Hanjiro Ambrose
Department of Civil and Environmental Engineering,University of California, Davis
Hanjiro is a 3rd year PhD candidate in Civil and Environmental Engineering at the University of California Davis. Hanjiro's research applies industrial ecology to the convergence of transportation systems, technology change, and environmental policy. His dissertation research looks at methodological issues in comparing technology alternatives in the heavy duty vehicle sector. His on-going research efforts also include electric vehicle battery LCA, critical energy materials, new mobility, and life cycle based policies for vehicles and fuels. Hanjiro is also a member of the Transportation Research Board, where he serves on the research subcommittee for Transportation and Sustainability.
Transit buses operate disproportionately in urban areas and impose pollution on local environments. To achieve both criteria and greenhouse gas emissions targets, transit agencies are considering new vehicle and fuel technologies for their fleets. Transit agencies are not well funded, and in many cases have not been able to raise ridership levels even with large subsidies. They often cannot afford increased purchase costs for buses unless they reduce bus service. Therefore, the question of cost for alternative fuel buses is hugely important for transit agencies. The objective of this study is to compare the life cycle energy, emissions, and costs for California transit agencies adopting new vehicle and fuel technologies into their bus fleets.
Zero Emissions Vehicles (ZEVs) typically refer to vehicles fueled by electricity, hydrogen, or other renewable fuels. The last fifteen years has witnessed a dramatic decline in the costs of vehicle hybridization, biofuels, renewable electricity generation, and vehicle light-weighting with advanced materials, enabling technologies for ZEVs, are key to increasing the efficiency of vehicles while shifting them away from direct fossil energy combustion. Rapidly improving economics of battery storage in particular is enabling new ZEV applications, such as transit buses. Today, there are a growing number of commercial offerings of ZEV buses for transit agencies to consider, as well as demonstration data to draw upon.
Policy is also driving adoption of ZEV transit buses through direct monetary incentives and increasingly stringent tail-pipe emissions standards. Promoting ZEV vehicle adoption is already a cornerstone of California vehicle policy, and new efforts by the California Air Resources Board is seeking to transition all public transit agency bus fleets to ZEVs by 2040. The policy fits within California’s goals to reduce greenhouse gas emissions (GHG) from transportation 80% from their 1990 levels by 2050. Cities in particular stand to benefit from synergies with GHG reduction efforts, and potentially ZEV adoption by transit agencies, due to improvements in local environmental quality and public health.
Transit agencies considering fleet technology upgrades need to consider the costs of vehicle ownership and operation when weighing vehicle purchase decisions. ZEV vehicle and fuel technology adoption offer new trade-offs between purchase and operation costs, uncertain vehicle and component system lifetimes, and the potential to consider environmental performance improvements. We present preliminary results on the life cycle environmental impacts and costs of production, use, and end-of-life for transit buses. We consider several scenarios of bus body type, powertrain configuration, use case, and fuel production pathway. Powertrain configurations include internal combustion (ICE), hybrid electric ICE, battery electric, and fuel cell hybrid. Fuel pathways refers to both fuel feedstock and production pathway, loosely grouped into gaseous, liquid, and electric.
These include both renewable and fossil production pathways, and reflect the costs and availability of different feedstock and production technologies. We also consider three functional units to characterize bus performance: passenger revenue miles, vehicle miles travelled, and a forty-foot bus equivalent.
• Infrastructure systems, the built environment, and smart and connected infrastructure , • Public policy and governance , • Sustainable urban systems
