Mitigating urban pollution: A comparative life cycle assessment of hydrogen, electric, and diesel buses for urban transportation

Abstract

Urban transportation systems, particularly public buses, contribute significantly to global pollution, creating an urgent need for sustainable solutions. Alternative fuel buses and other disruptive technological advancements in this field are essential to resolve these problems. The absence of studies on the life cycle assessment (LCA) of hydrogen-fueled buses, along with comparative analyses of alternative-fueled buses, makes this research particularly timely. This study develops a comprehensive LCA framework to measure the economic and environmental impact of using different technologies (i.e., hydrogen-fueled, electric, and diesel buses). Different fuel production methods were examined, considering operational factors such as energy consumption across various routes. This study contributes to enhancing the LCA methodology for public bus operations by using machine learning algorithms to cluster routes and identify optimal demonstration routes for analysis. The results highlight the impact of fuel production methods for hydrogen-fueled buses in the significant pollutant reductions (e.g., ${\mathrm{CO}}_2$ and ${\mathrm{NO}}_x$), despite their high life cycle costs. The proposed framework is validated with real data from Halifax, Canada, and expanded to assess public bus networks in cities with varying routes, topology, and population levels. The paper’s analyses consider future technological advances to lower costs, aligning them with electric buses over time. This study helps policymakers choose the best public bus alternatives to improve the economic, environmental, and social sustainability of urban transportation.