Emissions life cycle assessment of diesel, hybrid and electric buses

This paper applies a case study approach for Australia and calculates the equipment life cycle assessment of diesel, hybrid and electric buses. This study prepared the assessment according to the procedures and methodologies outlined in the ISO 14040:2006 Environmental Management - Life Cycle Assessment. The authors have chosen three bus models currently in service in the Australian bus fleet to serve as a baseline model for comparison. The amount of greenhouse gas emissions were calculated from the production, assembly, transportation, maintenance and disposal phases. The results in this study show that the electric bus has a higher total environmental impact than the diesel and hybrid bus, mainly due to the manufacturing of the lithium-ion battery. The results also show that the electric bus has a higher environmental impact than the diesel and hybrid bus (18.2% and 14.7% higher, respectively), albeit specific to the product life cycle and without including operation emissions. However, there are many opportunities to reduce product life cycle emissions, such as improvement in manufacturing efficiency, developing new battery technology and production in regions with low carbon-intense grid-mixes.