How do solar panel systems really work? Self-contained photovoltaic systems stand alone, as the name implies, these systems function entirely independently. Although these systems are widely used in places where there is no distribution of electricity, their use is increasing in urban areas. Mostly because there is no monthly electricity bill nor power back down. Such systems can work anywhere and operate totally independently of the distribution network. The stand-alone photovoltaic system contains solar panels and batteries. Solar batteries will accumulate electricity so that they can use it during the night and cloudy days. The design of these systems is functional. They can power the house with electricity for one to three cloudy days.
First, solar panels collect solar energy. Second, the single-voltage voltage produced in the solar panels passes through the voltage controller. Third, the inverter converts DC voltage to AC. Then the solar battery accumulates electricity. When the battery is fully charged, then the charging stops. After switching from direct current to alternating current, the current is distributed in all electrical devices. Electricity comes either only from the sun, or the sun and batteries, or only from batteries. It depends on the weather and the part of the day.
How do solar panel systems look inside
The sun’s energy is actually the energy of a photon. The conversion is possible by using two-layer silicon elements. The first layer is made of Si and has an excess of electrons (n-type) in its structure, while the second layer (also of Si) has a lack of electrons (p-type). The excess electron layer is exposed to solar photons. Quantities of solar radiation transmit energy to these electrons, providing conditions for the flow of electricity.
A transverse electric field is created as a result of the diffusion of electrons into (p) material and cavities into (n) material. When this field reaches a sufficient value, the diffusion process stops. The result is a “potential barrier” for carriers at the p-n junction itself. To obtain electrical power at the consumer connected to the solar generator (photodiode), it is necessary to photons from the solar spectrum with a semiconductor structure play three processes:
- The photon energy must be greater than or equal to the width of the gap (then the absorbed photons excite the electrons to a higher energy level. The electrons pass into the conductive zone
- Photoabsorption created an electron-cavity pair must be separated by an electric field so that the electrons move towards the (-) terminal and the cavities towards the (+) terminal
- Both charges thus obtained must pass the p-n junction without recombination
(a) – type p material
(b) – type n material
The working principle of solar panel
The main purpose of the working principle of solar panels is to generate electricity. There is a potential difference in the p-n boundary layer, which is the electric field, strength E, directed towards the layer p. When the surface of the plate n exposes to the sun, photons erupt an “excess” of electrons, which will accept the forces of the electric field. If an external electrical circuit forms between the ends of these plates, an electric current will flow through it. The current depends on the power density of the sun and the surface of the tile.
The electron-cavity pair created by the absorption of the photon is separated. That way, electrons move towards the (-) terminal and the cavities towards the (+) terminal. The solar generator acts approximately as a power generator. The current through the external electrical circuit depends on the surface density of solar radiation. And remains the same over a wide range of external circuit voltage. The characteristics of the Sun concerning its spatial position towards the Earth are such that the distribution of radiation outside the Earth’s atmosphere is almost constant. It expresses through a characteristic called the solar constant.
It is the value of solar energy that falls in a unit of time per unit area of the surface. But it has to be perpendicular to the flux of radiation in cosmic space at a mean Earth-Sun distance. As the temperature rises, the power of the solar generator decreases can achieve. In the real case, the operating temperature range is about 60-80 °C (140-180 F).
Coupling solar panels
The solar panels are coupled with and interact with a battery system. To keep higher output power, solar generators (solar cells) can be connected in series, in parallel, and combination. While a series connection increases the output voltage at the same current, a parallel connection achieves an increase in output currents. However, a combined connection increases both current and voltage. Unlike the current, the potential difference between the tiles does not depend on the surface of the tile. To obtain a certain voltage, it is necessary to connect the appropriate number of tiles per row.
A certain number is required to obtain a certain current connect a tile of a certain surface in parallel. When solar cells are coupled to the same or identical ones, the I-U feature is no problem. The problem arises when, for example, in the case of a series connection of two alike solar cells, one of them is illuminated by solar radiation of lower intensity, or will be in the shadows. Then, due to the non-linear nature of the I-U characteristics of the solar cells, in the conditions of a short circuit at the output ends, a larger current flows through the shaded solar cell than it can to generate.
For that reason, this cell becomes inversely polarized; it no longer works as a generator, but acts as a consumer. The total energy generated by illumination in the solar cell is consumed on this shaded one. Due to the dissipation of energy on it, this cell will heat up; it becomes “hot” which can lead to its damage.
Solar roof systems provide savings energy, reduce carbon emissions, and thus significantly help preserve the environment. By simply moving an electron through an external circuit, we extract direct current from the solar panels. The electricity we get in this way, we can use directly or charge in solar batteries. The direct current obtained from solar panels is not suitable for use on our home appliances that operate on alternating current. But there are also devices designed to work on direct current. To get DC from AC, we need an inventor, and then the current obtained from solar panels can also be used on home appliances.
Now, since you know how do solar panel systems really work and you want to install a panel on your roof, please contact us for a free consultation. Our team of experts will help you with the most suitable solution for your home or office. Saving money is important. You can even try a light bulb with solar charging, for example, GreeSuit Solar Powered Led Light Bulb.