An analytical indoor experimental study on the effect of soiling on PV, focusing on dust properties and PV surface material

Photovoltaic technology penetration is experiencing noticeable progress. However, its performance is significantly affected by soiling, which is influenced by several factors such as site characteristics, weather, tilt angle and surface orientation, surface material and dust properties. This indoor study investigates the effect of soiling on photovoltaic modules, focusing on dust properties and PV surface materials as influencing factors. A Solar simulator, spectrometer and SEM/ EDX were used to characterise and investigate the effect of accumulation of 13 different samples (ash, bird droppings, carpet dust, cement, charcoal, clay, coarse sand, laterite, loam soil, salt, sandy soil, stone dust and wood dust) on PV performance. The findings develop upon previous studies on the effects of dust particle accumulation on PV performance by using more dust samples and applying more rigorous techniques. The results show that charcoal appears to have the worst degradation effect on PV performance with about 98% reduction in short circuit current while salt seems to have the least impact with about 7%. The influence of 2 PV surface materials (acrylic plastic and low iron glass) on dust accumulation were examined, and results show that the acrylic plastic accumulates more dust when compared to low iron glass. Results also show that dry deposition has a reduced adhesion to the coupons compared to wet deposition. The findings could be used in selecting PV farm sites by avoiding areas with high pollution, and it could stimulate further research on selecting an appropriate mitigation technique. The ramifications caused because of soiling cannot be overlooked or overemphasis; as such there is a need to identify appropriate and cost-effective mitigation techniques that can continue to promote the global penetration of PV technologies and sustain its performance.