Could solar and wind farms create gardens of Eden in the desert?
According to a newly published study in the popular journal, Science, bringing rain to the desert with solar arrays and wind turbines is not far-fetched. The study is entitled: ‘Climate model shows large-scale wind and solar farms in the Sahara increase rain and vegetation’.
The researchers assert that as each solar and wind farm grows in size the ‘consequences’ for the climate increase too. With solar panels on the ground, the earth reflects less heat back into the atmosphere. And when turbines spin, warmer air is combined with cooler air. These occurrences can change the local climates.
Utilizing a climate prediction model, researchers suggest that rainfall would increase and with this more vegetation would grow.
This is not the first time scientists have asserted that big solar farms and wind farms could cause climate change. In 2012, the journal Nature put out a report that pointed to how wind turbines raise temperatures. The story looked at satellite imagery over Texas - a state with some of the world’s largest wind farms - and found that over a decade the temperature was raised by 0.72C (1.3F).
Speaking to the Telegraph in 2012, Liming Zhou, Research Associate Professor at the Department of Atmospheric and Environmental Sciences at the University of New York, said:
“Wind energy is among the world’s fastest growing sources of energy. The US wind industry has experienced a remarkably rapid expansion of capacity in recent years. While converting wind’s kinetic energy into electricity, wind turbines modify surface-atmosphere exchanges and transfer of energy, momentum, mass and moisture within the atmosphere. These changes, if spatially large enough, might have noticeable impacts on local to regional weather and climate.”
While climate change - and global warming - is mostly viewed as negative, bringing vegetation to the ever-creeping Sahara Desert may be more positive.
The latest study published in Science was completed by scientists at the University of Maryland. They considered climate and vegetation models and tested a theory that solar and wind farms could create a favourable climate in areas like the Sahara and Sahel. The theoretical result indicated that more rain would indeed fall in those areas.
Safa Motesharrei, UDM Systems Scientist and a lead author of the paper, told Engineering & Technology:
“The Sahara, the Sahel and the Middle East include some of the driest regions in the world while experiencing high growth of population and poverty. Our study has major implications for addressing the intertwined sustainability challenges of the ‘Energy-Water-Food’ nexus in this region.”
This study – with the promise of increased rain and vegetation - offers a solid counter-argument to those that suggest large-scale wind and solar farms adversely affect the climate.
The researchers at Maryland write:
“Our simulations show that both the wind and solar farms in the Sahara contribute to increased precipitation, especially in the Sahel region, through the positive albedo-precipitation-vegetation feedback.”
And the added benefit to solar and wind, in the long term, will be the replacement of fossil fuel technologies which currently power desalination plants. Motesharrei notes:
“Moreover, the availability of vast quantities of clean energy would allow for desalination of seawater and transporting it to the regions that suffer most from severe freshwater scarcity, in turn, leading to improvement of public health, expansion of agriculture and food production and even restoration of biodiversity.”
Gray, Louise. “Wind Farms Can Cause Climate Change, Finds New Study.” The Telegraph, Telegraph Media Group, 29 Apr. 2012, www.telegraph.co.uk/news/earth/earthnews/9234715/Wind-farms-can-cause-climate-change-finds-new-study.html.
Li, Yan, et al. “Climate Model Shows Large-Scale Wind and Solar Farms in the Sahara Increase Rain and Vegetation.” Science, American Association for the Advancement of Science, 7 Sept. 2018, science.sciencemag.org/content/361/6406/1019.