Abstract

The growing use of solar photovoltaic (PV) systems in aquaculture farms and water-resource management facilities has provided the groundwork for developing systems that require reliable and long-life energy storage solutions, especially in remote and/or off-grid locations that require powering aeration devices, water circulation pumps, monitoring devices, and control systems on a continuous basis. Battery aging, driven by inappropriate Depth of Discharges (DOD) as a main system costs and sustainable operating challenge, is still the weakest link in the system reliability, sustained operational cost, and long-term adequacy. This is particularly true for systems in (PV-coupled) energy for aquaculture applications. This study discusses the possible design of an intelligent DOD management system that ranked the possible designs according to the remaining energy in the battery during the charging cycle at the optimised solar PV–battery hybrid energy system, streaming tier applications. A system of mathematically informed approaches developed provides a quantitative measure of solar energy, the use of inverter systems, battery systems, and their storage systems to regulate a range of unloaded solar PV modules. A Genetic Algorithm (GA)-based multi-objective optimisation framework is used to find the optimal depth of discharge (DOD) while minimising both the Loss of Load Probability (LLP) and the Cost of Energy (COE), and simultaneously maximising the battery life and the system efficiency. The optimisation takes battery ageing behaviour, discharging, and charging efficiencies and operational constraints into account. Simulations reveal that the optimal DOD that balance’s reliability, battery cost, and longevity is 32%. At this operating point the system loss of load is completely eliminated, the battery longevity is 5 years, and there is an 85 - 90\% decrease in daily dependence on the electrical grid. The study confirms that the optimised battery depth of discharge (DOD) enhances the performance and economically feasible use of solar PV systems in aquaculture and water-resource management systems. The solution is efficient and versatile in sustainable energy use in aquatic systems and technologies.

Keywords: Solar PV–battery systems, Aquaculture power demand, Depth of discharge (DOD), Battery optimisation, Genetic algorithm (GA), Energy savings