Classification of photovoltaic glass: Photovoltaic glass substrates for solar panels, generally including ultra-thin glass, surface-coated glass, low-iron (ultra-white) glass. Depending on the nature of the application and the method of manufacture, photovoltaic glass can be further divided into three types: the cover plate of a flat-type solar cell, generally a calendered glass; and the surface of the flat glass is plated with a semiconductor material usually having a thickness of only several micrometers, conductive substrate for thin film solar cells and lens or mirror type glass used in the collector photovoltaic system. The characteristics and functions of these three products are completely different, and the added value is also very different.
Today’s most widely used solar photovoltaic glass is high transmittance glass, which is a low-iron glass and commonly known as ultra-white glass. Iron is an impurity in ordinary glass (except heat absorbing glass), and the presence of iron impurities, on the one hand, coloring the glass, on the other hand, increasing the heat absorption rate of the glass, thereby reducing the light transmittance of the glass.
The iron in the glass is introduced from the raw material itself, the refractory material or the metal material production equipment, etc., and cannot be completely avoided. One can only minimize the amount of iron in the glass through production control. At present, the iron content of solar cell glass is between 0.008% and 0.02%, while the iron content of ordinary float glass is above 0.7%, and low iron content impurities can bring high solar transmittance. For the most widely used 3.2mm thick and 4mm thick glass in the country, the visible light transmittance of sunlight is generally 90%~92%.
As one of the most important components of solar panels, solar photovoltaic glass requires that the glass plate must be highly transparent. Therefore, the iron content of the silicon raw material used for producing solar glass is very strict, and the Fe2O3 content is generally 140 to 150 ppm.
The application of photovoltaic solar glass: According to reports, the world’s first country using transparent flat glass as a substrate for solar cells is Germany. German technicians installed this kind of plate-shaped solar cell as a window glass on a building, which can directly supply the ingested electric energy to the households, and the excess electric energy can be input into the power grid. This initial solar cell glass is developed and utilized. It was soon followed by the United States and Japan, which accelerated the development and application of low-iron and ultra-thin glass for solar energy.