What is it?
There are several different types of solar thermal technologies available on the market. Each of these technologies works on the same basic principle: They transfer heat using the sun’s energy directly. These systems are usually comprised of a water storage tank (or geyser) as well as a solar collector element.
Solar thermal or Solar Water Heating (SWH) solutions comprise of several innovations and many mature renewable energy technologies that are well established for many years. Solar thermal solutions have been widely used in Greece, 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 collectors.
SWH systems are designed to deliver hot water for most of the year. However, during the cold months of winter, there may not be sufficient solar heat to deliver sufficient hot water. In this case, a gas or electric booster is normally used to compensate.