15 October 2018

How to boost rainfalls in the Sahara

A recent study published with Science shows how large-scale deployment of wind turbines and solar panels can affect local climate. The study, among the first on modelling climate effects, investigates the impact of wind and solar installations on vegetation and precipitations: While wind turbines lower the speed of high winds and produce electricity, solar panels change the reflectivity on the ground through the light-absorbing photovoltaic cells.

Researchers have proved that “wind farms mix warmer air from above, to raise minimum temperatures and create a feedback loop that drives greater evaporation, precipitation and plant growth”.

Large-scale implementation of wind and solar energy in the Sahara region could have major implications not only in terms of clean and renewable energy production but also in an increase of fertile land. According to a controlled experiment, the southern region of the Sahel could see an even larger increase in rainfall, which might lead to “major ecological, environmental and societal impacts”. Land restoration has a direct impact on food security and biodiversity but it is also linked to migration and conflict. A Clingendael & PSI study traces the link between landscape restoration activities and migration and security in Africa.

The key question is whether investors, national governments and international organisations are ready to invest in a region which can provide a combined power output of 79 terawatts of electricity – compared to the 22 terawatts consumed globally in 2017.