Solar panels convert sunlight to electricity using – among other things – silver, a fantastic conductor of electrons and an expensive material. UVA engineering professor Mool Gupta says it’s applied as a paste in thin lines you can see from outside the panel.
“Then they take it to high temperatures, around 700 degrees Celsius, and that converts into these silver contact lines, so it’s really bonded, so it’s not easy to peel off.”
But using a laser, Gupta says he can salvage the silver for re-use.
“We will take a high-power laser and program it so it only exposes the silver lines on the panel, and the laser being high-powered, it will vaporize.”
From that vapor, his lab will collect nano-particles of silver – an especially useful and valuable form of the precious metal. Scott Acton, chair of electrical and computer engineering at UVA, says the process could make recycling worthwhile since it’s cheaper and cleaner than current methods.
“We use acid to dissolve the photovoltaic components away from the wires," he explains. "It’s not only an expensive process, but it’s an environmentally dangerous process.”
Gupta’s lab recently won a $250,000 grant from the Department of Energy and will spend the next year experimenting. The university is hopeful and has already secured a patent on the process called laser ablation.
This report, provided by Virginia Public Radio, was made possible with support from the Virginia Education Association.
