FABRICATION AND TESTING OF A BOX TYPE SOLAR COOKER

Abstract

A model box solar cooker (BSC) was fabricated using locally available low cost materials. The BSC was compared with a renowned reflector solar cooker (CooKit) for thermal performance in heating water. The BSC and the CooKit constituted the experimental treatments in this study and each solar cooker type was replicated three times in a completely randomized design (CRD). The cookers were placed in a sunny spot away from buildings and trees to avoid shading. Six black plastic water bottles (800 ml) were filled with 700 ml of distilled water and placed in the centre of each cooker for energy generation monitoring. Each bottle had a hole drilled in the lid to accommodate an ordinary thermometer. The experiment was conducted on three selected days in January, February and March, 2014. Each trial run started at 10:00 hours and ended at 17:00 hours, with water temperature recorded every 10 minutes. The BSC recorded significantly (P < 0.05) higher peak water temperatures of 87C in January and 85.67C in February and these corresponded to mean energy gains of 0.17 MJ and 0.12 MJ, respectively, compared to 79.3C and 53.87C peak water temperatures (corresponding to 0.12 and 0.11MJ) recorded in the CooKit in the same months.. However, the mean cumulative energy generated by the CooKit (0.16 MJ) in March was significantly (P < 0.05) higher than 0.11 MJ gained in the BSC. These preliminary results have shown that the locally fabricated BSC has potential to provide adequate energy for pasteurising and possibly cooking various food products. Being a design based on local materials, it offers advantages of empowering local artisans and creating employment. It is recommended that further tests be conducted under varying weather conditions in order to identify points of possible design improvements before wide spread promotion.