Validation of a ship energy simulation tool using on-board data for performance optimization and digital twin applications

Nowadays, the urgent need to reduce the environmental impact of the whole maritime sector requires the adoption of energy-efficient and cost-effective technologies and strategies, supported by reliable digital tools. These tools play a crucial role in ship design, retrofitting, and real-time energy performance optimization throughout a vessel lifecycle. A key challenge in this context is the development of a high-fidelity simulation tool capable of replicating the actual operation of a ship onboard energy system, for the optimal design and operation of the ship as well as for integration into digital twin platforms. Such a tool must accurately model the complex interactions between different energy flows, operating conditions, and technological configurations to support informed decision-making. By ensuring a realistic representation of the ship energy behaviour, it enables the assessment of operational scenarios, optimization of system layouts, and evaluation of advanced technologies and alternative fuels. In this framework, this study presents the validation of an in-house simulation tool, developed in MatLab, and capable to assess energy, economic, and environmental performance of the ship-energy system, optimize its system layouts and operational strategies, and finally support decision-making in ship design and management. The proposed approach relies on dynamic simulation to evaluate ship energy system performance and is developed to replicate the energy behaviour of multiple ship energy systems configurations in a flexible and effective manner. The model accuracy was verified using operational data from a cruise ship, ensuring reliable predictions of energy loads, temperature, and system sizing. The validation results demonstrated minimal deviations - below 3.9% - between simulated and measured data. The insights obtained facilitate the identification of energy recovery opportunities and efficiency improvements, contributing to the development of digital twin applications in the maritime industry.