Sahara is the world's largest hot desert, but parts of it can be made green if massive solar and wind farms are being stored there, finding a new study.
These farms can increase the rain in the Sahara, especially in the nearby Sahel region, a semi-member area south of the giant desert, the researchers said in the study, published on September 7th in the journal Science.
"This increase in rainfall, in turn, leads to an increased vegetation hood, creating a positive feedback loop," studying senior scientist Yan Li, a postdoctoral scientist in natural resources and environmental science at the University of Illinois, said in a statement.
Researchers already knew that wind and solar farms can increase the heat and moisture in the areas immediately around them. But this study is among the first to model how wind and solar farms would affect Sahara, considering how growing green plants and trees would react to these changes, said Li, who began the study while a postdoctoral researcher in the department of atmospheric and Oceanic Science at the University of Maryland. [The 1
"Previous modeling studies have shown that large scale wind and solar plants can produce significant climate change on continental waves," says Li. "But the lack of vegetation feedbacks can make the modeled climate impacts very different from their true behavior."
Li and his colleagues simulated what would happen if wind and solar plants covered more than 3.4 million square kilometers (9 million square kilometers) of Sahara. On average, wind farms would generate about 3 terawatts, while solar plants would generate 79 terawatts of electric power in one year , they found.
There is a lot of energy. A terawatt can power about 10 billion 100 watt bulbs at the same time. "By 2017, the global energy demand was only 18 terawatts, so this obviously is much more energy than is currently needed all over the world, "said Li.
The model also showed that wind farms or Lack of local air temperatures to heat.
"Greater night heat occurs because wind turbines can improve vertical mixing and remove warmer air from above," the researchers wrote in the study. The rain also increased as much as 0.01 inch (0.25 millimeter) per day, on average in areas with wind farms, researchers found.
"This was a doubling of precipitation over what is seen in the control experiments," said Li.
Sahel would see even more rain, an increase of 0.04 inch (1.12 mm) a day areas of wind farms, which would help the vegetation to grow, scientists said. This means that an increase of 8 to 20 inches (200 and 500 mm) of rain per year in Sahel is sufficient to not be classified as desert. (Desires per definition are areas that receive less than 10 inches (250 mm) annual rainfall.)
The solar plants would also have a positive effect on temperature and rain, researchers said.
"We found that large-scale installation of solar and wind farms can provide more rainfall and promote growth in these regions," studying senior researcher Eugenia Kalnay, a prominent professor at the Department of Atmospheric and Oceanic Sciences at the University of Maryland, said in the statement . "The increase in rain is a result of complex changes between soil and atmospheres that arise because solar panels and wind turbines create uneven and darker areas."
If this model ever becomes reality, "the increase of precipitation and vegetation combined with clean electricity as a result of solar and wind energy could contribute to agriculture, economic development and social well-being in the Sahara, Sahel, the Middle East and other neighboring regions" , says Safa Motesharrei, a system researcher at the University of Maryland. statement.
"Sahara has expanded for decades, and solar and wind farms can help stop the expansion of this dry region," Russ Dickerson, a leader in air quality research and a professor at the Department of Atmospheric and Oceanic Science at the University of Maryland as was not involved in the study, said in a statement. "This looks like a win-win to me."
Original article about Live Science.