Abstract :
Modern cruise ships consume considerable amounts of energy and emit large quantities of greenhouse gases during their luxury trips compared with other types of tourism. During the last years the ports of Souda and Heraklion, Crete host a large number of cruise vessels. The carbon emissions of cruise ships during their mooring in the abovementioned ports have been estimated using data from the existing literature. The alternative fuels which can be used in these cruise ships decreasing their emissions have been also examined. The carbon emissions from the mooring of cruise vessels in Souda port in 2024 have estimated at 16,505 tnCO2 while in Heraklion port at 30,537 tnCO2. Cruise ships face mounting pressure to reduce their environmental impact and alternative fuels are central to this transformation. Several alternative fuels including LNG, biofuels, hydrogen, ammonia, methanol, and electricity can be used in cruise ships substituting the fossil fuels currently used like heavy fuel oil. The ports of Souda and Heraklion should develop the necessary infrastructure to provide alternative fuels and on-shore electricity to cruise vessels approaching these ports in the near future. The current study could be useful to ports’ authorities in Crete, to cruising companies as well as to the stakeholders of Cretan ports.
Keywords :
alternative fuels, carbon emissions, Crete-Greece, cruise ships, portsReferences :
- Walnum, H.J. Energy use and CO2 emissions from cruise ships – A discussion of methodological issues, Sustainable Destination Norway, 2011, Western Norway Research Institute. Available from: https://www.vestforsk.no/sites/default/files/migrate_files/vf-notat-2-2011-cruise.pdf
- Study of greenhouse gas emissions from ships – Final report to the International Maritime Organization, 2000, Norwegian Marine Technology Research Institute. Available from: https://wwwcdn.imo.org/localresources/en/OurWork/Environment/Documents/First%20IMO%20GHG%20study.pdf
- Howitt, O.J.A., Revol, V.G.N., Smith, I.J. and Rodger, C.J. Carbon emissions from international cruise ship passengers’ travel to and from New Zealand. Energy Policy, 38(5), 2010, pp. 2552-2560. http://dx.doi.org/10.1016/j.enpol.2009.12.050
- Cruising versus land vacationing, An analysis of vacation carbon footprints. Friends of the Earth. Available from: https://foe.org/wp-content/uploads/2023/04/Comparison_of_CO2_Emissions_v2.pdf
- Dijkstra, C. and Simon, V. The return of the cruise. How luxury cruises are polluting Europe’s cities. Transport and Environment, 2023. Available from: https://www.transportenvironment.org/uploads/files/2023-Cruise-ship-study.pdf
- Chen, Q., Lau, Y-Y., Kanra, M., Sun, X., Zhang, P. and Tang, Y-M. Using a bottom-up method to assess cruise ships activity impacts on emissions during 2019-2020 in China. Heliyon, 10, 2024, e27101. https://doi.org/10.1016/j.heliyon.2024.e27101
- Popek, M. Alternative fuels – Prospects for the shipping industry. TRANSNAV, 18(1), 2024, pp. 25-33. DOI: 10.12716/1001.18.01.01
- Survey of alternative fuels – Technologies for shipping, 2021, Union of Greek Shipowners. Available from: https://www.ugs.gr/media/13685/survey-of-alternative-fuels-technologies-for-shipping_may21.pdf
- Kouzelis, K., Frouws, K. and van Hassel, E. Maritime fuels of the future: what is the impact of alternative fuels on the optimal economic speed of large conventional vessels. Journal of Shipping and Trade, 7, 2022, 23. https://doi.org/10.1186/s41072-022-00124-7
- Comparison of alternative maritime fuels, 2019, SEA/LNG Ltd, Report No: 2019-0567. Available from: https://sea-lng.org/wp-content/uploads/2020/04/Alternative-Marine-Fuels-Study_final_report_25.09.19.pdf
- Koti, K. The impact of the CO2 emissions from cruise ships on the port’s air quality and the IMO legislation to reduce them: case study port of Piraeus, 2022, M.Sc. Thesis in Urban Port and Transport Economics, Erasmus University of Roterdam. Available from: file:///C:/Users/User/Downloads/Thesis-The-impact-of-the-CO2-emissions-from-cruise-ships-on-the-port-s-air-quality-and-the-IMO-legislation-to-reduce-them-Case-study-Port-of-Piraeus-1.pdf
