Fuller, RJ, Lhendup, T and Lu Aye 2005, 'Technical and financial evaluation of a solar dryer in Bhutan'Solar 2005, Renewable Energy for a Sustainable Future - A challenge for a post carbon world, Proceedings of the 43rd Annual conference of Australian and New Zealand Solar Energy Society, 28-30 November 2005, Dunedin.

Abstract

Bhutan is a mountainous country sandwiched between India and the Tibet. Agriculture forms the backbone of Bhutan’s economy. Chilli is the most important spice crop, for both sale and consumption. As the chilli harvest season coincides with the monsoon, it is not always possible to dry chilli. It has therefore become a common feature in Bhutan to see chilli flooding the local market for a relatively short period and then disappearing until the next season. This problem could be reduced if chilli could be dried when it is available abundantly. Solar drying may be a feasible option and therefore the technical and financial performance of a proven commercial-scale solar crop dryer has been evaluated for Bhutan. The performance of the complete dryer system has been predicted to dry chilli and beef strips using the solar simulation program, TRNSYS. From the technical evaluation, the average collector, pick-up and system efficiencies were found to be 30%, 23% and 14.5% respectively for chilli. The solar contribution to the load is approximately 24.4%. Similar performance figures were predicted for drying beef. However, the current dryer does not appear to be financially viable. The net present value is negative and the benefit cost ratio is less than unity.