Wind Turbines and Solar Farms Could Bring Oases to the Sahara Desert

Li and his team chose the Sahara as their research's focal point due to several of its unique qualities. "it is the largest desert in the world; it is sparsely inhabited; it is highly sensitive to land changes; and it is in Africa and close to Europe and the Middle East, all of which have large and growing energy demands," Li explained.

Bringing the rain to Africa

Their model revealed resulting complex near-surface air temperatures changes that in the end induced precipitations, literally "blessing the rains down in Africa". "The rainfall increase is a consequence of complex land-atmosphere interactions that occur because solar panels and wind turbines create rougher and darker land surfaces," explained study co-lead Eugenia Kalnay at the University of Maryland.

Regions with wind farms, in particular, showed precipitation rises of as much as 0.25 millimeters per day and in the Sahel those rates reached up to 1.12 millimeters a day. "This was a doubling of precipitation over that seen in the control experiments," Li said. 

The researchers made sure to simulate wind and solar power plants that would be large enough to cover our energy-hungry world's massive needs. "In 2017, the global energy demand was only 18 terawatts, so this is obviously much more energy than is currently needed worldwide," Li said.

This meant the farms would cover more than 9 million square kilometers. This range would see them generate an estimated average of about 3 terawatts of wind-powered electricity and 79 terawatts of solar based electrical power.

Vegetation growth triggered

But the best part of the study was what this rise in rainfall did to local vegetation, and further to the region's overall weather and environmental patterns. "This increase in precipitation, in turn, leads to an increase in vegetation cover, creating a positive feedback loop," Li said.

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The process could see this once dry and barren area become home to many green oases. "We found that the large-scale installation of solar and wind farms can bring more rainfall and promote vegetation growth in these regions," Kalnay revealed.

The researchers hope this increase of rainfall and vegetation, when complemented by the rise of clean electricity, could instigate local agricultural, economic and social advantages that would extend to the Middle East as a whole.

The study was published in the journal Science.