With the advancement of photovoltaic technology in recent years, double-glass solar modules have progressed quickly. The double-glass module, as opposed to the conventional single-glass module, employs photovoltaic glass rather than the backsheet, considerably enhancing the module’s performance in terms of water vapor resistance, corrosion resistance, fire prevention, and sand wear resistance. The application range of solar photovoltaic modules is expanded by general buildings and photo-complementation in agriculture/fishery.

Double-glass modules offer more benefits than single-glass modules.

First off, as glass has a nearly 0% water vapor transmission rate, the issue of EVA film hydrolysis brought on by water vapor entering the module need not be taken into consideration, making it particularly ideal for solar power plants in humid environments like beach and waterside;

Second, the glass has high wear, weather, and corrosion resistance, allowing the components to be employed in environments with powerful sandstorms, acid rain, and salt spray;

Third, the fire protection rating of double-glass modules has been increased, making them ideal for locations like industries and residences where fire threats must be avoided;

Fourth, the high degree of insulation provided by glass enables the components to operate at greater system voltages while reducing the cost of the power plant’s system.

At the moment, POE film and EVA film make up the majority of the encapsulation film for double-glass modules. Ethylene-vinyl acetate (EVA) film is a copolymer with the benefits of a low melting point, good fluidity, high transparency, and an established lamination method. Currently, it serves as the primary double-glass module packaging material.
When used on double-glass modules, the EVA film must be edge-sealed due to its low strength, high water vapor transfer rate, high water absorption rate, and poor weather resistance. However, during typical use, water vapor will still flow through, resulting in The film is atomized, which impairs light transmittance and lowers the module’s ability to generate electricity.

A brand-new class of polyolefin thermoplastic elastomer with a limited relative molecular mass distribution, a narrow comonomer distribution, and a controlled structure was created employing metallocene as a catalyst. Its name is POE, or poly(ethylene-octene).

There are now two different varieties of POE film available on the market; one is a non-crosslinked polyolefin packaging material that lacks a crosslinking agent and may fulfill usage requirements by combining functional polymers for heat resistance and adhesion. The other is a packaging material made of cross-linked polyolefin that contains a tackifier, a peroxide cross-linking agent, or a silane cross-linking agent. Regarding production methods and technology, this movie is comparable to the EVA movie.

The major benefit of POE film over EVA film is its low water vapor transfer rate and high volume resistivity, which guarantee component safety and long-term aging resistance in high-temperature and high-humidity conditions, allowing for prolonged component usage. The following are some examples of how POE film performs better than EVA film:

1. POE film has better aging resistance than EVA film because it is a copolymer of ethylene and octene, which has a saturated aliphatic chain structure and fewer tertiary carbon atoms. POE film exhibits good weather resistance, UV aging resistance, excellent heat resistance, and low temperature resistance.

2. Through modification techniques like photografting of polar monomers, plasma surface treatment, or reactive grafting modification on POE, with outstanding interface adhesive qualities, increase the bonding force between POE film and glass, backplane, and other materials.

3. It is appropriate for double-sided batteries with high efficiency, which may significantly improve the conversion efficiency of batteries. It may boost power generation rate and lower electricity cost compared to standard single-sided power generating modules. Additionally, there are more uses for the modules and they may be positioned vertically.

4. POE film is more suited for double-glass modules because to its higher cohesiveness and lower water vapor transmission rate, which enables the production of double-glass modules without edge sealing and extends their useful lives.

Although the present POE film offers the aforementioned benefits, it also has significant drawbacks that limit its widespread application in module manufacture, including limited fluidity, challenging processing, and problematic uniformity control.