(Digital Presentation) Fuel Cell and Battery Technologies for a 800kW Ferry: Two Optimized Scenarios
Authors: Gay Martin , Pourrahmani Hossein , Van herle Jan 
Published: July 2022

Many countries have set official targets to 100% phase out sales or registrations of new internal combustion engines (ICE) that use gasoline. Battery and fuel cell technologies have been suggested to be the best alternative for the current ICEs to be utilized in cars, buses, trucks, and boats. Although there have been studies to consider fuel cells and batteries for the cars, there are limited number of studies to consider these technologies for ferries. Different types of prime movers have been utilized to run the boats, however, most of the studies in the field are related to either the usage of fuel cell or battery as the prime mover of the boats, while the integrated system can improve the low range of batteries by maintaining high acceleration and fast re-fueling time.
Two well-known types of industrial Li-Ion batteries in the market are Nickel Manganese Cobalt (NMC), and Lithium Titanite Oxide (LTO). Among the existing Li-Ion batteries in the market, LTO enjoys from the highest performance, lifespan, and safety by higher costs, whereas NMC provides acceptable performance with low costs and high specific energy. In comparison to the batteries, proton exchange membrane fuel cells (PEMFCs) have faster refueling time and higher ranges, hence the integration of batteries and fuel cells can provide the needs of ferries.
In this study, the possibility of integrating the fuel cell technology and the battery is evaluated to provide 800kW electricity. PEMFC modules are integrated with a Li-Ion battery to have high ranges and efficiencies in fast refueling times for ferry applications. An optimization model was developed using the open source Julia programming language to determine the best combination of the batteries and fuel cells considering the size, weight, hydrogen consumption, and overall efficiency as the output parameters. The dynamic model captures the characteristics of the system by the changes in time and considers the impacts of batteries’ charging/discharging status on the overall performance. Two different novel scenarios are suggested to provide 800kW power for a ferry with a total length of 50.8m to transport 780 passengers considering the Lausanne-Evian round trip, which is 24km, in 70 mins. LTO and NMC type Li-Ion batteries are selected for these two different scenarios while PEMFC is the selected type of fuel cell for this ferry.
Dynamic models have been developed in the MATLAB software for both the battery and fuel cell modules. Based on the presented flowchart in Fig. 1, a quasi-static optimization model has been utilized for the power split. Results indicate that the total size, and hydrogen consumption of around 8 , and 36.1 kg/h, respectively, are needed in the first scenario to reach the maximum power of 800kW with 49.5% overall efficiency. The operating power of the integrated battery and fuel cell system is between 80kW to 720 kW, which is 10% to 90% of the maximum power. In the second scenario, the corresponding values of the size, and hydrogen consumption are around 8.23 , and 36 kg/h to reach the same power by the overall efficiency of 49.6%. The first scenario uses 8 modules of PEMFCs and one module of NMC while the second scenario uses LTO as the battery with the same number of PEMFCs. Fig. 2 also shows the transient performance characteristics of the integrated system in the first scenario considering the output power and the hydrogen consumption of the fuel cells, in addition to the output energy and the state of charge of the batteries.

Figure 1