Due to the more stringent regulations on pollutant and greenhouse gas emissions in the maritime transport sector, solutions are being sought to reduce or avoid the emissions generated during the operation of ships. The onboard installation of hydrogen-fuelled fuel cells is a solution respectful with the environment and the marine ecosystem through which ships navigate. In this work, the design of a wellboat and its power plant based on fuel cells fed with hydrogen and hybridised with batteries is conducted, making it a zero-emissions ship that can navigate Emission Control Areas (ECAs). The fuel cells used are polymer electrolyte membrane fuel cells (PEMFCs), and the hydrogen they consume is stored in tanks pressurised at 35 MPa, grouping these tanks into three standard containers (Twenty-Foot Equivalent Units) installed on an exposed deck. The electrical and propulsion needs of the ship are covered by the installed power plant, providing an average power of 1266 kW and a peak power of 2624 kW, making it possible to avoid the emission of 10.8 t of CO₂, 195 kg of NO_x and 9 kg of SO_x per 14 h mission.

The maritime industry remains a significant contributor to global greenhouse gas (GHG) emissions. In this article, a systematic study has been performed on the alternative fuel emissions of large cargo ships under different route scenarios and propulsion systems. For this purpose, a set of key performance indicators (KPIs) are evaluated, including total equivalent CO₂ emissions (CO_2eq), CO_2eq emissions per unit of transport mass and CO_2eq emissions per unit of transport mass per distance. The emissions analysis demonstrates that Liquified Natural Gas (LNG) paired with Marine Gas Oil (MGO) emerges as the most viable short-term solution in comparison with the conventional fuel oil propulsion. Synthetic methanol (eMeOH) paired with synthetic diesel (eDiesel) is identified as the most promising long-term fuel combination. When comparing the European Union (EU) emission calculation system (FuelEU) with the International Maritime Organization (IMO) emission metrics, a discrepancy in emissions reduction outcomes has been observed. The IMO approach appears to favor methanol (MeOH) and liquefied natural gas (LNG) over conventional fuel oil. This is attributed to the fact that the IMO metrics do not consider unburned methane emissions (methane slip) and emissions in the production of fuels (Well-to-Tank).

In accordance with the European Environment Agency and the International Energy Agency, shipping operations generate about 34% of the total nitrogen oxide emissions and 11% of the total carbon dioxide emissions produced by the transportation industry. The capacity of fuel cells to reduce harmful emissions makes them a very attractive and environmentally friendly energy conversion system. This work studies the application of a fuel cell–based auxiliary power plant fed with hydrogen on-board an existing oceanographic vessel. The objective is to eliminate emissions at port and to reduce pollution near inhabited areas. In addition, the power plant was sized to propel the ship at low speed reducing the noise emitted to the water during research tasks that require a low noise level. The type of fuel cell chosen is proton-exchange membrane fuel cell and the hydrogen that feeds it is stored in compressed form at 70 MPa reaching a total storage amount of 771 kg. The results show that a solution, as the one proposed in this study, is conceptually feasible. The amount of emissions avoided totals 7.95 t of carbon dioxide and more than 121 kg of nitrogen oxides per mission. Furthermore, the noise levels in the engine room are reduced under 90 dBA allowing a silent navigation mode as well as a noiseless ship at port.