Non-Destructive Material Characterization of Crystalline Silicon Solar Photovoltaic Panels

Crystalline silicon (c-Si) photovoltaic (PV) panels contain a mix of bulk materials (such as glass, silicon, and aluminum), toxic substances (like lead, tin, and copper), and precious metals. Due to solar panel designs not being standardized, their compositions vary. Panels with lead-based solder, for example, contain more lead than those with lead free alternatives. Naturally, this variability affects how panels are classified and handled at the end of their life. Transporters must determine if they’re hazardous waste, while recyclers must assess material content to estimate disposal costs and recovery value. The commonly used toxicity characterization and leaching procedure identifies hazardous content but is destructive, preventing material recovery and making its results nontransferable across different panel designs. Consequently, there is currently no reliable, non-destructive method to determine the hazardous and precious material content of spent c-Si PV panels, leading to uncertainty, increased transportation costs, and challenges in evaluating recycling profitability.

 

Researchers at Arizona State University have developed a portable device for non-destructive analysis of toxic and precious materials in spent c-Si PV panels. This novel analysis determines the precious and toxic materials concentrations contained in a spent c-Si PV panel without causing destruction to the PV panel. The invention can be used by transporters and recyclers of PV waste to determine the costs of transporting spent c-Si PV panels and the revenues from recycling c-Si PV panels. Because this invention is nondestructive and keeps the c-Si PV panel intact, it can be subsequently transported and recycled.

 

This technology enables objective determination of the hazardous and precious material content of spent c-Si PV panels to reduce transportation costs and incentivize recycling.