Environment

Turning the Sahara into a giant solar farm is so crazy it just might work

A photograph of the author, Austin Bailey.

By Austin Bailey

September 27, 2018

Turning the Sahara into a giant solar farm is so crazy it just might work

In This Article

  • The Sahara Desert has expanded by 10 percent over the past century.
  • Desertification gobbles up water sources and viable farmland.
  • Climate scientists have long searched for a way to reverse desertification.
  • A billion solar panels? Maybe that's the fix we need.

I know it sounds far-fetched at first, but hear me out. A scientist from the University of Maryland says we can beat the Sahara Desert into retreat with windmills and a few billion solar panels. And a computer simulation of her hypothesis back her up.

Relentless encroachment of the Sahara Desert is a grave issue for people in the Sahel, an arid strip of land that transverses Northern Africa between the desert and greener regions to the south. The Sahara has expanded by 10 percent in the past 100 years, and doesn’t show any sign of slowing. Drought and desertification suck up groundwater sources and put once-fruitful farming land out of commission. It’s a very real and tangible challenge for people in arid regions of Senegal, where vegetation has all but disappeared and growing seasons are shorter than they used to be. Farmers in the region grow a limited selection of crops specially adapted to dry, hot conditions, but even those crops sometimes fail.

Atmospheric scientist Eugenia Kalnay, who has done work for NASA and the National Weather Service, took this problem on and attacked it in a new way. She wanted to interrupt the cycle that begins when drought kills vegetation, which leaves the ground bare and ultimately brings more drought and further loss of green.

Kalnay wondered what would happen if dark solar panels on the ground could attract the sun’s rays, with the resulting heat bouncing air back into the atmosphere to spawn rainfall. She and a team of researchers created a computer simulation where 20 percent of the Sahara’s 3,600,000 square miles were covered with solar panels, along with wind turbines to boost air currents. The simulation predicted that this intervention would produce enough rainfall to bring back vegetation, especially along the Sahara’s Sahelian border.

 Before we can dive into this seemingly green solution, some real-life limitations have to be overcome. The solar farm needed to restore rainfall would have to be quite large, roughly the size of the United States. And what would we do with all that electricity? The proposed Sahara solar farm would produce four times more energy than the world currently uses.