Hydrogen-based technologies in maritime sector: technical analysis and prospective

The maritime transportation sector is one of the main contributors to global emissions of greenhouse gases (GHGs). The International Maritime Organization (IMO) has adopted a strategy to reduce these emissions from international shipping >50% by 2050, compared to 2008's emissions. Therefore, ship owners need to adopt solutions to bring emissions within these and other future limits by means of environmentally friendly fuels (hydrogen or hydrogen carriers) and high efficiency propulsion technologies (fuel cells). This paper focuses on the replacement of the conventional Diesel genset installed on a hybrid small-size ferry, with an innovative system based on PEMFC technology. A real case scenario is investigated: the total energy/power demand of the vessel is determined basing on a typical operational profile. Then, a preliminary redesign of its powertrain configuration is proposed along with an energy management strategy. The analysis has allowed to define the hydrogen consumption for a daily operation. Finally, different storage technologies involving both compressed and liquefied hydrogen have been considered and compared, in order to identify ship's weight and space requirements.