Model, energy and economic analyses of solid oxide electrolysis cells for clean hydrogen production

Green hydrogen is a good option for replacing fossil fuels. Renewable energy is used for water electrolysis to boost the descarbonization. A system of solid oxide electrolysis electrolyzer driven by the solar field of heliostat and photovoltaic panels with a battery bank is techno-economically investigated in the northeast of Brazil condition. Model of the cell, design of solar field and PV-Battery system are carried out. The system composed of 60 modules produces 112.8 kg/h of green hydrogen. The cell operates at 950 degrees C with a current density of 2500 A/m2 and reaches an efficiency of 95.33 %. The model has the highest relative error of 2.76 %. The Nernst voltage is the predominant voltage of cells, followed by the ohmic overpotential. The photovoltaic panels and battery have an average efficiency of 18.02 %. The solar field has an average efficiency is 34.6 %. The solar field and PV/battery bank account for 42.52 % and 39.65 % of global cost, respectively. The LCOH calculated is 9.43 US$/kg. Sensitivity analyses of the receiver and tower diameter and the lifespan battery on the LCOH are shown. Further researches are suggested.