Search

Due to the growing concerns of emissions from the shipping industry, the International Maritime Organization (IMO) has set strategies to reduce the CO 2 intensity by 40% in 2030 and cut total GHGs emissions by at least 50% by 2050, with 2008 as a baseline. Clean alternative marine fuels are widely recognized and used as a viable solution for reducing ship-related air pollution. Several studies including traditional reviews have been conducted to examine the literature on cleaner alternative marine fuels and their role in decarbonizing the shipping sector. However, these studies fail to unpack the main research actors, evolutionary nuances, and emerging research hotspots in this field. To quantitatively and qualitatively explore this research field, the current study adopts a bibliometric analysis. 583 eligible documents published from 2000 to 2020 were retrieved and merged from the Web of Science Core Collection and Scopus databases, and analyzed with the R-studio bibliometrix package (Biblioshiny). Results revealed that the field is growing significantly at a growth rate of 15.8%, with key contributions to the field originating from the USA. Liquified Natural Gas has been identified as the most researched alternative shipping fuel. However, recent trends show researchers turning their attention towards methanol, ammonia, and hydrogen fuels. By analyzing the frequently used keywords and relevant articles, it became clear that the research community has focused mainly on the potential of different alternative fuels as a replacement to conventional marine fuels to limit the emissions from the shipping sector from an environmental, technical, and economic perspective. The current study offers a basis for future research into the decarbonization of the shipping industry. [Display omitted] • Bibliometric study on clean marine fuels based on Web of Science and Scopus databases. • A growing research field with an annual growth rate of 15.8%. • Key authors, institutions and countries in the field have been identified. • LNG emerged as the most researched alternative shipping fuel. • Research hotspots and trends on clean marine fuels discussed. [ABSTRACT FROM AUTHOR]

One of the main setbacks to electric vehicles (EVs) adoption relates to the unavailability of the required charging stations across a jurisdiction. In addition, drawing the required energy of the EVs from a fossil fuel-dominated grid does not only minimize the cleaner benefits of EVs but also puts enormous pressure on an already stressed grid network in electricity-deficient regions like Sub-Saharan Africa (SSA). Hence, in the current study, six different 100% hybrid renewable energy systems based on powerplants of solar, wind, and biomass have been proposed for meeting the energy needs of 70 and 30 battery and fuel cell electric vehicles, respectively using Ghana as a case study. With the aid of HOMER Pro software and multicriteria decision-making tools, the hybrid system, biogas generator-photovoltaic emerged as the most feasible of the six proposed solutions from a technical, economic, and environmental standpoint. This winning system produces 3.9 GWh/yr and 55.6 tonnes/yr of electricity and hydrogen, respectively. The NPC, LCOE, LCOH, and payback period was recorded as $6.53 million, $0.52/kWh, $9.09/kg and ∼8 years, respectively. Approximately, 4 tonnes of GHG emissions are produced by the HRECS each year, and the amount of CO 2 emissions avoided from replacing 100 gasoline vehicles with the proposed EVs has been obtained as 460 tons/yr. With the aid of sensitivity analysis, it became apparent that the feasibility of the proposed systems could improve with improvement in components' efficiencies and lifetime, and reduction in unit costs. The current work has several contributions to the sustainable development goals (7, 8, 11, 13), and could aid in accelerating EV penetration in SSA. [Display omitted] • A hybrid RE standalone HRECS for EVs in Ghana. • Investigation by HOMER and CRITIC-PROMETHEE II methods. • PV + Biogas generator presents most feasible results for HRECS. • Break-even Grid Extension Distance investigated. • Standalone vrs grid-connectivity analysis. [ABSTRACT FROM AUTHOR]

A recent publication of two independently performed studies investigating a very similar topic of green shipping, applying very similar methods (bibliometric analysis) on very similar data sets (scientific databases) provides an opportunity for an unbiased analysis of what factors can impact the outcome of one's research. This discussion paper reviews and compares the two following papers: • Ampah, J.D., Yusuf, A.A., Afrane, S., Jin, C., Liu, H., 2021. Reviewing two decades of cleaner alternative marine fuels: Towards IMO's decarbonization of the maritime transport sector. J. Clean. Prod. 320, 128871. https://doi.org/10.1016/j.jclepro.2021.128871 • Kołakowski, P., Gil, M., Wróbel, K., Ho, Y., 2021. State of play in technology and legal framework of alternative marine fuels and renewable energy systems: a bibliometric analysis. Marit. Policy Manag. https://doi.org/10.1080/03088839.2021.1969460 This paper aims to conclude on the insights arising from both papers concerning their different methodological peculiarities. • Commentary on two independent bibliometric studies on alternative fuels for shipping. • Similarities and differences of both studies discussed. • Current commentary offers key insights into the use of bibliometric analysis. [ABSTRACT FROM AUTHOR]