Solar Dryers for Post-harvest Processing: An Alternative Approach for Conventional Drying Methods

Abstract

Fossil fuels and electricity are widely used as energy sources in most drying systems which results in high operational costs and environmental problems by increasing greenhouse gas (GHG) emissions. As a result, food producers have shifted towards clean energy-based technologies such as solar thermal energy in both direct and indirect form. Post-harvest losses are one of the major livelihood challenges for farmers. The use of drying technologies to preserve agricultural products has been promoted as a particular solution to overcome this challenge. Solar drying is one of the most efficient and cost-effective, renewable, and sustainable technologies to conserve agricultural products. This paper presents the different types of solar dryers that are widely used and details of construction and operational principles of the wide variety of practically-realised designs of solar-energy drying systems. Compared to open sun drying, the passive indirect solar dryer reduced drying time and increased the thermal efficiency. This study evaluates the performance of a solar dryer, a sustainable alternative to conventional food preservation technologies.