Thesis Defence: Decarbonization of the Canadian Bus Transit: A Life Cycle Sustainability Framework

Bhuwan Paudel, supervised by Dr. Kasun Hewage, will defend their thesis titled “Decarbonization of the Canadian Bus Transit: A Life Cycle Sustainability Framework” in partial fulfillment of the requirements for the degree of Master of Applied Science in Mechanical Engineering.

An abstract for Bhuwan Paudel’s thesis is included below.

Defences are open to all members of the campus community as well as the general public. Please email kasun.hewage@ubc.ca to receive the Zoom link for this defence.

---

ABSTRACT

Canadian transit agencies are exploring viable replacements for their diesel bus (DB) fleet to mitigate greenhouse gas emissions. Zero-emissions buses, such as electric and hydrogen fuel cell buses, show great potential due to no tailpipe emissions during their operation. However, the transition from diesel buses to zero-emission buses requires a comprehensive analysis; this should go beyond the environmental benefits during operation and should thoroughly examine the economic and social implications throughout their life cycle. The existing published literature reveals the need to develop a comprehensive framework that integrates indicators and multiple decision parameters over a life cycle perspective to analyze different options for replacing the existing fleet of DBs. This study aimed to develop a framework that incorporates life cycle thinking to compare the sustainability performance of transit buses. A life cycle sustainability assessment framework (LCSA) was developed for transit buses incorporating life cycle assessment (LCA), life cycle costing assessment (LCCA) and social life cycle assessment (SLCA) methods. Their individual outcomes were aggregated using the multi-criteria decision-making (MCDM) method -TOPSIS. The developed LCSA framework was applied to diesel, hydrogen fuel cell, and electric transit buses across provinces and territories of Canada. The results show that the environmental performance of the electric bus (EB) and hydrogen fuel cell bus (HB) was better than that of DB; HB has the most economic burden followed by DB and HB; and EB has the least social impact over the life cycle. The extent of these impacts in the three aspects of sustainability varies across the regions. Moreover, the life cycle performance of the EB during its operation using the future grid mix of 2030-2050 was analyzed. The prospect for the deployment of electric buses in Canada looks promising. With improvements in the electric grid, transit agencies will be able to attain even greater sustainability benefits. The proposed framework and the results of the sustainability assessment will help policymakers, transit agencies, researchers, and stakeholders integrate zero-emission buses into transit systems, paving the way for a more sustainable future.