A decision-making optimization model for ship energy system integrating emission reduction regulations and scheduling strategies

The International Maritime Organization (IMO) has established various emission reduction regulations to limit ship emissions. Ships can choose among several energy system strategies to meet relevant regulatory requirements, and choosing the right energy strategy can maximize the ship's profitability, which is particularly important for shipping companies. In this paper, several shipping industry information such as emission reduction regulations, ship parameters, and energy strategy characteristics are integrated, and the potential connection between the ship scheduling approach and alternative energy system strategies is considered. Then, a more efficient energy strategy selection model is proposed based on life cycle analysis, which is solved by a designed dynamic programming method. Compared with the state of the art, this paper provides a novel way for shipping companies to link changes in ship scheduling behavior to energy strategy choices, which was ignored by previous studies. The proposed method is applied to a 5,000 Twenty-feet Equivalent Unit (TEU) container ship. The results show that, compared to the traditional method, the proposed model allows to select more appropriate energy system strategies and to increase profitability by nearly 30%. And traditional approaches underestimate the profitability of fuel switching and installing open-loop scrubbers, the proposed approach may prompt shipping companies more towards adopting the above two energy system strategies. In addition, the proposed model can help shipping companies effectively cope with fuel price fluctuations. Finally, compared to other carbon reduction policies, the incorporation of ships into the carbon trading system will encourage them to use Liquefied Natural Gas (LNG), thereby effectively reducing ship CO2 emissions.