Drying for agricultural and marine products are one of the most attractive and cost-effective application
of solar energy. Numerous types of solar dryers have been designed and developed in various parts of the
world, yielding varying degrees of technical performance. Basically, there are four types of solar dryers;
(1) direct solar dryers, (2) indirect solar dryers, (3) mixed-mode dryers and (4) hybrid solar dryers. This
paper is a review of these types of solar dryers with aspect to the product being dried, technical and
economical aspects. The technical directions in the development of solar-assisted drying systems for
agricultural produce are compact collector design, high efficiency, integrated storage, and long-life
drying system. Air-based solar collectors are not the only available systems. Water-based collectors can
also be used whereby water to air heat exchanger can be used. The hot air for drying of agricultural
produce can be forced to flow in the water to air heat exchanger. The hot water tank acts as heat storage
of the solar drying system.