Abstract:The Sustainable Transport Energy Program (STEP) is an initiative of the Government of Western Australia, exploring hydrogen fuel cell technology as an alternative to the existing diesel and natural gas public transit infrastructure. This project includes three buses manufactured by DaimlerChrysler with Ballard fuel cell engines, operating in regular service alongside the existing natural gas and diesel bus fleets.The Life Cycle Assessment (LCA) of the Perth fuel cell bus trial determines the overall environmental footprint and energy demand by studying all phases of the complete 2 transportation system, including the hydrogen infrastructure, bus manufacturing, operation, and end-of-life disposal. LCA's of the existing diesel and natural gas transportation systems are developed in parallel.The findings show that the Perth fuel cell bus trial is competitive with the diesel and natural gas bus systems in terms of global warming potential, and eutrophication. Emissions that contribute to acidification and photochemical ozone are greater for the fuel cell buses.Scenario analysis quantifies the improvements that can be expected in future generations of fuel cell vehicles, and found a reduction of greater than 50% is achievable in the greenhouse gas, photochemical ozone creation, and primary energy demand impact categories.

The transit authority in Perth, Western Australia, has put several alternative fuel buses, including diesel-electric hybrid and hydrogen fuel cell buses, into revenue service over the years alongside conventional diesel and natural gas buses. Primary data from this fleet is used to construct a Life Cycle Cost (LCC) model, providing an empirical LCC result. The model is then used to forecast possible scenarios using cost estimates for next generation technologies. The methodology follows the Australian/New Zealand Standard for Life Cycle Costing, AS/NZS 4536:1999. The model outputs a dollar value in real terms that represents the LCC of each bus transportation technology. The study finds that Diesel buses deliver the lowest Total Cost of Ownership (TCO). The diesel-electric hybrid bus was found to have a TCO that is about 10% higher than conventional diesel. The premium to implement and operate a hydrogen bus, even if industry targets are attained, is still substantially greater than the TCO of a conventional diesel bus, unless a very large increase in the diesel fuel price occurs. However, the hybrid and hydrogen technologies are still very young in comparison to diesel and economies of scale are yet to be realised.

In this study we review the trends and trajectories of energy use and emissions in Australia's road transport sector. We find that energy use and emissions in heavy-duty vehicles are growing at a greater rate than light-duty vehicles, and that heavy-duty vehicle energy consumption will surpass that of light-duty vehicles by 2032. We explore whether popular light-duty alternative energy concepts, such as battery electric technology, are also competitive for heavy-duty vehicles. We observe that finding a sustainable energy technology that competes with the high energy density of diesel is a formidable challenge. Alternatives such as natural gas, propane and biofuels have managed to establish a beachhead. However, none have constituted a disruptive threat to diesel oil. The lack of any silver bullet technology indicates that further research into technology options is warranted. Hydrogen fuel cell systems have many characteristics which are attractive for the heavy-duty transport task, including complementarity with electric vehicles and a cross-benefit from developments in batteries and electric drivetrains. We conclude that for Australia, fuel cells may find their niche in the electrification of heavyduty drivetrains, in markets where zero emissions are desirable, and where range, duty cycle or payload requirements exceed the capabilities of battery-only vehicles.

Much of the hydrogen vehicle research to date has been conducted and demonstrated in wealthy nations, with very few exceptions. However, developing economies are largely dependent on public transportation, and struggle with air pollution and energy security concerns. The developing regions are in great need of alternative transportation solutions, and although many alternatives are being explored, hydrogen-fueled vehicles are emerging as one of the only technologies that can meet the demands for lower greenhouse gas emissions, lower emissions of air pollutants, and reduced dependence on imported energy. Most conventional buses in developing regions are built from an imported 'buggy-chassis', which is a functional bus chassis with an engine and other auxiliaries. Domestic companies extend the 'buggy-chassis' to full bus length, build the 2 body and cabin, and install other auxiliary systems. The existing infrastructure of the bus buggy-chassis market can be used to leverage hydrogen technology for mass production.This solution allows developing nations to import a state-of-the-art vehicle, with the possibility for significant local content in the final delivered product, while maintaining the flexibility for innovative technological developments and promoting hydrogen research within the developing economies. Indeed, a modular series-hybrid drivetrain can be made adaptable to a range of primary power sources such as an internal combustion engine or fuel cell engine. The modular approach provides an opportunity to reduce cost while still providing flexibility for innovation, and allows customers to tailor performance to suit their topographical and operational needs.

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