Roadmap for Ferry Electrification: an Italian Case Study

The predictability of their operations - characterized by fixed, short, and repetitive routes makes them particularly well-suited for battery-electric propulsion systems. However, from a grid perspective, electric ferries represent a substantial new load. Their progressive electrification will need to be matched by careful planning of grid connections and port infrastructure. These vessels will require high-power charging (on the order of megawatts) at docking stations, making it essential to coordinate the deployment of charging systems with upgrades to the local electrical grid and energy management strategies in ports.

In this paper, drawing on the experience gained through years of research and the collaboration with a transport operator that operates the fleets of the three major Italian lakes, we propose a structured methodology for developing a comprehensive roadmap aimed at the electrification of public transport maritime fleets and their integration into the power grids. Such an analysis includes analytical, qualitative, and quantitative assessments, considering the vessel side, the shore-side charging, and its integration within both the port and national power grids, focusing primarily on the technical, operational, and economic aspects.

The methodology is articulated through a series of sequential steps that guide the feasibility assessment process: identification and classification of vessels; operational profiles analysis; energy consumption estimation; battery system sizing; suitable charging technologies identification; power demand profile and load duration curve definition; grid connection types identification; and, finally, a cost analysis. The methodology is designed to be adaptable to various geographical contexts, making it suitable for different short-range public maritime transport systems, such as lagoon operations, island connections, and coastal fleets.

This structured approach is then applied to the real-world scenario of navigation on the three major Italian lakes - home to a fleet of about 100 vessels - with an electrification target set for 2050, the symbolic year for achieving climate neutrality in Europe. The results obtained have demonstrated the feasibility of full electrification for the categories of car ferries and passenger ferries. Based on the analysis of docking sites and the number of vessels at each location, the required connection power for each future charging hub has been identified, ranging from 1 to 3 MW. While the entire electrification process, including necessary infrastructure and grid connection upgrades, involves substantial investment, it proves to be economically sustainable, with the break-even point expected by 2055 - five years after the full electrification of the fleet scheduled for 2050.

The proposed framework provides practical elements for all the stakeholders involved with the transition, in particular transport operators and DSOs that will have to accommodate this new load. Its purpose is to support the assessment of electrification opportunities and to guide both strategic and operational decisions within the context of the sector’s energy transition and a smooth integration into the power system