A new study finds that there could be unintended consequences of building massive solar farms in deserts around the world. Open research argues that huge solar farms, such as in the Sahara, could introduce 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, a research director at the Hawkesbury Institute for the Environment at Western Sydney University. The results of their research were published in a February 11 article in The Conversation.
Solar panels are darker colors, such as black and blue, to attract and absorb more heat, but they are usually much darker than the ground around the solar panel. The station cites an article that claims that most solar panels are between 15% and 20% efficient in converting sunlight into usable energy. The researchers say the rest of the sunlight is brought back into the environment in the form of heat, “affecting the climate.”
The article mentions that in order to replace fossil fuels, solar farms should be huge – covering thousands of square kilometers, according to this article. Solar farms of this magnitude can have consequences for the environment, not only locally, but globally.
The authors of a 2018 study say that climate models show that the installation of a large number of wind turbines would double rainfall in the Sahara desert, and solar panels would increase rainfall by 50%. The researchers came to this conclusion by determining that solar panels and wind turbines would reduce the albedo on the earth’s surface. Albedo is the fraction of light that is reflected by a body or surface.
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The model revealed that when the size of the solar farm reaches 20% of the total area of the Sahara, it triggers a feedback loop. The heat emitted by darker solar panels (compared to the highly reflective desert soil) creates a steep temperature difference between the earth and the surrounding oceans, which eventually lowers the surface air pressure and causes wet air to rise and condense into droplets. rain. With more monsoon rainfall, the plants grow and the desert reflects less energy from the sun, because the vegetation absorbs light better than sand and soil. With more plants present, more water evaporates, creating a wetter environment that causes vegetation to spread.
Transforming the Sahara Desert into a lush, green oasis could have climate ramifications around the planet, including affecting the atmosphere, ocean, terrain, changing entire ecosystems, changing rainfall in the Amazon rainforests, inducing drought and the potential for more tropical cyclones.
According to researchers, the intentional effort to reduce the world’s temperature could do the opposite and could raise the planet’s temperature.
Covering 20% of the Sahara with solar farms raises local desert temperatures by 1.5 ° C according to our model. At 50% coverage, the temperature rise is 2.5 ° C. This heating is eventually spread around the globe by the movement of the atmosphere and the ocean, raising the average world temperature by 0.16 ° C for a coverage of 20% and 0.39 ° C for 50% coverage. However, the global temperature shift is not uniform – the polar regions would warm more than the tropics, increasing sea ice losses in the Arctic. This could further accelerate heating, 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 move away from fossil energy, but studies of the Earth system, such as ours, emphasize the importance of considering the many coupled responses of the atmosphere, oceans and land surface when examining their benefits and risks ”.