Wind and solar farms could bring down rainfall in Africa | Smart News

Expanding on 3.55 million square miles, the Sahara Desert sees its share of sunshine. But in addition to catching a serious sunburn, these energetic waves have a significant impact on the future of humanity. Last week in ScienceResearchers have proposed that the solar tissue and windmills of the world's largest hot desert can meet the world's energy needs several times and bring much-needed precipitation to these arid skies.

The Sahara is not entirely devoid of pockets of lush vegetation. In the bushy areas of the desert, dark vegetation acts as a mantle, absorbing sunlight and warming the ground, while large areas of light sand reflect the sun's rays, leaving the soil relatively cooler. The soft soil then pulls warm air upward, eliminating moisture from the atmosphere as it condenses and falls back to the earth as rain.

But such oases are rare and the desert is actually expansion. In the last century alone, the Sahara has become about 10% larger. As the desert grows, sterility breeds sterility. As the plant life is decimated, the dirt cools, undermining the driving force of precipitation and, with it, the possibility that life emerges from dry sands.

Faced with this vicious circle, researchers become creative. "It has come to my mind that the same [cycle could] to go in the opposite direction, so it would increase rainfall and vegetation, then more rainfall, "Eugenia Kalnay, one of the authors of the study, explained to Dan Charles at NPR.

One way to do this is to cover 20% of the Sahara with solar panels that convert the sun's rays into energy while absorbing sunlight, as vegetation would do. The grilled soil would then be ready to push the warm air towards the sky, thus favoring precipitation, possibly reducing vegetation to decimation.

Scientists could also deploy an arsenal of wind farms. The rotating turbines would also produce electricity, but these many wind farms concentrated in one area would also collectively slow the local wind speed and push together hot and cold air masses. Combined, reduced wind speeds and turbulence would cause air masses upward, favoring the formation of rain clouds.

Solar panels and wind turbines would be used primarily as a temporary boost as vegetation recovers, according to the researchers. In the model, the reintroduction of plants in some parts of the region would represent about 80% of the increase in rainfall in the coming years.

A group of researchers led by Kalnay and his colleague Yan Li modeled these scenarios to study their effects, as well as a third-party combining solar and wind energy, generating 82 terawatts of electricity …more than four times our total global energy consumption.

In the researchers' model, solar panels outperformed wind farms in terms of energy production, but the turbines had a greater impact on the climate, roughly doubling the predicted rainfall. Together, technologies have increased precipitation by about 150%.

Yet it is unlikely that the Sahara will turn into a tropical forest. And for the moment, researchers' solar panels and wind farms remain confined to a computer simulation. If a project were to be undertaken, even a fraction of this size, immense coordination would be needed, taking into account not only engineering logistics, but also money-market funds, government cooperation and cultural awareness. local populations.

Notably, the addition of solar panels and wind farms would also increase the average temperature in the region by about 5 degrees Fahrenheit. Moreover, with a touch of irony, the models work better with less efficient solar panels. As technology accelerates, solar panels that better convert energy would also drain the soil of hot air needed for precipitation production and even reduce local rainfall.

"In terms of willingness, yes, people are certainly ready and able to build dozens of power plants in the deserts and semi-deserts of Africa," said David Wright, archaeologist at Seoul National University. says Mary Beth Griggs to Popular science. "It is prudent to know if it is prudent to do it … there are more costs for such projects than simply ecological."

However, the potential impact of sustainable energy farms could be enormous and, at present, there is not much competition for Saharan real estate.

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