Solar panel composition and the various functions

Currently, crystalline silicon materials (including polysilicon and monocrystalline silicon) are the most important photovoltaic materials with a market share of more than 90%, and will remain the mainstream material for solar cells for a long time to come. Polysilicon production technology has long been mastered in the hands of 10 factories from 7 companies in 3 countries, such as the United States, Japan and Germany, resulting in a technology blockade and market monopoly. The demand for polysilicon comes mainly from semiconductors and solar cells. According to different purity requirements, divided into electronic grade and solar grade. Among them, for electronic grade polysilicon accounted for about 55%, 45% of solar grade polysilicon, with the rapid development of photovoltaic industry, the growth rate of solar cell demand for polysilicon is higher than the growth of semiconductor polysilicon is expected to 2008 solar polysilicon Demand will exceed electronic grade polysilicon. Total solar cell production in the world in 1994 was only 69MW, compared with nearly 1200MW in 2004, a 17-fold increase in just 10 years. Experts predict that the solar photovoltaic industry will surpass nuclear power as one of the most important basic energies in the first half of the 21st century.

Solar panels and various parts of the function:

(1) Tempered glass: Its role is to protect the power generation body (such as the battery), the selection of light transmission is required:

1. The light transmittance must be high (usually above 91%);

2. Super white tempered.

(2) EVA: used to bond the fixed glass and the main power generation (battery), the merits of transparent EVA material directly affect the life of the components exposed to air EVA easy to aging yellow, thus affecting the components of the light Rate, thus affecting the quality of power generation components In addition to the quality of EVA itself, the component manufacturers laminate process is also very large impact, such as EVA adhesive degree of non-compliance, EVA and toughened glass, backplane adhesive strength is not enough, will cause EVA Premature aging, affecting component life.

(3) Cell: The main function is to generate electricity. The mainstream power generation market is crystalline silicon solar cells and thin film solar cells, both of which have advantages and disadvantages of crystalline silicon solar cells. The cost of equipment is relatively low, but the consumption and Cell cost is high, but the photoelectric conversion efficiency is high, more appropriate in the outdoor sunlight power generation. Thin film solar cells, the relative cost of equipment, but the cost and low battery costs, but the photoelectric conversion efficiency relative to crystalline silicon cells more than half, but the weak light effect is very good, in ordinary light can also generate electricity, such as the calculator Solar cell.

(4) Back: role, sealed, insulated, waterproof. Generally use TPT, TPE and other materials must be resistant to aging, most components manufacturers are warranty 25 years, tempered glass, aluminum alloy generally no problem, the key is with the backplane and the silicone can meet the requirements.

(5) aluminum alloy: protective laminate, from a certain seal, support role.

(6) Junction box: protect the entire power generation system, play the role of current transfer station, if the components short-circuit Junction box automatically disconnect the short-circuit the battery string to prevent burnout The most critical junction box in the system is the choice of diodes, Different types of cells, the corresponding diode is not the same.

(7) Silicone: Sealing function, used to seal the interface between the component and the aluminum alloy frame, the junction of the component and the junction box Some companies use double-sided adhesive tape and foam to replace the silicone. Silica gel is commonly used in China. The process is simple, convenient and easy to operate, And low cost.