The marine industry must reduce emissions to comply with recent and future regulations. Solid oxide fuel cells (SOFCs) are seen as a promising option for efficient power generation on ships with reduced emissions. However, it is unclear how the devices can be integrated and how this affects the operation of the ship economically and environmentally. This paper reviews studies that consider SOFC for marine applications. First, this article discusses noteworthy developments in SOFC systems, including power plant options and fuel possibilities. Next, it presents the design drivers for a marine power plant and explores how an SOFC system performs. Hereafter, the possibilities for integrating the SOFC system with the ship are examined, also considering economic and environmental impact. The review shows unexplored potential to successfully integrate SOFC with thermal and electrical systems in marine vessels. Additionally, it is identified that there are still possibilities to improve marine SOFC systems, for which a holistic approach is needed for design at cell, stack, module, and system level. Nevertheless, it is expected that hybridisation is needed for a technically and economically feasible ship. Despite its high cost, SOFC systems could significantly reduce GHG, NOX, SOX, PM, and noise emissions in shipping.@en

Solid Oxide Fuel Cell (SOFC) systems have the potential to reduce emissions from seagoing vessels. However, it is unknown whether ship motions influence the system's operation. In this research, a 1.5 kW SOFC module is operated on an inclination platform that emulates ship motions, to evaluate the influence of static and dynamic inclinations on the system's safety, operation, and lifetime. The test campaign consists of a static inclination test, a dynamic test, a degradation test, and a high acceleration test. There were no interruptions in the power supply during the different tests, and no detectable gas leakages or safety hazards. Although the SOFC does not fail in any test condition, dynamic inclinations result in forced oscillations in the fuel regulation, which propagate through the system by different feedback loops in the control architecture, leading to significant deviations in the operational parameters of the system. Additionally, for motion periods from 16 to 26 s, reoccurring exceedance of the fuel utilisation results in a gradual reduction of the power supply. Several enhancements are recommended to improve the design of SOFCs and marine fuel cell regulations to ensure their safe operation on ships.

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Marine actors are showing an increased interest in the application of Solid Oxide Fuel Cells (SOFCs) for deep sea shipping, because of their high conversion efficiency, low pollutant emissions, and fuel flexibility. However, it is unknown how the operation of SOFC systems is affected by large inclinations and motions, which can be present in ships for instance by seawaves. The goal of this research is to evaluate the influence of static and dynamic inclinations on the operation and safety of SOFC systems. Ship motions are emulated using a one-axial oscillation platform up to 30 degrees of inclination. The SOFC system was successfully operated on the platform and demonstrated stable power production under a variety of test conditions without any noticeable safety hazards. The results of the experiments are used to propose design improvements for marine SOFC systems, ultimately contributing to reduce the emissions of the shipping industry.@en

An increasing demand in the marine industry to reduce emissions led to investigations into more efficient power conversion using fuels with sustainable production pathways. Solid Oxide Fuel Cells (SOFCs) are under consideration for long-range shipping, because of its high efficiency, low pollutant emissions, and fuel flexibility. SOFC systems also have great potential to cater for the heat demand in ships, but the heat integration is not often considered when assessing its feasibility. This study evaluates the electrical and heat efficiency of a 100 kW SOFC system for marine applications fuelled with methane, methanol, diesel, ammonia, or hydrogen. In addition, cathode off-gas recirculation (COGR) is investigated to tackle low oxygen utilisation and thus improve heat regeneration. The software Cycle Tempo is used to simulate the power plant, which uses a 1D model for the SOFCs. At nominal conditions, the highest net electrical efficiency (LHV) was found for methane (58.1%), followed by diesel (57.6%), and ammonia (55.1%). The highest heat efficiency was found for ammonia (27.4%), followed by hydrogen (25.6%). COGR resulted in similar electrical efficiencies, but increased the heat efficiency by 11.9% to 105.0% for the different fuels. The model was verified with a sensitivity analysis and validated by comparison with similar studies. It is concluded that COGR is a promising method to increase the heat efficiency of marine SOFC systems.

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This study presents the techno-economic analysis of a 100 kWe Solid Oxide Fuel Cell (SOFC) system for maritime applications fueled by methane, methanol, diesel, ammonia, and hydrogen. Two system configurations are considered for each fuel considering cathode off-gas recirculation (COGR) implementation to improve waste heat recovery both in terms of quantity and quality. The economic benefit of COGR is verified for all fuels, especially for methanol, hydrogen, and diesel, which present Levelized Cost of Exergy (LCOEx) reductions of about 10%, 9%, and 6%, respectively. Ammonia and methanol have the lowest LCOEx of about 0.260 EUR/kWh and 0.270 EUR/kWh, respectively, while hydrogen has the highest LCOEx of about 0.430 EUR/kWh. The sensitivity analyses suggest that fuel purchase cost, stack lifetime, and annual interest rate are the three parameters with the highest influence on the system cost. Overall, ammonia and methanol are the most promising fuels.@en

To continue its operations, the marine industry needs to comply with emission regulations. Solid Oxide Fuel Cells (SOFCs) are considered a promising solution, since it can generate energy athigh efficiency and low NOX, SOX and particulate matter emissions. Another advantage of SOFCsis fuel flexibility, meaning several fuels can be applied in SOFC systems. This brings up the question which fuel is most effective for a marine SOFC system. In this research, marine gas oil (benchmark), liquefied hydrogen, biodiesel, Fischer-Tropsch diesel, natural gas, methanol, dimethyl ether, and hydrogenare compared as bunker fuel. A comparison framework is proposed specialised for marine applications. The following decision criteria are selected: production capacity, volumetric/ gravimetric energy density, technological readiness, safety, fuel cost, cost of the fuel storage system, and emissions. The performance indicators are quantified for every fuel based on literature and supplier information.In the end, five alternative fuels are selected for marine SOFC systems on the selected criteria, which wille be used in further research.@en

Global endeavors to reduce emissions in the shipping industry are accelerating the interest in fuel cell system. This paper explores the application of different fuel cell types (LT-PEMFC, HT-PEMFC and SOFC) in combination with different fuels (LH2, LNG, MeOH and NH3) in expedition cruise ships. The goal of this paper is to evaluate the impact of the combination of fuel cell system implementation and operational profile on the design of expedition cruise vessels. Impact is expressed in ship size, capital cost, operational cost and emissions. The impact model takes into account: fuel storage, onboard fuel processing, fuel cell system characteristics, balance of plant components, fuel cost over operational lifetime and emissions of fuel cell & fuel processing. In the research, 7 different fuel cell systems and 3 different hybridization options are considered.@en