High-Power Laser Recycling of Crystalline Silicon Photovoltaic Modules

This study presents an innovative laser-based, interface-selective recycling method for end-of-life crystalline-silicon photovoltaic (PV) modules, addressing the growing solar waste problem from expanded solar deployment. The PV modules are designed to withstand outdoor conditions for decades, but their robust laminated structure makes component separation challenging due to their strong bonding and the brittle nature of glass and silicon. Conventional recycling approaches often damage silicon wafers and metallization, and shred the glass. The proposed technique utilizes a high-power, nanosecond-pulsed infrared laser at 1064 nm wavelength to induce localized photothermal dissociation of the encapsulant via interfacial heating, exploiting the transparency of glass and the encapsulant at this wavelength while enabling absorption by silicon. This facilitates the separation of intact glass and the recovery of full silicon wafers with minimal mechanical force and chemical intervention. The process was demonstrated for both monofacial and bifacial modules, utilizing laboratory-made and commercial samples. Post-treatment cleaning yields recovered glass with over 90% visible transmittance, comparable to new glass, and wafers retain metallization patterns critical for precious silver metal recovery. A prospective techno-economic assessment estimates laser recovery process costs at approximately $8.06 per monofacial module and $5.33 per bifacial module. These findings indicate the potential for a scalable, high-value recovery process that supports sustainable material management in the photovoltaic industry, offering a viable pathway toward an environmentally and economically advantageous recycling method.