Introducing the cold-ironing technique and a hydrogen-based hybrid renewable energy system into ports

Natural resources' unexpected nature makes renewable energy sources' power supply irregular and inflexible; weather conditions are impossible to be predicted. Energy storage systems are required to balance this green power supply and ensure both off-grid and autonomous infrastructures' stability and reliability. Various energy storage technologies are available, but the high initial capital cost and the uncertainty regarding future cost and performance are critical bottlenecks for possible investors. Batteries are the most common energy storage means, while hydrogen storage is one of the least used options. This research attempts to conduct a comparative technoeconomic analysis between a hybrid renewable energy power plant combined with a hydrogen energy storage system and the implementation of the cold-ironing technique. The test bed is the port of Milos, which is a Mediterranean island port. Thirteen scenarios were conceptualized, simulated, and assessed after examining and assessing the existing methods and technology using MATLAB and Homer Pro software. The economy of scale plays its role in this aspect as hydrogen storage systems' cost has been proven to be lower for larger infrastructures. Indicatively, the levelized cost of energy is significantly reduced for the two optimal scenarios, as there is a 41.3% decrease for the non-cold-ironing case and a 33.4% decrease for the cold-ironing one. Moreover, the carbon footprint for the suggested systems of all the examined scenarios is almost diminished, paving the way forward for turning the port into a nearly Zero Energy Port. This study also helps to comprehend the technoeconomic characteristics of hydrogen-based hybrid renewable energy systems for supporting the cold-ironing technique. HIGHLIGHTS A systematic methodology is presented to introduce the cold-ironing technique to a small Mediterranean port; Hydrogen-based renewable energy systems are a sustainable and feasible solution toward the nZEP concept; An optimally sized hybrid renewable energy system guarantees the unhampered 24-h port's operation; The suggested hybrid systems are capable of covering the port's energy needs fully even if the cold ironing is incorporated.

Automated summary

This study conducted a technoeconomic analysis comparing a hybrid renewable energy power plant with a hydrogen energy storage system to the cold-ironing technique. The results show that hydrogen storage systems have lower costs for larger infrastructures. Additionally, these hybrid systems significantly reduce energy costs and carbon footprint, contributing to the development of nearly Zero Energy Ports.