A new study finds that building huge solar parks in deserts around the world could have unintended consequences. The dazzling research claims that huge solar parks, such as those in the Sahara, can cause environmental crises, including changing the climate and causing global warming.
The study was conducted by Zhengyao Lu, a researcher in physical geography at Lund University, and Benjamin Smith, research director at the Hawkesbury Institute for the Environment at Western Sydney University. The results of their research were published in a Feb. 11 article in The Conversation.
Solar panels have dark colors such as black and blue to attract and absorb more heat, but are usually much darker than the ground around the solar panel. The message cites an article that claims 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 environment as heat, “affecting the climate.”
The article notes that to replace fossil fuels, solar parks would have to be huge – covering thousands of square miles, according to this article. Solar farms of this size have potential environmental impacts, not just locally but globally.
Authors of a 2018 study say climate models show that installing a large number of wind turbines would double precipitation in the Sahara, and solar panels would increase rainfall by 50%. The researchers came to this conclusion by determining that the solar panels and wind turbines would reduce albedo on the land surface. Albedo is the fraction of light that is reflected from a body or surface.
From The Conversation:
The model revealed that when the size of the solar park reaches 20% of the total area of the Sahara, it causes a feedback loop. Heat radiated from the dark solar panels (compared to the highly reflective desert floor) creates a strong temperature difference between the land and the surrounding oceans, eventually decreasing the air pressure on the surface and moist air rising and condensing into raindrops. With more monsoon rains, plants grow and the desert reflects less energy from the sun, as vegetation absorbs light better than sand and soil. If more plants are present, more water will evaporate, creating a more humid environment for the vegetation to spread.
Turning the Sahara Desert into a lush, green oasis could have climate changes all over the planet, including affecting the atmosphere, the ocean, the land, changing entire ecosystems, changing rainfall in the Amazon rainforests, causing drought and possibly more tropical cyclones.
The well-intentioned attempt to lower Earth’s temperature could potentially do the opposite and raise the planet’s temperature, the researchers say.
By covering 20% of the Sahara with solar parks, the local temperature in the desert rises by 1.5 ° C according to our model. At 50% coverage, the temperature rise is 2.5 ° C. spread around the world by motion of the atmosphere and ocean, increasing the world’s 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 are said to warm more than the tropics, increasing sea ice loss in the Arctic. This could further accelerate warming as melting sea ice exposes dark water that absorbs much more solar energy.
The authors conclude their paper by stating that renewable energy solutions “can aid society in the transition from fossil energy, but terrestrial systems studies like ours underscore the importance of considering the numerous linked reactions of the atmosphere, oceans and the land area when examining their benefits and risks. “