Recycling of PV modules
Though PV modules generally have a life cycle as long as two decades, the PV industry has a major interest in creating truly sustainable energy solutions that take into consideration the environmental impacts of all stages of the product life cycle, from raw material sourcing through end-of-life collection and recycling. Leading manufacturers embrace the concept of producer responsibility and set the highest environmental standards for their products. On a voluntary basis they put in place take-back and recycling programmes.
Thin film manufacturer First Solar, for example, has established a comprehensive, prefunded module collection and recycling program for solar modules. The program is designed to maximize the recovery of valuable materials and minimize the environmental impacts associated with PV system production. Approximately 90% (by mass) of each collected PV module is recycled for use in new modules or other new products. In this way, a waste management challenge for future generations can be prevented.
Stages of Recycling
Collection
Once at a recycling facility, the modules are collected in hoppers and loaded by forklift into a shredder.
Shredder
The modules are reduced in size by the shredder, which breaks the glass into large pieces.
Hammermill
The hammermill crushes the broken glass into 4-5mm pieces, small enough to ensure the lamination bond is broken.
Film Removal
The semiconductor films are removed by the addition of acid in a slowly rotating, stainless steel drum.
Solid-Liquid Separation
The drum is slowly emptied into a classifier where glass is separated from the liquids. A rotating screw conveys the glass up an incline, leaving the liquids behind.
Glass-Laminate Material Separation
A vibrating screen separates the glass from the larger pieces of laminate material (which formerly sealed the two pieces of glass together).
Glass Rinsing
The glass is rinsed to remove any residual semiconductor material that physically remains on the glass. The clean glass is packaged for recycling.
Precipitation
The metal-rich liquids are pumped to the precipitation unit and processed in three stages at increasing pH. The precipitated materials are then concentrated in a thickening tank. The resulting unrefined semiconductor material is packaged for processing by a third party to create semiconductor material for use in new modules.
Thin film manufacturer First Solar, for example, has established a comprehensive, prefunded module collection and recycling program for solar modules. The program is designed to maximize the recovery of valuable materials and minimize the environmental impacts associated with PV system production. Approximately 90% (by mass) of each collected PV module is recycled for use in new modules or other new products. In this way, a waste management challenge for future generations can be prevented.
Stages of Recycling
Collection
Once at a recycling facility, the modules are collected in hoppers and loaded by forklift into a shredder.
Shredder
The modules are reduced in size by the shredder, which breaks the glass into large pieces.
Hammermill
The hammermill crushes the broken glass into 4-5mm pieces, small enough to ensure the lamination bond is broken.
Film Removal
The semiconductor films are removed by the addition of acid in a slowly rotating, stainless steel drum.
Solid-Liquid Separation
The drum is slowly emptied into a classifier where glass is separated from the liquids. A rotating screw conveys the glass up an incline, leaving the liquids behind.
Glass-Laminate Material Separation
A vibrating screen separates the glass from the larger pieces of laminate material (which formerly sealed the two pieces of glass together).
Glass Rinsing
The glass is rinsed to remove any residual semiconductor material that physically remains on the glass. The clean glass is packaged for recycling.
Precipitation
The metal-rich liquids are pumped to the precipitation unit and processed in three stages at increasing pH. The precipitated materials are then concentrated in a thickening tank. The resulting unrefined semiconductor material is packaged for processing by a third party to create semiconductor material for use in new modules.
