Category — Micro (nano) climate change
“In any case there is an irony: environmental policy in the name of countering the human influence on macro climate is creating a substantial human influence on micro climate. If the natural climate is optimal, as some but not all ecologists believe, then industrial wind turbines add to the problem of man versus nature.”
I have long heard of micro-climates, isolated areas that have slightly different weather patterns than the surrounding larger area. I best remember hearing of the micro-climate of Northern California’s Napa Valley, a micro-climate that makes the area so good for growing grapes.
For the last several years, Somnath Baidya Roy has been pushing the concept that wind farms can affect the weather. While at the department of civil and environmental engineering at Duke University, Roy said:
“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.”
Roy also said at that time:
“It’s something like the wake from the propeller of a boat. Now this added turbulences mixes air up and down and creates a warming and drying effect near the ground.” He says the affects can be felt for miles and could have an impact on air conditioning costs and more money may have to be spent on irrigation of nearby crops.”
Wind farms tend to impact the weather more at night, which is when the wind is usually stronger and the most energy is generated.
WHAT THEY FOUND: 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. During the day, the effects from the disturbed airflow are negligible, since natural turbulence mixes the lower layers of the atmosphere. But the researchers found that in the predawn hours, when the atmosphere is less turbulent, a large windmill array could influence the local climate, raising temperatures by about 2 degrees Celsius (about 4 Fahrenheit) for several hours. The rotating blades could also redirect high-speed winds down to the Earth’s surface, boosting evaporation of soil moisture.
“Wind Farms Impacting Weather: Environmental Engineers Detect Turbines’ Turbulence Effects” Science Daily, 2005 October 1.
Roy is now atmospheric sciences professor at the University of Illinois at Urbana-Champagne and is continuing his research, but with some different findings. A study “Impacts of wind farms on surface air temperatures,” published in late 2010 in the Proceedings of the National Academy of Sciences, written by Roy and Justin J. Traiteur now shows: [Read more →]
August 2, 2011 3 Comments