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The International Maritime Organization proposes several strategies to eliminate the adverse effects of ship emissions. The most important is finding alternative fuels, such as hydrogen. The current paper aims to compare diesel and renewable hydrogen-powered ships using Life Cycle Assessment (LCA) and Life Cycle Cost Assessment (LCCA). As a case study, three different ships sailing in the Red Sea area are investigated. The environmental outcomes are presented in terms of global warming potential (GWP), photochemical potential, eutrophication potential, particulate matter and acidification potential. Producing hydrogen fuel onboard ships will increase the total carbon footprint by 10%–28% higher than the currently used diesel fuels. Economically, the cost-effective target will be achieved at the cost of hydrogen production by electrolysis below 5.15$/kg. [ABSTRACT FROM AUTHOR]

The current research deals with the possibility of relying on wind energy, specifically Flettner rotors; as a source of ships propulsion to reduce ships' emissions. The paper highlights the technical, environmental, and economic aspects of wind-assisted propulsion systems. As a case study, four Flettner turbines are examined to be used onboard a bulk carrier ship, considering three different routes. Technically, the ship's route and wind characteristics are the focal aspects that affect the output power of Flettner rotors. The economic results indicate that the payback periods for the selected Flettner rotors will be 7, 13, and 11 working years for the first, second, and third ship routes, respectively, with considerable levelised costs of energy. Environmentally, NOx and CO2 emissions will be decreased by 154.3 and 5089 ton per year, for longest route, with cost-effectiveness of 3350 and 89 $ per ton, respectively with a 10 percent interest rate. [ABSTRACT FROM AUTHOR]

The present study aims at quantifying prospective reductions of ships' emission of GHG in addition to the expected economic impact in case of applying various renewable energy technologies for seaports. As a case study, this paper investigates the prospect of converting Damietta Port, Egypt, to be an eco-friendly port with the focus on technical, logistic and financial requirements. The results prove the techno-economic feasibility of both offshore wind and fuel cell energy resources for the selected port. The paper's outcomes prove that the fuel cell, followed by a combined system of wind turbines and fuel cells appear to be the optimum selection with reference to green port technologies with an electricity unit cost of 0.10 and 0.11$/kWh, respectively. Furthermore, using of fuel cells and offshore wind turbines as green power strategies would achieve a reduction of CO2, NOx and CO emissions by 32,176, 8.32 and 53.2 ton per year, respectively. [ABSTRACT FROM AUTHOR]

Economic and population growths are the most important drivers of growing global energy demand. They led to a rapid development of international seaborne trade and an increase in the number of global vessels. Air pollution from these ships is of great concerns and regulations are currently enforced since May 2005 by the International Maritime Organization to limit such pollution. In this study, we will first review the current global energy demand and its driving forces over next decades, second evaluate the existing alternative fuels that can be used as a bunker fuel to reach sustainability with relatively small changes in the existing marine propulsion options and finally focus on near-term solution, which has the potential for large-scale use. The different alternative fuels were compared in terms of several parameters such as availability, renewability, safety, cost, performance, economy and compliance with emission regulations. This comparison revealed that liquefied natural gas could be considered as the future replacement to the current marine bunker fuel. This conclusion has been further verified by comparing diesel engine with different powers when using both heavy fuel oil and liquefied natural gas. The engines were compared against fuel consumption, cost saving as well as emissions. Liquefied natural gas has proved to be better than heavy fuel oil due to fuel cost reduction by about 31% per year and decrease in emissions of SOx, NOx, CO2 and particulate matter by about 98%, 86%, 11% and 96%, respectively. The resulted emissions from using liquefied natural gas were found to comply with the current International Maritime Organization regulations. Moreover, this article highlights the latest rules and regulations that govern the use of liquefied natural gas as marine fuel onboard ships. [ABSTRACT FROM AUTHOR]

The need for green energy sources without or with low emissions in addition to improve the using efficiency of current fossil fuels in the marine field makes it important to replace or improve current fossil-fuelled engines. The replacement process should work on narrowing the gap between the most scientific innovative clean energy technologies and the concepts of feasibility and cost-effective solutions. Early expectations of very low emissions and relatively high efficiencies have been met in marine power plants using fuel cell. In this study, steam and SOFC based reforming options of natural gas for PEM fuel cells are proposed as an attractive option to limit the environmental impact of the marine sector. The benefits of these two different reforming options can be assessed using computer predictions incorporating chemical flow sheeting software. It is found that a high overall efficiency approaching 60% may be achieved using SOFC based reforming systems which are significantly better than a reformed PEM system or an SOFC only system. [ABSTRACT FROM AUTHOR]