Comparative techno-economic analysis of integrated solar PV and methane–methanol production systems for enhanced waste management solutions

Abstract

As the global demand for sustainable energy solutions grows, the integration of renewable technologies into waste management systems has gained significant attention. This study investigates the integration of power-to-gas (P2G) and power-to-liquid (P2L) technologies within waste management units through a comprehensive techno-economic analysis. Multi-objective optimization was conducted to determine the optimal number of solar photovoltaic (PV) panels, aiming to maximize the Cumulative Fuel Production Potential (CFPP) while minimizing the Total Annual Cost (TAC). Five distinct scenarios were proposed, validated, and compared from technical, economic, and environmental perspectives. The five scenarios involve combinations of anaerobic digestion, gasification, mechanical biological treatment, power-to-gas, and power-to-liquid technologies for sustainable waste management and fuel production. The first scenario focuses on methane production, the second focuses on methanol production, and the other three focus on co-production of methane and methanol. The optimization revealed that scenarios 2 to 5 required approximately 8,500 to 8,900 solar PV panels, while scenario 1 necessitated only half that amount, indicating a consistent hydrogen demand across scenarios. Technically, scenario 3 exhibited the highest CFPP at 9.25 MJ/kg_MSW, showcasing significant fuel production potential. Economically, scenario 1 demonstrated the lowest TAC, while scenario 5 had the highest, suggesting that anaerobic digestion is more cost-effective than gasification. Environmentally, scenario 1 and scenario 5 also showed the lowest Global Warming Potential (GWP), highlighting the advantages of combining power-to-liquid and power-to-gas technologies in reducing carbon footprints. Overall, scenario 3 emerged as the most favorable option due to its optimal balance of high CFPP and moderate TAC.