Development of a solar powered hydrogen fueling station in smart cities applications

This paper reports main criteria for design, realization and validation of a solar-powered hydrogen fueling station in a smart city application relevant to an on-site hydrogen production plant. The program has been developed by CNR-ITAE together with other industrial partners in the framework of the Italian research project called i-NEXT (innovation for greeN Energy and eXchange in Transportation). The i-NEXT hydrogen production plant is located in the Municipality of Capo d'Orlando, Sicily, it is fed by a microgrid able to receive energy from solar radiation by a 100 kW rooftop photovoltaic plant and connected with a battery energy storage of 300 kWh (composed by 16 sodium nickel chloride high temperature batteries). The plant is able to deliver hydrogen and electricity for an electric and hydrogen vehicles fleet. The hydrogen fueling station includes four subsystems: a hydrogen production system by electrolysis, a compression system, a high-pressure storage system and a hydrogen dispenser for automotive applications. It is able to generate in the hydrogen production subsystem through an alkaline electrolyzer of 30 kWh: 6.64 Nm3/h of H2 with a gas purity of 99.995% (O2 < 5 ppm and dew point < −60 °C). The compression subsystem has a three stage compressor with a rated gas flow rate of 5,2 Nm3/h and a delivery pressure of 360 bar. The compressed H2 gas is stored in a high-pressure tanks of 350 L capacity allowing, in this way, a supply through a dispenser system of two automotive's tanks of 150 L @ 350 bar in less than 30 min. This paper reports the design and the development results coming from a first test campaign.