Search Results (13)

Fast patrol boats account for a large number among the numerous vessels used in naval fleets. Owing to their operational characteristics, which involve relatively high speeds, they contribute to emissions significantly. This study presents an optimized design concept for a diesel–battery hybrid electric propulsion system integrated into the general ship design process for fast patrol boats. The optimization design uses mixed-integer linear programming to determine the most eco-friendly shares ratio of battery and diesel usage while satisfying high-endurance operational scenarios. A shares ratio of 1.259 tons of diesel to 2.88 tons of batteries was identified as the most eco-friendly configuration capable of meeting a 200-nautical-mile operational scenario at a maximum speed of 35 knots for the selected case study. A quantitative comparison through a global warming potential (GWP) analysis was conducted between conventional diesel propulsion systems and the designed diesel–battery hybrid electric propulsion system, using a life-cycle assessment (LCA) standardized under the ISO framework. The analysis confirmed that the optimized hybrid propulsion system can achieve a GWP reduction of approximately 7–9% compared with conventional propulsion systems. Few studies have applied LCA in this field, and the application of batteries as hybrid secondary energy sources is viable and sustainable for high-endurance scenarios. Full article

Recently, environmental regulations have been strengthened due to climate change. This change comes in a way that limits emissions from ships in the shipbuilding industry. According to these changes, the trend of ship construction is changing installing pollutant emission reduction facilities such as scrubbers or applying alternative fuels such as low sulfur oil and LNG to satisfy rule requirements. However, these changes are focused on large ships. Small ships are limited in size. So, it is hard to install large facilities such as scrubbers and LNG propulsion systems, such as fishing boats that require operating space. In addition, in order to apply the pure electric propulsion method, there is a risk of marine distress during battery discharge. Therefore, the application of the electric–diesel hybrid propulsion method for small ships is being studied as a compromised solution. Since hybrid propulsion uses various energy sources, a method that can estimate effective efficiency is required for efficient operation. Therefore, in this study, a Bond graph is used to model the various energy sources of hybrid propulsion ships in an integrated manner. Furthermore, based on energy system modeling using the Bond graph, the study aims to propose a method for finding the optimal operational scenarios and reduction ratios for the entire voyage, considering the navigation feature of each different maritime region. In particular, the reduction gear is an important component at the junction of the power transmission of the hybrid propulsion ship. It is expected to be useful in the initial design stage as it can change the efficient operation performance with minimum design change. Full article

The trend in the development of maritime and river propulsion systems is to make a transition from hydrocarbon to more environmentally friendly solutions. This contributes positively to the solution of the problems identified by the International Maritime Organization (IMO) regarding the high emissions of polluting gases emitted by maritime transportation. Currently, there is a wide variety of systems available due to the development of mobility technologies focused on decarbonization. This paper presents an analysis of technological alternatives for boats with electromobility applications and propulsion systems in the waterway field. First, a description of the operation of boats with electric motors, the different energy sources, and the alternative propulsion options is presented. Then, the electromobility technologies are characterized, analyzing the different configurations between the power source and the propulsion system. The results show a comparative table of technologies and their advantages and disadvantages. In addition, the most environmentally friendly technologies present significant challenges for large-scale implementation due to their recent development. In the short term, hybrid systems technologies present advantages over the others, as current systems are available, with the addition of equipment with higher efficiency and lower environmental impact. Full article

In Korea, fishing boats account for 65,452 out of 71,174 coastal ships, and aging ships are a leading cause of environmental problems and economic loss. To solve this problem, the government has enacted a policy to promote the development and distribution of environmental vessels. Electric propulsion systems and hybrid systems are suggested as alternatives. However, to study whether this hybrid system is environmentally friendly, a system for measuring the performance of conventional diesel-powered ships was developed and measured. A case study applying the battery hybrid system was analyzed through a Matlab/Simulink simulation, and the effect of reducing the carbon dioxide emissions by 7.6% was verified. In addition, comparing with a case where the load-sharing optimal control was introduced, we proved that the carbon dioxide reduction with the controller was 10.7%. By applying the results of this study to various countries with different fuel production processes through the LCA technique, it was confirmed that the battery hybrid system is eco-friendly from the energy production stage, rather than unconditionally, according to the national power production method. Additional research is needed to reflect the aging trend of the entire fleet and to create a detailed category classification through future research. Full article

