The difference between fully tempered components and semi-tempered components

In our impression, common silicon-based photovoltaic modules are composed of solar cells, backsheets, glass, frames, etc. From their structure, photovoltaic modules can be subdivided into single-sided and bifacial modules. The difference between the two is that bifacial modules can work together on both sides to generate electricity at the same time. Bifacial modules have more advantages over traditional single-sided modules in this regard, because As the technology matures and manufacturing costs decrease, double-sided products have gradually occupied the main market. According to CPIA, they will account for 67% of the market in 2023 and gradually increase.
Different from single-sided modules in some aspects, double-sided modules use transparent glass or transparent backsheet on the back. The front side can generate electricity normally, and the back side can also receive reflected and scattered light to generate electricity, and the power is 60% to 90% of the front side. The power generation power Compared with traditional single-sided modules, it increases by 4% to 30%, and its BOS cost is also reduced.
Glass is divided into fully tempered and semi-tempered according to the degree of physical tempering: fully tempered glass is 4 to 6 times stronger than ordinary glass, and semi-tempered glass is only 3 times stronger. During the production process, only semi-tempered glass with a thickness of less than two millimeters can be processed into semi-tempered glass. The tempering thickness requirements are higher. For photovoltaic modules, the front is most likely to be impacted, so the glass material on the front determines the strength and impact resistance of the module. Semi-tempered modules are composed of two 2.0mm semi-tempered glass and battery cells on both sides, while fully tempered glass The front uses 2.5mm, 3.2mm or 2.8mm fully tempered glass, and the back uses a transparent organic backplane.
There is a non-negligible risk of semi-tempered components bursting when used in daily life. They may explode due to external force or self-explode. The main reason for self-explosion is uneven stress, such as uneven stress during the lamination process and uneven mechanical stress from the fixture during installation. In particular, frameless components will self-explode due to great thermal stress in places with large temperature differences between day and night. In addition, if the impurities in the glass itself exceed the intrinsic strength, they will also self-explode. Fully tempered components are less risky and use a transparent backing plate to not only handle thermal stress but also resist load.
Cost reduction and efficiency increase will always be the main theme of the photovoltaic industry. Considering safety, quality and efficiency, bifacial modules are safer, better quality and lower cost. Fully tempered modules may become the mainstream trend in the future.