A novel model to estimate the cleaning frequency for dirty solar photovoltaic (PV) modules in desert environment

Accumulated dust on solar photovoltaic (PV) modules can significantly decrease their energy output in desert environment. Therefore, cleaning the deposited dust on the PV module surface is crucial in engineering applications to maintain the high power output of solar power plants, especially in desert areas. Nevertheless, it is difficult to predict the reasonable cleaning frequency for PV modules by traditional methods. In this paper, a novel model to simply estimate the cleaning frequency was developed for dirty PV modules in desert areas based on the dust deposition velocity and the relationship between deposited dust density and PV module power performance. The studied parameters are the installation tilt angles, the dust concentration in the ambient air and the representative average particle diameter. Based on this model, module cleaning frequency for desert regions is approximately 20 days when the power output reduction and particle concentration equal to 5% and 100 μg/m3, respectively. In addition, the effects of accumulation density, average particle diameter, tilt angles and wind velocity on the cleaning frequency are discussed and analyzed respectively.