The EU-funded NEMOSHIP R&D project focuses on developing modular battery energy storage systems (BESS) including a digital platform for real-time energy optimization and monitoring. This presentation will focus on two key use cases based on DFDS ferry operation across the British Channel: the first is a fully electric ferry with a 100-nautical mile range, powered solely by BESS. The second is a hybrid ferry combining Corvus Pelican fuel cells running on liquid hydrogen and associated BESS. This has a 300-nautical mile range. These use cases leverage digital twin simulations, integrating weather data and resistance models to optimize energy efficiency and drive fleet electrification.