关键词: 减排策略, 碳排放权交易, 减速, 岸电, 船舶成本

Abstract: As the process of globalization and transnational trade continue to rise, shipping pollution is becoming increasingly serious, and reducing pollutant emissions from ships has become an inevitable choice for the long-term development of shipping. In the face of the increasingly serious shipping pollution problem, various international organisations have formulated corresponding policies. At present, there are mainly three types of emission reduction strategies: First, emission reduction strategies in ship navigation, mainly deceleration strategies, including deceleration during navigation and deceleration when entering and leaving the harbor. Secondly, emission reduction strategies in ports, which mainly involve in the provision of shore power in ports for ships at berth. And thirdly, emission reduction strategies for ships themselves, which mainly include the use of desulphurisation devices, clean energy and drag-reducing paints. Market instruments for emission reduction mainly include carbon tax and carbon emission trading. Compared with carbon tax, Emission Trading Scheme (ETS) has the advantages of internationalisation and marketisation, which can exclude the interference of regional governments and give full play to the role of the market. Therefore, since the EU ETS came into effect in 2005, it has been widely supported by most countries and regions. Existing studies focus on the emission reduction effect of single-type emission reduction strategies, pay less attention to the net profit of shipbrokers, and only study the deployment or decision-making of shipping companies mainly based on the carbon tax approach. The question of how shipbrokers can maximize their profits by taking into account the existing emission reduction strategies and market instruments for emission reduction is an urgent one. Specifically, firstly, what is the optimal combination of emission reduction strategies that ship operators should consider? Further, what is the impact of fuel prices and carbon allowance prices?
In this paper, based on the three most effective emission reduction strategies in carbon emission trading mechanism, which are deceleration, alternative maritime power in ports, and anti-fouling and drag reduction coatings of the low-surface energy, we present a mixed integer nonlinear programming model by minimizing the total costs including the annual operating revenue, fuel cost, emission reduction strategy cost, emission cost, and comprehensive cost. Then, we use variable substitutions to transform the model and obtain some results of convexity properties. Finally, to test the practical effect of the model, we take some Trans Pacific routes provided by Yangming as an example and, through numerical simulation, we obtain the optimal emission reduction strategies for shippers under different carbon emission quotas. We further give a sensitivity analysis of fuel price and carbon emission quota price. The results show that the annual net operating profit of the shipbroker decreases with the increase in the deceleration ratio when only the deceleration emission reduction strategy is considered. Secondly, under carbon emissions trading, the change in carbon auction allowances has no effect on the choice of emission reduction strategy of ship operators, but only affects the net profit. Moreover, the emission reduction effect is most significant when ships choose to connect to shore power, and the emission reduction effect of shore power becomes more significant as the cleanliness of the supply grid increases. In addition, the lower the price of fuel, the higher the annual net operating profit of the shipowner. The price of carbon emission allowances includes the carbon auction price and the carbon purchase price, and the price change trend of both prices in the market is consistent, and the price of carbon emission allowances to the annual net operating profit is consistent with the fuel oil price.
This paper mainly makes the following contributions: First, it explores the cost and makes a benefit-based analysis of the three mainstream emission reduction strategies, namely, deceleration of the ship sailing process, connection of shore power at berths, and the use of antifouling and drag reduction coatings, conducts a comparative analysis of the results of the combinations of the different emission reduction strategies to obtain the optimal combination of emission reduction strategies, and compares the various combinations of the strategies. Secondly, under the background of carbon emissions trading, the emission cost calculation method of different emission reduction strategies is proposed. Based on the known carbon emissions trading and the emission quotas obtained by ship operators, the calculation of emission costs and the selection of emission reduction strategies in this context are studied.

Key words: emission reduction strategy; carbon emission trading; deceleration; alternative maritime power; ship cost