Development of a Solar Paddy Dryer with Hybrid Heating System

This study is about the development of a fixed-batch solar paddy dryer integrated with photovoltaic power source which provide the required power for integrated components other than solar collector and heat tube and a power source for the alternative water heating system. Thermal energy coming from the sun was collected using evacuated heat tubes. The thermosiphon effect allows the hot water from the tank to flow in the copper tubes, which serves as the heater to dry up the grains and acquired the desired moisture content. A hybrid heating system was implemented to somehow improve the performance of the dryer. Data logging of temperature, moisture, voltage, and drying time was done automatically using sensors and microcontroller. The result showed that the dryer was able to dry the paddy, i.e., to reduce the moisture of paddy NSIC RC222 to around 14% which is the milling requirement, in 47 minutes, the shortest average time which occurred at 12:00 PM time of day while the longest average drying time was 83 minutes which occurred at 4:00 PM.