What is EVA (ethylene vinyl acetate) Film for Solar PV Panels

What is EVA?

EVA is the acronym for ethylene vinyl acetate. EVA films are an essential material used for traditional solar panel lamination

Why we need EVA films and how are they integrated into solar PV panels?

To protect solar photovoltaic cells from adverse weather conditions, these are laminated (embedded) between transparent EVA films in a vacuum and under heat and compression with the aid of a lamination machine.

Through the heat (up to 150°C), the EVA film begins to melt, and through the compression, it associates with the solar photovoltaic cells.

Once the EVA films have been laminated, they play a significant role in preventing moisture and dirt penetrating the solar PV panels. Besides, they help to soften the impact of shocks and vibrations and therefore protect the solar photovoltaic cells and its circuits.

Problems associated with the EVA film

There are different problems associated with the EVA film, which can impact the solar PV module:

• Delamination is a process where the EVA film starts to separate from the glass and backsheet. This allows air and moisture inside the solar PV panel resulting in corrosion. The reason for this problem is if the EVA film is not cured correctly during the lamination process.

• Browning is a change in color of the EVA film and occurs when certain additives used to prevent browning and enhance UV resistance, start to disappear (if stored or handled incorrectly). This can cause bleaching and blistering at the EVA film and the solar backsheet, again resulting in cell corrosion.

Therefore, it is important to choose a manufacturer which produces quality solar PV panels.

Quality solar panels have EVA film with the following properties:

Durability

Superior EVA film should be stable in difficult weather circumstances, such as elevated temperatures, high humidity, and UV exposure.

Adhesive bonding

Under the right conditions, EVA film will have good adhesive bonding to the rough glass plate. Besides, the EVA layer should bond very well to the solar backsheet.

Excellent transparency

Quality EVA film has an excellent transparency. This means that the optical transmission is acceptable (it does not block too much sunlight trying to reach the solar photovoltaic cells). It also has low thermal resistance.

The choice of EVA encapsulant used in the manufacturing of solar PV panels significantly influences the end product’s lifespan and its susceptibility to defects  and, eventually, the yield of the whole solar PV system in which the solar PV panels are used.

GWELL provide turnkey solution for EVA solar film production project, welcome to contact us.