Classification and application of solar photovoltaic glass
Photovoltaic glass classification. Photovoltaic glass substrates for solar cells generally include ultra-thin glass, surface-coated glass, and 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, namely, 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. Thin film battery conductive substrate; 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 widely used solar photovoltaic glass is a high transmittance glass, which is a low iron content glass, which is 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 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%. Low iron content impurities can bring high solar transmittance. For 3.2mm thick and 4mm thick glass, which are widely used in China, the visible light transmittance of sunlight generally reaches 90%~92%.
As one of the important components of solar energy equipment, 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 140-150 ppm.
The application of photovoltaic glass. According to reports, the world's first country using transparent flat glass as a substrate for solar cells is Germany. German technicians installed the plate-shaped solar cell as a window glass on a building, which can directly supply the ingested electric energy to the household, and the excess electric energy can be input into the power grid. The 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.