The machining of composite materials has been an area of intense research for the past couple of decades due to its wide range of applications, from automobiles to air crafts or from boats to nuclear systems. Non-conventional machining, especially electric discharge machining (EDM), is found to be a good machining option for meeting the required outputs. To overcome the challenges of machining complex shapes, wire electric discharge machining (WEDM) was developed. Al6351 composites was observed to be extensively used in nuclear applications. Therefore, identifying the kerf width and surface roughness are important criteria for the dimensional accuracy of the final product. The present work aims at predicting the behavior of the two major machining parameters which are kerf width and surface roughness of Al6351 composites in wire EDM by creating a mathematical model using ANOVA for different combinations of the reinforcements and comparing the variations in the coefficients for different combinations of reinforcements. The developed model has been validated by conducting similar set of experiments in Al6351-5% SiC-1% B₄C hybrid composite. From the work, it was identified that pulse on time and current are the major contributing factor for kerf width and wire feed rate was observed to be contributing to the surface roughness. The validation results show an average variation of 8.17% for kerf width and 11.27% for surface roughness. The work can be successfully utilized for prediction of the kerf width and surface roughness of the composites manufactured with Al6351 as the base matrix material. Full article

The topics of zero-emission/energy buildings and electric mobility are increasingly being discussed as solutions to alleviate the environmental burden caused by energy consumption and CO₂ emissions in both sectors. This study investigates a zero-energy hotel building supported by a hybrid ocean renewable energy system, which interacts with several zero-emission electric boats. Nine different combinations of floating photovoltaics (FPV) and wave energy converters (WEC) are investigated to compensate for their different fluctuations and the stochasticity of energy generation. Using TRNSYS 18 to perform modeling and simulation, a comprehensive techno-economic-environmental analysis of the hybrid system was conducted. The results indicate that when the total annual generation ratios of WEC and FPV are 76% and 24%, respectively, this combination can achieve the best energy weighted matching index (WMI). The WMI reached its maximum (0.703) when 16 boats were sailing at 15 km/h for a distance of 7.5 km. However, increasing the number of boats to 16 does not help improve economic returns or reduce the annual operational equivalent CO₂ emission factor of the hybrid system. Depending on the maximum number of electric boats designed for this study, the non-dominated WMI would be limited to 0.654. Full article

Integrated photovoltaic-fuel cell (IPVFC) systems, amongst other integrated energy generation methodologies are renewable and clean energy technologies that have received diverse research and development attentions over the last few decades due to their potential applications in a hydrogen economy. This article systematically updates the state-of-the-art of IPVFC systems and provides critical insights into the research and development gaps needed to be filled/addressed to advance these systems towards full commercialization. Design methodologies, renewable energy-based microgrid and off-grid applications, energy management strategies, optimizations and the prospects as self-sustaining power sources were covered. IPVFC systems could play an important role in the upcoming hydrogen economy since they depend on solar hydrogen which has almost zero emissions during operation. Highlighted herein are the advances as well as the technical challenges to be surmounted to realize numerous potential applications of IPVFC systems in unmanned aerial vehicles, hybrid electric vehicles, agricultural applications, telecommunications, desalination, synthesis of ammonia, boats, buildings, and distributed microgrid applications. Full article

In this paper, an effective control strategy is proposed to manage energy distribution from fuel cells and batteries for hybrid electric boat applications. The main objectives of this real-time control are to obtain fast current tracking for the batteries’ system, the DC bus voltage stability by using a fuel cell, and energy load distribution for a hybrid electric boat under varying demand conditions. The proposed control strategy is based on a combination of frequency approach and current/voltage control of interleaved boost converters to reduce the hydrogen consumption by the fuel cell and improve the quality of energy transfer. The frequency approach was dedicated to managing the DC power-sharing between the load, the fuel cell, and the batteries’ storage system by extracting the power references. The closed loop control system utilized to control the energy is based on the DC/DC converters. The performance evaluation of the proposed control strategy has been tested through a real-time experimental test bench based on a dSPACE board (DS1104). Full article

