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 heavy-duty drivetrains, in markets where zero emissions are desirable,
and where range, duty cycle or payload requirements exceed the capabilities of battery–
only vehicles.