Vanadium Redox Flow Battery in Hybrid Propulsion Systems for Marine Applications

Nowadays, the challenge of reducing air pollutants, which passes through increasingly stringent regulations on emissions, is also central in the maritime sector. A possible solution to overcome these limits could be the introduction of alternative propulsion systems to classic diesel engines. In the present work, the performance of a Hybrid Propulsion System (HPS) in marine, consisting of an internal combustion engine and a Vanadium Redox Flow Battery (VRFB) allowing an independent power and capacity sizing, was analyzed. Specifically, through a dynamic modeling, a daily work cycle has been simulated on the basis of a real load request. The possibility of implementing a hybrid system independent from a ground-based charging system was evaluated, in relation to the analyzed work cycle, by identifying the size of the battery (70 kW/ 5.8 kWh) and its minimum charging power (23 kW) necessary for the autonomous operation. Together with the results of the dynamic analysis, experimental results obtained on a real VRFB prototype of the innovative concept design implemented are provided.