With the dynamic growth in both the global hunger for electrical energy and the share of variable renewable energy sources in the energy mix, distribution networks are facing new challenges where conventional solutions may not be the best ones. The increase in load in distribution grids is routinely countered by network development and expansion, in a great part to supply for on-peak load demand, which could also be done by utilizing supplementary technologies to lessen the need for or defer such expansion. Vehicle-to-grid technology could efficiently contribute to handling this issue, as electric vehicles can potentially function as storage capacities to mitigate the fluctuations of power generation. The battery energy storage systems of hybrid or completely electric watercraft, which are becoming increasingly popular, are no exception, either. These vehicles represent a considerable potential to create more complex vehicle-to-grid solutions for countries with significant inland or seaport networks, for example, Hungary, with the largest lake of Central Europe. Since there is only deficient information on the topic, the main goal of this study was to explore the energy storage capacities of small electric boats in the context of Lake Balaton, Hungary. By this example, the paper presents the potential utilization of Europe’s significant network of sea and inland recreational ports for the purpose of energy storage. Similarly to other European countries, Hungary’s energy strategy for 2030 also includes the promotion of virtual production integration, local energy communities and micro-grid solutions. At the beginning of 2021, the small electric boats in the sailing marinas of Lake Balaton represented a cumulative energy storage capacity of 4.8 MWh, which may reach even 15.6 MWh by 2030, by the promotion of micro-grid solutions. The innovative novelty of this study is that it regards small fully electric boats not just as vehicles, but also explores their energy storage potentials. The novel goal of these examinations is to explore the volume of the energy storage potentials of the small fully electric boats around Lake Balaton, the knowledge of which may facilitate the creation of new types of flexibility services related to energy storage. Full article

With the continuous development worldwide of the inland shipping industry, emissions to the atmosphere have become a serious threat in terms of pollution. Hybrid power technology is an important means for reducing pollution due to emissions from ships. This paper considers a power train series in a hybrid electric inland waterway boat. From the analysis of the structure and principle of the power train, the parameter design for its key devices is presented, and a novel energy control strategy is proposed. Navigation experience shows that the proposed design method and control strategy are useful and satisfactory. Full article

All-electric ships are now a standard offering for energy/propulsion systems in boats. In this context, integrating fuel cells (FCs) as power sources in hybrid energy systems can be an interesting solution because of their high efficiency and low emission. The energy management strategy for different power sources has a great influence on the fuel consumption, dynamic performance and service life of these power sources. This paper presents a hybrid FC/battery power system for a low power boat. The hybrid system consists of the association of a proton exchange membrane fuel cell (PEMFC) and battery bank. The mathematical models for the components of the hybrid system are presented. These models are implemented in Matlab/Simulink environment. Simulations allow analyzing the dynamic performance and power allocation according to a typical driving cycle. In this system, an efficient energy management system (EMS) based on operation states is proposed. This EMS strategy determines the operating point of each component of the system in order to maximize the system efficiency. Simulation results validate the adequacy of the hybrid power system and the proposed EMS for real ship driving cycles. Full article

We have produced a new-type of plug-in hybrid boat. This boat has excellent environment characteristics running by electricity, while having the ability of long-distance cruising and long distance reliability because of the diesel engine. The excellent performances of this plug-in hybrid boat system are described. Full article

Electric boats (EBoats)¹ have a major role to play for the transportation of passengers, and even goods, into the centre of the cities endowed with seaborne or fluvial paths or in each places to fit the environmental rules decided by local authorities to limit the access to protected water areas. Waterways accessing downtown are identified in many cities as relevant commuting solutions. Three market segments are emerging based on the boat uses: spare-time activities, public transportation services and goods or services applications. These boats have been developed for inland as well as maritime waters: they exist in pure electrical or hybrid versions depending on needs. They use lead acid, NiCad or lithium batteries technology. The French Electric Boats Association (AFBE), including 60 members, has identified to key levers for the development of this market: strengthening the industry position and boosting the governmental incentives. This document offers a description of the most significant electric boats applications in France, while providing the technical key points that allowed such efficient services to be reached. Full article