Abstract:
Shading, caused by soiling deposition has drastic impact on performance degradation
of polycrystalline module and it categorized into soft shading and hard shading due
to smoke and smog particles respectively. This research was conducted in a controlled
homemade soiling station to observe the changes in the deposition trend of smoke and
smog particles due to the variation in tilt angles of PV module. The significance of
indoor experiments was to investigate the effect of specific parameters in a few hours
while the rest of all other environmental factors were kept constant. Results showed
an increasing trend of deposited smoke and smog particles with lower tilt angle and
vice versa. It was found that smog particles had more negative impact on short-circuit
current of polycrystalline module 32.4%, 28.3% and 21.4% than smoke particles
8.31%, 6.24% and 3.02% at a 10o, 33.6o and 60o after 4-cycles, respectively. The
particle size of smog lied in between 0.46μm to 7.37μm while, smoke particles had
range in 152.02 to 402.71 nm. It was studied that the number of cycles and tilt angles
had direct proportion with particles agglomeration and had inverse proportion in
particles accumulation. The deposition trend, chemical composition, morphology, and
optical losses of particles had been characterized by optical microscope (O.M),
scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDS),
fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and
Ultraviolet-visible (UV-Vis) spectroscopy techniques. This study is important in
understanding the soiling loss on surface of PV module due to different pollutants and
recommending cleaning techniques for its better performance.
