What is solar thermal energy?
Solar thermal energy has become one of the most interesting solutions for obtaining hot water in a simple way and saving energy. A complete, scalable proposal that is also relatively easy to amortize, in economic terms.
Since the beginning of time, the power of the sun has been fundamental to the advancement of our civilization. From the first discoveries of Archimedes, applied to the world of war, to the most recent high-efficiency thermal solar panels, this technology has become a great alternative to other much more polluting systems when it comes to having hot water and even heating for our home. So that you have the necessary knowledge to take better advantage of the benefits of this energy, we reveal all the secrets about it.
A little history
Leaving aside the Roman torch lighter or the Archimedean sunbeam, the first solar thermal collector in history would be Horace Saussure’s hot box. An invention that consisted of a glass box with a black interior and surrounded by insulation, which reached temperatures of up to 109 degrees inside. This technology served to create the first flat plate solar heaters, with which to enjoy hot water comfortably, constituting the basis of the current systems for harnessing solar thermal energy.
Later, inventions such as Lavoisier’s solar furnace for metals or Charles Wilson’s seawater distiller arrived. However, the main milestone in the field of thermal energy would be Clarence Kemp’s Climax water heater. This product combines a hot box with tanks exposed to the sun. A system that would be used for a long time and with different evolutions, until reaching the current solar collector systems.
How solar panels work
The operation of the thermal plates that are used today to take advantage of the sun’s energy is very simple. These plates have high-quality crystals, capable of capturing the maximum amount of sunlight and concentrating them in an interior where different copper pipes are placed. Cold water flows through the interior of these pipes, which, thanks to the power of photothermal energy, becomes hot water.
Among the advantages of this system is the obvious energy saving, given that the use of electricity or gas to heat water is one of the least efficient solutions. In return, solar hot water does not need any external energy, it allows it to be stored until needed and has a very adequate performance, thanks to the scalable nature of any solar thermal power plant that we set up in our home. Remember that this solar panel does not require more connections than plumbing, necessary for hot water to flow.
By the way, the system by which a solar thermal installation works helps us to understand how solar energy works. In fact, this is the same approach used by photovoltaic panels. The difference is that these plates do not have tubes but solar collectors, cells capable of converting heat into electrical energy efficiently. Halfway between the two, we have mixed plates, which are useful for thermal and photovoltaic solar energy uses.
Another important clarification before continuing: although it may seem the same, thermal solar panels should not be confused with those that work through a photothermal system. Compared to direct heating from the sun in thermal systems, photothermal systems capture electrical energy through the plates and use it to heat the water through a traditional thermo and electrical resistance system.
Applications of thermal solar panels
Once we know how solar panels work to heat water, it is time to know what we can do with that hot water. It has two main applications: domestic hot water and hot water for heating.
Starting with the use for DHW, the truth is that we have already dropped how the system works, which has not changed much in its approach since the days of the old Climax heater. The idea is to achieve a high concentration of thermal energy both in the area of the solar panel and through which the water flows. It is also interesting to heat the storage tank, from which the water that feeds our taps comes out. By the way, if you have a farm and want to enjoy that hot water without problems, just get a 12v portable shower, which you can connect directly to your car’s cigarette lighter and to the solar panel tank, being a simple solution and a test of the usefulness of these plates.
Regarding heating with solar panels, the principle applied has been the same, although the size of the water tanks is generally increased, in order to have more energy at night. The main difference is the application of hot water, which in this case is connected to a radiator system or even to underfloor heating. This last proposal is the most convenient option to heat your home with reduced consumption and without inconvenience, thanks to the high heat transmission offered by the water as it travels through this circuit.
If you have come this far and you are interested in knowing if this system is of interest to you for your home, the best thing you can do is put yourself in the hands of professionals and ask for a budget adapted to your needs. What we can tell you are the benefits that this system brings you, in terms of savings.
The main advantage of a solar system is that, once the investment is made, there is hardly any maintenance for many years. Another advantage is that there are no fuels to burn and no pollution. In addition, the system is independent, so you only depend on the power of the sun. This is the only drawback, having to depend on the sun to have hot water.
The most interesting question to mount one of these systems is that, at present, there are different lines of subsidies with which to cover part of the cost of the installation or access soft loans for these solar panels. Since these aids depend on the autonomous communities, it is enough to check what they have to offer you when setting up one of these facilities.