Reducing carbon footprint in ports through electrification and flexible energy management of ships

Abstract

The environmental impact of maritime transport has become a central concern for the international community. The Carbon Intensity Indicator and the Emissions Trading System are key mechanisms pushing the shipping sector towards more sustainable and less polluting solutions, including the adoption of alternative technologies to diesel generators and the reduction of heavy fuel oil employment. Port areas are particularly controlled, as the environmental impact of shipping operations affects both the environment and human-inhabited areas. Given that the electrification of ports (cold ironing) is not yet widespread globally, this work proposes an on-board poly-generation system equipped with high-temperature proton exchange membrane fuel cells and batteries to meet energy demands during entry, dock, and exit from port areas. Various operational strategies (rule-based energy system management) for managing on-board technologies are analysed, offering a range of potential applications based on the on-board availability of hydrogen and battery discharge modes, with the aim of reducing the ship’s environmental impact in port areas. Additionally, to fully electrify the poly-generation system, this study explores replacing auxiliary oil-fired boilers with heat pumps for steam production, integrating this technology into the low-temperature engine cooling circuit to enhance energy efficiency and eliminate emissions from auxiliary systems. By implementing these technologies alongside the developed operational strategies, it is possible to achieve an 80–90% reduction in carbon dioxide emissions in the port area, improving the carbon intensity indicator by 4.74%, from 11.06 to 10.38.