A Comparative Study of Energy Storage Systems and Active Front Ends for Networks of Two Electrified RTG Cranes

Feras Alasali,Antonio Luque,Rayner Mayer,William Holderbaum

doi:10.3390/en12091771

Abstract

The global consumerism trend and the increase in worldwide population is increasing the need to improve the efficiency of marine container transportation. The high operating costs, pollution and noise of the diesel yard equipment is leading sea ports to move towards replacing diesel RTG cranes with electric Rubber Tyre Gantry (RTG) cranes which offer reduced environmental impact and higher energy efficiency. However, ports will require smarter solutions to meet the increased demand on the electrical distribution network due to the electrification of RTGs. This paper aims to highlight the peak demand problem in the two electrical cranes network and attempts to increase the energy saving at ports by using two different technologies: Energy Storage System (ESS) and Active Front End (AFE). This article introduces one of the first extensive investigations into different networks of RTG crane models and compares the benefits of using either AFE or ESS. The proposed RTG crane models and network parameters are validated using data collected at the Port of Felixstowe, UK. The results of the proposed RTG cranes network show a significant peak demand reduction and energy cost saving.

Highlights

According to trade statistic data from the World Shipping Council (WSC) 127.6 million twenty-foot container equivalent unit (TEUs) were exported and imported globally in 2014, a 4.3% increase from the previous year [1]
Based on the energy saving on low voltage network of two cranes, this study introduces a signification energy saving at port level and a significant energy cost saving scenario by using a central Energy Storage System (ESS) or Active Front End (AFE) to feed a greater number of cranes
This paper investigates the behaviour of the power flows and energy saving for a two rubber tyred gantry (RTG) crane network with different scenarios: energy storage system (ESS) and active front end (AFE)

Summary

Introduction

According to trade statistic data from the World Shipping Council (WSC) 127.6 million twenty-foot container equivalent unit (TEUs) were exported and imported globally in 2014, a 4.3% increase from the previous year [1]. The United Nations 2016 Review of Maritime Transport report shows that the world gross domestic product expanded by 2.5% compared to 2014 and the world seaborne trade expanded by 2.1% [3]. To face the accelerated growth of the world seaborne trade, ports need to improve the efficiency of handling operation by installing significant infrastructure. Port facilities to complete the container handling process from land to sea or are costly to build and operate. The high operating costs, pollution and noise emissions associated with the diesel yard equipment’s, is leading sea ports to move towards replacing diesel rubber tyred gantry (RTG) cranes with electric RTG cranes which are more environmentally friendly and have higher energy efficiency. The use of electrical compared to diesel RTGs can reduce the CO2 emissions by 60–80% and the maintenance costs by around 30% [4]

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Results

Conclusion