Solar energy has been used for time immemorial by man for his energy needs. The intensity of use of solar energy also increased as human race progressed through the initial ages when sun was put to use not only for warmth, but also for productive applications.
Drying was perhaps the most important of such productive applications. Drying of food grains, fruit and meat for storage, drying of timber and firewood, drying of earthen utensils, etc. were some such productive applications where sun’s energy was put to effective use.
We can say that food drying is a very simple ancient skill. It requires a safe place to spread the food where dry air in large quantities can pass over and beside thin pieces. Sun is often used to provide the hot dry air. Dry, clean air including dry cold air from any source will dehydrate food. Draping food over branches or spreading it on wide shallow baskets on the roof is an old widespread tradition still in use around the world. Many other arrangements have been used to support a thin spread of food pieces. Some options that have been used are to thread the pieces on a cord or a stick and hang it over a fire, wood stove or from the rafter. Or one can bundle herbs or strawflowers and suspend them from bushes or a door knob or nails in rooms with good ventilation. Read More »Use of solar energy for preservation of agricultural products