The hybrid combination of hydrogen fuel cells (FCs) and batteries has emerged as a promising solution for efficient and eco-friendly power supply in maritime applications. Yet, ensuring high-quality and cost-effective energy supply presents challenges. Addressing these goals requires effective coordination among multiple FC stacks, batteries, and cold-ironing. Although there has been previous work focusing it, the unique maritime load characteristics, variable cruise plans, and diverse fuel cell system architectures introduce additional complexities and therefore worth to be further studied. Motivated by it, a two-layer energy management system (EMS) is presented in this paper to enhance shipping fuel efficiency. The first layer of the EMS, executed offline, optimizes day-ahead power generation plans based on the vessel's next-day cruises. To further enhance the EMS's effectiveness in dynamic real-time situations, the second layer, conducted online, dynamically adjusts power splitting decisions based on the output from the first layer and instantaneous load information. This dual-layer approach optimally exploits the maritime environment and the fuel cell features. The presented method provides valuable utility in the development of control strategies for hybrid powertrains, thereby enabling the optimization of power generation plans and dynamic adjustment of power splitting decisions in response to load variations. Through comprehensive case studies, the effectiveness of the proposed EMS is evaluated, thereby showcasing its ability to improve system performance, enhance fuel efficiency (potential fuel savings of up to 28%), and support sustainable maritime operations.
The paper presents a comprehensive review of the current status of integrated high temperature proton exchange membrane fuel cell (HT-PEMFC) and methanol steam reformer (MSR) systems. It highlights the advantages and limitations of the technology and outlines key areas for future improvement. A thorough discussion of novel reformer designs and optimizations aimed at improving the performance of the reformer, as well as different integrated MSR-HT-PEMFC system configurations are provided. The control strategies of the system operation and system diagnosis are also addressed, offering a complete picture of the integrated system design. The review revealed that several processes and components of the system should be improved to facilitate large-scale implementation of the MSR-HT-PEMFC systems. The lengthy system startup is one area that requires improvements. A structural design that is more compact without sacrificing performance is also required, which could possibly be achieved by recovering water from the fuel cell to fulfill MSR's water needs and consequently shrink the fuel tank. Reformer design should account for both heat transfer optimizations and reduced pressure drop to enhance the system's performance. Finally, research must concentrate on membrane materials for HT-PEMFC that can operate in the 200–300 °C temperature range and catalyst materials for more efficient MSR process at lower temperature should be investigated to improve the heat integration and overall system efficiency.
Due to the increasing impacts of ships pollutants on the environment and the preventive laws that are tightening every day, the utilization of all-electric ships is a recent emerging technology. Being a promising technology, the usage of fuel cells as the main energy resource of marine vessels is an interesting choice. In this article, an all-electric hybrid energy system with zero emission based on fuel cell, battery, and cold-ironing is proposed and analyzed. To this end, actual data of a ferry boat, including load profiles and paths, are considered to assess the feasibility of the proposed energy system. The configuration of the boat and energy resources as well as the problem constraints are modeled and analyzed. Finally, the boat's energy management in hourly form for a one-day period is implemented. The improved sine cosine algorithm is used for the power dispatch optimization, and all models are implemented in MATLAB software. Based on the analysis results, the proposed hybrid system and the energy management method have high performance as an applicable method for the marine vessels. In addition, to be a zero-emission ship, the proposed system has an acceptable energy cost.