A 5.2-million-panel solar farm recently turned on in China highlights the question of what will happen to the loads of valuable metals and electronic waste when the sun-catchers go out of service decades from now.
Some experts think the deluge of old panels will create a burgeoning recycling market worth $626 million by 2033, according to a Dimension Market Research report via Yahoo Finance.
To that end, researchers from China’s Wuhan and Northeastern universities have developed a more environmentally friendly way to repurpose valuable panel components, including silicon and silver. These are harder to gather than the metal frame and glass surfaces that also form the systems, per Interesting Engineering. The technique uses less power and is reported to be highly effective.
If the process can be scaled, it could prevent renewable-sector waste from hitting trash heaps. CNBC reported last year that around 90% of old or broken solar panels end up in landfills because recycling is expensive.
The breakthrough is a “simple salt-etching approach to recycle … solar panels without using toxic mineral acids,” the research team wrote in an abstract published by Nature.
It starts with a “highly reactive” molten mixture of salt and potassium hydroxide at 392 degrees Fahrenheit. The panel components are dipped in the mixture for two seconds and then again for up to two minutes.
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“The short exposures allowed layers of material to separate while remaining largely intact,” per IE’s Ameya Paleja.
The heat breaks down some materials, while the sodium or potassium hydroxide works on others. Silicon is “etched” away, and silver wiring separates and floats in the water. A filter catches 99% of the precious metal. With some other techniques, including electroplating, lead, tin, copper, and aluminum can be recovered as well. Water is added to stop the “etching reaction.” The solution can be reused and leaves a nontoxic byproduct, according to IE.
Additionally, recycling about 2.2 pounds of panels with this method prevents nearly 31 pounds of planet-warming air pollution and reduces “power usage by a factor of 220,” according to Paleja.
Data collector Statista reports that solar energy generated 5.5% of the world’s electricity last year, with more innovations and large farms being regularly announced. The tech could make home systems more affordable and expand community solar program accessibility. The latter can save you an average of $150 a year without installing equipment at home.
What’s more, new operations like Solarcycle in Georgia are already in development to ensure valuable materials from old panels can be reused.
New solvents, baths, and other methods being invented can help to expand cleaner solar power, limiting heat-trapping pollution from getting into the atmosphere via the burning oil, gasoline, and natural gas that’s extracted from fossilized plant waste. As our planet warms, experts are finding that the high heat is negatively impacting even children’s academic performance.
Recycling, smart technology, and renewable energy are ways to facilitate cooling.
“This study presents a viable approach for sustainable management of end-of-life … solar panels, paving the way to a circular economy,” the Chinese research team wrote in Nature.
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