The installation of large-scale wind and solar power generation facilities in the Sahara could cause more local rainfall, particularly in the neighboring Sahel region. This effect, could increase coverage by vegetation, creating a positive feedback that would further increase rainfall.
Wind and solar farms offer a major pathway to clean, renewable energies. However, these farms would significantly change land surface properties, and, if sufficiently large, the farms may lead to unintended climate consequences. In this study, we used a climate model with dynamic vegetation to show that large-scale installations of wind and solar farms covering the Sahara lead to a local temperature increase and more than a twofold precipitation increase, especially in the Sahel, through increased surface friction and reduced albedo. The resulting increase in vegetation further enhances precipitation, creating a positive albedo–precipitation–vegetation feedback that contributes ~80% of the precipitation increase for wind farms…
This highlights that, in addition to avoiding anthropogenic greenhouse gas emissions from fossil fuels and the resulting warming, wind and solar energy could have other unexpected beneficial climate impacts when deployed at a large scale in the Sahara, where conditions are especially favorable for these impacts. Efforts to build such large-scale wind and solar farms for electricity generation may still face many technological (e.g., transmission, efficiency), socioeconomic (e.g., cost, politics), and environmental challenges, but this goal has become increasingly achievable and cost-effective
Exceprts from Yan Li, Climate model shows large-scale wind and solar farms in the Sahara increase rain and vegetation, Science, Sept. 7, 2018