Integrating Life Cycle Assessment and the Analytic Hierarchy Process for Sustainable Decision-Making in Silicon Recovery from Photovoltaic Panels

The rapid expansion of photovoltaic (PV) energy has intensified concerns about end-of-life panel management, particularly the environmental impacts of improper disposal and inefficient silicon recycling. PV panel waste may reach approximately 78 million tons by 2050, making sustainable silicon recovery a critical challenge. This study integrates global warming potential (GWP)-based life cycle assessment with the analytic hierarchy process (AHP) to prioritize three prospective silicon-recovery scenarios (baseline, optimistic, and pessimistic) for Brazil through 2050. A system-dynamics simulation projects silicon stock, recovery, and cumulative GWP for each scenario; these are combined with recovery efficiency and regulatory feasibility criteria (weights of 63.3%, 26.0%, and 10.6%; consistency ratio = 0.003) in the AHP model. The optimistic scenario achieved the highest priority score (0.967), followed by the baseline (0.752) and pessimistic (0.132) scenarios. Sensitivity analysis confirmed that this ranking is robust to ±10% variation in any single criterion weight, with the regulatory feasibility weight requiring an approximately seven-fold increase (to ≈72% of total weight) to overturn it. The results support LCA–AHP integration as a strategic decision-support framework for circular-economy policy in the Brazilian PV sector, adaptable to other national contexts facing similar regulatory and infrastructure constraints.