Rural Technologies

Solar power as a source of renewable energy is very useful in drying food items. Many places in rural India as well as urban India do not get sufficient power supply throughout the day. In such places, solar dryer can be useful devices for drying food items hygienically. Apart from solar radiation and natural convection of air currents in the dryer, one more feature has been added to improve the drying of fruits and vegetables. The feature is based on simultaneous generation of electricity by a solar panel and using it for creating an induced draft of air by fans installed in the dryer. These installed exhaust fans are run to force moisture-laden air outside the dryer. This dryer achieves sufficiently high chamber temperature and dries product in accelerated manner. The solar dryer with the capacity of 25 kg of fresh food per batch is used for drying tomato slices, brinjal slices, potato wafers, green chilies, apricot pieces, mango slices, grapes, fish etc. By use of this dryer, the drying process is made 1.5 times faster than normal sun drying procedure resulting in substantial weight reduction.