1. The warranty period of component power is not less than 25 years, and the warranty period of process and materials is not less than 10 years;
2. The attenuation rate of crystalline silicon modules should not be higher than 2.5% in the first year, not higher than 0.6% in subsequent years, and not higher than 17% in 25 years.
The high efficiency and reliability of the photovoltaic module life cycle are two important connotations of the quality of photovoltaic power generation. For a long time, Trina Solar has started from the source of the quality of photovoltaic modules - key materials, taking the environmental durability of materials as the assessment object, selecting materials with high transmission, high resistance and high weather resistance, and paying attention to the performance of photovoltaic modules throughout the life cycle situation.
01
Photovoltaic glass
Photovoltaic Glass
Introduction to glass: Low iron tempered suede glass (also known as white glass) has a light transmittance of more than 93% in the wavelength range of solar cell spectral response (320-1100nm), and has a high light transmittance for infrared light greater than 1200 nm. Reflectivity. At the same time, the glass can withstand the radiation of solar ultraviolet rays, and the light transmittance does not decrease. The glass should be clean and free of moisture, and the two surfaces of the glass should not be touched with bare hands.
Glass thickness: 3.2mm (single glass)/2.0+2.0mm (double glass) or thinner
Distinction: new coated glass (ARC) / tempered glass / semi-tempered / tin-coated float semi-tempered (double glass back glass)
Tempered glass self-explosion: When judging whether it is a self-explosion, you need to find the "butterfly spot" of the initiation point, and then you can often see small black spots from the thickness direction, which are nickel sulfide stones. In addition, the uneven distribution of stress may also cause self-explosion, which requires improving the uniformity of heating and cooling by improving the tempering process, so as to reduce the surface tensile stress formed by blocking cooling in this part as much as possible.
Advantages of double-glass modules: better cope with harsh environments, better insulation, fire resistance, sand resistance, corrosion resistance, and zero water permeability; while perfectly matching double-sided cells to achieve double-sided power generation, it has better anti-turnover process. EL cracking performance. In high-temperature and high-humidity areas, it is recommended to use double-glass modules with zero water penetration: the double-glass structure can isolate most of the natural aging factors. Put an end to EVA hydrolysis.
Reliability test: The experimental test compares the performance of double-glass and ordinary backplane components under different strict reliability tests such as DH, TC, TC+HF, etc. The experimental results are shown in the figure. It can be seen that under different reliability test items, The power attenuation of double-glass modules is smaller than that of backplane modules.
02
backplane
Photovoltaic Backplane
Introduction to the back sheet: The back sheet is located on the back of the photovoltaic module, which protects and supports the cells, and has reliable insulation (voltage resistance), water resistance (water vapor barrier), and aging resistance (UV resistance, corrosion resistance) . The global climate environment is diverse, such as tropical high humidity, cold and dry, desert arid, mild environment, etc., and the environmental pressures faced by components are also different.
Backplane material and structural design: The most common are TPX, KPX and PET, among which T film (PVF) and K film (PVDF) in the "sandwich" structure are fluorine-containing film layers, and their main functional characteristics are UV resistance. Good receptivity and barrier ability; P layer is made of PET material, and its main functional characteristics are good insulation and water barrier properties.
03
Packaging film
Encapsulants
The structure of the film: The main component of the EVA packaging film is ethylene-vinyl acetate copolymer. When cross-linked by heat, the cross-linking agent decomposes to form active free radicals, which triggers the intermolecular reaction of EVA to form a network structure and generates thermosetting heat. Melt glue; POE encapsulation film is a thermoplastic elastomer obtained by metallocene-catalyzed ethylene-α-octene copolymerization. It has the characteristics of narrow molecular mass distribution and belongs to a high stereoregular polymer.
The role of the film:
1. Bonding (bonding glass, battery and backplane into one);
2. Block air and water vapor;
3. Certain elasticity, buffering, and protecting the battery slices.
Performance requirements:
4. Requirements for high transmittance;
5. UV resistance;
6. Peel strength at a certain degree of crosslinking.
Surface pattern:
Increase friction with cells to prevent poor spacing and exhaust during lamination.