Smart tubular phase change material for PV module thermal management: Automated electrical and thermal efficiency enhancement using IoT control

A hybrid photovoltaic-thermal (PV-T) system significantly enhances the electrical power by removing the excess heat from the PV module and utilises it as a useful heat energy for hot water applications. The existing hybrid applications mainly depend on the manual water flow operation, which increases the operational cost of the system. In this study, an ESP32 IoT chip was used to automate the water flow for the developed PV with fully controlled (PVPCM-FC) and semi-controlled tubular-PCM (PVPCM-SC). The unmodified PV module (PVnoPCM) temperature was fed to the ESP32 for decision-making with the predefined water flow rate. Throughout the experimentation period, the ESP32 automatically varied the water flows between 0.2 L/min and 0.8 L/min. As a result, PVPCM-FC achieved a peak and average cooling effect of 15.91 °C and 11.39 °C, whereas the PVPCM-SC achieved 13.04 °C and 9.16 °C, respectively. Due to a reduction in PV module temperature, the corresponding electrical power and efficiency were enhanced by 1.86 W and 1.27% for PVPCM-FC and 1.4 W and 0.93% for PVPCM-SC, respectively. Overall, the combined efficiency for PVPCM-FC and PVPCM-SC was 96.72% and 83.74%, respectively, whereas PVnoPCM gained 14.53% due to the lack of thermal management. It is found that the IoT-assisted cooling method is cost-effective and suitable for commercialisation.