Improved integrated optical model and experimental validation for bifacial solar receiver

Bifacial solar receiver is one of the main forms of solar energy utilization. However, the unique optical properties of bifacial solar receiver make performance prediction more difficult. This study proposed an improved integrated optical model, which combined an improved empirical solar model based on Linke turbidity factor with an irradiance model based on Monte Carlo ray tracing method. Also, under varying environmental conditions, an optical performance test platform for bifacial solar receiver was built to verify improved integrated optical model by comparing with the integrated results of different empirical solar models and irradiance models. The results show that, under sunny-dominated with few clouds, and partly cloudy conditions, improved empirical solar model achieves the smallest error with experiment in global horizontal irradiance compared with the existing empirical solar model available for cloudy condition (Model 1) and empirical solar model for sunny condition (Model 2), with a maximum relative error of less than 12.27 %. The irradiance prediction accuracy of view factor method under all empirical solar models tested is lower than that of Monte Carlo ray tracing method. Improved integrated optical model combining improved empirical solar model with Monte Carlo ray tracing method has the highest calculation accuracy, and the maximum relative error between simulated and experimental irradiance distribution on front and rear sides of bifacial solar receiver is less than 15.8 %. In summary, improved integrated optical model proposed in this study can realize the accurate evaluation of bifacial solar receiver optical performance under sunny and partly cloudy conditions, providing novel insights into the development of optical models for bifacial solar receiver.