Insights into circular material and waste flows from c-Si PV industry

Abstract

A material flow model for the production of Bifacial Selective Emitter 60-cell p-type Cz PERC (Passivated Emitter and Rear Contacted) glass-backsheet modules with aluminium frame was built. The selected module represents mature technologies in the PV industry and their manufacturing is considered to take place in China in a production cluster with an annual module capacity of 5 GWp. In a first step, data acquisition and validation for wafer, cell and module fabs took place. The data were used to generate the reference system lifecycle inventories (LCI) and extended waste databases for the reference wafers, cells and modules. A set of potential circularity actions, such as the vertical integration of the operations and waste revalorisation strategies, had been proposed and their environmental performance and cost assessed by means of a life cycle assessment (LCA) and a total cost of ownership (TCO). Our results show that 87% of the waste can be reduced and revalorised, this represents a circular flow of raw materials of 18,756 Mg per year from a 5GWp PV module production cluster. Environmental impact reductions of 0.6–2.3% are estimated for different impact categories. We also estimate a cost reduction potential of 2.59% from total module costs.

Photovoltaic Manufacturing Factories and Industrial Site Environmental Impact Assessment

“…The scope of the analysis focuses on the creation of inventories of components from the civil, structural, and architectural (CSA) and process disciplines, which are necessary for the construction and set-up of the industrial site. The process analysis considers the reference sequence defined by Brailovsky et al (2023) for the production of Cz-ingots, monocrystalline wafers, PERC solar cells and PV modules [6]. Two comparative LCAs are conducted, one to compare the annualized environmental impacts between our analogous own models (OMs) with the Ecoinvent (EI) ones, and a second comparison to evaluate the environmental impacts of alternative building systems.…”

“…In a second step, the integration of all the analogous inventories was carried out based on the identification, listing and quantification of the process equipment, facilities equipment and construction components, organized as a bill of materials (BOM) for each factory and the industrial site ancillary facilities, as shown in Figure 1. The Fraunhofer ISE technoeconomic assessment software SCost (Version 6.0) [21] was used to model the selected process sequence from Brailovsky et al (2023) [6]. A throughput analysis was performed to generate the required tools for each of the production processes.…”

“…At the same time, this growth entails an increase in the consumption of resources for production and the consequent environmental impacts. As such, sustainable pathways for manufacturing products along the PV value chain are of high relevance to minimize those impacts for the expected terawatt-scale deployment of PV [2][3][4][5].…”

“…Research on the environmental impacts of the PV value chain, with respect to its constituent materials, especially the critical raw materials, the efficiencies of the different generations of PV technologies, as well as their subsequent performance in the operational stage, is widely available and published [6][7][8][9][10][11][12][13]. However, there is almost no research or literature related to the environmental impacts of infrastructure developed in the service of the PV manufacturing production chain [14].…”

An Updated Life Cycle Assessment of Utility-Scale Solar Photovoltaic Systems Installed in the United States

“…However, EOL LCAs drew from earlier publications (Stolz et al 2017;Ravikumar et al 2016;Latunussa et al 2016). Other studies, such as circular economy material flow studies (Brailovsky et al 2023;Bartie et al 2021), industry advances, and best practices (Walker 2018;Chen et al 2016;Curtis et al 2021b;International Finance Corporation 2015) were reviewed for verification of modern installation projects, material demands, and process energy intensities. Data from different publications were compared whenever applicable, and critical processes (e.g., polysilicon energy inputs, concrete use for system install, etc.)…”