A Solar Energy System Design for Green Hydrogen Production in South-Western Nigeria, Lagos State, Using HOMER & ASPEN

Solar system design for green hydrogen production has become the most prominent renewable energy research area, and this has also actively fueled the desire to achieve net-zero emissions. Hydrogen is a promising energy carrier because it possesses more energy capacity than fossil fuels and the abundant nature of renewable energy systems can be utilized for green hydrogen production. However, the design of an optimized electrical energy system required for hydrogen production is crucial. Solar energy is indeed beneficial for green hydrogen production and this research designed, discussed, and provided high-level research on HOMER design for green hydrogen production and deployed the energy requirement with ASPEN Plus to optimize the energy system, while also incorporating fuzzy logic and PID control approaches. In addition, a promising technology with a high potential for renewable hydrogen energy is the proton exchange membrane (PEM) electrolyzer. Since its cathode (hydrogen electrode) may be operated over a wide range of pressure, a control process must be added to the system in order for it to work dynamically efficiently. This system can be characterized as an analogous circuit that consists of a resistor, capacitor, and reversible voltage. As a result, this research work also explores the Fuzzy-PID control of the PEM electrolysis system. Both the PID and Fuzzy Logic control systems were simulated using the control simulation program Matlab R2018a, which makes use of Matlab script files and the Simulink environment. Based on the circuit diagram, a transfer function that represents the mathematical model of the plant was created, and the PEM electrolysis control system is determined to be highly significant and applicable to the two control systems. The PI controller, however, has a 30.8% overshoot deficit, but when the fuzzy control system is compared to the PID controller, it is found that the fuzzy control system achieves stability more quickly, demonstrating its benefit over PID.

Modeling and Simulation of Hydrogen Energy Storage System for Power-to-gas and Gas-to-power Systems

By collecting and organizing historical data and typical model characteristics,hydrogen energy storage system(HESS)-based power-to-gas(P2G)and gas-to-power systems are developed using Simulink.The energy transfer mechanisms and numerical modeling methods of the proposed systems are studied in detail.The proposed integrated HESS model covers the following system components:alkaline electrolyzer(AE),highpressure hydrogen storage tank with compressor(CM&H_(2) tank),and proton-exchange membrane fuel cell(PEMFC)stack.The unit models in the HESS are established based on typical U-I curves and equivalent circuit models,which are used to analyze the operating characteristics and charging/discharging behaviors of a typical AE,an ideal CM&H_(2) tank,and a PEMFC stack.The validities of these models are simulated and verified in the MicroGrid system,which is equipped with a wind power generation system,a photovoltaic power generation system,and an auxiliary battery energy storage system(BESS)unit.Simulation results in MATLAB/Simulink show that electrolyzer stack,fuel cell stack and system integration model can operate in different cases.By testing the simulation results of the HESS under different working conditions,the hydrogen production flow,stack voltage,state of charge(SOC)of the BESS,state of hydrogen pressure(SOHP)of the HESS,and HESS energy flow paths are analyzed.The simulation results are consistent with expectations,showing that the integrated HESS model can effectively absorb wind and photovoltaic power.As the wind and photovoltaic power generations increase,the HESS current increases,thereby increasing the amount of hydrogen production to absorb the surplus power.The results show that the HESS responds faster than the traditional BESS in the microgrid,providing a solid theoretical foundation for later wind-photovoltaic-HESS-BESS integration.

Towards high-performance and robust anion exchange membranes(AEMs)for water electrolysis:Super-acid-catalyzed synthesis of AEMs

The increasing demand for hydrogen energy to address environmental issues and achieve carbon neutrality has elevated interest in green hydrogen production,which does not rely on fossil fuels.Among various hydrogen production technologies,anion exchange membrane water electrolyzer(AEMWE)has emerged as a next-generation technology known for its high hydrogen production efficiency and its ability to use non-metal catalysts.However,this technology faces significant challenges,particularly in terms of the membrane durability and low ionic conductivity.To address these challenges,research efforts have focused on developing membranes with a new backbone structure and anion exchange groups to enhance durability and ionic conductivity.Notably,the super-acid-catalyzed condensation(SACC)synthesis method stands out due to its user convenience,the ability to create high molecular weight(MW)polymers,and the use of oxygen-tolerant organic catalysts.Although the synthesis of anion exchange membranes(AEMs)using the SACC method began in 2015,and despite growing interest in this synthesis approach,there remains a scarcity of review papers focusing on AEMs synthesized using the SACC method.The review covers the basics of SACC synthesis,presents various polymers synthesized using this method,and summarizes the development of these polymers,particularly their building blocks including aryl,ketone,and anion exchange groups.We systematically describe the effects of changes in the molecular structure of each polymer component,conducted by various research groups,on the mechanical properties,conductivity,and operational stability of the membrane.This review will provide insights into the development of AEMs with superior performance and operational stability suitable for water electrolysis applications.