Views:15 Author:Site Editor Publish Time: 2020-05-20 Origin:Site
Solar panels are devices which use solar energy to generate electricity. Compared with ordinary batteries and rechargeable batteries, they are green products that are more energy-saving and environmentally friendly.
2.Types of Solar Panels
Currently, solar panels usually divide into three types: monocrystalline, polycrystalline (also known as multi-crystalline), and thin-film.
1) Monocrystalline Solar Panels
The photoelectric conversion efficiency of monocrystalline silicon solar cells can reach about 15%, with a maximum of up to 24%, which performs best among all types of solar cells. However, it cannot be universally used due to its high production cost. Because the single crystal is generally encapsulated with tempered glass and waterproof resin, it is sturdy and durable, with a service life of up to 15 years and a maximum of 25 years.
2) Polycrystalline Solar Panels
When it comes to the manufacturing process, polycrystalline silicon solar cells is similar to that of monocrystalline silicon solar cells, but the former has much lower photoelectric conversion efficiency, and the figure is about 12% (The Polycrystalline solar cells listed by Sharp in 2004 has the world's highest efficiency that can reach 14.8%). In terms of production cost, it is cheaper than monocrystalline solar cells, the material is easy to manufacture, and save power consumption. It has been greatly developed because of the relatively low total product cost. Besides, it has a shorter service life than that of monocrystalline silicon solar cells. From the perspective of cost performance, monocrystalline silicon solar cells are slightly better.
3) Thin-film Solar Panels
Thin-film solar panels appeared in 1976. They are completely different from monocrystalline silicon and polycrystalline silicon solar panels, with a greatly simplified process, less consumption of the silicon material, and lower power consumption. Their main advantage lies in that they can also generate electricity in low light conditions. However, their main problem is that they have low photoelectric conversion efficiency that is not stable enough. International advanced thin-film solar panels just reach about 10% conversion efficiency. It is will decline over time.
3.Components of Solar Panels
1. Tempered glass: Its function is to protect solar cells. The selection of tempered glass is very important. First, it must ensure high light transmittance (generally more than 91%). Second, it has to be treated with ultra-clean tempering.
2.Solar cells: Their main function is to generate electricity. Crystalline silicon solar cells and thin-film solar cells are the mainstream in the market of power generation subject. Each has its advantages and disadvantages.
3.Backsheet: It plays a significant role in a solar PV panel, such as sealing, insulation, and waterproof. A poor-quality solar backsheet can cause degradation of the product, unwanted maintenance, and replacements related to extra costs.
Thus, a high-quality backsheet must protect against:
Ultra-violet radiation, which is harsh on most polymer materials
Dryness, wind, dust, sand, and chemicals
Humidity and vapor penetration
Besides, it must be scratch-resistant, especially during installation and maintenance. It should also be stable at a temperature range between -40°C and +85°C.
4.Junction box: it is used to protect the entire power generation system and act as a current transfer station. If the component is short-circuited, the junction box automatically disconnects the short-circuit battery string to prevent the entire system from being burned out. What’s the most important is to select diodes. The corresponding diodes are different according to the type of solar cells in the component.
4.How to distinguish three types of solar cells?
1)Monocrystalline solar cells
Monocrystalline solar cells are made from single crystalline silicon. They usually have a colored appearance. Besides, the cells themselves also tend to have quite a cylindrical shape.
To keep costs low and the performance at a optimal level, the manufacturers often cut out the four sides of the monocrystalline cells. Although this can offer them a recognizable appearance, it is also quite wasteful. They often have the highest efficiency and quality among the three main material.
2)Polycrystalline Solar Cells
Polycrystalline solar panels were first introduced to the public in 1981. Unlike monocrystalline cells, they do not need each of the four sides to be cut, which can cause less waste.
The silicon is melted and poured into square molds instead of cutting. Then it can result in perfectly shaped square cells. When it comes to the price and efficiency, the polycrystalline solar panel is regarded as the mid-range panels among the three main materials.
3)Thin-Film Solar Cells
Unlike monocrystalline and polycrystalline solar cells, thin-film solar cells are made by placing several thin photovoltaic layers on top of each other to creates the module, and they have less efficiency. As a new technology, it is perfect for houses with issues of shading and needs more space. Aesthetically, the cells appear as a flat sheet with no lines that run through the panels. There are a few different types of thin-film solar cells including Amorphous silicon, Cadmium telluride, Copper indium gallium selenide, Organic PV cells.