Energy transition pathways highlighted all-electric ships powered by lithium-ion batteries as a solution for decarbonising short-sea shipping. The increasing diffusion of electric vehicles (EV) in the market can enhance the techno-economic performance of battery-powered electric ships. The emerging vehicle-to-grid (V2G) with a bi-directional flow of power provides the power grid access to mobile energy storage, increases the integration of renewable energy sources (RES), decreases electricity costs during peak hours and creates economic benefits for EV owners, network operators and energy retailers. The increasing number of EV, growing research into V2G and lack of onshore charging stations (OCS) are key factors that create common ground for integrating vehicle-to-ship (V2S) in short-sea shipping. The V2S provides battery-powered electric ferries (BEF) access to mobile energy storage of the accumulated battery capacity of the EV being transported. The integration of V2S is simulated on the BEF that are navigating on relatively short, medium and long Croatian ferry routes to cover the entire range of possible practical applications. The simulations considered different monthly occupancy rates ( OR ) and state-of-charge ( SOC ) of the transported EV to indicate the techno-economic feasibility of the V2S. The results demonstrate that V2S has benefits for both the BEF and EV owners.

The environmental sustainability of the battery-powered electric ferry (BEF) depends on the share of renewable energy sources (RESs) in the power system. The BEFs impose significant load on the power grid and it is challenging to achieve their sustainability in isolated energy systems (IES), such as islands that have limited land available for integrating RESs. The proposed solution for achieving the sustainability of BEF in such challenging environments is the integration of a standalone onshore charging station (OCS) powered with a hybrid offshore RES. The nexus between the electricity supply of the offshore photovoltaic (PV) and wind power systems and the electricity demand of BEF can reduce the required capacity of the energy storage systems (ESSs) and improve the environmental and economic performance of the standalone OCS. This study considered 45 standalone OCS scenarios to select the share of the offshore RES that matches the BEF electricity demand and improves the economic and environmental indicators of the standalone OCS. The model included characterisation of the offshore RES electricity supply, BEF electricity demand, critical excess of electricity production (CEEP), critical deficit of electricity production (CDEP) and costs. Simulations were conducted in EnergyPLAN, which used a high-resolution spatiotemporal dataset (8784 h) for the Island of Cres for 2030. The results confirmed that standalone OCS with the hybrid offshore RES provides a better match with BEF electricity demand compared to the scenarios based on an individual offshore RES.