Thermodynamic solar energy is a combination of aerothermal and solar thermal energy.
Aerothermal energy uses a heat pump to lower the temperature of a coolant and circulate it in thermal contact with the outside. Because the difference in temperature with respect to the environment is very high, a heat transfer from the hot (ambient) to the cold (coolant) medium is achieved according to the laws of thermodynamics. A very important thermodynamic feature in this aspect is that the speed with which heat is transferred is greater the larger the temperature difference.
Solar thermal energy is based on heating the cooling fluid through solar radiation. This fluid is circulated through the solar panels that capture solar irradiation by increasing the temperature of the fluid.
Thermodynamic solar energy is a system that takes advantage of the difference between the temperature of the liquid that circulates inside the thermodynamic panels and the ambient temperature. The liquid that circulates inside the panels is a coolant at a very low temperature. According to the laws of thermodynamics, the temperature difference between the environment and the coolant generates a transfer of energy in the form of heat from the environment to the thermodynamic panel liquid.
Uses of thermodynamic solar energy.
The main use of this system is the generation of domestic hot water (DHW). Generally in family homes, but it can also be used in other industrial applications where the use of hot water is required.
Advantages of thermodynamic solar panels.
The main advantage of an installation of a thermodynamic solar panel is that energy can be generated in almost any condition. The necessary requirement is that the outside temperature is not lower than the coolant temperature. Thus, unlike thermal solar energy, the panels continue to capture thermal energy from the environment.
The main disadvantage of thermodynamic panels is that, due to the need to operate with a heat pump, electricity consumption is constant. In optimal weather conditions the generated electrical power can reach 4 watts per watt of electrical energy consumed. However, if the weather conditions are not optimal we can stay at one or two watts of thermal energy obtained per watt of electricity.
How thermodynamic solar energy works.
A thermodynamic solar energy installation is composed of a thermodynamic panel that tries to absorb the greatest amount of heat from the environment in which it is surrounded by a cooling gas at a very low temperature (around -4ºC) that circulates through its inside.
The heat pump has a compressor that moves the refrigerant gas from the thermodynamic panel to an expansion system, the heat pump is the only element that consumes electricity.
The accumulator is the third element of our thermodynamic solar installation, inside there is a coil through which the refrigerant gas passes at an elevated temperature producing a heat exchange and heating the water for later use.
Comparison of thermodynamic solar energy with solar thermal energy
Thermodynamic solar energy is a system to generate thermal energy more complicated, but more complete than solar thermal energy. Solar thermal energy only captures heat through solar energy while a thermodynamic system also takes advantage of the heat in the environment, therefore, it has more elements.
On the other hand, thermodynamic solar energy has the advantage that it is able to extract energy not only from the sun but also from ambient air, wind or even rainwater, therefore, it is not as dependent on a changing resource as the Sun. Thanks to this, it will continue to offer some performance in a wider schedule and in a greater diversity of weather conditions.
We also have to keep in mind that a thermodynamic panel is much lighter and smaller than a thermal panel, which can give us more versatility when installing it.