Solar water heating (SWH) or solar hot water (SHW) systems comprise several innovations and many mature renewable energy
technologies that have been well established for many years. SWH has
been widely used in Greece, Cyprus, Turkey, Israel, Australia, Japan,
Austria and China.
In a "close-coupled" SWH system the storage tank is horizontally mounted immediately above the solar collectors on the roof. No pumping is required as the hot water naturally rises into the tank through thermosiphon
flow. In a "pump-circulated" system the storage tank is ground- or
floor-mounted and is below the level of the collectors; a circulating
pump moves water or heat transfer fluid between the tank and the