Solar panels are devices that directly or indirectly convert solar radiation energy into electrical energy by absorbing the photoelectric effect or photochemical effect. The main material of solar cells is silicon, but due to its high production cost, it cannot be widely and commonly used. Therefore, the material of solar photovoltaic modules must use high-quality silicon materials. The reason why solar panels can generate electricity is that if the roof is covered with solar cells, the house can be self-sufficient in electricity, but sunlight cannot shine outside or directly on the wall . The surface of the solar panel is composed of two parts with different properties: 1. When the solar panel is illuminated by light, it can convert light energy into electrical energy, causing the circulationn of current from one side to the other. . This conversion process is called photoelectric conversion. Design solar panels based on this principle. Solar panels can generally emit electricity equivalent to 1/10 of the light energy received, provided they are illuminated by sunlight or light. In order for solar panels to minimize light reflection and convert light energy into electrical energy, light energy is generally placed. in its It is covered with an anti-reflective film. The surface of the photoelectric converter is purple In order to prevent sunlight from reflecting directly on the surface of the sun, solar cells can convert light into electrical energy through the reflective surface of the sun. reflector. Not long ago, scientists succeeded in developing a high-efficiency solar panel.
What are solar panels?
The materials required for solar panels are as follows:
1. Tempered glass: Its role is to protect the main power generating body (such as cells), and there are requirements for its selection in light transmission. Yes, the light transmittance should be high (generally above 91%) and it should be treated with ultra-white tempering.
2. EVA: Used to bond and fix the tempered glass and the main body of power generation (battery sheet). The quality of the transparent EVA material directly affects the lifespan of the exposed EVA component. the air is prone to aging and yellowing, which affects the light transmission of the module, thereby affecting the power generation quality of the module. In addition to the quality of the EVA itself, the module manufacturer's lamination process also has a big impact. For example, the bonding degree of EVA is notcomplies with standards and EVA is bonded to tempered glass and backplanes. Insufficient strength will cause premature aging of EVA and affect the service life of components.
3. Cells: The main function is to produce electricity. The main market for power generation is crystalline silicon solar cells and thin-film solar cells, both of which have their own advantages and disadvantages. The equipment cost of crystalline silicon solar cells is relatively low, but the consumption and costs of cells are high. However, the photoelectric conversion efficiency is also high, so it is more suitable to generate electricity under outdoor sunlight.
Thin film solar cells have relatively high equipment costs, but the battery consumption and costs are very low, but the conversion efficiencyone photoelectric is more than half that of crystalline silicon cells, but the low light effect is very good, under ordinary light. Can also produce electricity, like solar cells in a calculator.
4. Backplate: Function, sealing, insulation and waterproofing. Typically, TPT, TPE and other materials are used and must resist aging. Most component manufacturers offer a 25-year warranty. Tempered glass and aluminum alloys are generally no problem. The key is whether the backplate and silicone can meet the requirements.
5. Aluminum alloy: protects rolled parts and plays a certain sealing and supporting role.
6. Junction Box: Protects the entire power generation system and serves as a power transfer station. If a component is shorted, the junction box will disconnectAutomatically short circuit the battery string to avoid burning. the entire system. The most critical part of the junction box is the diode. Depending on the cell type of the module, the corresponding diodes are also different.
7. Silica gel: sealing function, used to seal the junction between components and aluminum alloy frames, components and junction boxes. Some companies usually use double-sided tape and foam to replace silica gel. used in China and the process is simple, convenient, easy to use and inexpensive.
The following describes two methods of manufacturing solar panels.
Solar panel manufacturing method (1)
The first step: first put the titanium dioxide powder into a mortar and grind it with the adhesive, then use a glass rod to slowly grind it on the conductive glass Apply a film to theon it to make a film of titanium dioxide. Put the titanium dioxide film under an alcohol lamp to sinter and solidify for 10-15 minutes, then let it cool. Step 2: Use natural dyes to color the titanium dioxide. .As the picture shows, put the fresh or frozen black plums, mountain plums, pomegranate seeds or black tea, use a large spoon to extract the juice, then put the titanium dioxide film to color. 5 minutes until the film layer turns dark purple. Whether both sides of the film layer are colored. If it is uneven, you can put it in and soak it for 5 minutes, then rinse it with ethanol and gently dry it.
Step 3: Make the positive and negative electrodes of the battery. It is composed of a layer of SnO2 conductive film, and a layer of graphite is evenly coated on the conductive surface with a pencil 6B.
Step 4: Add electrolyte and use the solution containing iodide ions as the electrolyte of the solar cell. As the picture shows, just add one to two drops of electrolyte on the surface of the titanium dioxide film.
Step 5: Assemble the battery. Place the colored titanium dioxide film on the table, drop one or two drops of electrolyte containing iodine and iodide ions on the film, and then place the conductive surface of the negative electrode Press on the titanium dioxide membrane. Offset the two pieces of glass slightly so that the exposed part can be used as the electrode for the test. Use two pliers to tighten the battery and your solar battery is ready.
Step 6: Test the battery Under outdoor sunlight, a solar cell with an open circuit voltage of 0.4V and a short circuit current of 1mA/cm2 can be obtained.
