# Innovative Strategies for Combining Solar and Wind Energy with Green Hydrogen Systems
###### Abstract
[PERSON] et al. [8] proposed an intelligent multi-objective optimization strategy for H\({}_{2}\) energy storage systems (HESSs) in solar- or wind-powered reverse osmosis systems. The study evaluated three green H\({}_{2}\) storage methods: gas hydrogen storage (GH\({}_{2}\)), liquid hydrogen storage (LH\({}_{2}\)), and material-based hydrogen storage (MH\({}_{2}\)). GH\({}_{2}\) had the highest overall life cycle cost (568,164.60 USD/year), whereas LH\({}_{2}\) had the greatest inherent risk due to explosion dangers. MH\({}_{2}\) outperformed GH\({}_{2}\) and LH\({}_{2}\) in terms of cost (18.92%) and safety (42.86%), although temperature control during H\({}_{2}\) emission posed issues. The findings offer an equitable strategy for constructing sustainable HESSs that takes into account both economic and safety factors. [PERSON] et al. [9] investigated the optimization of green H\({}_{2}\) synthesis from solar and wind energy to give high-temperature heat to Europe's hard-to-abate production industries. They used geospatial analysis to improve the sizing of plant components such as PV and wind capacity, electrolyzers, and hybrid storage that combines compressed H\({}_{2}\) and lithium-ion batteries. The study indicated that the levelized cost of H\({}_{2}\) (LCOH) varied between 3.5 and 8.9 EUR/kg, with wind-rich regions having the lowest costs. Optimal H\({}_{2}\) storage might satisfy industrial demand for two to three days. Furthermore, a consistent demand profile lowered costs by about 11%, and the majority of scenarios fulfilled EU emission targets. [PERSON] et al. [10] conducted an analysis of the energy, exergy, and exergy-economic (3E) performance of various systems aimed at green hydrogen production, namely wind, solar pond, and ocean thermal energy conversion (OTEC) systems. They employed a trilateral cycle (TLC) to enhance heat matching, combined with a thermoelectric generator (TEG) for efficient waste heat recovery. The findings indicated that wind systems yield the highest exergy efficiency ranging between 5.8% and 10.47% at wind speeds of 8 to 12 m/s while simultaneously maintaining the lowest cost rate at 66.08 USD/h. However, the salinity gradient solar pond (SGSP)-based system emerges as the most cost-effective option for hydrogen production, with costs fluctuating between 42.78 and 44.31 USD/GJ. This reveals significant economic implications for the future of sustainable energy. Although the performance metrics of wind systems are commendable, the overall economic advantage provided by the SGSP system cannot be overlooked. [PERSON] et al. [11] conducted a comprehensive analysis of renewable energy capabilities across 27 EU nations and the UK specifically examining solar, wind, hydro, and green hydrogen. The research identified Austria, Belgium, and Germany as frontrunners in renewable energy production; however, Germany stands out as the foremost producer. Green hydrogen, particularly in Germany and France, serves a crucial function as an alternative fuel. Regions such as Northern Sweden and Germany are recognized as potential hubs for green electricity (this is significant, because it highlights emerging markets). The study underscores the necessity of balancing supply and demand while emphasizing the EU and UK's notable progress and commitment to sustainability objectives in the energy sector. Although challenges remain, the findings paint a promising picture for future energy strategies. [PERSON] et al. [12] investigated recent advancements in the generation of green hydrogen (GH) utilizing water electrolyzers powered by renewable energy sources. Their emphasis spans solar, wind, and hybrid systems. They conducted a comprehensive examination of various electrolyzer types, placing particular focus on proton exchange membrane (PEMWE) and alkaline water electrolyzers (AWEs). Notably, PEMWE can achieve an extraordinary hydrogen purity level of 99.9999% alongside superior current densities.