Life cycle analysis of metals in emerging photovoltaic (PV) technologies: A modeling approach to estimate use phase leaching

• Published in: Journal of cleaner production Vol. 186; pp. 632 - 639
• Main Authors: Celik, Ilke, Song, Zhaoning, Phillips, Adam B., Heben, Michael J., Apul, Defne
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 10-06-2018
• Subjects: Emerging photovoltaic; Long term leaching; Metal release; Use phase toxicity; Emerging photovoltaic; Use phase toxicity; Metal release; Long term leaching
• ISSN: 0959-6526; 1879-1786
• DOI: 10.1016/j.jclepro.2018.03.063

The potential release of toxic metals from damaged emerging photovoltaic (PV) cells has raised concerns about the safe use of these new types of PVs. In this study, this concern was addressed by analysing the life cycle toxicity of metals (cadmium, copper, lead, nickel, tin and zinc) that are commonly used in emerging PVs. In estimating the potential metal release, a new model that incorporates field conditions (crack size, time, and glass thickness) and physiochemical properties (diffusion coefficient and solubility product) was introduced. The results show that the use phase toxicity of copper and lead can be higher than the extraction phase toxicity. Thus, precautionary loss limits to manage toxic impacts from the use phase were proposed. Also, the toxicity from different layers of perovskite, copper zinc tin sulphide (CZTS), and quantum dot (QD) type of solar cells was compared. It was found that cadmium sulphide (compared to zinc oxide and tin oxide) and lead (II) sulphide (compared to lead (II) iodine and CZTS) were less toxic alternatives for the electron selective layer and light absorber, respectively. Finally, in comparing the toxic metal releases of the PVs to today's coal power plants, it was seen that the metal emissions from PVs are expected to be several times less than the emissions from coal.
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•Toxic metals can be released from photovoltaic cells during the use.•We introduced a theoretical model to find the leaching rate of metals.•We addressed the toxicity concerns regarding the safe use of PVs by analyzing the metals.•The CuSCN and PbI2 can leach out quickly, thus, cause high toxicity during the use phase.•Precautionary loss limits to manage toxic impacts from the use phase should be used.