In a new study with applications for the Middle East, a pair of US researchers finds wind turbines could help to reduce the adverse effects of climate change on agriculture, during the hotter summers that we expect in our future.
We already know that wind power is a way to prevent climate change, because it reduces our dependence on fossil fuels. But what if wind turbines can also reduce the effects of our fossil energy dependence: the rise in temperatures, and the catastrophic effects that that is predicted to have on agriculture?
What if wind turbines can provide a little cooling effect – almost like giant fans in the sky – helping to also mitigate the effects of climate change? It turns out, that is exactly what happens.
Researchers have completed a months-long research program aimed at studying how wind turbines on US farmlands interact with their surrounding crops.
The preliminary findings were announced at the annual meeting in San Francisco of the American Geophysical Union by Ames Laboratory associate and agricultural meteorology expert Gene Takle, a researcher at the U.S. Department of Energy’s Ames Laboratory and Julie Lundquist, assistant professor, Department of Atmospheric and Oceanic Sciences, at the University of Colorado at Boulder, joint appointee at the U.S. Department of Energy’s National Renewable Energy Laboratory, and Fellow of the Renewable and Sustainable Energy Institute.
Lundquist’s team uses a specialized laser known as a lidar to measure winds and turbulence from near the Earth’s surface to well above the top tip of a turbine blade.
“Our laser instrument could detect a beautiful plume of increased turbulence that persisted even a quarter-mile downwind of a turbine,” Lundquist said.
The study did not assess whether the effects were in fact beneficial to the health and yield potential of soybeans and corn planted nearby. However, their finding that the turbines increase airflow over surrounding crops, suggests this is a realistic possibility.
“The turbulence resulting from wind turbines may speed up natural exchange processes between crop plants and the lower atmosphere,” Takle said.
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.
Moving air reduces moisture by helping dry the dew that settles on plants beginning in late afternoon. Reducing crop moisture reduces the likelihood of fungi and toxins can grow on plant leaves.
In addition, having drier crops at harvest could help farmers reduce the cost of artificially drying corn or soybeans, the researchers surmise.
Although the study was based in the US Midwest – because turbines and farmland already share space there, and are like to do so even more in the future – applications for other nations and crops too.
Typically, these are regions, like Egypt, that have good wind speeds to drive turbines. However, the wind speeds are greater at a higher level, so that without turbines sweeping air downward, at ground level air movement can be negligible on hot summer days, even in regions with good wind speed.
The researchers believe a potential benefit to crops could be that increased airflows could enable plants to more readily extract atmospheric CO2, a needed “fuel” for crops.
The effects are subtle, says Takle, “But in certain years and under certain circumstances the effects could be significant.”
“When you think about a summer with a string of 105-degree days, extra wind turbulence from wind turbines might be helpful. If turbines can bring the temperature down below 100 degrees that could be a big help for crops.”
Previous studies have found that US corn and soy crop yields in the Midwest could decrease by up to 82 percent under the most likely scenario, due to too many heatwave days (anything over 86%) in summers by as soon as 2080.
In Egypt, wheat production is estimated to lose up to 36% if average temperatures rise by just four degrees.
If nearby wind turbines could shave a few degrees of local heat waves, we could save agriculture in regions in which it is expected to be destroyed.
Via Wind Daily
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