A Real-Time Evaluation Strategy of the Dust Deposition Based on Irradiance Comparison for Photovoltaic Panel

The energy efficiency of the photovoltaic (PV) panel is greatly influenced by the dust deposition, especially in a PV plant covering a wide area. However, hitherto there has been a lack of a real-time measurement technique for the dust deposition degree. To solve this problem, in this paper, some evaluation indicators are defined, and then a real-time evaluation strategy is proposed. In order to calculate these indicators, a method and three simplification methods based on some established equations (or equation sets) are proposed to obtain the equation solution for the irradiance. This solved data is compared with the irradiance directly measured by the sensor, so the dust deposition degree can be successfully evaluated. Finally, some simulations and experiments verify the feasibility, availability and workability of the proposed irradiance solution methods and the designed evaluation strategy. The simulation and experiment results show that the errors of the solved irradiance values are always less than 2.5%. Meanwhile, these results also show that the real-time dust deposition degree can be successfully characterized by the defined indicators in this evaluation strategy, even if it is compared with other work. Therefore, this work is very beneficial to judge the energy efficiency of the PV system and plan the cleaning schedule of the PV panel.