Conclusions
Many environmental parameters affect the energy production from photovoltaic modules and dust could be one of the main reasons for its degradation. The dust, which represents a mixture of different pollutants, is determined by the geographical site. Important ambient conditions that affect dust characteristics are variation in wind velocity, direction and magnitude, humidity, rain amount and instantaneous intensity and seasonal variations. Due to the fact that they are systematically studied in various locations of the Earth, the PV dust accumulation phenomena can be better understood and addressed. This study was performed in order to investigate the natural dust accumulation process on the front cover glass of PV modules during the non-heating season in one of the most polluted European cities, Kraków, in different meteorological conditions. The time-dependent particle deposition and their correlation to the air pollution with particulate matter were analysed. The data contained in this paper will be useful for prediction of dust deposition on the basis of environmental conditions which are of interest to system developers and operators.