Design, Construction and Testing of a Hybrid Photovoltaic (PV) Solar Dryer

Abstract

A hybrid photovoltaic solar dryer was designed, constructed and tested in the Department of Food Science and Technology, Modibbo Adama University of Technology Yola, Nigeria. The thin layer drying behaviour of tomato slices using a hybrid drying method compared to solar and open sun drying was investigated. The dryer consists of solar collector, photovoltaic solar panel, battery and drying chamber. The dryer was operated as both a solar-energy dryer and as a hybrid solar dryer. The drying performance of the dryer was evaluated with fresh tomato slice and compared with open sun drying under the same climatic conditions. The dryer recorded a raised temperature of 62℃ attainable in the drying chamber of hybrid dryer and 54oC attainable in the drying chamber of solar dryer. The moisture content of tomato slices was reduced from 94.22 % wet basis to 10 % in 6 hours for hybrid drying method while it took 9 hours to achieve the same moisture content reduction in the solar dryer. The average drying rate and the efficiency was computed as 0.0800kg/h and 71% for hybrid dryer and 0.0578kg/h and 65% for solar-energy dryer respectively. The quality of the tomato samples dried using the hybrid dryer was superior to those of solar and sun drying methods. From the result of this study it shows that a hybrid solar-energy dryer using photovoltaic (PV) solar panel suggested a promising process for adoption to preserve tomato which can prevent it from spoilage and post-harvest losses. The good quality and shelf stable dried tomato slices is indicative for a sustainable productivity that will create a sound avenue for economic growth in tomato producing regions of the world.