ENHANCEMENT OF GRANITE STONE FLAT PLATE COLLECTOR EFFICIENCY USING MULTIPLE COVERS

Solar energy in Indonesia has high potential to be developed because Indonesia is a region that has sunlight all the year with a radiation intensity of 900kW/m². This study uses flat plate collectors with granite stone absorber and multiple covers. The aim of this study is to know the effect of multiple covers on the collector performance. The covers employed were 1, 2 and 3 made of transparent glass. To test the collector, several volumetric flow rates of water were run, i.e. 300cc/min, 400cc/min, and 500cc/min. The pipes as the duct buried in the absorber were arranged in parallel comprising 7 copper pipes with a nominal diameter of 1/2 inch. The overall size of the collector was 100 cm x 80 cm x 10 cm. The results show that at the volumetric flow rates of 300 and 400 cc/min, increasing the cover number decreasing the performance and efficiency of the collector, while at the higher volumetric flow rate of 500 cc/min the effect is not significant or deteriorated.