An international team of researchers from the United States, China and Italy in a report recently published in Science has suggested the installations of windmills and solar farms could have unexpected beneficial climate impacts when deployed at a large scale in the Sahara region of Africa. The research suggests that covering the entire Sahara desert with solar panels and windmills would not only help power the world, it would also improve the local climate, double rainfall and increase vegetation in the region.
This is a very important discovery as the Sahara which covers large sections of Africa including Algeria, Chad, Egypt, Libya, Mali, Mauritania, Morocco, Niger, Western Sahara, Sudan and Tunisia is the world’s largest hot desert and one of the harshest environments on the planet with half of the Sahara receiving less than an inch of rain per year, and the rest receives up to 4 inches (10 centimetres) per year. The infrequent rain is usually torrential and there is little or no vegetation in most part of the region.
According to Discover Magazine, the idea to construct massive renewable energy installations in a desert came from livestock. It was explained that as a result of sheep, goats and cows in the Sahel, a semi-arid transition region south of the Sahara, chowing down on foliage the landscape in the Sahel changed from dark, light-absorbing vegetation to bright, reflective sand, which led to drought and hampered plant growth.
This information inspired the research on whether large solar panel farms would reduce surface reflectivity and push the feedback loop in the opposite direction, toward more rainfall with the thought wind farms might boost precipitation by pushing air and moisture up into the atmosphere near the turbine fields.
The team of researchers on putting their idea to the test in a climate model of wind and solar farms in the Sahara desert, with a vast 3.5 million square miles of simulated energy tech that would generate a whopping 82 terawatts of electrical power, which is more than the 18 terawatts of total energy the world currently uses. The model incorporated dynamic changes to vegetative cover and the resulting increase in vegetation further enhances precipitation, creating a positive albedo–precipitation–vegetation feedback that contributes ~80 per cent of the precipitation increase for wind farms. This local enhancement is scale dependent and is particular to the Sahara, with small impacts in other deserts. This scheme, when perfected and deployed, could be a game changer in the Sahara as the area which is currently suffering from socioeconomic hardship due to lack of fresh water, would feel the most benefit from such a scheme as according to the model precipitation in the region could jump up by nearly 20 inches per year.
Although according to the model the renewable energy installations will lead to an increase in local temperature, the researchers concluded that the effect is small and called for more research.