Experimental and theoretical evaluation of hydrogen production via PV-assisted alkaline electrolysis

Energy resources have become the most important issue of all countries in the world because of the rapid increase in the population worldwide, the continuous development of technology, the role of the countries in their relations and economic prosperity. On the other hand, due to the decrease in the production rates of these limited resources every year, the depletion of reserves, the increase of awareness about global warming and greenhouse gas emissions, and more restrictive regulations to protect nature, humanity has led to the search for different energy resources. Considering the negative effects of fossil fuels, it has become a necessity to turn to alternative energy sources, especially hydrogen as an energy carrier, and to make maximum use of these sources. However, this demand for clean fuel energy during its production is a critical issue and a completely green production chain should be needed in order not to harm nature. Especially for electrolysis cells, electricity must be supplied from renewable sources. Hydrogen technologies give extremely positive signals for the medium and long term in the energy arena of the future. In particular, it has become a necessity to resort to hydrogen as an energy carrier and to get the maximum benefit from these sources. Because hydrogen emission is only water. It provides zero carbon emissions and is good as a high energy density, it has such advantages as one of the most promising energy carriers for the future. In order to contribute to this direction, hydrogen production was carried out by alkaline electrolysis method, which can be adapted to the application of an on grid supply system with renewable sources. In this study, a renewable electrolysis system is designed, which provides the necessary voltage for electrolysis from an 80 W PV panel with a DC-DC converter and stores the excess electricity in batteries. Firstly, this system was simulated in MATLAB/Simulink and then the experimental part was carried out and the results were compared. All experiments were carried out at 25℃ and 1000 W/m² irradiation in Adana, Turkey. As a result of the simulation, the PV panel power was found to be 81 W, while it was found to be 77.15 W in the experimental study. Since the results obtained have close values with each other, the results of the system to be simulated can be observed approximately without installing such a system anywhere in the world. In electrolysis system, Pt with a surface of 2 cm² was used as the anode, and four different electrodes with a surface of 0.36 cm² were used as the cathode. A graphite electrode with a surface of 0.36 cm² was produced and its surface was covered with different metals and decorated. Appropriate cathode performance was determined with the aid of polarization curves. The decomposition potential and hydrogen gas volume were obtained with the two-electrode configuration. The hydrogen gas volume was determined with a graduated cylinder filled with 1 M KOH electrolyte. The hydrogen performance of G, G/Ni, G/NiCo and G/NiCoAg was compared. G, G/Ni, G/NiCo, and G/NiCoAg produced 30 mL, 31 mL, 42 mL and 78 mL of hydrogen gas, respectively, end of 30 minutes of electrolysis time by applying a voltage of 3V. Thanks to these thin coatings and decorations, the electrocatalytic properties of the electrodes were increased and it was proved that there was a serious increase in hydrogen production.