*3.3. Cost–Benefit Analysis of Recycling*

Figure 5 offers a cost–benefit analysis on recycling c-Si PV modules in their EoL. The negative cost values (benefits) show the revenue that can be realized the PV waste, while the positive cost values indicate the private and external cost of PV EoL management. The economic value of recovered materials through FRELP method was found to be USD 13.6/m<sup>2</sup> while the private cost of the method was calculated as USD 6.7/m2. Taking the difference results in USD 7 of net economic benefit per recycling 1 m2 of c-Si waste PV panel using FRELP method. This high net economic benefit value is due to the high material recovery rates in the FRELP. In the FRELP method, the material recovery rates are 96.2% (aluminum), 98% (glass), 74.5% (copper), 38.6% (silicon) and 11.3% (silver) [20]. However, the breakdown of the total revenue that can be realized from the reselling of the material recovery is 46% (aluminum), 25% (silver), 15% (glass), 11% (silicon) and 3% (copper), based on the market prices of these commodities [35] (see Supplementary Information Table S8). These results indicate that the substantial increases in the net economic benefit from c-Si PVs are hindered by the limited recovery rate of silver. For example, increasing the recovery rate of silver from 11% to 20% will result in a nearly 25% increase (from 13.62 to 16.22) in the total benefits from material recovery.

**Figure 5.** Total cost breakdown of the full recovery end-of-life photovoltaic project (FRELP) method.

The recycling process is a net benefit to the society, even when we include the externality costs of recycling. The total cost of c-Si recycling, including both private and external costs, is USD 12.43 without considering the benefit from recovered materials. When this benefit is added, the cost—or more accurately the benefit—is USD 1.19, meaning there is still a benefit from recycling c-Si PV even when the externality costs of recycling are considered. The total cost of PV recycling we found is USD <sup>−</sup>1.19/m2, meaning that it is cheaper to recycle and use PV panels made from recycled materials than it is to throw these materials away at their end-of-life and use virgin materials.

Our net economic benefit results are consistent with the existing literature studies. Adamo et al. [36] also analyzed the cost of waste c-Si PV waste and reported that the cost of c-Si PV recycling varies from 8–19 EUR/m<sup>2</sup> (assuming that the c-Si PV module weighs 16 kg/m2). The higher benefits in Adamo et al.'s result can be explained due to the modeling approach of transportation and disposal. Adamo et al. ignored the cost of transportation and tipping fees and only modeled the cost of the recycling process for the net economic benefit. If we performed the same analysis as Adamo, our result would show a USD 13/m2 benefit, which is consistent with Adamo et al.'s result. Choi and Fthenakis calculated the net benefit as about 23 USD/module for thin-film CdTe PV technology [7,36]. The higher benefits from CdTe technology can be attributed to the high yields (>90%) of expensive materials (i.e., tellurium, cadmium) from the recycling of thin films.
