Experimental investigation of PV module cooling using phase change materials

The high surface temperature of a photovoltaic (PV) module negatively affects its overall efficiency and power output. In the present work, the effects of various simple cooling methods, including a passive method using phase change materials (PCM) have been investigated for a 50-watt (W) PV module made of polycrystalline Silicon (Poly-Si). As a cheap PCM, the locally available wax mixed with palm oil was used for the investigated cooling approaches. Two different PCM mixes were utilized: for the copper tubes, 70% wax and 30% palm oil (melting temperature ~ 45.5ºC), and for the aluminium boxes, 80% wax combined with 20% oil (melting temperature ~ 48ºC) was used. A data-logging device for recording output power and panel temperatures during tests was developed using an ESP-32 microcontroller and several sensors (current, voltage, and temperature). The aluminium box-based PCM cooling method with aluminium fins is found to be the most effective passive cooling method with maximum temperature reduction and efficiency. With this approach, panel temperature is lowered by more than 20% when solar irradiation exceeds 800 W/m2. Furthermore, with a lower deterioration rate of 0.0584 %/ºC, the panel efficiency varies from 12.6% to 13.6%.