Solar water heating technology is fast emerging as the most energy -efficient and inexpensive method of water heating and perhaps the only solution to todays challenge of increasing energy costs, rising pollution levels and rapidly depleting energy sources. Honeywell Solar Water heaters work on thermosiphon principle, a highly trusted and efficient system of water heating. The solar collector comprises evacuated tubes that are optimized in geometry and performance. These tubes are constructed from two concentric glass tubes, half spherically closed on one side & fused together on the other side; the gap between them is evacuated & afterwards hermetically plugged (vacuum insulation). The internal glass tube has a highly selective & qco friendly aluminum nitrite sputter layer on its external surface, that acts as an absorber, to effectively capture solar power.