Increased operating temperatures of PV modules lead to reductions in output voltage, maximum power, and energy conversion efficiency. Therefore, an effective yet resource-efficient cooling strategy is essential. This study focuses on the implementation of a water-drip cooling system with an automatic temperature activation threshold control to maintain PV panel temperatures within an optimal range.
The experiment was conducted using two identical 200 Wp monocrystalline PV modules. One module was equipped with an automatic water-drip cooling system controlled by temperature sensors and a solenoid valve, with activation thresholds set at 45°C-40°C, 48°C-43°C, 50°C-45°C, dan 55°C-47°C, while the other module served as an uncooled control. Electrical parameters (voltage, current, power) and panel temperature were recorded using a microcontroller-based data logger at a 1-second interval. The tests were performed under clear sky conditions in an open-field environment to ensure maximum solar irradiance exposure.
The results demonstrate that water-drip cooling significantly reduced panel temperature, thereby enhancing power output and module efficiency. At the lowest activation threshold (45°C-40°C), the maximum power (Pmax) increased by 18.39% and conversion efficiency improved by 11.17% compared to the control module. In contrast, at the highest threshold (55°C-47°C), Pmax only increased by 10.68% with efficiency gains of 8.75%. The cooling effect was more prominent in improving maximum voltage (Vmax) rather than maximum current (Imax), consistent with the thermal behavior of silicon solar cells, where elevated temperatures predominantly cause voltage drops.
Temporal analysis revealed that the most significant cooling effect occurred during peak irradiance hours (approximately 11:00–14:00), when the surface temperature of the uncooled panel could exceed 60°C, while the cooled panel at the optimal threshold was maintained below 48°C. Under these conditions, the module efficiency was sustained above 18% despite high solar exposure. Furthermore, the water-to-power gain ratio indicated that the 45°C–40°C scenario provided the best balance between electrical performance enhancement and water usage efficiency, making it the most suitable configuration for field applications.
This study confirms that an adaptive temperature-controlled water-drip cooling system offers a practical and low-cost solution for improving PV performance in tropical climates. These findings are relevant for the optimization of small- to medium-scale solar power systems, particularly in high-temperature regions