Evacuated Tube Collector (ETC) Solar Water Heating systems use triple-layered Borosilicate glass tubes designed for high efficiency, even in cold weather. The outer surface of the inner tube is coated with a selective absorbing material such as copper (Cu), aluminum (Al), or stainless steel (SS) wafers.
These coatings enhance solar radiation absorption and effectively transfer heat to the water inside the tubes. This advanced technology is highly cost-effective and provides rapid water heating performance.