Solar panel production method (2)
1. The first step is to connect the battery sheets in series with copper tape. A battery chip is equivalent to a small power generation unit, which can generate a current of 0.5V and 5.2A. By connecting a number of battery chips in series with copper strips, it is possible to obtain more energy production.
2. Then the battery sheets must be sealed and isolated from air, otherwise they will gradually decompose until the generated power reaches zero. Therefore, the second step is to use tempered glass, EVA and backplates. After heating and vacuuming, the cells can be sealed between the glass and the back panel.
3. However, tempered glass is not durable enough and is easily damaged, especially at the corners. Therefore, the third step is to place aluminum frames around it to protect it. Afterthe above three steps, the solar panel is produced.
Detailed information
Application fields of solar panels
1. User Solar Power Supply: (1) Small power supply 10- 100W It is used for military and civilian life in remote areas without electricity, such as plateaus, islands, pastoral areas and border posts, such as lighting, televisions, radios, etc. (2) 3-5 kW connected to the household roof grid; power generation system; (3) Photovoltaic water pump: solves the problem of watering and irrigating deep water wells in areas without electricity.
2. Transportation field: such as navigation beacon lights, road/railroad signal lights, warning/signal lights, Yuxiang street lights, high-altitude obstacle lights, highway wireless telephone booths /railroads, lunsupervised route changes. food, etc.
3. Communication/communication field: unattended solar microwave relay station, optical cable maintenance station, broadcast/communication/messaging power system; rural operator telephone photovoltaic system, small communication machine, soldier GPS power supply, etc. .
4. Oil, marine and meteorological fields: cathodic protected solar power systems for oil pipelines and reservoir valves, standby and standby power supplies for oil drilling platforms, ocean sensing equipment, observation equipment meteorological/hydrological, etc.
5. Lighting power supply: such as garden lights, street lights, portable lights, camping lights, mountaineering lights, fishing lights, black light lights, lightingrubber tapping, energy saving lamps, etc.
6. Photovoltaic power plants: independent photovoltaic power plants from 10KW to 50MW, wind and solar (diesel) complementary power plants, various charging stations for large parking power plants, etc.
7. Solar buildings: The combination of solar power generation and building materials will make future large-scale buildings electricity self-sufficient, which is a major development direction for the future.
8. Other fields include: (1) Automotive support: solar cars/electric cars, battery charging equipment, car air conditioners, fans, cold drink boxes, etc. (2) Solar hydrogen regeneration; generation and fuel cells Power generation system; (3) Power supply for seawater desalination equipment (4) Satellites, engispace ns, space solar power plants, etc.
References Baidu Encyclopedia - Solar panels
Do solar panels radiate?
Modules Solar cells are made from imported (or domestic) monocrystalline (or polycrystalline) silicon solar cells connected in series and parallel, and are hot-pressed and sealed with tempered glass, EVA and TPT, and are surrounded by frames made of aluminum alloy, resistant to wind and hail. Strong and easy to install. It is widely used in solar lighting, lamps, household power supply, road transportation, construction and photovoltaic power plants and other fields.
Component composition: low iron tempered glass (also known as white glass), with a common thickness of approximately 3.2mm. In the wavelength range of the spectral response of solar cells (320-1100 NM), the light is scattered. transmission reaches more than 90%, it has high reflectivity for infrared light above 1200NM. This glass is also resistant to ultraviolet rays and light transmission does not decrease. The quenching performance conforms to the national standard GB9963-88 or the impact resistance of the packaged components reaches the performance indicators specified in the ground silicon solar cell environmental test method of the national standard GB9535-88. EVA: EVA is a hot melt adhesive with a thickness between 0.4 mm and 0.6 mm. It has a flat surface, uniform thickness and contains a crosslinking agent. It is non-sticky and anti-sticky at room temperature. After some adjustment and hot pressing, fusion bonding and cross-linking will occur and it will become completely transparent. Cured EVA can resist atmospheric changes andis elastic. It encapsulates the battery part by "covering and padding" it, and combining it with the top protection material - glass, and the back sheet of the bottom protection material (TPT, BBF, etc.) to use the battery part. vacuum lamination technology in one. On the other hand, once glued to the glass, it can increase the light transmission of the glass, play the role of anti-reflection and improve the efficiency of the solar panel. Solar cell: Solar cell is the smallest photoelectric conversion unit and its size is generally 125*125 or 156*156. The operating voltage of solar cells is around 0.5V and generally cannot be used alone as a power source. Once solar cells are packaged in series and parallel, they become solar panels. Their power is generally from a few watts to tens of watts, from one hundred watts to more than two hundred watts, and can beused as a separate energy source.
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EVA is used to bond and fix tempered glass and the main body of power generation (such as battery cells). The quality of the transparent EVA material directly affects the service life of the EVA component. exposed to air is prone to aging and degeneration, thereby affecting the light transmission of the module, thereby affecting the power generation quality of the module. In addition to the quality of the EVA itself, the module manufacturer's lamination process also has. a big impact. For example, the bonding degree of EVA is not up to standard, and EVA and tempered glass, backplane, insufficient bonding strength will cause premature aging of EVA and affect the lifespan life of the components.