总辐射表积尘对光伏性能比评估的影响及校正方法

Abstract We investigated the impact of pyranometer soiling on the accuracy of PV module performance ratio (PR) evaluation and also propose methods to optimize cleaning intervals for pyranometers. By comparing the soiling rates of the pyranometer and PV module at a site in Mumbai, India, we found that pyranometer soiling rates were significantly lower, ranging from 36 % to 48 % of PV module soiling rates. Soiling of pyranometers led to an underestimation of module soiling rates from PR by 30–43 %, causing delayed detection of optimal cleaning intervals. This delay resulted in substantial energy and revenue losses, as illustrated by a 100 MW PV plant case study. To address this, a daily irradiance uncertainty threshold of 1 % was established, aligning with industry standards, to optimize pyranometer cleaning frequency. The optimal cleaning interval was determined to be 3–4 days for Mumbai. We also recommend pyranometer cleaning intervals for 103 global locations, considering local soiling rates. Furthermore, we analyzed the diurnal variation in pyranometer soiling. We found that temperature-corrected PR during early morning and late afternoon hours reduces errors caused by pyranometer soiling. The proposed methodology provides practical guidelines to mitigate the effects of pyranometer soiling, enhancing the reliability of PV performance evaluation and optimizing maintenance scheduling.