## 2 Energy Prediction and Fault Detection in Solar-Hydrogen Systems  
### Solar-Hydrogen Systems  
Solar-hydrogen systems are emerging as a promising sustainable energy solution, integrating solar power with hydrogen production to address growing energy demands and environmental concerns. These systems can produce clean hydrogen from water using various methods, including electrolysis powered by photovoltaics, thermochemical water splitting, and photoelectrochemical cells. The integration of solar energy and hydrogen production offers multiple benefits, such as electricity generation, heating, cooling, and freshwater production [16; 17]. Solar-hydrogen systems can be implemented in distributed residential settings, providing a comprehensive energy solution that combines photovoltaics for immediate electricity needs and hydrogen production for energy storage and transportation. While challenges remain, including cost and efficiency improvements, solar-hydrogen technologies show promise for a sustainable future. Life cycle assessments indicate that photoelectrochemical cells may offer the most sustainable option for hydrogen production when considering environmental impact, resource use, and efficiency [18]. Solar electricity technologies, particularly crystalline silicon photovoltaics and wind turbines, have shown remarkable growth, but producing solar fuels remains more complex [19]. Hydrogen, as a versatile energy carrier, plays a crucial role in the transition to a clean energy economy [20]. Solar-driven water electrolysis, which combines photovoltaic (PV) technology with water electrolyzers, is a promising technique for creating green hydrogen. This device splits water into hydrogen and oxygen via electrolysis, which is powered by PV-generated electricity. The generated hydrogen has the ability to store energy for a long time and be utilized as a clean energy carrier. There are several different setups, such as photoelectrochemical water-splitting systems, PV-water electrolyzer systems, and PV-rechargeable energy storage-water electrolyzer systems. Although wind turbines and crystalline silicon photovoltaics are currently at the forefront of renewable energy deployment, research on alternate photovoltaic technologies and synthetic fuel production methods is still ongoing. Notwithstanding several obstacles, solar-powered water electrolysis exhibits potential for expansion, ranging from domestic to commercial uses, thereby promoting a more sustainable energy environment [21; 22]. The development of sustainable energy can benefit greatly from the merging of solar energy with hydrogen generation. Hydrogen is a very efficient means of storing solar energy, mitigating intermittent power outages, and guaranteeing a consistent flow of electricity. These systems help mitigate climate change by reducing greenhouse gas emissions by substituting solar-produced hydrogen for fossil fuels. Because of its adaptability, hydrogen may be used for a wide range of processes in industry, transportation, and the production of energy. Energy security is improved by solar-hydrogen systems because they lessen dependency on imported fuels and centralized infrastructures. These integrated systems have payback times between 2.8 and 6.7 years, demonstrating their economic viability. Although solar hydrogen generation methods have advanced significantly, more development is necessary before they can be widely used [23; 24; 22] All things considered, integrating solar and hydrogen energy offers a viable way to achieve sustainability and energy independence. A potential approach to the generation and storage of sustainable energy is the combination of solar-hydrogen systems. Infrastructure for hydrogen storage, electrolyzers, and solar panels are important parts. The goal of research is to increase the scalability and efficiency of these systems, with a focus on photovoltaic-electrochemical, photocatalytic, and photoelectrochemical water-splitting techniques.