The wind and the sun of the Sahara could feed the world – and make the desert green

Where on Earth could you install three million wind turbines?

What about the Sahara Desert?

A computer model in a recent large-scale climate modeling experiment simulated a Sahara with three million wind turbines and incredible solar panels covering one-fifth of its nine million square kilometers of land.

"We have put in place a quantity of solar power generation capacity that would power the entire energy consumption of the Earth four times more," said Daniel Kirk-Davidoff. Quirks and quarks"moderator Bob McDonald, quantifying it as some 79 terawatts of electricity production from solar energy.

A large scale wind farm in the Sahara could look like this one in Australia, just add 3 million turbines. (AFP / Getty Images)

Kirk-Davidoff, from the Department of Atmospheric and Oceanic Sciences at the University of Maryland, and his colleagues wanted to understand if massive solar and wind facilities in the desert would have side effects – good or bad.

It turns out that a vast arid and hot expanse where few people live and grow has enormous potential: enough sun and persistent wind to power the entire planet – and a few – and make some parts of the desert green .

"When we spend about as much wind energy in the Sahara, we found that it would be about three terawatts of wind power," said Kirk-Davidoff, who is also the lead researcher for Underwriter's # 30 renewable division. Lab in Albany, NY

He said that at present, the global demand for electricity is only about 2.5 terawatts, and that the total global energy demand for the Last year was 18 terawatts.

Increased precipitation, more natural vegetation

The study also revealed that a solar and wind farm could change the climate and increase precipitation by 0.25 millimeters per day on average, which represents a 50% increase. This is important for a region that receives very little rainfall.

A large solar farm in Arizona. In the researchers' computer model, solar panels cover one-fifth of the Sahara Desert. (Daniel Kirk-Davidoff)

The solar panels would do this by blackening and warming the surface of the Sahara, which would create a thermal updraft, said Kirk-Davidoff.

"If you warm up the surface, it will lead to condensation, and an upward movement causes clouds and condensation, which could result in some extra rain."

Wind turbines would also increase precipitation, but differently. The turbines mix warm air from the top and evacuate as much as possible the momentum of the atmosphere. This facilitates the passage of the wind from high pressure to low pressure areas.

"In this case, more moisture has occurred in this area, which facilitates cloud formation and precipitation."

According to the models, even this small amount of rainfall has led to an increase in natural vegetation in areas where there is already some plant growth, such as the Sahel region in the Sahara. And this created a positive feedback loop, according to Kirk-Davidoff.

"The extra vegetation itself absorbed a little more solar radiation and caused an additional reaction that continued to dampen the area a little bit more."

The computer model suggests that a Sahara with maximum wind and solar power would also see an average rainfall increase of about 0.25 millimeters per day (Daniel Kirk-Davidoff)

In simulation, the Sahara becomes wetter and greener and provides a wealth of power for the entire planet. The question is whether all this is realistic.

Kirk-Davidoff admits that the models were a bit superior, but adds that wind and solar are the future.

"We can not afford to burn a lot more fossil fuels because that leads to global warming and it's bad for us." But more recently, wind and solar energy has become extremely cheap and a place like the Sahara is very likely to be developed in one way or another for the production of wind and solar electricity. "