Research and analysis of heliostat optical efficiency based on data envelopment analysis

This paper establishes a model for the tower solar heliostat field to calculate optical efficiency performance indices, including cosine efficiency, shadow blocking efficiency, truncation efficiency, and atmospheric transmittance. The data envelopment analysis method is used to score and analyze all the indicators affecting the energy efficiency. This provides theoretical support for the design end optimization of the heliostat fields. The study shows that the cosine efficiency DEA score is $\mathbf{0 . 9 9 9 9}$, the shading efficiency DEA score is 0.9762, the truncation efficiency DEA score is $\mathbf{0 . 8 8 9 0}$, the atmospheric transmittance DEA score is $\mathbf{0 . 8 2 0 9}$, and the mirror reflectivity DEA score is $\mathbf{0 . 8 7 2 5}$. It can thus be concluded that the cosine efficiency is the most significant factor influencing the energy efficiency of solar heliostat fields, followed by the shading efficiency. In the design of heliostat fields, it is therefore essential to give priority to the effects of cosine efficiency and shadow masking efficiency on optical efficiency, in order to enhance the overall performance of solar power generation. The findings of this study are of significant value to the field of solar thermal power generation.