Fotovoltaik Panellerde Gölge Ve Toz Etkisinin Analizi
Özet
In the present study, the effect of dust deposition and shade on 5 Watt mini photovoltaic (PV) panels was analyzed through outdoor fieldwork and indoor laboratory experiments. For the outdoor field tests, two groups of mini PV panels were set up at five different angles within a range of 6°–50° in the Hacettepe University Solar House garden, with one group being manually cleaned and the left for dust to accumulate. The effects of daily dust deposition and accumulated dust deposition were analyzed by measuring the short circuit current, the temperature and radiation values for each panel at noon on clear and sunny days, normalizing the short circuit current values to 1000 W/m2 and 25°C standard test conditions. It was observed that the short circuit current value of the cleaned panels was higher than the uncleaned panels under the effect of the daily dust deposition, and that after cleaning the dust from the surface, panel performance improved. It was also observed that the level of dust deposition reduced as the angle of tilt was increased. In addition to manual cleaning, the effect of natural cleaning though such means as rainfall was also analyzed. Increase occuring in dust deposition on some rainy days shows that rainfall may cause the accumulation of dust instead of cleaning the dust.
In the indoor laboratory experiments, artificial dust deposition and artificial shading experiments were carried out using powdered red clay, yellow silty soil and silty sand samples as artificial dust depositions. The current-voltage (I-V) characteristics of the PV panels under illumination were analyzed by scattering various amounts of dust onto the panels in a homogeneous manner, and it was observed that the obtained power decreased as the density of the three different dust deposition materials increased. Experiments were conducted for the 6°–40° tilt angle range, and it was observed that as the tilt angle increased, the amount of dust on the panel decreased, and that the normalized power value decreased with increased dust density. Red clay soil was mixed with water and sprayed onto the panel, and it was found that more power was obtained than with the same amount of red clay soil but without water. In order to analyze the effect of shade under laboratory conditions, the I-V characteristics of the panels under illumination were analyzed by creating homogenous shading and partial shading in different directions using cardboard, tissue paper and waxed paper. Under the shaded conditions simulated using waxed paper, which has high permeability, higher power values were obtained that with cardboard and tissue paper. Although the I-V, P-V curves linearly shift as the shading rate increases under homogenous shading conditions, the panel behavior without bridging diode at partial shading is analyzed.
