SOLAR AIR HEATING PROJECT
TEA DRYING / WEST JAVA, INDONESIA
A solar tea leaf dryer was installed at a plantation in Malabar, West Java, Indonesia. The perforatedcollector system was built with the assistance of the R&D Centre for Applied Physics – LIPI, and was funded by the Canadian government in cooperation with the Association of South East Asian Nations(ASEAN). The purpose of the project was to determine the feasibility of using solar energy to displace oil as the heating system for the wilting of tea leaves. The solar air heating system SAH was ableto meet the full heating load for tea drying at a payback of 1.5 years, not including design and development costs. New projects would have to include these, but they would be offset by credits foreliminating the fossil fuel heating system.
The system is designed to wilt tea leaves through a batch process using the existing drying troughs and shelter. The troughs aremanually loaded with tea leaves from a trolley that moves through the wilting area. An axial fan delivers solar-heated air at a rate of up to 24,000L/s to a chamber beneath the troughs. The 600 m2 solarcollector is mounted on the north-facing roof of the shelter at an angle of 22o with the horizontal. The heated air then rises through the troughs and the tea leaves, carrying moisture with it. In 1993and 1994, prior to installation of the solar system, industrial diesel oil was used at an average rate of 0.11 litres per kilogram of tea. After the conversion, no oil was burned and only the fanrequired energy. It is estimated that approximately the same amount of fan energy was required before and after the conversion. In September 1994, three of the solar-heated troughs produced 108,000 kg ofhigh-quality wilted tea for a total saving of 11,880 L of oil. The cost of oil is $0.40 per litre. At this rate, the solar system is expected to deliver 850 MWh of heat on an annual basis.