Solar cells are also called rechargeable batteries or photovoltaic cells. They are made of semiconductors and apply the principle of converting light into electricity. Semiconductor is a special substance between a conductor and an insulator. When two different types of semiconductors are combined, a “junction” forms on the bonding surface. The secret of solar cells lies in this “junction”.
Like atoms of any material, semiconductor atoms are also composed of positively charged nuclei and negatively charged electrons. For example, there are 4 electrons in the outer shell of a semiconductor silicon atom, which rotate around the nucleus in a fixed orbit. When affected by external energy, these electrons break away from the orbit and become free electrons, leaving a "hole" in their original position. In the silicon crystalm pure, the number of free electrons and holes is equal. If boron, gallium, and other elements capable of capturing electrons are doped into a silicon crystal, it becomes a hole-type semiconductor, usually represented by the symbol P; if phosphorus, arsenic and other elements capable of releasing electrons are doped into it, it becomes an electronic type semiconductor, represented by the symbol N. If these two semiconductors are combined, the interface will form a P-N junction. The P-N junction is like a wall that hinders the movement of electrons and holes. When exposed to sunlight, the electrons receive light energy and are directed towards the N-type region, making the N-type region negatively charged. At the same time, the holes are directed towards the P-type region, which makes the P-type region positively. accused. In this way, an electromotive force is generated on both sides of theP-N junction, commonly called voltage. Scientists call this phenomenon “photovoltaic phenomenon”. If a wire is used to connect the two ends of the P-N junction, a current will be generated.
Which brand of solar power is good - Baidu
1 How long do solar street lights last
To about. 5 to 10 years. Since solar street lights are composed of many parts, the lifespan of each component is different, so the specific lifespan should be based on actual conditions. Generally, the lifespan of street lights can reach about 10 years, the lifespan of solar panels is about 10-20 years, the lifespan of LED lights is about 50,000 hours, and the lifespan of batteries is more than 5 years old. .Therefore, after careful consideration, the usage time is about 5-10 years.
2. What are the advantages of solar street lights?
1.Energy saving: Solar street lights absorb sunlight to make the lamps shine. This resource being inexhaustible, it can be used by everyone. Over time, it significantly reduces energy consumption compared to traditional street lights.
2. Safety: Ordinary street lights must assume that the wires are connected and powered before they can be used, so problems such as wire aging and power failure may occur during operation, posing certain safety risks. Solar street lights do not need to use AC power. They absorb the light source directly through the solar panel, then store it in the battery, then convert it into light energy when needed, so there is no safety risk. 3. Environmental protection: Solar energy uses high-tech technology from installation to exploitation. Not only will it not pollute the environment, but also will have no radiation effect. It is fully consistent with the current understanding of green. environment.protection concept.
Does solar photovoltaic power generation have any impact on the human body?
01 Huangming (famous Chinese brand, well-known Chinese brand, ten main brands of solar water heaters)
02 Sanle (domestic free product, top ten solar water heaters, large enterprises)
03 Tianpu (national free product, top ten solar water heaters) solar water heaters, large enterprises)
04 Sheng Group (China famous brand, first-line brand/brand, top ten solar water heaters)
05 Billion Home Energy (famous brand of China, first-line brand/brand, top ten solar water heaters)
06 Sun Rain (Chinese famous brand, first-line brand/brand, top ten solar water heaters)
07 Zhannan (Chinese famous brand, ten solar water heater) water heater, export famous brand)
08 Tsinghua Sunshine (Chinese famous brand, top-tier brands/brands) , top ten solar water heaters)
09 Linorite (Chinese famous brand, first brand leading brands/brands, listed companies)
Solar panels can directly convert energy thermal into electricity?
As far as I know, solar photovoltaic power generation is not harmful to the human body. The photovoltaic power generation system converts solar energy into electrical energy based on the principle of voltaic effect produced by light. It is pollution-free and radiation-free. Electronic devices such as inverters and distribution cabinets have passed EMC (electromagnetic compatibility) testing. so there is no harm to the human body. However, the energy production processPhotovoltaic can produce a certain amount of light pollution, which can cause some irritation to human health. In daily life, you must take protective measures to avoid direct exposure to light pollution.
Solar panels can directly convert thermal energy into electrical energy.
Solar power generation methods There are two solar power generation methods: one is the light-heat-electricity conversion method and the other is the light-direct conversion method. electricity.
(1) The light-heat-electricity conversion method uses thermal energy generated by solar radiation to produce electricity. Generally, a solar collector converts the absorbed thermal energy into steam as the working fluid and then drives it away. a steam turbine to produce electricity. The first process is a process ofconversion of light into heat; the second process is a process of converting heat into electricity.
(2) The direct light-to-electricity conversion method uses the photoelectric effect to directly convert solar radiation energy into electrical energy. The basic device for converting light into electricity is the solar cell.
According to currently known technology, only photovoltaic solar panels can directly convert the sun's radiant heat into electrical energy. Thermoelectric conversion materials directly convert thermal energy into electrical energy. It is a completely solid energy conversion method that does not require chemical reactions or fluids.
Therefore, there is no noise, no wear, no fluid leakage and no volume during the power generation process. With the advantages of a small size, un light weight, easy movement and long service life, it occupies an "irreplaceable" position in special application fields such as military batteries and long-range space. sensors, long-distance communications and navigation, and microelectronics.
Detailed information:
Composition of the solar panel and functions of each part:
(1) Tempered glass: Its function is: To protect the main body of power generation (such as battery cells), there are requirements for its light transmission:
(2) EVA: Used to bond and fix tempered glass and the main body of power generation (battery cells). The advantages of transparent EVA material are: Defects directly affect the life of the component. EVA exposed to air is prone to aging and yellowing, thereby affecting transmissionion of light from the component and thus affecting the life of the component. quality of energy production of the component. In addition to the quality of the EVA itself, the component manufacturer's lamination process also has a great impact if the bonding degree of the EVA is not up to standard and the bonding strength between the EVA and tempered glass. , and the backplane is insufficient, this will cause premature aging of the EVA and affect the service life of the 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.
Crystalline silicon solar cells have relatively low equipment costs, but high consumption and cell costs. However, the conversion efficiency photoedElectricity is also high and they are more suitable for generating electricity under outdoor sunlight.
Thin film solar cells have relatively high equipment costs, but the consumption and battery costs are very low, but the photoelectric conversion efficiency is more than half of that of cells made of crystalline silicon, but the low light effect is very good, under ordinary light. Can also produce electricity, like solar cells in a calculator.
(4) Back plate: Function, sealing, insulation and waterproofing. Typically, TPT, TPE and other materials are used and must be resistant to aging. Most component manufacturers offer a 25-year warranty. Tempered glass and aluminum alloy generally pose no problem. .
(5) Aluminum alloy: protects rolled parts and plays a certain rolee sealing and support.
(6) Junction box: Protects the entire power generation system and acts as a power transfer station. If any component is shorted, the junction box will automatically disconnect the shorted battery string to avoid burning. of the entire system. The most critical thing in the junction box is the selection of diodes depends on the type of cells in the module, and 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 use double-sided tape and foam to replace silica gel. commonly used in China. The process Simple, practical, easy to use and inexpensive.
Baidu Encyclopedia-Solar Panels