what is the structural composition of solar panels?

Solar panels, also known as photovoltaic panels, are devices that convert sun’s radiation energy through absorption using either the photoelectric or photochemical effect into electrical energy. The structure of a solar panel consists of layers of materials that work together to produce an electric current when exposed to sunlight.

Let's examine the structural composition of solar panels.

Its function is to protect the main power generation body (solar cells). Tempered glass is expected to possess exceptional transparency and remarkable hardness. It should be able to accommodate significant day-night temperature variations and endure even the harshest weather conditions.

The solar cells are extremely fragile and cannot be directly attached to tempered glass. Instead, EVA film is needed to act as a bonding agent in the middle. Similarly, when connecting the battery board with the backsheet, EVA film also plays a critical role in bonding. While EVA film does possess excellent light transmittance, it tends to yellow when in contact with air, which can significantly impact power generation efficiency. Therefore, the technical requirements for packaging are very high.

Solar cells are the core components, divided into polycrystalline silicon and monocrystalline silicon cells, and their main function is to generate electricity. Solar cells typically come in relatively small sizes, with two options available: 125mm and 156mm. Their shape is rectangular, allowing for the tightly arranged in series. A regular solar panel typically has either 64 or 72 cells.

4. Backsheet

The term backsheet literally means the sheet on the back. It must be sealed, insulated, waterproof, and resistant to aging. Typically, TPT or TPE materials are used for creating this component. While the lifespan of a backsheet may be shorter than that of glass and aluminum frames, it can still last up to 25 years.

There is also a type of bifacial solar panel, and the backsheet is made of tempered glass. This type of double glass solar panel has better transparency and higher power generation efficiency.

The solar panel frame is made of aluminum alloy material, which has excellent strength and corrosion resistance. It reliably supports and safeguards the entire panel, providing a robust housing that ensures longevity. Additionally, the installation holes for the panel are conveniently integrated within the frame, effectively linked to the photovoltaic bracket via the frame for a seamless installation process.

The main function of a junction box is to connect the electricity generated by solar cells to external circuits. It not only facilitates this critical connection but also serves as a reliable seal, shielding the outgoing lines of photovoltaic modules from water and dust. In addition to these functions, the junction box also plays a vital role in ensuring the safe functioning of the photovoltaic module system. For instance, in the event of a short circuit, the junction box will automatically disconnect the short-circuited cells string, preventing the entire system from burning out.

Silicone is primarily utilized for the purpose of bonding and sealing laminated photovoltaic modules, as well as for bonding frames to glass and junction boxes to both backsheets and glass. Additionally, it plays a vital role in serving as a sealing and connecting agent.