## 1 Introduction  
Energy storage is a crucial component in the design and performance of HRESs, particularly in agricultural applications [1]. While conventional electrical storage systems, such as batteries (e.g., lead-acid and lithium-ion), are widely used and remain essential for general-purpose electricity storage in HRESs [2], alternative approaches like water tank storage--gravitational storage through elevated water reservoirs--have gained attention for specific applications like irrigation. In these cases, the stored energy is directly utilizedin the form of water pressure or gravitational flow. Water tank storage offers a context-appropriate, economically viable, and environmentally sustainable solution, especially for irrigation systems. Its integration into rural agricultural energy models can reduce dependency on costly battery systems and enhance long-term system resilience, particularly in regions with limited financial and technical resources. The increasing global demand for sustainable and reliable energy sources has intensified research on HRESs. These systems, which integrate multiple renewable energy sources, such as photovoltaic (PV) and wind energy, provide a promising solution for energy supply in remote and off-grid areas. One of the key applications of HRESs is in agricultural irrigation [3], where energy demand is variable and depends on seasonal water needs. Given the challenges associated with grid extension in rural areas, standalone renewable energy systems have emerged as an effective alternative to ensure sustainable irrigation. Despite the potential benefits of HRESs, their implementation poses several challenges, including optimal system sizing, cost-effectiveness, and energy reliability. A well-designed HRES must balance the trade-offs between initial investment costs, energy generation efficiency, and environmental impact. In this context, optimization techniques play a crucial role in determining the most suitable system configuration that can ensure a stable energy supply while minimizing costs. Hybrid renewable energy systems (HRESs) have gained significant attention in agricultural applications, particularly for irrigation [4]. The integration of solar photovoltaic (PV) and wind energy has been widely studied as a means to provide reliable power to irrigation systems, especially in regions with high solar radiation and wind availability. Several studies [5; 6; 7] have explored different HRES configurations for agricultural use. Some researchers have focused on optimizing energy efficiency and economic feasibility, while others have emphasized reducing carbon emissions and environmental impact. Many of these studies have demonstrated that hybrid systems can significantly reduce reliance on fossil fuels, lower operational costs, and improve sustainability. However, optimizing system design for specific geographical locations remains a challenge due to variations in climate, energy demand, and resource availability. [PERSON] et al. [8] assessed the viability and economic considerations of a hybrid renewable energy system designed for agricultural and irrigation applications in Dongola, Sudan. They evaluated combinations of solar panels, wind turbines, diesel engines, batteries, and converters to determine the best economical and eco-friendly arrangement. The ideal configuration achieved a 95% reduction in emissions and fuel consumption, with a net present cost of 24.16 $ million and a levelized cost of energy of 0.387 $ per kWh. Moreover, they illustrated, via sensitivity analysis, a reliance on solar radiation, wind velocity, and interest rates, emphasizing the significance of renewable energy in rural advancement. [PERSON] et al. [9] introduced a hybrid renewable energy system (HRES) designed for the sustainable irrigation of a farm situated in a remote region of Al-Jafr, Jordan. It amalgamated solar and wind resources with sophisticated optimization methodologies to improve energy efficiency.