Solar thermal energy is a technology designed to use sunlight to obtain thermal energy (heat). This heat is often used to heat water used in homes, businesses, swimming pools, and to heat the interior of a building (space heating).
In order to heat the water using sunlight, the solar collector heats the working fluid pumped through it. The working fluid is heated as it is pumped through the collector. The now heated fluid is then pumped out of the collector and through the heat exchanger.
The heat exchanger is usually made of copper and is usually located in a solar energy storage tank. This allows the heat transfer in the fluid - to be exchanged into the water in the storage tank.
The tank is the basic component of any solar thermal system because it stores all the heat generated by the solar collector for use when needed.
Solar collectors are classified by the Energy Information Administration (EIA) as high, medium or low temperature collectors.