About 20-30% of food grains, 30-50% vegetables, herbs, and fruits are lost right on farm before they reach the markets. Food security is under threat due to post harvest loss of tubers, grains, vegetables, spices, fruits, and herbs. Even fishes and meat are not left out of this loss. The most viable, cost-efficient and safe method of eliminating post-harvest loss of food items/materials is Solar Drying. Basically, Solar drying employs natural convection, forced ventilation, solar radiation (from the sun), and the greenhouse effect for effective drying. The benefits of solar drying in post harvest management cannot be overemphasized.
Benefits of Solar Drying
- Solar drying preserves food materials for proper storage. The food material nutrients, taste, colour essential oil and other inherent properties are better preserved by solar drying.
- Solar drying is more hygienic and efficient than traditional open sun drying.
- Solar drying shields food material from dust, insects, birds, roaming pests, and microbial contamination.
- Solar drying prevents spoilage, improves product hygiene, storability, availability, marketing, and profitability.
- Solar drying improves farmers’ income, food safety, food security, and food availability.
- Materials that can be solar-dried are but not limited to; Moringa leaves, Chilli pepper, Okra, Ugu leaves, Melon, Thyme, Coriander, Stevia, Tea, Curry, Basil, lemongrass, Garlic, Ginger, Tumeric, Herbs, Spices, Crayfish, Melon, Cassava chips, Yam chips, Potatoes chips, Plantain chips, Banana slices, Bitter leaves, Hibiscus flowers (Zobo), Utazi, Melon, Mango slices, Black pepper, Coffee, Cocoa beans, Maize, Fish, meats, livestock feed, etc.
Types of Solar Dryer
Basically, we have Passive Solar Dryer (PSD) and Hybrid Solar Dryer (HSD). PSD uses only solar radiation (from the sun) and natural ventilation for drying materials. It has a small drying capacity while HSD uses solar radiation (from the sun), forced ventilation (heat extraction fans/Blowers), and optional external heating sources (from gas, charcoal or electricity) for improving internal temperature and drying efficiency especially when sunlight or heat captured is not sufficient. It has a bigger drying capacity.
The solar dryer can also be classified according to shape and they include Solar Tunnel dryer, Solar Greenhouse Dryer, Solar Brick Dryer, Solar Tent Dryer, Solar Box dryer, Solar Cabinet Dryer, etc.