Abstract:
The application of flat heat pipes on solar panel cooling was studied. The solar panels used in the test were amorphous type (thin film) of 1.25 m X 1 m size and the rated power was 140 watts at the standard temperature of 25 oC. However, when the solar panels were used in actual conditions, the solar panel temperature was higher due to accumulated heat. As a result, the power production was reduced. So the objective of this study was to reduce the solar panel temperature and to increase the power of generation by comparative testing between the normal solar panel and the solar panel equipped with flat heat pipes. The heat pipes were copper pipe with inner thread acting as a wick for pumping liquid from evaporator portion back to the condenser portion. The heat pipe of 7 units were used. Each heat pipe consisted of a flat evaporator portion jointed with a round condenser portion. The distilled water was used as the working fluid. The evaporator was attached to the back of the solar panel with the silicone in between as the heat transfer paste. In testing, the normal solar panel and the solar panel equipped with heat pipes were placed in the area where both panels received the same solar radiation at all time. The solar intensity, the temperature and power of both panels, and the ambient temperature were recorded at every 15 minute between 11:30 am and 15:30 pm for a period of 11 days. From the result, it was found that the temperature and electric energy of normal solar panel were 59.7 oC and 2,090 Wh respectively, and also the temperature and electric energy of solar panel equipped with heat pipes were 57.3 oC and 2,340 Wh respectively, at the average environmental temperature of 37.4 oC. In conclusion, solar panel equipped with heat pipes reduced the panel temperature of 2.4 °C and increased the electric energy of 250 Wh or 12 % from the normal solar panel.