As populations expand and cities grow, the horizontal development of sustainable initiatives, coupled with the preservation of natural resources and the shift towards agricultural ventures, has led to an increased necessity for road lighting to mitigate traffic accidents. The burgeoning field of photovoltaic (PV) energy is significantly altering the energy paradigm, gaining prominence within regional energy mixes and power systems. This study presents an examination of various off-grid solar PV system designs for the illumination of the Kuwaiti roundabout, highlighting the distinct differences among these approaches. Through mathematical modeling and subsequent validation via PVsyst software, the focus is placed on sophisticated light emitting diode (LED) street lighting systems featuring automatic controls powered by solar energy. LEDs, acclaimed for their energy efficiency and longevity, are progressively supplanting traditional lighting technologies worldwide. This investigation explores multiple system configurations, transitioning from centralized systems employing sodium flashlights to autonomous systems with LED lamps. Key challenges such as power consumption, spatial limitations, and network load considerations are addressed. Innovative solutions including dual-voltage lamps and charge controllers are introduced, pinpointing optimal design strategies for roadway applications, which have implications for sustainable urban lighting paradigms. Additionally, the proposal of a solar-powered searchlight underscores potential cost-effectiveness, reflecting the continuous evolution of solar lighting technologies. Collectively, the findings underscore the crucial role of comprehensive design considerations in achieving efficient and sustainable lighting solutions within urban settings.

The increasing shift towards sustainable and net-zero targets has heightened interest in substituting hydrogen for natural gas in gas turbines and combined cycle power plants. This study investigates the compressibility of hydrogen within gas compressors, situated upstream of gas turbines, particularly when blended with various gases. Emphasis was placed on the inherent properties of hydrogen, including its behavior under compression, susceptibility to material embrittlement, and the influence of its gas characteristics on compressor performance. An extensive examination of prevalent compression methods, notably centrifugal compressors, was conducted to evaluate their efficacy in managing hydrogen at varying blend ratios. Issues related to material compatibility and safety were highlighted, alongside the formulation of reliable compression processes crucial for hydrogen-rich gas mixtures. Operational challenges posed by different hydrogen fuel proportions were identified, with proposed solutions including the implementation of precision control systems or the introduction of innovative materials. The study culminates in a discussion on prospective research directions and necessary technologies for effective hydrogen-rich gasification compression technology. The findings offer critical insights for ongoing initiatives aimed at enhancing and promoting hydrogen compression technology, facilitating the integration of hydrogen into existing infrastructures and supporting the sustainable development of the energy sector.

The provision of fresh, drinkable water is essential for human survival. Solar stills, devices that utilize solar energy to produce pure water, face the disadvantage of low productivity. This study proposes a novel solar still design aimed at enhancing thermal performance through the incorporation of stepped types and additional modifications, such as the integration of magnets, to further augment thermal efficiency. Experimental evaluations were conducted outdoors under the climatic conditions of Thi-Qar throughout the year 2023. The findings indicate that solar stills with the innovative stepped design achieved a productivity increase of 39.329% and 31.745%, respectively, compared to conventional designs. Furthermore, the inclusion of magnets resulted in an additional enhancement of 136.2% in productivity compared to the same design without magnets. Solar evaporation is highly regarded for passive water desalination due to its abundant resources, high efficiency, and lack of carbon emissions. Recent advancements have seen the development of bio-inspired solar evaporators that efficiently harvest solar energy and convert it into heat. However, challenges persist regarding the relatively low freshwater production rate and harvesting efficiency. Key areas for improvement include the absorption properties of the evaporator material and the evaporation efficiency of saline water. Water evaporation primarily occurs at the top surface of saline water, with the rate significantly influenced by the temperature difference between the evaporating surface and the surrounding atmosphere. To achieve a substantial temperature difference, broad-band solar absorbers with advanced microstructures have been designed to enhance solar absorptance and minimize heat loss via radiation on evaporating surfaces. Despite the development of sophisticated photothermal materials and evaporators, practical solar evaporation under simple fabrication processes remains elusive.

The study aimed to compare the effects of thermal stratification ($S$), anisotropic parameters ($k^*$ and $\theta$), and buoyancy force distribution parameter ($m^*$) on natural convection in fluids characterized by high and low Prandtl numbers. The second-order coupled partial differential equations governing the problem were initially converted into ordinary differential equations through the Laplace transform technique. The D'Alembert method was then applied to systematically decouple these equations without altering their original order. Subsequently, the closed-form solutions in the Laplace domain were transformed into their respective time domains using a numerical scheme based on the Riemann sum algorithm. The research established that reverse flow is feasible under certain conditions, occurring more rapidly in fluids with lower Prandtl numbers. Additionally, it was observed that an increase in $k^*$ and $S$ reduces skin friction on the bounding plates, whereas an increase in $\theta$ enhances skin friction on both channel walls.