**1. Introduction**

Solar photovoltaic (PV) technology plays an increasingly important role as a key energy source [1,2] As this technology grows, it is important to ensure that each process in the life cycle of PVs is sustainable [3,4]. The environmental impacts from manufacturing and operation of solar PV panels have been widely studied [5,6] and more recently, there has been a growing interest in understanding the environmental impacts of the end-of-life (EoL) management of solar panels [7–9]. Solar panels last from 20–30 years before weather and external conditions necessitate their retirement [10,11]. Because the mainstream, large-scale use of PV technology is relatively new, the infrastructure to recycle solar panels is not yet built for the capacity it must handle in the future [12]. The decrease in the price of PV modules' and the reduction in the environmental impact of solar systems in comparison to traditional fossil fuel technologies has led to many more large-scale solar plants being installed [11,13]. The global annual PV power capacity installed was equal to 114 GW in 2019, a net year-on-year increase of 17.5% from 2018 [14,15]. This rapid increase in panel use necessitates responsible, industrial-scale recycling and disposal processes.

In developing recycling processes for solar panels, it is important for us to understand both the cost and environmental impacts of the technology. The environmental impacts of EoL management of solar PV panels has received great attention recently; many authors have estimated the environmental impacts of EoL of solar panels using the life cycle assessment method [16–20] These studies highlighted that the majority of the impacts are associated with chemical usage for process recycling as well as the transportation of PV waste at the EoL of PVs. These studies also widely found that the environmental harm that can be avoided by recovering materials from PV panels is greater than the environmental harm caused from the energy and fuel that it takes to recycle them. The cost of recycling solar panels has also received great attention [21–24]. The cost assessment studies concluded that the PV recycling process cost—more specifically, using mechanical and/or thermal methods—is the major contributor to the cost of EoL management of PV waste. Since these studies either focus on the cost or environmental impacts, and since each study focuses on a different recycling process, we cannot deduce how cost and environmental information relate to one another for a given recycling process. Besides, environmental cost PV EoL management has been largely ignored in the literature.

In this study, we addressed this issue by studying the "full recovery end of life photovoltaic project" (FRELP) method of recycling crystalline silicone (c-Si) panels. The FRELP approach has found technological solutions for every step of the c-Si PV treatment process and has been successful in translating this information into a technically and economically feasible industrial process design [20]. We monetized the environmental impacts of c-Si PV recycling using this approach to obtain the externality costs of the FRELP method. We also analyzed the FRELP method to estimate its private costs. We then created our cost model, which compares these private to externality costs and showed the net benefits of the FRELP method by comparing the economic and environmental benefits that can be supplied from the recovered materials and processes associated with EoL management.
