Seasonal Trends of Soiling on Photovoltaic Systems

This work investigates the seasonal variability of photovoltaic soiling losses over a 12-month period for 15 soiling stations deployed in the USA. We present a new parameter able to rank the sites according to the cumulative losses occurring over 3- and 6- month periods. The relations between soiling losses and particulate matter are briefly discussed, as well. Moving from long-term to shorter-term data increases the complexity of the analysis: monthly correlations are found to have lower accuracy than the longer-term ones presented in the literature.