Investigation of Environmental Parameters Influencing the Performance of Solar Panel and to Optimize Its Performance in Dusty Environment

Abstract

The performance of PV panel is primarily dictated by the solar radiation falling on its surface. This research study showed that the power output of the panel decreases almost linearly with the decrease in intensity of solar radiation falling on its surface. Whenever the panel experiences shading across its surface, the solar radiation reaching its surface reduces, which degrades its performance. Moreover, the experimental results indicated that the continuous shading of other cells in the PV panel increases the temperature of an un-shaded cell and glass substrate. The surface temperature of PV panel has an adverse impact on its electrical parameters. In this regard, an experiment was carried out to investigate the influence of PV panel surface temperature on its electrical parameters. The results of this study showed a significant reduction in the performance of PV panel with an increase in its surface temperature. A 5 W polycrystalline PV panel experienced a 0.39% decrease in open circuit voltage for every 1ºC increase in panel surface temperature. Similarly, there was 0.72% and 0.49% decrease in maximum power output and fill factor, respectively. Humidity is also one of the environmental parameters that affect the performance of PV panel. A laboratory study was carried out to understand the effect of relative humidity on the performance of a 20 W polycrystalline PV panel. The results of the experiments demonstrated that with 32.80% (i.e., from 65.40% to 98.20% relative humidity) increase in relative humidity level the panel power output reduced by 35.82%. The accumulated airborne dust particles on the panel surface creates a barrier in the path of sunlight, which significantly reduces the amount of solar radiation falling on the panel surface. The present study proved that the deposition of smaller size dust particles on the panel surface blocks the solar radiation more prominently compared to larger size dust particles. This reveals that the reduction in the panel performance due to the accumulation of smaller size dust particles is higher than that of the larger size dust particles. Moreover, the performance of PV panel was studied under three types of dust pollutants, namely red soil dust, lime stone dust and iron ore dust. The results ofvii this study demonstrated that the performance of PV panel not only affected by the mass of dust deposition on its surface but it also influenced by the type of dust pollutants. The reduction in short circuit current and maximum power output due to mass of dust deposition (i.e., 12.86 gm of dust deposition) on the panel surface (i.e., of area 0.1489 m2) were respectively, 39.58% and 43.18%, compared to a clean panel, after five days of its exposure to outside regime (in surface iron ore mines). However, the reduction in open circuit voltage was 4.35%, which is not of much significance when compared to short circuit current and maximum power output. To validate these field results, a laboratory study was conduted which showed 44% reduction in short circuit current and 44.75% reduction in maximum power output with 13gm of dust deposition (nearer to the field conditions) on the panel surface. Similar to field study the reduction in open circuit voltage was also low (i.e., 5.47%) in laboratory study. Thus, the deposition of dust on the panel surface having a negavative impact on its performance. Therefore, an automatic dust cleaning system was developed to clean the accumulated dust from the surface of the panel. The laboratory study was conducted with the help of developed cleaning system, using a 10W polycrystalline PV panel (which is having an area of 0.0952m2), under 442W/m2 solar radiation. This study showed an improvement of 25% in the short circuit current of a cleaned panel with respect to a dusty panel (which is created by deposition of 3gm of iron ore dust). Moreover, there was improvement in open circuit voltage and maximum power output by 2.80% and 27.98%, respectively.