Economic-Comparative Study for Carbon Neutrality During Ships Docking and in Port Operations: A Path Towards Maritime Sector Decarbonization

According to the International Energy Agency (IEA) reports, the maritime sector was responsible for around 2% of global energy-related Carbon Dioxide (CO2eq) emissions in 2020 (i.e., 714 Mton). Currently, Heavy Fuel Oil (HFO) is used for supplying main and auxiliary Internal Combustion Engines (ICEs) on board ships, therefore it is responsible for local and global pollution. As matter of fact, HFO is contaminated with several different compounds including aromatics, sulfur, and nitrogen, making emission upon combustion more polluting compared to other fuel oils. In order to reduce pollution in maritime sector, the International Convention for the Prevention of Pollution from Ships (MARPOL) has prohibited ships using of HFO in ports. In this purpose, new solutions involving cleaner fuels as well as new propulsion technologies are needed. This paper is aimed to evaluate the environmental advantages that can be reached by replacing the HFO with low emission fuels and alternative power technologies. In particular, three cases have been investigated: i) ICEs fed by diesel, ii) Fuel Cell Systems fed by “Yellow” hydrogen, iii) Fuel Cell Systems fed by “Green” hydrogen. The analysis has been carried out by applying the Well-to-Waves (WTW) method for estimating and comparing the avoided CO2eq and NOx emissions. Moreover, the economic feasibility has been carried out by estimating the investment and operating costs.