A Comparative Environmental Life Cycle Assessment Study of Hydrogen Fuel Electricity and Diesel Fuel for Public Buses

Hydrogen fuel and electricity are energy carriers viewed as promising alternatives for the modernization and decarbonization of public bus transportation fleets. In order to choose development pathways that will lead transportation systems toward a sustainable future, the authors developed an environmental model based on the Life Cycle Assessment approach. The model tested the impact of energy carrier consumption during driving as well as the electricity origin employed to power electric buses and produce hydrogen. Energy sources such as wind, solar, waste and grid electricity were investigated. The scope of the study included the life cycles of the energy carrier and the necessary infrastructure. The results were presented from two perspectives: the total environmental impact and global warming potential. In order to create a roadmap, an original method for choosing sustainable development pathways was prepared. It was shown that the modernization of conventional bus fleets using hydrogen and electrical pathways can provide significant environmental benefits from both perspectives, but especially in terms of global warming potential. It was emphasized that attention should be paid to the use of low- and zero-emission energy sources, because their impact often strongly influenced the final environmental judgment. The energy carrier consumption also had a strong impact on the results obtained, and that is why efforts should be made to reduce it. In addition, it was confirmed that hydrogen and electricity production systems based on electricity generated by a waste-to-energy plant could be an environmentally reasonable dual solution for both sustainable waste management and meeting transport needs.