Review of issues and opportunities for glass supply for photovoltaic production at multiterawatt (TW) scale

Current solar photovoltaic (PV) installation rates are inadequate to combat global warming, necessitating approximately 3.4 TW of PV installations annually. This would require about 89 million tonnes (Mt) of glass yearly, yet the actual production output of solar glass is only 24 Mt, highlighting a significant supply shortfall (3.7 times). Moreover, there is scarce information about the iron content of many sand deposits worldwide. Low-iron sand is required for PV glass production, to make the glass highly transparent and reduce the absorption of solar energy. Additionally, glass manufacturing leads to significant emissions, with fossil fuels being the primary energy source. Recycling offers a promising partial solution, with some available techniques enabling the clean recovery and reuse of end-of-life PV glass (cullet) for new panels. Similarly, methods such as the Hot Knife and Delam processes could recover entire glass cover sheets for potential reuse in new PV modules. Furthermore, there is an opportunity to establish new glass factories with lower emissions through strategies such as hydrogen fuel adoption, electrification, and waste heat recovery.