Simulation promises rain for the Sahara
Solar and wind farms could bring water and greenery to this giant desert
With its blistering sunshine and strong winds, the Sahara attracts numerous energy projects, but new research suggests that these wind and solar farms are doing more than just producing clean renewable energy. “We found that the large-scale installation of solar and wind farms can bring more rainfall and promote vegetation growth in these regions,” explains Eugenia Kalnay from the University of Maryland, US. “The rainfall increase is a consequence of complex land-atmosphere interactions that occur because solar panels and wind turbines create rougher and darker land surfaces.” A modelling technique has revealed that the environment around the turbine blades and solar panels may be transformed, which could more than double rainfall in the area. “As a result vegetation cover increases by about 20 per cent,” says the first author of the study, Yan Li. “This increase in precipitation in turn leads to an increase in vegetation, creating a positive feedback loop.” The transformation is a result of the turbines contributing to the mixing of heat in the atmosphere by pushing the warmer air down to the surface and increasing land surface friction, which leads to a higher chance of rain. Solar panels also reduce the amount of light reflecting from the desert, further increasing the likelihood of rainfall. The simulation was based on a solar farm about the size of the United States built alongside wind turbines covering around 20 per cent of the Sahara. If a project of this size was established, it would mean not only the greening of the desert but also the production of significant amount of green energy.