# Green Hydrogen Production--Fidelity in Simulation Models for Technical-Economic Analysis
## 4 Simulation Results and Discussion  
### Micro-Grid Case Study  
The following Figure 8 details the micro-grid equipment used in this study, which is part of the Micro-Grid Laboratory of the Universidad de Cuenca, Ecuador. It consists of a 15 kW PV system with 60 modules from the Atersa brand (Elecnor, Valencia, Spain), Samsung 44 kWh lithium batteries (Samsung, Gyeonggi-do, Republic of Korea) as the ESS, includes a 2-level bi-directional power converter, GPTech (Spain), and the Heliocentris EL500 electrolyzer (Italy) (see Tables 2 and 3), which produces 500 NI/h at a pressure of 30 bar, with a purity of 99.94% from distilled water and a constant load of 2.39 kW to the PCC with the electrical grid. The hydrogen produced as compressed gas is stored in four tanks (50 L each) at a maximum pressure of 200 bars (Spain) [27].  
The data for this simulation are presented in the following table.  
Figure 6: Hydrogen production with H\({}_{2}\)SO\({}_{4}\) electrolyte volume 2 lt, and stainless steel electrodes: (a) electrode area 50 cm\({}^{2}\), (b) electrode area 100 cm\({}^{2}\).  
Figure 7: Optimal conditions for obtaining hydrogen with the electrolyte at 25 °C.  
The following Algorithm 1 details the steps and configuration for energy control and management. The input parameters to the algorithm required as the measurement points are established according to the scheme in Figure 1. For this, the Modbus communication stations of the equipment must be initialized at a set time. Subsequently, these values are read and processed in real time for the reference values towards the ESS inverter [27; 38]. The SoC control limits the energy delivery capacity autonomously, thus offering security during the management system. The system response is practically instantaneous, so the PV energy is stored in the ESS after covering the demand of the electrolyzer.  
\begin{table}
\begin{tabular}{l c c} \hline \hline
**Description** & **Parameter Value** & **Unit** \\ \hline PV System (60 modules 15 \(\times\) 4 array) & 15 & kW \\ Lithium battery bank (11 Cells) & 44 & kWh \\ EL500 electrolyzer & 2.39 & kW \\ Bi-directional inverter & 500 Vdc/230 Vac & V \\ Power grid & 150 & kVA \\ Storage tanks (4 \(\times\) 50 L) & 200 & bars \\ \hline \hline \end{tabular}
\end{table}
Table 2: Integrated micro-grid equipment.  
Figure 8: Case study at the Micro-Grid Laboratory, Universidad de Cuenca, Ecuador.  
\begin{table}
\begin{tabular}{l c c} \hline \hline
**Description** & **Parameter Value** & **Unit** \\ \hline Type of Electrolyzer & 1 & PEM \\ H\({}_{2}\) production rate & 8.33 & L/min \\ Working pressure & 30 & bar \\ Water consumption & 0.4 & L/h \\ Water specification & 10 & \(\upmu\)S/cm \\ Power supply options & AC 220 V–50 Hz DC 40 V–80 V & V \\ Operative power consumption & 2390 & W \\ Universal gas constant \(R\) & 0.082 & L-atm/mol-K \\ Voltage supply & 48 & V \\ Current density & 0.2 & A/cm\({}^{2}\) \\ Temperature & 298 & K \\ Number of cells & 72 & \\ Faraday’s constant & 96,485 & C/mol \\ Electrochemical equivalent & 2 & cm \\ Area & 76.1362 & cm\({}^{2}\) \\ Current \(I\) & 15.2272 & A \\ Voltage cell & 2.4 & V \\ Ohmic resistance of electrolyte \(R_{u}\) & \(8.05\times 10^{-5}\) & \(\Omega\)-m\({}^{2}\) \\ Ohmic resistance of electrolyte \(R_{d}\) & \(-2.5\times 10^{-7}\) & \(\Omega\)-m\({}^{2}\) \\ Over temperature shut down & 65 & \({}^{\circ}\)C \\ V\({}_{\mathrm{Ohmic}}\) & 0.1486 & V \\ System efficiency & 60 to 80 & \% \\ \hline \hline \end{tabular}
\end{table}
Table 3: Hydrogen production data and equipment parameters.