Evaluation of hydrogen production cost in different real case studies

Use of hydrogen and production are issues of wide interest while just room towards aspects relevant to hydrogen economy now is lacking. This paper deals with an estimate of the hydrogen production cost in a solar-powered hydrogen refueling station for smart cities applications in the site of Capo d'Orlando in Sicily considering design, building, characterization and operation. A cost analysis done shows economic and environmental benefits relevant to exploitation of the facility. The analysis deals with a comparison of data relevant to costs of hydrogen produced by water electrolysis derived from three different case-study; namely: Hydrogen production by using only the electric energy coming from the main grid, Hydrogen production by using electric energy from a photovoltaic plant grid-connected, Hydrogen production by using electric energy coming from integration of photovoltaic plant grid connected with an electric storage system. The hydrogen and electric energy refueling station is a demonstration experimental facility belonging to the Italian research project i-NEXT (innovation for greeN Energy and eXchange in Transportation). CNR-ITAE jointly with industrial partners developed in the framework of the Italian research project i-NEXT a demonstration on-site hydrogen production plant at Capo d'Orlando in Sicily. The hydrogen production plant is connected to a microgrid fed by means of a 100 kW photovoltaic plant installed on rooftop; it is connected with a facility of 300 kW h battery electric energy storage (made up by 16 high temperature batteries sodium nickel chloride). So, the plant is able to provide hydrogen and electric energy for an electric and hydrogen vehicles fleet. The hydrogen refueling station consists of four sections: the module of electrolysis hydrogen production section (HPPS), able to produce, by means of a 30 kWh alkaline electrolyser, 6.64 Nm3/h of hydrogen with a gas purity of 99.995% (O2 < 5 ppm and dew point < -60 degrees C); the module of hydrogen compression section (HCS), made by a three-stage compressor with a rating gas flow rate of 5.2 Nm(3)/h and a delivery pressure of 360 bar; a module of high pressure storage section (HSS), made by high-pressure tanks having a total capacity of 350 liters; and the last module for automotive applications of hydrogen dispenser section (HRS), that allowing a supply of two automotive's tanks of 150 liters @ 350 bar in less than thirty minutes.