Development of intercity net-zero energy systems for supporting the medium-distance zero-emission passenger and logistics ferries with coastal electric grid interactions

Realising zero-emission harbour-to-harbour passenger and logistics ferries is critical for establishing sustainable transport systems. This zero-emission goal faces various challenges, including the high energy demands of ferries and the limited availability of low-carbon energy sources. To address these challenges, ocean energy systems, such as offshore wind turbines and floating photovoltaics, may offer a promising solution. These systems harness the power of the ocean to generate renewable energy and provide a reliable and sustainable energy source for medium-distance electric ferries. This study proposes a hybrid system to enhance energy interaction among electric ferries, renewable energy sources and the local grid. The system aims to enhance the utilisation of renewable energy and evaluate the integrated technical, economic and environmental performance of the hybrid system. The simulations are conducted via Trnsys. A non-dominant case in Scenario D, equipping submarine cables, shows a high on-site renewable energy weighting matching index of approximately 0.7, achieving a positive relative net present value of approximately 64.9 million HKD. The study provides a comprehensive assessment of the hybrid system and a sensitivity analysis of the key economic performance factors. The results of this study can inform policy decisions regarding the development of renewable energy and transport systems. Moreover, the proposed hybrid system shows high potential to address the challenges of sustainable ferry transportation by utilising ocean renewable energy sources, thereby reducing emissions and promoting environmental sustainability in harbour cities.