Abstarct: Abstract In recent years, photovoltaic (PV) systems have become one of the most promising sources of clean and renewable energy. However, the temperature rise on the surface of PV panels due to direct solar radiation leads to a decrease in electrical efficiency and lifetime. This study aims to improve the thermal and electrical performance of PV panels by employing oscillating heat pipes (PHPs) as a passive, self-sustained, and high-efficiency cooling method. PHPs transfer large amounts of heat through the natural oscillation of liquid and vapor phases without requiring additional electrical power. The research methodology consists of both numerical and semi-empirical approaches. In the numerical part, a two dimensional model of the two-phase flow and thermal field inside the PHP was developed using the Navier–Stokes equations and the Volume of Fluid (VOF) method in ANSYS Fluent. Real solar radiation and heat flux boundary conditions were applied to simulate realistic operating environments. In the semi-empirical approach, a simplified predictive model was developed baxsed on the numerical data to accurately estimate the thermal behavior while significantly reducing computational time. The effects of working fluid type (water and ethanol), pipe turns, and filling ratio on the system performance were systematically investigated. temperature by 12–15 °C on average and enhances cooling efficiency by up to 43% compared to the non-cooled case. The proposed semi-empirical model demonstrates high predictive accuracy and can be applied for fast and optimized design of passive PV cooling systems on an industrial scale. Overall, PHP-baxsed passive cooling provides an effective and economical solution to enhance the stability and performance of