# Multicriteria Analysis of Alternative Marine Fuels in Sustainable Coastal Marine Traffic
## 5 Discussion and Conclusions
Further, each Member State is obliged to adopt National Policy Frameworks (NPF) for the development of the market as regards alternative fuels in the transport sector and the deployment of the relevant infrastructure pursuant to Article 10 (2) of Directive 2014/94/EU. According to adopted NPF, Croatia will emphasize the simultaneous development of infrastructure and markets for all alternative fuels in transport. Compared to other alternative fuels, the filling infrastructure for hydrogen is the least developed. Furthermore, regarding shore-side electricity supply points (ESP) there are currently two inland waterways ports that offer ESP, and the 2025 target is to have seven shore-side electricity supply points in TEN-T Core Network ports. Regarding LNG, there are no LNG refueling points in the maritime ports in Croatia. The NPF target is one LNG refueling point in the TEN-T Core Network by 2025 (port of Rijeka) and in total seven maritime LNG refueling points (located in the main ports) in 2030. In the scenario developed for the purposes of NPF, by 2040, LNG ships that are engaged in coastal liner shipping will take up to 50% of the total energy consumption in the coastal shipping market [45]. Results obtained by this research follow the targets plotted in the NPF where the focus is placed precisely on upgrading/building the seven shore-side electricity supply points and LNG refueling points. In the final ranking of the alternatives, hydrogen also gained relatively high scores from all three groups of stakeholders, but for example this fuel is not considered for transport in NPF. In this context, where the national goals and planned actions are set, when reaching final decisions, a compromise between the different groups of stakeholders may be needed; indeed, this would be crucial. The government experts will certainly look at the wider context in order to adhere to the drawn development guidelines. This analysis, likely the first of this type in this area, can serve as a solid basis for strategic planning. In drafting a new Strategy of Maritime Development and Integrated Maritime Policy in Croatia, a set of policies considering alternative marine fuels can be developed applying an approach similar to the one presented in this paper. This approach could be applied to policy making in other areas by adapting the respective alternatives, goals, and criteria. The findings of this study have to be seen in light of some limitations. One of the limitations of this study could be related to the different types of ships used in coastal transportation (fast ships, ro-ro), so further research can analyze alternative fuel options for each particular type of ship. Future research could be based on a wider range of experts as well as a combination of available data from other similar studies. Furthermore, selection of an alternative fuel should be evaluated considering the energy-quantity ratio, which reflects on the space requirements for fuel storage and additional operational costs. Conceptualization, N.M., H.U.B. and T.K. ; methodology, N.M. and T.K. ; software, T.K. ; validation, H.U.B. and L.R.L. ; investigation, N.M.; resources, N.M. and H.U.B. ; data curation, N.M.; writing--original draft preparation, N.M. and T.K. ; writing--review and editing, H.U.B. and L.R.L. All authors have read and agreed to the published version of the manuscript. This research is partially supported through project KK.01.1.1.02.0027, a project co-financed by the Croatian Government and the European Union through the European Regional Development Fund--the Competitiveness and Cohesion Operational Programme. Data regarding average ship age distribution in Croatia, and the age-consumption ratio of coastal line ships in the Republic of Croatia are provided by Croatian Coastal Liner Shipping Agency. The authors are grateful to Croatian Coastal Liner Shipping Agency (www.agen cija-zolpp.hr, accessed on 1 February 2021) for providing data used in this paper.