Solar panel related knowledge
First, the principle of solar cell power generation: Solar cells are a pair of devices that respond to light and convert light energy into electricity。 There are many kinds of materials that can produce photovoltaic effect, such as: monocrystalline silicon, polycrystalline silicon, amorphous silicon, gallium arsenide, selenium indium copper, and the like。 Their power generation principle is basically the same, and the crystal power generation process is now described by taking a crystal as an example。 P-type crystalline silicon is doped with phosphorus to obtain N-type silicon to form a P-N junction。 When the light illuminates the surface of the solar cell, part of the photons are absorbed by the silicon material; the energy of the photons is transferred to the silicon atoms, causing the electrons to move away, and the free electrons accumulate on both sides of the PN junction to form a potential difference when the external circuit is turned on。 At this time, under the action of this voltage, a current will flow through the external circuit to generate a certain output power。 The essence of this process is the process of converting photon energy into electrical energy。
Second, there is no difference between polycrystalline silicon solar cells and monocrystalline silicon solar cells. The life and stability of polycrystalline silicon solar cells and monocrystalline silicon solar cells are very good. Although the average conversion efficiency of monocrystalline silicon solar cells is about 1% higher than the average conversion efficiency of polycrystalline silicon solar cells, since monocrystalline silicon solar cells can only be made into quasi-squares (four tops are arcs), when composing solar cell modules When a part of the area is filled, and the polycrystalline silicon solar cell is square, there is no such problem, so the efficiency of the solar cell module is the same.
In addition, since the manufacturing process of the two solar cell materials is different, the energy consumed in the manufacturing process of the polycrystalline silicon solar cell is about 30% less than that of the monocrystalline silicon solar cell.
The single crystal silicon battery has high battery conversion efficiency and good stability, but the cost is high. Monocrystalline silicon cells have broken through the technical barrier of more than 20% photoelectric conversion efficiency as early as 20 years ago.
The cost of polycrystalline silicon cells is low, and the conversion efficiency is slightly lower than that of Czochralski silicon solar cells. Various defects in materials such as grain boundaries, dislocations, micro defects, and impurities in materials, such as carbon and oxygen, and contamination in the process. The transition metal is considered to be the gateway for the photoelectric conversion rate of polycrystalline silicon cells to never exceed 20%.
Characteristics of monocrystalline silicon solar cells: 1。 High photoelectric conversion efficiency and high reliability; 2。 Advanced diffusion technology to ensure uniformity of conversion efficiency throughout the film; 3。 Using advanced PECVD film forming technology on the surface of the battery It is coated with a deep blue silicon nitride anti-reflection film with uniform color and beautiful appearance。 4。 High-quality metal paste is used to make back field and electrode to ensure good conductivity。 Polycrystalline silicon can be used as a raw material for drawing single crystal silicon, and the difference between polycrystalline silicon and single crystal silicon is mainly manifested in physical properties。 For example, in terms of anisotropy of mechanical properties, optical properties, and thermal properties, it is much less pronounced than monocrystalline silicon; in terms of electrical properties, polycrystalline silicon crystals are much less conductive than monocrystalline silicon, and even have little conductivity。 In terms of chemical activity, the difference between the two is extremely small。 Polycrystalline silicon and single crystal silicon can be distinguished from each other in appearance, but the true identification must be determined by analysis of the crystal plane orientation, conductivity type, and resistivity。 Supply is in short supply and the development prospects are very broad。 Because of this, many people say that whoever masters polysilicon and microelectronics technology will master the world。
Third, the series can increase the output voltage, and the parallel can provide the output current. This is achieved by a series-parallel method, for example: 220 volts at 10 amps is required. Using 880 panels of 0.5 volt 5 amp output, 440 in series as the first group, then a second group, and then two groups in parallel, can get 220 volts 10 amp output.
Fourth, solar panel standard testing
Solar panel standard test method Solar panel standard test method Solar panel standard test method Solar panel standard test method (simulated solar light)
1. Open circuit voltage: use 500W tungsten halogen lamp, 0~250V AC transformer, the light intensity is set to 3.8~4.0 million LUX, the distance between the lamp and the test platform is about 15-20CM, and the direct test value is the open circuit voltage;
2. Short-circuit current: use 500W tungsten halogen lamp, 0~250V AC transformer, the light intensity is set to 3.8~4.0 million LUX, the distance between the lamp and the test platform is about 15-20CM, and the direct test value is short-circuit current;
3。 Working voltage: use 500W tungsten halogen lamp, 0~250V AC transformer, the light intensity is set to 3。8~4。0 million LUX, the distance between the lamp and the test platform is about 15-20CM, and the positive and negative poles are connected in parallel。 Resistance, (calculation of resistance value: R = U / I), the test value is the working voltage;
4。 Working current: use 500W tungsten halogen lamp, 0~250V AC transformer, the light intensity is set to 3。8~4。0 million LUX, the distance between the lamp and the test platform is about 15-20CM, and a corresponding resistance is connected in series, ( The calculation of the resistance value: R = U / I), the test value is the operating current。