Comparison between performance of man-made and naturally cleaned PV panels in a middle of a desert

Abstract Two sets, each contains eight PV panels, were selected from this PV array. The first set consists of the first panel in each row of the PV array panel and the other set consists of the last panel in each row. The first set was man-made cleaned only once (on 1st October 2014) during the period from Nov.2013 to Feb 2015 (called “Clean”) and the other set were not cleaned at all and is left to nature (called “Dirty”). The study reveals that the average actual solar electricity produced by each PV panel in Set A (1.0612 kWh) is more than the expected (from the developer) by 16% and is less than the expected (from the literature) by 7.2% while for Set B the actual daily solar electricity from each of these “dirty” PV is found to be 0.9687 kWh and is more than the expected (from developer) by 5.9% and is less than the expected (from the literature) by 15.3%. For 15 months span, the Dirty PV panels (Set A) will produce, in average, less solar yield than the Clean by about 9%. The study also reveals that the monthly solar electricity gained from the two sets is less than expected by 45% ( in October), followed by 37% (in November), due dust accumulation if panels were not cleaned once a month. However, the annual loss in solar electricity reaches 7% if panels cleaned only once a year while it reaches 17% if not cleaned at all but left for naturally cleaning. The annual yield (year 2014) from this solar station was 716.7 MWh which could reach 839 MWh if cleaned once a month, i.e. loss in solar electricity of 122 MWh. The correlation between the produced solar electricity compared to the expected versus the day of the year for the two sets was made and it is found to have an acceptable R value.