December 19, 2010
Wind Turbines Alter Farm Microclimates
Researchers at the U.S. Department of Energy’s Ames Laboratory and the University of Colorado find evidence that wind turbines alter microclimates for farm crops, possibly for the better.
“We’ve finished the first phase of our research, and we’re confident that wind turbines do produce measureable effects on the microclimate near crops,” said Ames Laboratory associate and agricultural meteorology expert Gene Takle. According to Takle, who is also a professor of agricultural meteorology and director of the Climate Science Program at Iowa State University, the slow-moving turbine blades that have become a familiar sight along Midwestern highways, channel air downwards, in effect bathing the crops below via the increased airflow they create.
Wind turbines might reduce temperature extremes and lengthen growing seasons.
For instance, crops warm up when the sun shines on them, and some of that heat is given off to the atmosphere. Extra air turbulence likely speeds up this heat exchange, so crops stay slightly cooler during hot days. On cold nights, turbulence stirs the lower atmosphere and keeps nighttime temperatures around the crops warmer.
“In this case, we anticipate turbines’ effects are good in the spring and fall because they would keep the crop a little warmer and help prevent a frost,” said Takle. “Wind turbines could possibly ward off early fall frosts and extend the growing season.”
Global climate engineering is controversial. Yet microclimate alteration using wind turbines looks like it is not going to generate much if any opposition.
What about producing power? paraphrasing The Who, "Meet the new great green hope, same as the old one."
"The past freezing fortnight in the United Kingdom shed an especially illuminating light on the dottiness of relying on wind power. Because winds are frequently very low during the coldest weather, our shiny new green energy source was able only to supply one 500th of the exceptionally large demand, as much of the country experienced unprecedentedly low early winter temperatures. It is for similar reasons that Germany, despite its vast investment in wind power, has not been able to decommission a single one of its conventional power stations."
October 1, 2005
Roy says, "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.
Evaporation would seem the main reason for the cooling effect. Well duh!
Dec. 17, 2008
“Turbulence creates stronger mixing of heat and moisture, which causes the land surface to become warmer and drier,” Baidya Roy said. “This change in local hydrometeorological conditions can affect the growth of crops within the wind farm.”
I wonder how much money was spent to figure out the obvious.
I think the author should get a second opinion on this. Wind causes plants to use energy that would otherwise go into growth. There is also wind chill; the dry bulb temperature might be higher, but a breeze can cause the effective (wet bulb) temperature to be very low.
When gardeners hear a frost alert, they run out and cover plants, they do not run out and stick fans in the garden.
Randall, why should microclimate alteration be controversial ? We have been manipulating microclimates for millenia, eg tree-lines, hedgerows, rock walls, irrigation, ad nauseum.