Comparative analysis of tree leaves and paper shading materials on solar photovoltaic performance in Makindye, Uganda

Shading is a major factor affecting the reliability and efficiency of photovoltaic (PV) systems, particularly in tropical urban areas where incident solar radiation is frequently blocked by trees, buildings, leaves, and paper litter due to moving wind. This study examined the effects of paper shade and Ficus lyrata leaves on the electrical performance of a 40 W monocrystalline solar panel in Kansanga, Makindye Division, and Kampala, Uganda. As part of an experimental design, the panel was exposed to unshaded conditions as well as one, two, and three layer shading configurations using paper and leaves. Solar radiation, ambient temperature, cell temperature, voltage, current, power output, and panel efficiency were also calculated. The experiment was conducted between 9:00 a.m. and 5:00 p.m. for 80 days. The effects of shading intensity and material type on panel performance were assessed using descriptive statistics, regression, correlation, and analysis of variance (ANOVA). The average voltage (24.85 V), current (1.22 A), power production (30.24 W), and efficiency (12.61%) were all highest on the unshaded panel. The average power output dropped from 15.28 W to 7.45 W and efficiency from 5.70% to 2.90% under leaf shadowing, while the average current fell from 0.64 A for one leaf layer to 0.32 A for three layers. More significant performance losses were caused by paper shading, which decreased the average current from 0.43 A to 0.21 A, the power output from 10.35 W to 4.80 W, and the efficiency from 4.21% to 1.88%. Paper shaded conditions showed a stronger correlations (r = 0.63) than leaf-shaded situations (r = 0.58), according to correlation analysis. According to regression analysis, leaf shading explained only 9.1% of the difference in panel efficiency (R 2 = 0.09, p = 0.06), but paper shading explained 35.3% (R 2 = 0.35, p < 0.001). Similarly, 14.4% and 12.8% of the difference in power output were explained by shading by paper and leaves, respectively. The results show that shading dramatically lowers solar performance, and because paper has a lower light transmittance than leaves, it causes more electrical losses. In order to improve solar energy output in tropical areas, the study emphasizes the significance of appropriate panel positioning, regular cleaning, and plant control.