Hybridizing waterborne transport: Modeling and simulation of low-emissions hybrid waterbuses for the city of Venice

Hybrid-electric powertrains are among the most promising technologies for abating emissions from marine vessels in sensitive areas. However, their effectiveness strongly depends on the context they operate into. This paper attempts to evaluate the potential impact on air quality of hybridizing the diesel- powered waterbuses that currently operate in the city of Venice as part of the local public transportation network. Simulation models for conventional, series hybrid and parallel hybrid marine powertrains were developed and applied to the typical operational mission of one of these waterbuses. For the hybrid powertrains, an Energy Management Strategy is also obtained using a Dynamic Programming - based optimization algorithm. The results show that both hybrid architectures have high emission-reducing potential, with the series hybrid offering the greatest benefits.