A solar panel also called Photovoltaic panel Is a device that measures on average generally 1m70 by 1m, and which converts part of the solar radiation in electrical energy. There are two types of photovoltaic panels. On the one hand, mono- and polycrystalline panels, which represent 90% of the current market, and on the other hand, thin film panels.
These panels are made up of 60 to 120 photovoltaic cells, manufactured using a semiconductor material: silicon. It is the chemical element The most abundant on Earth after oxygen, it is found in the Earth's crust, in the form of sand or quartz. Quartz, the second most abundant mineral on Earth.
How do you make a monocrystalline or polycrystalline solar panel?
We start by mixing sand or quartz with wood, and we bring this mixture to very high temperature in order to get silicon. But at this stage silicon is not yet ready to be used in the manufacture of a panel. We still need the purify chemically, the bake again for form ingots, cut these ingots into tranches thinner than a hair, doping silicon with Boron and Phosphorus and Print an electrical circuit on the cell. Photovoltaic cells of a dark blue color are thus obtained that are united for monocrystalline cells and cells that have the appearance of a mosaic for polycrystalline cells.
This type of panel itself combines several technologies. We will therefore be interested in CIGS technology, which is one of the most widespread. So first of all what does this acronym stand for, CIGS stands for Copper Indium Galium Selenium. These are the elements that mainly make up this type of panels. What can you remember about this second type of panels? Simply that it had to revolutionize solar energies by reducing production costs. But silicon panel manufacturing prices have fallen so much that CIGS technology has lost all its appeal.
In fact, this conversion is made possible thanks to the silicon that makes up the cells. Like all the matter that surrounds us, silicon is made up of atoms and the particularity of silicon is that the electrons that orbit around these atoms Are agitated in all directions when exposed to the sun's rays, which generates a Electrical voltage.
But this is not enough to create electricity. It is necessary to force the flow of electrons in a very specific direction. So we go create a surplus of electrons on the top layer of the cell by doping it with phosphorus atoms, which has more electrons than silicon. On the lower layer of the cell, boron atoms are placed, which have a deficit of electrons.
Thanks to this, when light hits the solar panels, electrons flow from the top layer to the bottom layer of the cell, which creates an electric current.
Concretely, most monocrystalline panels have a efficiency between 18 and 24%. Of course The more sunlight your panels are exposed to, the more electricity they will produce. Therefore, in cloudy or snowy weather, your panels will continue to produce but in less quantity than during a nice summer day.
However, solar panels do not produce electricity at all during the night. If you want, you can install lithium batteries which will store the electricity produced during the day to provide it to you again during the night.
Now, we are going to see all the elements you need for your solar installations. As we have just seen, solar panels generate electricity when exposed to light. But to be quite precise, they produce direct current, and your house and the electrical grid use alternating current.
Just add a Photovoltaic inverter Who converts the direct current to alternating current. The solar panels are connected to one or more inverters and then to your electric meter. For a solar panel to produce the most electricity, it must be optimally placed to receive as much light as possible. Before dimensioning a photovoltaic installation, various factors must be taken into account. It is necessary to take into account the available area to determine the maximum power of the future installation. Orientation and inclination are also to be considered in order to maximize electricity production during the year.
La roofing is the most common location for private and professional installations.
It is possible to integrate the panels into the roof or to place them on the roof.
The first choice is to replace part of the roof covering with the panels.
The principle of the second choice is to install the panels above the roof using a support. Solar panels can also be placed on the facade.
This technique is less widespread because of its production efficiency, which is lower than rooftop installations (30% less production for the same amount of sunlight). In addition, panels placed on facades will be likely to be more influenced by external elements (trees, neighborhood) and their shade.
Buildings that cannot be installed on the roof can install their solar panels on the ground. This system is very easy to implement and can be optimally oriented. However, it is necessary to have a wide area of land.
