Energy and Greenhouse Gases Life Cycle Assessment of Electric and Hydrogen Buses: A Real-world Case Study in Bolzano Italy

The transportation sector plays an important role in the current effort towards the control of global warming. Against this backdrop, electrification is currently attracting attention as the life cycle environmental performance of different powertrain technologies is critically assessed. In this study, a life cycle analysis of the public transportation buses was performed. The scope of the analysis is to compare the energy and global warming performances of the different powertrain technologies in the city fleet: diesel, full electric and hydrogen buses. Real world monitored data were used in the analysis for the energy consumptions of the buses and to produce hydrogen in Bolzano. Compared to the traditional diesel buses, the electric vehicles showed a 43% reduction of the non-renewable primary energy demand and a 33% of the global warming potential even in the worst consequential scenario considered. The switch to hydrogen buses leads to very different environmental figures: from very positive if it contributes to a further penetration of renewable electricity, to hardly any difference if hydrogen from steam-methane reforming is used, to clearly negative ones (approximately doubling the impacts) if a predominantly fossil electricity mix is used in the electrolysis.