Heat transfer enhancement technology provides many advantages in heat exchanger applications. Thermal energy storage is a technology that stocks thermal energy by heating or cooling a storage medium so that the stored energy can be used later for heating and cooling applications and power generation. The experimental investigation was carried out for heat convection in tubes with significant temperature differences (400 and 600°C), which were used convective heat transfer in a tube with air-water steam and heat conduction oil in the high temperature solar thermal power generation system. From the experiment, the results recorded with an average maximum temperature for air, water, and steam up to 422.4, 413.9, and 405.7℃, respectively, with the outer wall temperature of 600℃. Similarly, for an external wall temperature of 400°C, the average maximum temperature was obtained up to 351.2, 310.9, and 308.1℃, respectively. Therefore, from the experimental results, when the How to cite this article: Ullah, F. ( 2021). Performance assessment of convective heat transfer in tubes with a temperature difference in the high-temperature solar power generation system.