Multi-Factorial Assessment of Inclined Surface Solar Radiation Using Photovoltaic Data and Solar Radiation Transposition Models: A Case Study in China

Abstract

Power generation of photovoltaic~(PV) panels depends on the solar radiation directly incident on the inclined surface. The precise acquisition of solar radiation on an inclined plane is a matter of interest to scholars. This study conducts a comprehensive analysis of the performance and applicability of solar radiation transposition models, with a focus on PV data from Wuhan and Zhangbei in China. Twelve solar radiation transposition models, including both isotropic and anisotropic models, are employed in this research to evaluate their accuracy under different latitudes. By using actual PV power generation data, along with some evaluation metrics, the study validates the predictive performance of these models. The results indicate that anisotropic models, particularly the Hay model, exhibit superior prediction capabilities. This model, which accounts for a more comprehensive range of scattering radiation components, provides more accurate estimates of inclined surface radiation compared to isotropic models. In multi-month analyses for both Wuhan and Zhangbei, all the R² of the Hay model exceed 0.98, demonstrating stable radiation predictions across different seasons and latitudes. The findings of this study provide essential theoretical support for optimizing the tilt angle of PV panels and enhancing energy conversion efficiency. The Hay model, in particular, is recommended as the best choice for estimating inclined surface radiation in China and similar climatic conditions.

Keywords: Solar radiation Transposition models Anisotropic models Isotropic models Power generation