The crystalline silicon solar cell itself has poor mechanical strength and is prone to rupture. The moisture and corrosive gases in the air will gradually oxidize and corrode the electrode, which cannot withstand the harsh working conditions in the open air. For this reason, solar cells are usually packaged by photovoltaic glass through EVA and the back panel.Photovoltaic glass in the photovoltaic modules to protect the battery from water and gas erosion, blocking oxygen to prevent oxidation, high and low temperature resistance, good insulation and aging resistance.Photovoltaic glass is a kind of silicate glass with low iron content, also known as ultra-white embossed glass.
The photovoltaic glass used in crystal silicon cell is different from float glass. The upper surface of photovoltaic glass is suede, which makes it difficult for the light directly onto the surface of the module to produce specular reflection. The lower surface is embossed, which can enhance the adhesive force with EVA film.
The main components of photovoltaic glass
The main raw materials of photovoltaic glass include quartz sand, soda ash, limestone, dolomite, sodium nitrate, glauber salt, sodium pyroantimonate, aluminum hydroxide, etc.Quartz sand mainly plays the role of network formation body, the dosage usually occupies the majority of the glass component, soda ash is mainly used to provide sodium oxide, mainly to reduce the melting temperature of glass;The main role of limestone is to adjust the viscosity of the glass to the appropriate value, so that the glass molding time to meet the requirements of molding, glauber salt is mainly used as a clarifier, used to eliminate bubbles in the glass, to provide glass transmittance.
Photovoltaic glass raw material consumption ratio
Photovoltaic glass is usually prepared by calendering method, and the production process can be divided into two stages: sheet production and deep processing.The original production mainly includes batching, melting, calendering, annealing and cutting.Around 1100 ℃ in the rolling process, the molten glass, a calender rollers rolling and cooling, to a certain speed reaches a certain thickness, a certain width, a certain pattern, through the glass of a rate of 91.5%, and then after annealing lehr, make the glass has a relatively stable stress curve, to have a certain strength, not easy broken, is conducive to cutting, processing glass.It is necessary to point out that there is a difference between the production line of photovoltaic embossed glass and float glass.
Deep processing process is usually the original glass coating and toughening, coating is to improve the transmittance of photovoltaic glass, toughening is to increase the mechanical properties of glass, toughened glass bending strength is 3~5 times that of ordinary glass, impact strength is 5~10 times that of ordinary glass, improve the strength but also improve the safety.
Photovoltaic glass process flow
The performance of 02 photovoltaic glass requires that photovoltaic glass must have good light transmittance. Generally speaking, the light transmittance of uncoated steel sheet (wavelength range from 380nm to 1100nm) is usually more than 91%, while the light transmittance of coated glass after deep processing can reach the level of 93.5%.In addition, photovoltaic glass needs to meet certain weather resistance and mechanical properties. According to GB T 30984.1-2015 “solar energy glass part 1 ultra-white embossed glass”, the minimum performance of photovoltaic glass used for photovoltaic modules should meet the following requirements.
Photovoltaic glass industry in China
Photovoltaic glass industry barriers is higher, the concentration is higher, the production need long-term accumulation of experience and one-stop production process, and need a larger initial investment, the capacity of 900 tons/day photovoltaic glass kiln need initial investment RMB 9, 550 tons of stove investment takes about 3-400 million yuan, and large kiln had lower manufacturing cost compared with ordinary kiln (low energy consumption to 20%). As a result, photovoltaic glass industry has obvious scale effect, and the large amount of molten core technology mainly in the hands of leading enterprises,Small and medium-sized enterprises are relatively lack of technical strength and economic strength to invest in the construction of 1000 tons of kilns.
Since China broke the technological threshold of photovoltaic glass production in 2006, the domestic photovoltaic industry has developed rapidly in less than 10 years. After relying on imports entirely, China has become the world’s largest producer of photovoltaic glass. More than 90% of the world’s crystal silicon modules use photovoltaic glass produced in China.Compared with foreign enterprises, China’s photovoltaic glass has obvious advantages in quality and cost.As of December 2017, there are 24 ultra-white calented-glass products, 40 kilns and 135 production lines in China, with a total production capacity of 21,290 tons/day. Calculated according to the industry average yield level of 78%, the domestic production of ultra-white calented-glass raw pieces is about 14,773.20 tons/day
Market expectations
2018 will be the first year for the launch of two-sided components, and the market share of two-sided components will increase rapidly, which will effectively drive the demand for photovoltaic glass.According to the calculation, the demand of photovoltaic glass is shown in the following table. Considering that some old photovoltaic glass kilns need cold repair in 2018, the actual production capacity of photovoltaic glass will be lower than the nominal production capacity, and the supply and demand of photovoltaic glass in 2018 is in a tight balance.
According to the results, since Q4 2017, photovoltaic glass tight supply and demand, at the beginning of 2018, under the premise of photovoltaic industry in the first quarter is off-season, buck the rise in the price of photovoltaic glass, the coating sheet in 31 yuan per square meter or more, the price of the glass in 21 yuan per square meter or so, the price of the rebound in prices will make photovoltaic glass enterprise gross margin level are improved significantly.
Post time: Apr-14-2020