The transition to renewable energy, specifically solar panels, is increasingly popular. There has been an innovation to place solar panels floating on water. However, floating solar panels (FSP) affect the water quality parameters below them. This study aims to analyze the concentration of water temperature, dissolved oxygen (DO), and biochemical oxygen demand (BOD) spatially in the area surrounding the FSP in Lake Mahoni, examining the influence of air temperature on water temperature as well as the influence of water temperature on DO and BOD. During three weeks of observations, samples were collected from 9 sampling points around the FSP, once a week in the morning and afternoon. Data processing and analysis were performed using descriptive statistical methods, normality tests, comparative tests, correlation tests, and spatial mapping. The highest results indicate DO, BOD, and temperature changes between the upstream area and below the FSP ranged from -1.77 to 0.48 mg/l, -2.68 to 1.78 mg/l, and -0.50 to 0.60°C, respectively. Conversely, the highest changes from below the FSP to the downstream area ranged from -1.55 to 4.54 mg/l, -1.91 to 3.34 mg/l, and -0.30 to 0.80°C, respectively. Water temperature and DO show patterns below the FSPs area, but no pattern is observed in BOD. A significant positive correlation was found between air and water temperature (ρ=0.945, p=0.005). A significant correlation was observed between water temperature and DO (ρ=0.87, p=0.002) and BOD (ρ=0.803, p=0.009) upstream of the FSP in the afternoon. In contrast, there was no significant influence on water temperature, DO, or BOD in the morning (P>0.05) in the upstream area and below the FSP. © The Authors, published by EDP Sciences.