INVENTORY OF WASTE MATERIALS FROM SILICON INGOT AND WAFER MANUFACTURING FOR A CIRCULAR PV VALUE CHAIN

Photovoltaics (PV) is one of the most important renewable energy. During the production of Si-based PV panels, large resource flows are generated, and many waste materials are generated. The challenge for recycling is connected to the material properties: The composition, purity and morphology will determine how the current waste should be processed in order to realize the potential value. We have therefore performed a waste inventory for three important material flows occurring from monocrystalline silicon ingot and wafer manufacturing in the PV production value chain: Si kerf from sawing of wafers, silica from crucibles used in CZ-Si ingot pulling and graphite from CZ crystal growth furnaces. A series of characterization and analysis methods, have been used to investigate the chemical composition, phases, size and morphology etc. of the three waste materials. Possible contamination sources were discussed. The waste inventory results give an overview of the materials quality and property, and their potential for
recycling and re-use in the PV section and other application fields.