The depletion of fossil fuel sources has become one of the most discussed issues with regard to energy production. The search for alternative energy sources comes as a solution to this problem.
Solar energy is the most abundant form of clean energy in nature. Consequently, solar heaters are invading homes, hotels, industries, buildings, rural properties and other places where they are needed.
A basic solar water heating system consists of solar collector plates and a water reservoir known as a Boile.
The collector plates are responsible for absorbing solar radiation. The thermal energy absorbed by the plates is transmitted to the water that circulates inside their copper pipes.
The thermal reservoir is a container for storing heated water. They are copper or stainless steel cylinders, but thermally insulated with CFC-free polyurethane (Chloro-fluoro-carbon) to minimize heat loss through the thermal conduction process. This way, the water remains heated and ready for consumption at any time of the day or night. The cold water box feeds the reservoir, keeping it full at all times.
Water circulates between the collectors and the reservoir thanks to a process called thermofission. In this process, the water from the collectors, which is warmer, is less dense than the water in the reservoir, therefore, the colder denser water pushes the hot water into the reservoir, generating circulation.
In more sophisticated systems, where the volume of water is greater, such as swimming pools, for example, water circulation is done with the aid of hydraulic motors.
By Kleber Cavalcante
Graduated in Physics
Source: Brazil School - https://brasilescola.uol.com.br/fisica/aquecimento-agua-por-energia-solar.htm