Performance of peak shaving policies for quay cranes at container terminals with double cycling

Abstract

Double cycling is used to improve the efficiency of quay cranes (QCs). However, higher QCs utilization increases the highest observed peak power demand of QCs, leading to a higher energy-related costs. Thus, this paper investigates the opportunities for peak shaving the power demand of QCs with double cycling by limiting the number of lifting QCs or the maximal energy demands of QCs. And some evaluation indicators are selected for assessment including the observed peak power demand, the productivity and utilization of QCs and the average waiting time of yard trucks (YTs). Considering the complexity and uncertainty of container terminals, this study establishes an agent-based simulation model to describe the operation processes of QCs, YTs and yard cranes (YCs), and visualize the power demands of QCs with double cycling. Finally, a series of computational experiments are carried out to explore the possibility of peak shaving the energy demand of QCs. The results show that both peak shaving policies are capable to reduce the power peaks of QCs with double cycling. And the policy of limiting maximal energy demands of QCs performs better which reduces the maximum energy demand as well as protecting electrical equipment without compromising higher QCs’ productivity. And the established agent-based simulation model can provide decision support for terminal operators to manage their energy consumption more smartly.