Researchers from the Ames Laboratory and the University of Colorado have spent a few months wandering through corn fields on farms in the Midwest to gather information on how wind turbines interact with surrounding farm land. The data collected so far indicates that the turbines may offer more than the sustainable production of electricity, they may also benefit surrounding crops by helping them stay cooler and dryer, fight off attack from fungi and toxins and improve CO2 extraction.
Led by Ames' Gene Takle and Julie Lundquist from the University of Colorado, the research team recorded most of its measurements during the spring of 2010 in Midwestern corn fields with wind farms close by. They used a combination of wind-measuring instruments called anemometers to determine the intensity of turbulence and a lidar - a specialized laser that records winds and turbulence from near the Earth's surface to well above the top tip of a turbine blade. Plant moisture and temperature readings were also collected.
The instruments placed upwind and downwind recorded persistent increased turbulence up to a quarter of a mile from the turbine. According to Takle and other studies, the turbines channel air downwards, increasing airflow to surrounding crops. This is thought to speed up natural processes such as heat exchange - keeping crops cooler during hot days and stirring up air in the lower atmosphere to make things a little warmer at night, which could help to ward off early frosts in the Fall. The process could also increase carbon dioxide extraction from the air and soil.
More turbulence may also help dry out dew that settles on crops and therefore limit the time window that fungi toxins have to establish on leaves. Drier crops could also negate the need to artificially dry corn or soy at harvest time.
The researchers say that it's early days for the study but results obtained so far indicate that turbines could have a subtle impact on crop yield. However, in certain years and under certain circumstances the impact could potentially be significant. "We've finished the first phase of our research, and we're confident that wind turbines do produce measurable effects on the microclimate near crops," said Takle.
The team's preliminary findings were presented to the Fall meeting of the American Geophysical Union in San Francisco recently.
The researchers hope to continue their observations throughout the next growing season and add to the data already collected. They're also looking to develop a specific turbine predictions model rather than continue to use an adapted computational fluid model that's normally used to better understand the impact of tree cover on the surrounding environment.
In the following short video, Gene Takle from the Ames Laboratory talks about the project:
