Integrated shore power deployment problem in an inland shipping network

Abstract

Shore Power (SP) is an effective measure to reduce air pollutants in ports by enabling docked ships to switch from diesel fuel to shoreside electricity. However, the promotion of SP faces the "chicken and egg dilemma": the use of SP requires both ports and ships to adopt SP technology. The benefits of SP investment for ships depend on the SP infrastructure readiness at all the ports they visit, while the return on investment for ports depends on the proportion of visiting ships equipped with SP facilities. This paper aims to explore the integrated shore power deployment problem in an inland shipping network from the perspective of the government. To this end, an integer linear programming model is proposed to maximize the total economic and environmental benefits of all ports in the shipping network by determining the optimal number of SP berths to be retrofitted in each inland port and the specific ships to be equipped with SP receiving facilities. Due to the fluctuations in fuel prices, the SP-capable ships’ mixed berthing energy choices at each port are also captured. Based on the model, the differentiated impacts of three subsidy policies provided by the government, i.e., SP price subsidy, per usage subsidy, and capital subsidy ratio for onboard SP investment, on the benefits of the ports as well as the SP deployment decisions are examined. Taking the Yangtze River container shipping network in China as a case study, the numerical results suggest that full deployment of SP in the container shipping network does not appear to be cost-effective. Instead, installing SP facilities with different levels at particular ports and ships is optimal. The results also reveal that all the proposed subsidies can effectively reduce the investment cost or usage cost of SP, thereby enhancing its economic attractiveness to ship owners. However, there exists an optimal subsidy level for each type of subsidy, beyond which the net benefits of the system may surprisingly decrease due to the diminishing marginal returns and the increased financial burden on the government.