Sustainable Ship Design Generator: A tool for preliminary ship design models with alternative energy carriers

Abstract

The maritime shipping industry is under increasing pressure to reduce its environmental footprint in response to ambitious short- and long-term decarbonization targets set by the International Maritime Organization (IMO). These targets focus primarily on reducing greenhouse gas emissions and accelerating the transition toward more sustainable ship propulsion systems. As a result, shipowners, designers, and policymakers are actively exploring alternative energy carriers that can replace or complement conventional fossil fuels. However, evaluating the feasibility of these alternatives during the early stages of ship design remains complex and time-consuming. Current ship design generators and feasibility assessment tools often lack the capability to systematically compare different energy carriers in a consistent and automated way. This research aims to address this gap by developing a method and corresponding tool that automates early-stage feasibility studies for ships powered by alternative energy carriers.

The primary objective of this research is to enable the automated exploration of design alternatives based on different energy carriers while supporting early-stage decision-making in ship design. The study focuses on four promising alternatives to conventional marine fuels: batteries, hydrogen, ammonia, and methanol. These energy carriers are evaluated through several key parameters that influence ship design, including energy density, storage conditions, tank types, applicable regulations, power generation technologies, and spatial requirements for engine and tank rooms. These aspects are essential for determining the feasibility of integrating alternative energy systems into vessel designs and for generating realistic general arrangements during the conceptual design phase.

The research begins with a comprehensive literature review on alternative energy carriers and their implications for ship design. This review also examines the capabilities of existing ship design generators. The analysis reveals that current design generators do not explicitly support the independent creation of design spaces for different energy carriers prior to comparing their optimal configurations. Consequently, designers lack an automated framework that allows them to explore and evaluate multiple energy carrier options simultaneously within a consistent modeling environment.

To address this limitation, the study proposes a novel design method and develops a parametric tool capable of automatically generating and evaluating alternative ship designs based on different energy carriers. The tool creates separate design spaces for each energy carrier and evaluates them according to predefined performance criteria such as speed, autonomy, lightweight ship weight (LSW), and total resistance. The generated design alternatives can then be compared to identify the most suitable energy carrier configuration for a given set of operational requirements.

The tool was tested through five case studies involving different types of cargo vessels. The results demonstrate that the developed method can generate feasible design solutions and provide useful insights into the comparative performance of the considered energy carriers. Among the tested options, methanol generally produced the most favorable results in terms of achieving the required speed and autonomy while maintaining relatively low lightweight ship weight and total resistance. Ammonia ranked second, followed by hydrogen and battery-based systems. However, the study also identified several discrepancies between the generated models and real-world vessel designs. In particular, the lightweight ship weight was consistently underestimated, leading to overly optimistic performance predictions for certain configurations.

Validation of the tool was conducted by comparing calculated lightweight ship weight and resistance values with known reference data. The average deviation was approximately 20% for lightweight ship weight and 11.3% for total resistance. Although these deviations highlight the need for further refinement, the results indicate that the proposed method can provide meaningful insights during the early stages of ship design.

Overall, this research demonstrates the potential of automated design tools to support the evaluation of alternative marine fuels in early-stage ship design. Future improvements should focus on refining weight estimation methods, incorporating additional ship systems, and integrating three-dimensional modeling capabilities to further enhance the tool’s accuracy and decision-support capabilities.