Performance Analysis of Solar Dryers for Agricultural Produce Preservation in Zamfara State, North West Nigeria

Post-harvest losses in Zamfara State, North West Nigeria, are exacerbated by inadequate and unaffordable drying technologies, resulting in significant food and income losses for farming households dependent on grain and vegetable production. This study analyses the technical performance of locally fabricated solar dryers for drying tomatoes, groundnuts, and maize in selected farming communities of Zamfara State. Three solar dryer designs, including an indirect forced convection dryer, a direct passive dryer, and a mixed-mode solar dryer, were fabricated and tested under field conditions across two post-harvest seasons. Temperature profiles, drying rates, moisture reduction efficiency, and product quality outcomes were measured and compared against traditional open-sun drying methods. Energy performance metrics including collector efficiency and system coefficient of performance were computed for each design. Results demonstrate that the indirect forced convection dryer achieved moisture reduction from 65 percent to 12 percent in tomatoes within nine hours, outperforming open-sun drying which required two to three days with significant microbial contamination. Cost analysis shows that locally manufactured solar dryers reduce drying costs by 52 percent relative to conventional fuel-powered driers. The study recommends integration of solar dryer fabrication curricula into vocational training centres operated by the Zamfara State Agricultural Development Programme. Keywords: solar dryer, agricultural preservation, post-harvest losses, Zamfara State, food security.