Effect of dust and weather conditions on photovoltaic performance in Doha, Qatar

Photovoltaic (PV) power generation performance in desert environments is affected by surface soiling due to dust deposition. In this study, PV performance, ambient dust and weather conditions were measured continuously from June 1 through December 31, 2014 at a solar test facility in Doha, Qatar. Averaged over the seven months, the PV performance loss due to soiling was 0.0042+/-0.0080 per day for modules cleaned every sixth month, and 0.0045+/-0.0091 per day for modules cleaned every second month, in terms of a “cleanness index” based on the PV module's temperature-corrected performance factor. The daily change in a PV module's cleanness index was negatively correlated with the daily average ambient dust concentration, positively correlated with wind speed, and negatively correlated with the relative humidity. A multivariable regression model was developed to quantitatively relate the daily change in PV module cleanness index with the dust concentration, wind speed, and relative humidity. From the results of this study, it is clear that dust deposition on PV panels can cause significant loss in PV power generation in Qatar. Additional research is needed to refine the mathematical PV power generation performance and the ambient environmental variables, so as to enable accurate simulation of PV solar power plant performance based on environmental data.