According to a new study, there could be unintended consequences of setting up massive solar farms in deserts around the world. The striking research claims that large solar farms, such as in the Sahara, could usher in environmental crises, including climate change and global warming.
The study was conducted by Zhengyao Lu, a researcher in physical geography at Lund University, and Benjamin Smith, director of research at the Hawkesbury Institute for the Environment at West Sydney University. The results of their research were published in a February 11 article in The Conversation.
Solar panels are darker colors like black and blue to attract and absorb more heat, but it is usually much darker than the ground around the solar panel. The report cites an article claiming that most solar panels are between 15% and 20% efficient at converting sunlight into usable energy. The researchers claim that the rest of the sunlight is returned to the surrounding environment as heat, which affects the climate.
The article notes that solar farms need to be huge to replace fossil fuels, which according to this article should cover thousands of square kilometers. Solar farming of this magnitude may have environmental consequences, not only locally but also globally.
Authors of a 2018 study say that climate models show that the installation of many wind turbines would double the precipitation in the Sahara desert, and solar panels would increase the precipitation by 50%. The researchers came to this conclusion by determining that the solar panels and wind turbines would reduce the albedo on the land surface. Albedo is the fraction of light reflected by a body or surface.
From the conversation:
The model revealed that when the size of the solar farm reaches 20% of the total area of the Sahara, it causes a feedback loop. Heat released by the darker solar panels (compared to the highly reflective desert soil) creates a steep temperature difference between the land and the surrounding oceans that eventually lowers the surface air pressure and causes moist air to rise and condense into raindrops. With more rainfall rainfall, plants grow and the desert reflects less solar power, as vegetation absorbs better than sand and soil. With more plants, more water evaporates, creating a more humid environment that allows vegetation to spread.
The transformation of the Sahara Desert into a lush, green oasis can have climate change on the planet, affecting the atmosphere, the ocean, the land, changing entire ecosystems, changing precipitation in Amazon’s rainforests, causing droughts and causing more tropical cyclones.
The well-intentioned attempt to lower the world temperature could, according to the researchers, possibly do the opposite and raise the temperature of the planet.
To cover 20% of the Sahara with solar farms, local temperatures increase by 1.5 ° C according to the model. At 50% coverage, the temperature rise is 2.5 ° C. This warming is eventually spread around the world by atmosphere and ocean movement , which increases the world average temperature by 0.16 ° C for 20% coverage and 0.39 ° C for 50% coverage. However, the global temperature shift is not uniform – the polar regions will become warmer than the tropics, increasing the ice loss in the North Pole. This can further accelerate warming, as melting sea ice exposes dark water that absorbs much more solar energy.
The authors conclude their article by saying that renewable energy solutions “can help society to move from fossil fuels, but Earth systems studies like ours emphasize the importance of the many linked reactions of the atmosphere, oceans and land surface when considering the benefits and risks. “