Review of speed optimisation for ship energy efficiency: methods, taxonomy and challenges

Review article, 2026

Ship speed optimisation represents a key strategy for promoting maritime energy efficiency and decarbonisation under the industry's green transition. While considerable progress has been made in energy consumption modelling and algorithm development, key obstacles remain in addressing time-varying uncertainties and achieving integrated energy efficiency optimisation. This review systematically evaluates the state-of-the-art in ship speed optimisation, with a specific focus on energy-saving mechanisms, including objectives, boundary conditions, and energy consumption prediction models. A novel taxonomy categorises methodologies into static, offline dynamic, and online dynamic optimisation, providing a comparative analysis of their efficacy in enhancing energy performance. The paper also investigates co-optimisation frameworks that integrate ship speed optimisation with energy management, route optimisation, scheduling, and trim control, with the aim of improving overall energy efficiency. Key energy-related challenges are scrutinised, particularly the impact of time-varying factors—such as meteorological volatility and port congestion—on the robustness of energy-saving outcomes. The review also addresses the transferability of ship speed optimisation models across ship lifecycles and operational regions. Finally, an outlook on future research is offered, advocating for intelligent, adaptive energy-control systems and autonomous efficiency management for the next generation of green shipping.