Experimental assessment of a new prototype solar dryer integrated with a photovoltaic system

Abstract

An indirect solar dryer is a system designed mainly to dry food and crops using solar energy. Unlike direct solar dryers, where products are directly exposed to solar radiation, indirect solar dryers use an air circulation system to transfer the sun’s heat to the products, avoiding direct exposure, thus preserving their quality and properties while harnessing a renewable energy source. Therefore, in this study, a new solar dryer prototype consists of an electrical resistance equipped with a photovoltaic system was designed and evaluated. The measurements were taken in the eastern region of Morocco (mechanical and energy laboratory at the technopole centre)in August 2023, during which tomatoes with an initial moisture content of 92.45% were taken as a sample for assessing the overall efficiency of the new prototype. The main purpose of this work is to solve the problem of non-uniform drying rate of products within the same drying tray. When evaluating the new prototype against the conventional indirect solar dryer, the main parameters taken into account were moisture content, temperature at different positions and variation in drying efficiency. According to the results, the drying efficiency of the new prototype ranges from 60% to 100% throughout the day. Additionally, over a 7-hour drying period, the moisture content of all five samples from the new prototype decreased by 35.45%, while the moisture content in sample A of the conventional indirect solar dryer decreased by 27.95%.