# Exploring and Modeling the Incentive Strategies of New Energy Ship Application in Yangtze River
## 1 Introduction  
The significant role of China in global trade has been underpinned by its status as the most important maritime center in the world [1]. As an important part of the comprehensive transportation system, the Yangtze River shipping has a natural green gene and ecological advantages. The Yangtze River is the busiest inland waterway in the world [2], which had 79,631 inland-river transport ships, a net load capacity of 127.41 million tons, an annual inland cargo volume of 3.97 billion tons, and an inland cargo-transportation turnover of 1835.68 billion ton-km in 2023 [3]. It is worth noting that transportation on the Yangtze River has shown a stepped growth from upstream to downstream, with Jiangsu and Shanghai handling 58.8% of the total flow. The main points on the river with the highest transport include Chaotiamen, the Three Gorges Dam, and Chenglingji. Nantong Port registered the highest annual traffic flow, peaking at 545,117 trips. Seasonal variations were identified, with peak traffic in March and off-season periods in January and December [4]. The Yangtze River, being the most heavily utilized inland waterway globally, has witnessed a significant surge in carbon emissions due to its extensive transportation activities. Ships act as vehicles for transportation activities; thus, ship emission reduction is crucial in Yangtze River shipping. According to recent research, the CO\({}_{2}\) emissions from inland vessels within the Yangtze River Basin exhibited a remarkable upward trend from 2007 to 2022. Specifically, the emissions escalated from 2.418 million tons in 2007 to 10.801 million tons in 2022, marking an approximate 4.47-fold increase [1]. This substantial growth in emissions not only reflects the intensive usage of the waterway for transportation but also underscores the pressing need for effective emission reduction strategies to mitigate the environmental impact on the regions along the river [2]. The implementation of low-carbon and zero-carbon alternative fuels is viewed as a crucial element in reaching the established objective [5; 6; 7]. Some studies have been developed on the use of alternative fuels for ship propulsion, including application cost, technical approaches, and policy measures. For ship propulsion applications and application cost, it mainly deals with LNG, methanol, hydrogen, ammonia, biofuels, and fuel cells; several studies have examined the economic and environmental potential of these alternative fuels within the maritime sector [8; 9; 10; 11; 12; 13; 14; 15; 16; 17], and new energy ship applications are still profitable in the future, but are affected by the cost of ship construction, fuel prices, and later operating costs [18; 19; 20]. For the policy measures, some scholars believe that strong policy measures would ensure the promotion of alternative fuel ships [19; 21; 22]. Other scholars used exploratory factor analysis, structural equation model, or multivariate logic model to analyze the key determinants affecting the choice of new energy ships [23; 24; 25]. Most of the inland-river transport ships in the Yangtze River system are mainly diesel-powered. Among them, LNG, electric propulsion, pure electric, or other alternative fuel ships account for less than 1%. At present, most shipping enterprises are not highly motivated to apply NESs. Combining the literature and market analysis, three key factors impact the implementation of new energy ships (NESs):  
* It is evident that the application of the new energy ships to the decarbonization of shipping will inevitably lead to increasing costs for ship owners and operators [26]. As per the current LNG and pure battery-powered ships, their costs have risen by more than two-fold and 25%, respectively, compared to diesel-powered ships [27]. The cost of recovering methanol dual-fuel engine conversion will increase by 28.16% compared to equivalent diesel engine costs [8].