How solar panels work. Solar panels are already being used to power a wide variety of equipment, from mobile gadgets to electric cars. First used to power space stations more than 40 years ago, solar panels are now firmly established in everyday life as a source of clean, free energy. The sun has always sent and still sends billions of kilowatts of radiant energy to the earth and this source will continue to do so for millions of years to come.
One of the energy sources is a solar panel that generates alternative energy from the sun. It is relatively new, but has already gained popularity in Europe due to its high efficiency and reasonable cost. Solar panel is an almost inexhaustible source of energy, capable of storing and converting light rays into energy and electricity. In Ukraine, a new source of energy is gradually gaining popularity.
How solar panels work. Operating Principle of Solar Cells.
On the principle of solar cells is a constant current photoelectric generator, which uses the effect of converting the rays of energy into electrical energy. More specifically, solar cells utilise the property of semiconductors based on silicon crystals. Quanta of light hitting a semiconductor wafer knock out an electron from the outer orbit of that chemical element’s atom, which creates enough free electrons to generate an electric current. However, one or two silicon elements are not enough for the voltage and power of such a source to be sufficient for household applications.
Therefore, they are assembled into complete panels, where they are connected in parallel or in series. The area of such panels may vary from a few square centimetres to several square metres. By increasing the number of panels, it is possible to achieve a higher power output from a energy solar panel.
However, the performance of a solar panel depends not only on the area, but also on the intensity of the sunlight and the angle of incidence of the rays. Consequently, the performance of the solar panel depends on the area and geographical latitude where the house is located, on the weather and time of year, and on the time of day. In addition, in order for the solar panel system to work and supply energy to the grid, a number of additional electrical devices must be installed, in particular.
-An inverter that converts direct current to alternating current;
-A rechargeable battery whose role is to store energy and smooth out voltage variations due to changes in light conditions;
-A battery charge controller that prevents the battery from overcharging or discharging prematurely.
All this is called an autonomous power supply system based on solar panels.
How solar panels work. What is the principle of an alternative energy source?
Firstly, the photovoltaic cells are silicon wafers. Silicon, on the other hand, is similar to pure silicon in its chemical composition. It is this nuance that has made it possible to lower the cost of a solar cell and put it on the assembly line already.
It is imperative that silicon is crystallised as it is itself a semiconductor. Monocrystals are much easier to make, but they do not have many facets, due to which the electrons are able to move in a straight line.
It is important to know that the addition of phosphorus or arsenic increases the electrical conductivity. Also one of the important properties of silicon is its invisibility to infrared radiation. Thanks to this element, the converter blocks only absorb the useful parts of the solar spectrum.
Sequence of operation of a solar panel. How solar panels work.
1. the energy of the sun enters the plates.
2. The plates heat up and release electrons.
3. the electrons actively move along the conductors.
4. The conductors give a charge to the batteries.
The design and operating principle of a power source can be described as simple.
It consists of just two parts: the main body; the converter units. In most cases, the casing is made of plastic. It looks like an ordinary tile, to which the converter units are attached.
The transducer block is a silicon wafer. It can be made in two ways: polycrystalline; monocrystalline. The polycrystalline method is the least expensive and the monocrystalline method is considered the most efficient. All other additional parts (e.g. controllers and inverters), microcircuits are attached only to increase the performance and function of the energy source. Without them, the solar panel will also be able to function.
There are two types of connection: in series; in parallel. The only difference is that the parallel connection increases the current and the series connection increases the voltage. If there is a need to maximise the operation of two parameters at once, parallel-serial is used.
But it is worth bearing in mind that high loads can cause some contacts to burn out. Diodes are used to prevent this. One diode is capable of protecting one quarter of the photocell. If they are not in the device, there is a good chance that the entire energy source will cease to function after the first rain or hurricane.
Like any technical device, a solar panel has its own performance and technical specifications, which differ between models, from different manufacturers, but with a rather small discrepancy. For a solar panel area of approx. 0.2 m², the module output is approx. 10 W. The voltage at maximum load is approx. 25 V. The short-circuit current is approx. 500 µA. The module weighs approx. 2 kg. Typical efficiency of a solar panel is 14 to 18%. The service life of such a plate is at least 25 years