can disturb wind flow. After adding this data to the model, the researchers observed that the surface air temperature over the wind farm regions increased by about one degree Celsius, which averages out to an increase of .15 degrees Celsius over the entire global surface.

The wind turbines on land reduced wind speed, particularly on the downwind side of the wind farms, which reduced the strength of the turbulent motion and horizontal heat transport processes that move heat away from the Earth’s surface. This resulted in less heat being transported to the upper parts of the atmosphere, as well as to other regions farther away from the wind farms.

In addition to changes in temperatures and surface heat fluxes, they also observed changes in large-scale precipitation, particularly at the mid-latitudes in the Northern Hemisphere. Although these changes exceeded 10 percent in some areas, the global total changes were not very large, according to Prinn and Wang. 

Although Prinn and Wang believe their results for the land-based wind farms are robust, Wang called their analysis a “proof-of-concept” study that requires additional theoretical and modeling work, as well as field experiments for complete verification. 

Now looking at this picture, are we all 100% sure that Wind resource is really safe enough and will not cause any problem to climate even if they grow in numbers like other resources..?? I seriously doubt..!

References:
Prinn & Wang (2010). Potential climatic impacts and reliability of very large-scale wind farm. Journal of the European Geosciences Union , 10, 2053-2061.
http://www.atmos-chem-phys.net/10/2053/2010/acp-10-2053-2010.html
http://www.iea.org/textbase/nppdf/free/2010/key_stats_2010.pdf