Working of the System Evacuated Tube Collector work on "twin glass tube" technology. The Sun's rays fall on the evacuated tubes panel which collects the radiations & converts them into heat energy. The solar heat energy thus collected is used to heat the water passing through the tubes. A temperature difference is created the hot water with low specific gravity rises up & the cold water comes down.(Thermo siphoning Principal)The hot water is then stored in insulated tank above & from there, it is distributed to required end points for bathing, washing, cleaning, etc.