Construction of a photovoltaic cell and principle of operation.
A photovoltaic cell, also known as a solar cell, is one of the basic elements that make up a photovoltaic installation. This is where the phenomenon of capturing energy from the sun takes place, so that it can then be converted into electricity with the appropriate voltage, intensity and frequency. What is it made of, how does it work, and what is the specific phenomenon that takes place in it?
Solar cell – construction
A photovoltaic cell has different names: photovoltaic cell, solar cell, or photovoltaic cell . Cells are elementary parts of photovoltaic panels. In order for them to successfully convert solar energy into electricity, they must be made of semiconductor materials. They are usually silicon, selenium or germanium. The cells are connected in series (series connection) and thus we obtain solar batteries.
Simply put, a photovoltaic cell consists of two layers of semiconductors. The first one on top is a thin, transparent layer. A negative electrode and an anti-reflective coating are placed on top. The bottom is the positive electrode. The second bottom layer is thicker. Both layers are separated by an appropriate potential barrier, based on pn junctions, that is, non-autonomous semiconductors. This structure is necessary for the correct operation of the system.
Monocrystalline cells are currently the most advanced option. We will recognize them by their black color. They are the most effective. By choosing these panels, we can count on the most efficient electricity production using the least space possible. Its efficiency is around 15% to 19%.
The blue color of the cells is almost certainly polycrystalline panels . “Almost certainly”, since they can be confused with solar collectors of the same color. Although not long ago polycrystalline panels were the most popular, now monocrystalline cells are beginning to replace them. Although people with more space choose more affordable options, in practice it is less effective. Its efficiency is about 14% -16%.
The principle of operation of a photovoltaic cell.
The task of photovoltaic cells is to convert solar energy into electricity. How it happened? The light reaches the cell, which, as we know, is made up of photons on their smallest scale. The silicon in the cell absorbs the photon and knocks the electron out of position, forcing it to move, and as we know from physics lessons, the motion of electrons is the flow of electric current.
Simply obtaining electricity in the process described above is not enough. This is because direct current is generated at the cell level and we have alternating current in our household plugs. Therefore, for the proper functioning of the installation, an inverter, also known as an inverter, is needed. It is a very important part of the whole system, because it is your job to convert direct current to alternating current. More recently, in the most modern and advanced systems mikroinwertery is used , connected directly to each cell. In this way, the efficiency of the photovoltaic operation is raised to an optimal level.
5 things you should know about cells
- The most efficient type of photovoltaic cells are monocrystalline cells, that is, those that can be recognized by their black color. Stilo Energy uses this type of cell in its facilities. The performance against polycrystalline panels is unmatched. In addition, saving space is also important, which is of great importance in the context of ergonomics.
- Solar cells are also used to power the electronics of space shuttles and probes, Earth’s artificial satellites. After all, energy must be sourced from somewhere, where classical fuel methods cannot be used. Therefore, photovoltaics is an inspiration for many independent farm owners, located in areas where electrification does not reach.
- A single photovoltaic cell has a low power (approx. 0.4, -0.5W), so they are connected in series or in parallel to obtain the desired value that best suits the user.
- When we consider various renewable energy sources, such as sun, wind, water, we must first recalculate the use of the selected source not only in terms of our needs, but also possibilities. Photovoltaic solar energy is the most accessible and efficient option. Because the light from our closest star reaches almost everywhere in the same degree.
- Photovoltaic energy is not just a way to save specific financial resources. It is also a great way to combat air pollution. In the age of ubiquitous smog, it is a remedy for the polluted air that we are all forced to breathe. It is worth noting, however, that unlike surface agents that act more at the level of symptom control, the energy of the sun is the elimination of the causes.