A solar battery is a combination of several photovoltaic cells, that is, devices capable of converting solar radiation into electric current. The more such elements are included in the battery, the greater the difference in electrical potential it can create.
The principle of operation of photocells is based on the phenomenon of the internal photoelectric effect, discovered by E. Becquerel in 1839. But only from the middle of the twentieth century, thanks to scientific and technological progress, it became possible to produce compact, cheap and efficient solar cells. And, accordingly, immediately opened ample opportunities for the use of solar panels, consisting of them.
If we explain the principle of operation of a photocell in the simplest words, then it is a semiconductor consisting of two silicon wafers with certain additives. These additives create an excess of electrons in one plate and a lack of them in the other. In order to prevent excess electrons from spontaneously moving into the zone where they are not enough, the so-called blocking layer zone is located at the border of these two layers. This movement can only occur under external influence.
Such external influence is the photons of sunlight. Having received their energy, the electrons become able to overcome the resistance of the blocking layer zone. A potential difference will appear in the semiconductor, therefore, a current will begin to flow.
The strength of the electric current directly depends on the number of photons captured by the surface of the photocell. And this amount, in turn, depends on many factors, the most significant of which is the intensity of solar irradiation. Based on this, it is easy to understand why solar panels are widely used, primarily in the southern regions. In countries such as Spain, Italy, Greece, Turkey, etc., solar energy makes up a significant part of the total energy consumed, especially in summer.
Of course, solar panels have drawbacks. They cannot work around the clock without a light source, so it is necessary to connect devices to them to stabilize the voltage and accumulate an electric charge. They are relatively lightweight and therefore require a lot of deployment space. However, they have many advantages. Where it is possible to do with small capacities, and at the same time it is impossible to connect to electrical networks, solar panels are simply irreplaceable. Well, manned spaceships and stations cannot do without them at all.
