Graduation Date

Summer 2021

Document Type



Master of Science degree with a major in Environmental Systems, option Energy, Technology, and Policy

Committee Chair Name

Dr. Arne E Jacobson

Committee Chair Affiliation

HSU Faculty or Staff

Second Committee Member Name

Dr. Charles Chamberlin

Second Committee Member Affiliation

HSU Faculty or Staff

Third Committee Member Name

Dr. Peter Alstone

Third Committee Member Affiliation

HSU Faculty or Staff

Subject Categories

Environmental Resources Engineering


This study analyzes the techno-economic feasibility of converting the conventional transit bus fleet of the Humboldt Transit Authority (HTA) into a battery-electric or a hydrogen-fueled bus fleet. The study identifies which of these technologies represents the more economically viable investment for HTA by analyzing the costs and benefits associated with each pathway. Both pathways involve zero-emission or low-emission technologies.

The study outcomes suggest that the conversion of the HTA’s current conventional fleet to an electric fleet is more feasible than conversion to a hydrogen fuel cell bus fleet. The total discounted cost (3% rate) of converting the 21-bus conventional fleet to electric or hydrogen buses during the period from 2021-2040 is $27 and $62 million, respectively.

Currently, HTA’s total cost of the current conventional fleet is $110 per hour of operation (excluding capital cost, as the buses are in service). The capital cost to purchase a new set of conventional buses is reportedly $71/hr. The corresponding estimated costs for battery-electric and hydrogen-fueled fleets including capital costs are $167/hr and $390/hr, respectively. The total cost of conversion includes various cost components, such as the capital cost of buses and charging/refueling infrastructure, the operation and maintenance (O&M) cost of buses and associated charging/refueling infrastructure, revenue generated by low carbon fuel standard (LCFS) credits, and other related costs for the period from 2021-40. This period is consistent with the timeline recommended by the California Air Resources Board (CARB).

The transition to zero-emission buses is proposed to be carried out in two phases for both technologies, with Phase I occurring from 2021 to 2025 and Phase II from 2025 to 2030. For the battery-electric bus option, the study also analyzed the optimized charging time for the buses while keeping demand below 750 kW with continuous charging during non-peak hours.

Citation Style



Thesis/Project Location