Development and promotion of solar dryer technology for drying of crop products in North-Western Himalayas


Principal Investigator : Dr. R K Aggarwal,Associate Professor, Department of Environmental Science, Dr Y.S. Parmar University of Horticulture & Forestry, H.P.

Co-Principal Investigator : Dr. Rakesh Sharma & Dr. S K Bhardwaj.

Contact details:

Email : rajeev1792 [at] rediffmail [dot] com  Tel No. :01792-252023

Thrust Area : Harnessing & conserving Renewable energy

Project Area : 10 villages of four to six blocks of Four Districts of Himachal Pradesh


  • To study the physico-chemical and sensory quality evaluation of solar dried products. 
  • To standardize packaging and storage requirements for dried products.
  • To study the shelf life of dried products.
  • Demonstration, installation and popularization of the developed technology.



  • A modular indirect solar drier with thermal storage system, temperature controller, and dry air at inlet has been developed.
  • The physico-chemical quality parameters of Pomegranate, Dhingri, Red chilli, Apple, Peas, Tomatoes, Kiwi have been studied and tabulated
  • The shelf life of the abovementioned dried products has been studied and tabulated
  • 10 solar driers have been installed at different locations in HP and UK.
  • 11 awareness training programs have been conducted.
  • 7 technical trainings for carpenters were organized in the field.
  • Indirect solar dryer developed for the drying of fruits, vegetables, seeds and medicinal plants.
  • A thermal storage system comprising of iron scraps and gravel has been provided at the bottom of solar collector, and covered with aluminum sheet to increase its efficiency.
  • Thermocol insulation has been provided at the bottom of solar air heater to reduce heat loss.
  • 7 crops (Pomegranate, Red Chili, Dhingri, Kiwi, Apple, tomato and green peas) have been dried in solar dryer and compared with open sun drying and electric oven.
  • The quality parameters like TSS, reducing sugars, total sugars and pH of dried products were compared with three modes of drying.
  • Water activity of dried products has also been determined to work out shelf life of dried products.
  • The samples (with treatment and without treatment) of each crop were dried in open sun, electric oven and solar dryer. The shelf life of the dried products has been worked out.
  • 11 awareness training camps for farmers have been conducted.
  • 7 trainings of two days' duration each, have been organized for carpenters in the field.
  • 2 specialized technical trainings were organized at Nauni campus for carpenters from UK and HP.
  • 17 solar dryers have been installed at different altitudes in HP and UK.(11 under the project and 6 were installed at beneficiary cost)
Solar dryer technology Solar dryer technology and the dried products
Solar dryer technology and the dried products Solar dryer technology and the dried products
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