Solar Cabinet Dryers: An Initiative by SEED

Solar dryers are devices that use solar energy to dry substances, especially food. Generally, direct solar cabinet driers are used to dry small quantities of food or vegetables in moderate drying temperatures (45–55°C) and airflow rates. Society for Energy, Environment and Development (SEED) was founded in 1987 by a few professionals with expertise in engineering, management, solar energy, law, and social work. The purpose of this NGO is to draw upon the expertise of these fields of study to create awareness about the environment and energy issues and creating devices to enhance the quality of life. SEED promotes community development activities under a four-fold programme of employment, entrepreneurship, health and education.

‘SEED’ Solar Cabinet Dryers are becoming popular from micro enterprise level to industrial level. The dryers have been designed and developed with different models indicating the different capacities of the products and to different climatic conditions in the country. Table 1 presents the specifications of these dryers.

All of them are commercialized and 225 solar dryers of different models with varying sizes have been installed in 15 states in India and exported to countries, such as Australia, Mauritius, Malaysia, Saudi Arabia, and Tanzania. Some of the large sizes are to be transported to different places in India for installation in knock-down conditions and two engineers are to be deputed for installation and demonstration of solar dryers at site. These installations are for processing of fruits, vegetables, and fish at different locations in India as well as in other countries.

Installation of Dryers in Leh, Ladakh

Two solar dryers of SDM-200 and SDM-100 models were supplied and installed at two educational institutions of the same campus, namely, Sher-e-Kashmir University of Agriculture Sciences & Technology and Krishi Vigyan Kendra, Leh, Ladakh. After installation, training was imparted to the staff of the educational institutions of the University. These dryers are used for drying of fruits and vegetables, such as apricots, tomatoes, etc. The performance of SDM-200 and SDM-100 is given in Table 2.

These are high-efficiency solar cabinet dryers whose design was improved by insulating cabinet walls for reducing thermal losses. This enhanced temperature in the cabinet at about 60°C at 1.00 P.M. when the temperatures during day time are 15–18°C in the morning. This was in the month of June in 2016. The temperature between ambient and cabinet dryer are about 41°C at noon in the two places of Sher-e-Kashmir University of Agriculture Sciences & Technology and Krishi Vigyan Kendra, Leh, Ladakh. This is the highest temperature in the cabinet dryers during the season and most suitable for drying of apricot and tomatoes to increase the shelf life and to add value to the products. This gives an excellent performance of the cabinet dryer in areas with difficult terrain and living conditions to give an opportunity for local population to add value to their local produce with zero energy cost.

Impact of Solar Dryer in Mitigating Climate Change

The ‘SEED’solar cabinet dryer operates entirely on solar energy, which is eco-friendly. The energy cost of the operation of the dryer is zero. In addition to this great advantage, it operates on zero-carbon emission. Also, it is a clean and non-polluted energy source. The total impact of solar dryer is given in Table 3.

Conclusion

The University authorities certified that the solar dryer performance is the best and very useful for drying of fruits and vegetables. Earlier also, ‘SEED’supplied four solar dryers of SDM-50 model to Ladakh Ecological Development Group, Leh, Ladakh. The overall performance of solar dryers is best suitable for drying fruits and vegetables grown in the Himalayan region.

Prof. M Ramakrishna Rao and Mr G Harikrishna, Society for Energy, Environment & Development (SEED), Hyderabad, India. Website: seed@seedngo.com