How Solar Thermal Energy Works

Solar thermal energy is necessary if you want to heat domestic hot water (DHW) with clean and 100% renewable energy. At Hogan hot water solar we have a wide range of solar thermal products, we provide you with the devices to use to generate this type of energy. So that you can better value your purchase, we have prepared an article for you that answer the question of how solar thermal energy works.

What is the Operation of Solar Thermal Energy?

This type of energy obtained from the Sun is generated with solar collectors, a hydraulic circuit, a heat exchanger, a solar accumulator, primary solar circuit pumps or circulation pumps.

Solar Collectors

They are solar panels that allow capturing the Sun’s energy and heating the heat carrier fluid that circulates inside the solar collectors. There are different types of solar collectors, depending on the performance you want to obtain.

Hydraulic Circuit

It refers to the circuit of pipes and conduits through which the hot water will circulate. In the most common installations this circuit will be closed. The primary circuits of solar thermal energy are usually made of copper.

Heat Exchanger

It refers to the installation that allows the heat obtained with the solar panels to be taken to the drinking water. In this way, heat is transferred from one fluid to another without mixing and the two circuits remain independent.

Solar Accumulator

This device is used to be able to accumulate the energy generated with the solar collectors and use it in those circumstances that are not conducive to it. Thanks to solar accumulators you can cope with energy demand even when there is not enough solar radiation. It is a way to make the most of energy, since hot water is not always consumed when energy from the Sun is being captured.

Circulation Pumps or Primary Solar Circuit Pumps

They are necessary to provide enough energy to transport the fluid through the circuit. These are the basic elements for a solar thermal generator system to work. However, there are other accessories that help optimize performance and improve system safety, such as isolations, expansion vessels, traps, heat sinks, etc.

Optimize a Solar Thermal Energy Installation

These elements are used to improve the performance of the installation and to increase the safety of the installation.


A solar thermal installation needs to have an insulation system to prevent heat losses from occurring outside.

Glass of Expansion

These types of vessels are used only in closed circuits and serve to absorb the expansions of the fluids found in a circuit, caused by the increase in temperature. There are two types, open or closed.


They are used to extract the air accumulated in the primary circuit and which causes problems in the operation of the installation. Traps must be installed in high areas.

Heat Sinks

They are essential to prevent dangerous temperature increases from occurring in the primary circuit of the solar energy installation. It is key to dissipate the excess heat in case of not being used. There are different types: static dissipaters, fan heaters, etc.

Security Valve

This type of element controls the pressure in the primary circuit and works as follows: as soon as the calibration value is reached, the valve discharges a liquid that prevents the installation pressure from reaching dangerous limits for solar collectors and the rest of the installed devices.

Ethylene Glycol Liquid

It is the antifreeze liquid necessary to transport the heat captured by the solar panels to the circuit for heating domestic hot water (DHW).

Automatic Control of Solar Thermal Energy

It is a key device for the entire system to function properly. It includes temperature measurement probes in panels and tanks, programming, activation system for electrical heat sinks, etc.