Temperature Performance Evaluation of Parabolic Dishes Covered with Different Materials in Iwo, Nigeria
Solar radiation reaching the earth is considered to be affected by some parameters like diffusion. This radiation is reflected or scattered by air molecules, cloud and aerosols (dust). Parabolic dishes made of different materials (glass, foil and painted surface) were used to concentrate energy on a copper calorimeter filled with water. A thermometer was inserted in each of the copper calorimeter placed at the focus of the dishes. The experiment was performed from March to April (a period of five weeks), from 9:00am to 5:00pm daily with readings obtained at intervals of 30 minutes every day for one week and was later changed to hourly readings for the remaining four weeks. The initial and final temperatures of the water were determined. The parabolic dish with glass material gave the highest temperature of 56.9oC followed by foil with an average temperature of 48.7oC and painted silver colour with an average temperature of 45.1oC for the daily variation. For the other weeks, the average temperature of the dish with glass was 57.6oC for foil, 46.9oC and painted silver colour, 40.8oC. The parabolic dish with glass is able to generate a higher temperature compared with foil and painted silver colour.
Keywords: Glass, Foil, Silver Colour and Parabolic Dish.