Exploratory Study on Liberation of Glass from Photovoltaic Cells of Solar Panels
Restricted (Penn State Only)
- Author:
- Sharmba, Tsunami
- Graduate Program:
- Energy and Mineral Engineering
- Degree:
- Master of Science
- Document Type:
- Master Thesis
- Date of Defense:
- October 21, 2024
- Committee Members:
- Mohammad Rezaee, Thesis Advisor/Co-Advisor
Barbara J Arnold, Committee Member
Shimin Liu, Program Head/Chair
Nelson Yaw Dzade, Committee Member - Keywords:
- solar
solar recycling
solar panels
sustainability
glass liberation
material recovery - Abstract:
- As solar energy expands globally, the pressing issue of managing end-of-life solar panels becomes critical. By 2030, solar panel waste could reach 8 million tons, and by 2050, this figure may soar to 80 million tons. Without effective recycling processes, over 90% of decommissioned panels in the U.S. currently end up in landfills, where hazardous materials like lead and cadmium can leach into the environment, posing severe ecological and health risks. This study focused on the glass liberation process from photovoltaic (PV) cells, a critical step in solar panel recycling, by evaluating several mechanical methods: rod milling, ball milling, stirred milling, roll crushing, and hammer milling, to transform solar panel waste management from an environmental liability into an opportunity for sustainable critical mineral and material recovery to address society needs and an enhanced circular economy. The experiments revealed varying levels of effectiveness. Rod milling, ball milling, and stirred milling proved ineffective for selective glass liberation, generating only partial size reduction without substantial liberation. In contrast, roll crushing showed promise, achieving 48-63% mass reduction of PV cells while preserving their integrity. Hammer milling was also found to be efficient in size reduction and enhanced liberation but produced mixed glass and PV cell fragments. Based on these findings, a proposed process was developed that integrates initial ¼” screening, roll crushing, secondary screening, and hammer milling followed by physical separation to maximize glass liberation and metal recovery. This approach reduces the overall PV cell mass by 67%, lowers shipping costs to downstream smelting processes, and minimizes the carbon footprint of recycling. The study concludes that refining this proposed process could pave the way for more efficient and sustainable recycling methods, supporting a circular economy and aligning with the United Nations Sustainable Development Goals (SDGs), particularly SDGs 7, 9, and 11.