There are several types of photovoltaic solar panels on the market for domestic use. The most common types are:
The main difference between the different types of photovoltaic plates is the purity of the silicon used. The purer the silicon, the better aligned its molecules are, and the better it converts solar energy into electricity.
In this way, a direct relationship is established between the purity of silicon and the efficiency of solar panels. Conversely, increasing the purity of silicon implies more expensive processes.
Crystalline silicon is the basis for monocrystalline and polycrystalline cells.
Monocrystalline Silicon Cell Solar Panels
In monocrystalline solar panels monocrystalline silicon (mono-Si) solar cells are quite easy to recognize due to their coloration and uniform appearance, which indicates high purity in silicon.
In this type of photovoltaic panels, monocrystalline cells are made with blocks of silicon or ingots, which are cylindrical in shape.
Subsequently, with the aim of reducing the manufacturing costs of monocrystalline photovoltaic cells and optimizing their performance, the four sides of the cylindrical blocks are cut to make silicon sheets. This cut is what gives them this characteristic look.
One of the simplest ways to clearly distinguish a monocrystalline solar panel from a polycrystalline one is that in the polycrystalline cells the cells do not have rounded corners and are perfectly rectangular.
The basic difference between a monocrystalline and a polycrystalline solar cell is the composition of the silicon crystal. Monocrystalline cells are made of a single type of silicon crystal, that is, when the crystal was manufactured, the growth of the silicon crystal itself was controlled so that it only formed in one direction, achieving a fairly perfect alignment of all the components of the glass.
In contrast, in polycrystalline cells, the growth of the silicon crystal is not controlled, so the crystal grows in all directions creating a set of different crystals linked together.
Silicon polycrystalline photovoltaic panels
Polycrystalline photovoltaic panels, unlike monocrystalline panels, do not use the Czochralski method in their manufacture. In this type of solar panel, the raw silicon is melted and poured into a square mold. It is then cooled and cut into perfectly square sheets.
The first polycrystalline silicon solar panels appeared on the market in 1981.
Polycrystalline cell-based solar panels have a long history in the industry, since their manufacture started as early as the 1980s.
Its greatest advantage over monocrystalline cells starts from a lower cost production process, which lowers the final price of these systems.
Photovoltaic cells from polycrystalline solar panels are more affordable. On the other hand, they have some disadvantages: The lower heat tolerance of these cells means that they have a lower efficiency than the monocrystalline alternative.
Specifically, it is estimated that the panels that include these cells have an efficiency ratio of a maximum of 16%, mainly due to the lower amount of silicon that they incorporate.
The negative effect that high temperatures have on these cells, which makes them even less attractive than monocrystalline cells for users residing in warm areas, as well as their lower efficiency with respect to space, also appear as disadvantages of these systems.
Thin-layer photovoltaic solar panels
The basis of these panels is to deposit several layers of photovoltaic material on a base. Depending on the material used, we can find thin layer panels of amorphous silicon (a-Si), cadmium telulide (CdTe), copper, indium, gallium and selenium (GIS / CIGS) or organic photovoltaic cells (OPC).
Depending on the type, a thin layer module has an efficiency of 7-13%. Because they have great potential for domestic use, they are increasingly in demand.
Hybrid solar panels
This type of panel allows to obtain electrical energy and thermal solar energy for sanitary hot water and heating in the same solar panel.
In the solar hybrid panel, photovoltaic technology and solar thermal energy are integrated: photovoltaic solar energy absorbs solar radiation, while the part that is not capable of accumulating, thermal heat, is recovered through a heat exchanger. hot.