Comprehensive investigation for power degradation of dust-covered photovoltaic modules based on the overlap model: A case study

Abstract

Dust accumulation on photovoltaic (PV) modules is a common and frequent issue. To investigate the effect of dust on PV module power degradation, this study proposes a dust shading lifetime degradation model for PV modules based on the overlap model. Evaluating the service life of PV modules without considering power generation efficiency is of limited value. Therefore, this study conducted two case studies on dust-covered PV modules, investigating the effects of dust accumulation on the power performance and power degradation of PV modules. The results indicate that while dust accumulation may prolong the service life of PV modules, the increase in power generation due to extended life is insufficient to offset the losses caused by reduced efficiency. Additionally, the short-circuit current of dust-covered PV modules is negatively correlated with dust deposition density, whereas the open-circuit voltage remains largely unaffected. A quantitative relationship between short-circuit current and dust deposition density was established. Power loss due to dust accumulation is more pronounced at high irradiance levels, and under strong irradiance, dust accumulation slightly reduces the module temperature. The rate of solar-induced degradation was found to be positively correlated with dust deposition density and negatively correlated with particle size. Finally, the accuracy and reliability of the proposed lifetime model were validated based on experimental verification.