- Kizielewicz, J. Monitoring Energy Efficiency and Environmental Ship Index by Cruise Seaports in Northern Europe. Energies, 15, 2022, 4215. https://doi.org/10.3390/ en15124215
- Dragovic, B., Tzanatos, E., Tselentis, V., Mestrovic, R. and Skuric, M. Ship emissions and their externalities in cruise ports. Transportation Research Part D. 61(6), 2015, pp. 289-300. http://dx.doi.org/10.1016/j.trd.2015.11.007
- Doundoulakis, E., Papaefthimiou, S. and Sitzimis, I. Environmental impact assessment of passengers ferries and cruise vessels: the case study of Crete. European Transport, 87, 2022, paper No 2. https://doi.org/10.48295/ET.2022.87.2
- Marashian, A., Böling, J. M., Razminia, A., Hyvönen, J., Vettor, R., Gustafsson, W., Pirttikangas, M. and Björkqvist, J. Combined engine configuration and speed optimization for fuel savings on cruise ships. Ocean Engineering, 322, 2025, Article 120387. https://doi.org/10.1016/j.oceaneng.2025.120387
- Gonsalves, F., Meyer, P., Billot, R., Pasdeloup, B. and Lorang, M. Optimal design and operation of cruise ship multi-energy systems: an MILP formulation. 2023. hal-04310676. Available from: https://hal.science/hal-04310676v1/file/Optimal_design_and_operation_of_cruise_ship_multi_energy_systems__an_MILP_formulation%281%29.pdf
- Esteve-Pérez, J., Río-González, M.D. and Gutiérrez-Romero, J.E. Forecast Analysis of Pollutant Emissions of Cruise Ship Routes in Western Mediterranean. Applied Sciences, 13, 2023, 8149. https://doi.org/10.3390/app13148149
- Wang, K., Wang, J., Huang, L., Yuan, Y., Wu, G., Xing, H. et al. A comprehensive review on the prediction of ship energy consumption and pollution gas emissions. Ocean Engineering, 266, 2022, 112826. https://doi.org/10.1016/j.oceaneng.2022.112826
- Percic, M., Vladimir, N., Korican, M., Jovanovic, I. and Haramina, T. Alternative Fuels for the Marine Sector and Their Applicability for Purse Seiners in a Life-Cycle Framework. Applied Sciences, 2023, 13, 13068. https://doi.org/10.3390/ app132413068
- ClassNK Alternative fuels insight, version 3.1, July 2025. Available from: https://download.classnk.or.jp/documents/ClassNKAlternativeFuelsInsight_e.pdf
- Wang, Y. and Iris, C. Transition to near-zero emission shipping fleet powered by alternative fuels under uncertainty. Transportation Research Part D, 142, 2025, 104689. https://doi.org/10.1186/s41072-022-00124-7
- Foretich, A., Zaimes, G.G., Hawkins, J.R. and Newes, E. Challenges and opportunities for alternative fuels in the maritime sector. Maritime Transport Research, 2, 2021, 100033. https://doi.org/10.1016/j.martra.2021.100033
- Elg, M., Molchanov, B., Krishnan, A., Sandberg, A. and Hinz, T. Holistic view to decarbonizing cruise ships with a combination of energy saving technologies and hydrogen as fuel. Energy Conversion and Management, X, 26, 2025, 100953. https://doi.org/10.1016/j.ecmx.2025.100953
- Ellis, J. and Tanneberger, K. Study on the use of ethyl and methyl alcohol as alternative fuels in shipping, 2016. Report prepared for the European Maritime Safety Agency. Available from: file:///C:/Users/User/Downloads/Study%20on%20the%20use%20of%20ethyl%20and%20methyl%20alcohol%20as%20alternative%20fuels-2.pdf
- Exploring next-gen energy efficiency technologies for cruise ships. Available from: https://www.dnv.com/expert-story/maritime-impact/exploring-next-gen-energy-efficiency-technologies-for-cruise-ships/
- Cruises in Crete during 2023-2024 (In Greek). Available from:
- Alternative Sources of Power, European Maritime Safety Agency. Available from: https://www.emsa.europa.eu/sustainable-shipping/alternative-fuels.html
- Vourdoubas, J. Estimation of carbon emissions due to tourism in the island of Crete, Greece. Journal of Tourism and Hospitality Management, 7(2), 2019, pp. 24-32. http://dx.doi.org/10.15640/jthm.v7n2a3
- Vourdoubas, J. Energy consumption and use of renewable energy sources in hotels: A case study in Crete, Greece. Journal of Tourism and Hospitality Management, 4(2), 2016, pp. 75-87. http://dx.doi.org/10.15640/jthm.v4n2a5
- https://www.greekcruise.gr/index.php/port/cruisestatistics/24

