Design and simulation of integrated solar-hydroelectric systems: Complementary renewable profiles and MATLAB/Simulink-based analysis

The increasing penetration of renewable energy sources necessitates the development of hybrid energy systems capable of ensuring reliability, economic viability, and operational flexibility. This study investigates the optimal design and techno economic performance of a hybrid renewable energy system (HRES) integrating photovoltaic (PV) generation and hydropower for a selected case study in Türkiye. In this study, a Solar-Hydroelectric (SHE) hybrid system was designed and modeled using MATLAB/Simulink. The system is designed to supply an annual electrical load of approximately 10,500 MWh, while minimizing total system cost and improving energy reliability. A comprehensive optimization framework is employed to determine the optimal capacities of the SHE facility. The results indicate that the optimal configuration consists of 4.375 MW of PV capacity combined with an existing 3.065 MW of hydropower, enabling effective load coverage throughout the year. The total initial investment cost of the proposed system is estimated at 3.3 million USD, with an annual operating cost of 150,000 USD. The hybrid configuration achieves a levelized cost of energy (LCOE) of 0.02685 USD/kWh, which is lower than that of comparable single source hydroelectric power plant (HEPP) systems. The integration of solar PV significantly reduces hydropower dependency during dry seasons and enhances overall system flexibility. In addition, the hybrid system improves energy utilization and reduces curtailment while maintaining supply reliability. Also, an enhanced MATLAB/Simulink design is demonstrated in this study. The findings demonstrate that solar-hydropower hybridization represents a technically feasible and economically competitive solution for expanding renewable energy deployment in Türkiye. The proposed approach provides practical insights for policymakers and energy planners aiming to develop cost-effective and sustainable hybrid energy systems.