Techno-economic assessment of an advanced integration between SOFC and ICE onboard a short-distance ferry

Although maritime transportation is an efficient form of transport between countries inside and outside the European Union (EU), it contributes to the EU's total carbon dioxide emissions by about 4%. Therefore, it is mandatory to investigate innovative solutions to make the global maritime sector more sustainable and maximize energy efficiency. Motivated by the fact that Solid Oxide Fuel Cell (SOFC) systems already showed their reliability in the maritime sector (in preliminary demonstration projects) and to be integrated with other power systems, the current paper aims to investigate an innovative integration between turbocharged SOFC and internal combustion engine (ICE) to generate the power demand of short-distance ferries (a lake ferry and an island ferry). The hybrid system’s operation is proposed to have dual operation modes: (i) during cruise operation modes, it will be based on both ICE and SOFC to maximize energy efficiency thanks to the valorization of anode-off gas from SOFC to be used (mixed with natural gas) as a fuel in ICE; (ii) using SOFC only to generate the electrical power required for hoteling operations in port areas. A techno-economic analysis is performed to simulate the hybrid system at different power capacities of SOFC (targeting 10%-20% of the power required for the ferry). The hybrid system efficiency is evaluated to be between 46.6%-48.9% based on SOFC power share. The economic benefit of increasing SOFC power share is verified for the island ferry which presents an almost similar levelized cost of energy (LCOE) of about 225-231 €/MWh, and it is lower than the lake ferry’s LCOE by 30%-43% in different scenarios. Moreover, the gravimetric and volumetric power densities of the hybrid system are 24.3-35.3 kW/ton and 13-20.4 kW/m3, respectively, based on the investigated scenario and the ferry.