Impact of natural soiling on the transmission of PV cover plates

Deposition of dust on PV panels has been shown to decrease the energy production of the panel. In this study dust was allowed to accumulate on glass plates, similar to those used for PV cover plates, in Commerce City Colorado. The plates were exposed to the environment for varying lengths of time and at several tilt angles in order to accumulate varying amounts of dust. The amount of dust and the transmission through the glass plate were measured. Results showed that the light transmission was significantly effected by dust accumulation. For dust accumulations of less than 1.5 g/m², light transmission was reduced by 6% per g/m² of dust accumulation. Additionally the data indicate that incidence angle does not impact the transmission reduction caused by dust deposition.