The composition and basic composition of solar panels, let's see which ones you have overlooked?
Issuing time:2019-12-30 17:37
A solar cell is also called a "solar chip" or "photocell", which is a type of photovoltaic semiconductor sheet that directly generates electricity using sunlight. Single solar cells cannot be used directly as a power source. As a power source, several individual solar cells must be connected in series, in parallel, and tightly sealed into components. A solar panel (also called a solar cell module) is an assembly of a plurality of solar cells, which is the core part of a solar power system and the most important part of a solar power system. The main ingredient is "silicon".
With the continuous increase of human demand for clean energy, solar power generation is receiving more and more attention. At present, the mainstream solar power generation equipment on the market mainly uses solar panels as an intermediate medium to convert solar energy into electrical energy, thereby promoting the work of the entire load. The solar panel is mainly composed of glass, battery sheet, back panel, EVA, junction box, aluminum frame and other parts.The reliable performance and price of each component will directly affect the service life and sales price of the solar panel, and then affect The entire solar power system.
Solar panels are currently the mainstream solar power generation equipment, which has advantages such as long development history, low manufacturing cost, and high photoelectric conversion efficiency. The solar panel is mainly composed of cell sheet, glass, back sheet, EVA (Ethylenevinyl acetate), aluminum frame, junction box and other parts.How to choose parts with low cost and high reliability of operation has become the main research topic of various battery manufacturers. . During the outdoor use of solar panels, it is affected by geographical environment and climatic environment. To this end, system designers need to consider the feasibility of the design scheme and maximize the energy output from multiple aspects.
Solar panel structure and production process
The solar panel is mainly composed of aluminum frame, glass, high-permeability EVA, battery sheet, high-cut EVA, back panel, junction box and other parts.
The main components of solar panels
According to the different cell preparation processes, it is mainly divided into single crystal cells and polycrystalline cells, of which single crystals are mainly grown by pull-up method, and polycrystals are mainly grown by ingot method.Since the growth method is different, The two types of cells have different internal lattice structures, weak light response, and conversion efficiency.
According to the different use environment of the battery panel, it is mainly divided into low-iron non-coated tempered glass and coated tempered glass (closed-loop anti-reflection film after coating first and then tempered). In environments with a lot of sand and dust particles such as deserts, it is recommended to use uncoated glass to reduce film loss.
EVA mainly acts as an adhesive in the entire solar panel, and is divided into high-transmission EVA (glass surface) and high-cutoff EVA (back surface). The degree of cross-linking of EVA generally needs to be controlled at 80% to 90% (Xylene extraction method), peeling strength between EVA and glass≥60N / cm, peeling strength with backsheet≥40N / cm, light transmittance> 91%, tensile strength≥16Mpa, elongation at break≥500 %, Longitudinal shrinkage ≤3%, transverse shrinkage ≤2%, water absorption <0.1%, etc.
The backplane material is used as a contact layer with the environment. Its yellowing index, cracking condition, breakdown voltage, and water vapor barrier capacity will all affect the service life of the battery panel. Currently, the main types of backplanes include TPT, KPE, TPE, KPK, FPE, and nylon. TPT and KPK are the most commonly used types of backplanes. T refers to DuPont's polyvinyl fluoride (PVF) material, K refers to Arkema's polyvinylidene fluoride (PVDF) material, and P refers to polyethylene terephthalate (PET) film. Support skeleton function.
PVF materials have the characteristics of stable structure and good weather resistance, and are widely used in outdoor environments. However, PVF materials have relatively low fluorine content, are prone to pinholes, and have relatively weak water vapor barrier capabilities. Increasing the thickness of the PVF film layer to ensure product quality, resulting in relatively high prices for TPT backplanes.
At present, silicon solar panels mainly use integrated full-filled junction boxes, with a waterproof and dustproof rating of IP67. Three bypass diodes are usually installed inside the junction box. The diodes and strings are connected in parallel. Under normal conditions of the battery board, the diodes are in the reverse cutoff state, but when the battery board is blocked, etc., the battery chip cannot be used at this time. The photoelectric conversion is normally realized, and the load will be dissipated due to the current flow. At this time, the bypass diode changes from the reverse cut-off state to the forward conduction state, and the current will flow through the diode, thereby reducing the risk of component damage.
Solar cell panels generally use anodized aluminum frame, the average thickness of the oxide film is not less than 15 microns, the surface Vickers hardness is not less than 8.0HW, the degree of curvature is ≤0.3mm / 300mm, and the aluminum frame has mounting holes and water leakage holes. , Grounding holes, etc. to meet the project site structural design requirements. The conventional anodized aluminum frame is recommended to be installed at an area 500 meters away from the coastline, and the salt water area is recommended to use a salt spray aluminum frame. The average thickness of the oxide film is not less than 18 microns to prevent seawater from eroding the aluminum frame and reducing the Service life.
Solar Panel Product Certification
At present, for conventional silicon-based solar panels, mainly including basic certification (IEC61215, 61730-1 / -2, UL1703), salt spray certification (IEC61701), ammonia resistance certification (IEC62716), PID (Potential Induced Degradation) certification ( IEC62804), dust test (IEC60068), etc. In addition to the above certifications, some countries have their own local certification requirements, such as JET certification in the Japanese market, CEC listing in the Australian market, and MCS certification in the UK market.
Solar panels have become a potential alternative to traditional thermal and hydroelectric power generation. In order to further meet market demand, battery manufacturers need to start from the perspective of production cost and quality control to manufacture low-cost, high-performance power generation equipment.
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