The solar cell is made of high-crystalline silicon material, and the solar cell module is laminated with high-strength, light-transmitting solar-specific tempered glass and high-performance, UV-resistant special sealing material. It can be used normally in the harsh environment of ice, snow and temperature changes. In the process of use, solar cells are the most basic form in the form of modules. A single module can be several watts to hundreds of watts, and there are various specifications to choose from. Recently, a new type of solar cell module has appeared, which is characterized by a built-in controller, which can maintain a high conversion efficiency with changes in sunlight intensity.
Solar cell modules should be designed in accordance with the requirements of the International Electrotechnical Commission IEC: 61215: 1993 standard, and the production process is strictly in accordance with the standard production, which can ensure its quality, electrical performance and service life requirements. The following indicators should be met:
(1) The dielectric strength of the solar cell module is greater than 100MΩ.
(2) The service life of the product is more than 25 years.
(3) Operating temperature range: -40~+85℃.
The basic properties of solar cells are as follows:
(1) Photoelectric conversion efficiency η% is an important factor for evaluating the performance of solar cells. At present, the laboratory conversion efficiency of single crystal silicon solar cells is η≈24%, and the industrialization is η≈15%.
(2) The single cell voltage (0.4~0.6V) is determined by the physical properties of the material.
(3) Fill factor FF% is an important index for evaluating the load capacity of solar cells [FF=(Im×Vm)/(Isc×Voc), where: Isc is short-circuit current; Voc is open-circuit voltage; Im is optimal working current ; Vm is the best working voltage].
(4) The effect of temperature on solar cells. The surface of the solar cell module is made of composite material, which is laminated by a laminator, which has good air tightness, weather resistance, corrosion resistance and mechanical strength. The use of double grid lines makes the solar cell module package more reliable. When the solar cell is manufactured, it is chemically treated first, and the surface is made into a suede like a pyramid, which can reduce reflection and better absorb light energy. Using ABS plastic junction box, aging resistance, waterproof, moisture-proof performance is good. With bypass diodes can reduce damage caused by partial shadows. 36 or 72 monocrystalline or polycrystalline silicon solar cells are used in series to form 12V and 24V various types of modules. Solar cell modules consist of the following materials:
Cell. Adopt high-efficiency (above 14.5%) monocrystalline silicon or polycrystalline silicon solar cell packaging to ensure the output power of the solar cell module design.
Grass. Using low-iron tempered suede glass (also known as white glass) with a thickness of 3.2mm, the light transmittance in the wavelength range of solar cell spectral response (320~1100nm) is more than 91%, and it has a high reflectivity for infrared light greater than 1200nm. At the same time, the glass can withstand the radiation of solar ultraviolet rays, and the light transmittance does not decrease.
(1) Waterproof, hailproof and windproof. Generally, solar cell modules are packaged with tempered glass, and the aluminum alloy frame used should have high strength and strong mechanical shock resistance. The installation is fixed with metal brackets, which can withstand strong winds above level 10.
(2) Standard test conditions: (AM1.5) The irradiance is 1000W/m2, and the battery temperature is 25℃.
(3) Insulation voltage: ≥600V.
(4) Frame grounding resistance: ≤10Ω.
(5) Windward pressure: 2400Pa.
(6) Fill factor: 73%.
(7) Short-circuit current temperature coefficient: +0.4mA/℃.
(8) Temperature coefficient of open circuit voltage: -60mV/℃.
(9) Working temperature: -40~+90℃.
At present, there are two main encapsulation forms of solar cells: one is “epoxy board” encapsulated with epoxy resin with high transparency, and the other is laminated module encapsulated with “low iron” tempered glass. Laminated components have high production costs, complex processes and long service life, with a lifespan of more than 25 years in normal use. Epoxy board has the advantages of flexible production size, low cost, short production cycle, and fast production speed. Its biggest disadvantage is that the solar cell is aging, fast decay, poor performance stability, and short service life. Although the epoxy package has a beautiful appearance, the working life of the solar cell is only 1 to 2 years. Therefore, low-power solar lawn lights below 1W can be packaged in the form of glue drop if there is no excessive life requirement. For solar lawn lights with a specified service life, the laminated package should be used. In addition, there is a solar cell that uses silicone gel for drop glue encapsulation, and its working life can reach 10 years.
1. Structural specifications of monocrystalline silicon solar cell modules
(1) Monocrystalline silicon solar cell module structure. The physical diagram of the monocrystalline silicon solar cell module is shown in Figure 1, and the structure of the monocrystalline silicon solar cell module is shown in Figure 2.
(2) Specifications of monocrystalline silicon solar cell modules. Solar cell parameters are: no-load voltage and short-circuit current, the product of which is the power of the solar cell, that is, P=V×I. In the formula: P is the electric power, the unit is watt (W); V is the voltage, the unit is the volt (V); I is the current, the unit is the ampere (A). There are also working voltage and working current. The working voltage is generally 80% to 90% of the no-load voltage, and the working current is generally 80% to 90% of the short-circuit current.
2. Structural specifications of polycrystalline silicon battery modules
The structure of the polycrystalline silicon battery module. The physical diagram of the polycrystalline silicon battery module is shown in Figure 3, and the structure diagram of the polycrystalline silicon battery module is shown in Figure 4.