A paper published in the new issue of Science in the United States says that large wind and solar power generation facilities will change the surface characteristics. If it is distributed in the Sahara Desert of about 9 million square kilometers, the precipitation in this area will be 0.24 mm per day. Increased to 0.59 mm, precipitation in the Sahel region, arid areas south of the Sahara Desert, will also increase significantly.
Researchers at the University of Maryland, the University of Illinois, Beijing Normal University, the International Center for Theoretical Physics in Italy, and the Institute of Atmospheric Physics of the Chinese Academy of Sciences have reached this conclusion through climate and dynamic vegetation simulation experiments. Simulations from supercomputers show that increased precipitation can increase vegetation coverage in these areas by about 20%.
The study pointed out that the impact of wind and solar power on regional climate is achieved by two different feedback mechanisms: wind power equipment increases surface friction, causing air to move upwards and produce precipitation; while solar power generation reduces surface reflectivity, which also helps to increase precipitation.
The study believes that the increase of precipitation will promote the growth of vegetation, and the restored vegetation will further reduce the reflectivity and increase the surface friction, which in turn will promote the increase of precipitation and form a positive feedback mechanism.
The Sahara Desert and the Sahel are among the driest regions in the world. Li Yu, the first author of the paper and a postdoctoral fellow at the University of Illinois, said: "We chose the Sahara because it is the largest desert in the world, sparsely populated and highly sensitive to land changes."
Simulation experiments have also shown that such large wind and solar power generation facilities have no significant negative impact on regional climate, making local energy, water and food supplies more sustainable.