Towards Multi-TW Scale Manufacturing of PV Technologies: Challenges Related to Material Consumption
Abstract
A critical concern for the photovoltaics (PV) industry is ensuring sustainability and material availability at the terawatt (TW) level. With current silver consumption level of industrial PERC solar cells (16.3 mg/W), achieving a multi-TW production (3 TWp e.g) would consume 170% of the 2019 global silver supply. The silver usage needs to be reduced to less than 5 mg/W to ensure a sustainable use of silver in PV industry, but even at this level a 3 TW market would consume 50% of global silver supply. Such a massive reduction in the Silver consumption will lead to significant increases in finger resistance losses and strict limitations on the cross-sectional area of fingers that can be used, which imposes severe challenges to industrial solar cells especially for TOPCon and SHJ. Although the use of silver-free interconnection schemes such as Smartwire can slightly relax constraints on silver usage, those technologies also have sustainability concerns, as 20% of the world bismuth supply can only produce 330 GW of solar panels, and no more than 2 wires per side can be used for a 3 TWp production scale. Another key concern is the use of ITO in SHJ solar cells. 20% of the global indium supply is only sufficient for a SHJ production scale of 35 GWp, and a multi-TW market can only be achieved if the thickness of ITO layers was reduced to 0.97 nm per side.