Polycrystalline solar panels appeared in 1981. At the heart of these devices are molten polycrystals of silicon. The essence of the method of producing batteries is that the raw material is poured into the mold, and then, after cooling, the plate is cut into squares. The silicon cells are intensely blue.
Purpose of solar cells, their advantages and disadvantages
Polycrystalline panels allow you to convert the energy of the sun's rays into electricity. This is relevant for homes in which there is no connection to the public grid, and provide backup power. With these devices, you can also charge laptops and mobile devices.
Each element has a protective coating of tempered glass.
The output of products with a voltage of 12-24 V and power from 5 to 300 W is produced. The useful life is about 25 years.
The advantages of polycrystalline panels include:
- Low cost (production of these products is not costly, which allows the creation of cheap panels);
- Shock resistance and airtightness of the structure, allowing to use them in any difficult conditions;
- Easy to maintain (but clean the panels regularly from dust);
- Absolutely silent operation, due to the lack of moving components and maximum simplicity of design;
- Environmentally friendly products;
- Easy installation and installation.
But solar panels have some drawbacks:
- Relatively low efficiency (up to 16%) compared with single-crystal structures;
- A large area is required for installation;
- Some note some external unattractiveness.
The main characteristics of polycrystalline solar panels
Today, firms produce plates of two sizes - 5 or 6 inches. They are most often used to create local and mobile power stations. For example, you can take the panel with you to light a couple of tents in nature or to support the work of a refrigerator in a country house during the departure of the owners.
Polycrystalline solar panels have the following characteristics:
- For installation, they require quite a lot of space, when compared with monocrystalline analogues. But in the conditions of technical progress, all the best aggregates are produced, which are similar in size to single crystals. It should be noted that the largest panels are amorphous.
- The sensitivity of polycrystalline panels is low. By the coefficient of converting the energy of solar rays into electrical energy, they are inferior to amorphous panels, which produce excellent energy even in poor illumination. Crystalline products react very strongly to changes in light intensity.
- As a result of testing, it was found out that the annual output of polycrystalline modules is low in comparison with single-crystal modules. But they are more productive than amorphous.
- The cost of polycrystalline modules is relatively low, monocrystals cost an order of magnitude more. But the cheapest are still amorphous models.
- Battery performance also depends on the temperature at which they operate. It is proved that polycrystalline solar panels react to temperature increase. If you change even by 1 degree, their performance drops. Therefore, the more the battery warms up in real operating conditions, the lower the nominal power becomes.
What to look for when buying
When buying solar panels, it is worth considering the rate of their degradation. The loss of efficiency of a quality panel is 1 percent per year. It should be noted that crystal panels lose their properties more slowly than amorphous ones, that is, by about 20-25 percent for 25 years of use. But if a low-quality module falls, then the rate of efficiency decrease can reach 20 percent in the first year.
Despite the fact that monocrystalline panels have more attractive quality characteristics, polycrystalline modules are more popular.