A Methodological Framework for Designing a National Solar Equipment Waste Management System: The Case of Benin

The rapid expansion of photovoltaic (PV) systems in developing countries is leading to a growing accumulation of end-of-life solar equipment waste (DES), while dedicated management infrastructures remain largely underdeveloped. This study proposes a generalizable methodological framework that integrates waste flow estimation, special cost-minimization, and financial visibility analysis to support the national-scale design of solar equipment waste management system. The approach combines (i) the estimation of end-of-life quantities of solar panels, batteries, and control equipment based on installed capacities and lifetimes, (ii) a GIS-based special optimization model to determine the optimal number and location of collection centers by minimizing investment and transportation costs, and (iii) a comprehensive financial assessment of the proposed system. The methodology is applied to the case of Benin, where several zoning configurations are evaluated. Results indicate that an optimal configuration of three collection centers strategically located in Ten-Dora/Sinendé, Dassa-Zoumè, and Tori-Bossito, minimizes total system costs while ensuring nationwide coverage. The financial analysis indicates that, under an appropriate mixed financing scheme combining public subsidies and bank loans, the project is economically viable, with a positive Net Present Value (NPV) of approximatively 304 million CFA, a Profitability Index of 1.68, an Internal Rate of Return (IRR) of 17% and a Discounted Payback Period of about 4.5 years. Overall, the proposal framework provides a robust decision-support tool for policymakers and investors aiming to develop sustainable and economically viable solar waste management systems in developing countries.