POE는 주로 태양광 모듈 포장재로 사용되는 접착 필름에 단일 물질로 활용됩니다.
To enclose and safeguard the solar cells in photovoltaic modules, an adhesive film is positioned between the tempered glass/backsheet of the module and the solar cells.
Structure of a photovoltaic module
태양전지의 패키징 공정은 비가역적이고 모듈의 작동 수명은 일반적으로 25A 이상이 요구되기 때문에 필름의 절대값은 구성 요소에서 높지 않지만 그 품질은 제품의 품질과 수명을 직접적으로 결정합니다. 따라서 작동 중에 접착 필름의 광 투과율이 감소하거나 황변과 같은 고장 문제가 발생하면 태양전지는 폐기되어 모듈을 사용할 수 없게 됩니다.
현재 태양광 모듈에 사용되는 가장 일반적인 두 가지 유형의 캡슐화 필름은 POE 필름과 EVA 필름입니다. EVA 접착 필름은 열경화성 접착 필름으로 내후성이 떨어지고 수증기 전달률이 높으며 강도가 낮습니다. 수증기는 여전히 필름을 정상적으로 통과할 수 있으며, 이는 필름을 분무화하여 투과성을 변화시킵니다. 또한 EVA 필름은 쉽게 분해되어 아세트산 분자를 방출하여 유리, 백플레인 및 기타 부품을 부식시키고 수명을 단축시킵니다.
In recent years, it has also been discovered that there is a major potential-induced degradation (PID) phenomena in the EVA film, which causes a dramatic decrease in the output power of solar power plants.
최근에는 발전소의 출력을 크게 감소시키는 전위 유도 열화(PID) 문제가 EVA 필름에 상당 부분 존재한다는 사실도 밝혀졌습니다.
Low water vapor transmission rate and high volume resistivity of POE film over EVA film ensure the safety and long-term aging resistance of photovoltaic modules in high temperature and high humidity environments, allowing for the modules’ long-lasting and effective use.
Performance evaluation of POE and EVA
EVA and POE each have advantages and disadvantages in the realm of photovoltaics. EVA is inexpensive, simple to produce, storage resistant, quick to crosslink, and performs well when bonded to glass and the backplane; the benefits of POE are mostly related to its superior material performance and anti-PID performance. Excellent, high resistivity, strong resistance to water vapor, low temperature resistance, and resistance to yellowing.
The primary drawbacks of EVA are that vinyl acetate is prone to hydrolysis in hot, humid, and oxygen-rich situations, creating acetic acid that corrodes soldering strips and battery sheet surfaces and also interacts with sodium in glass to produce a significant amount of free movement. Na ions, which results in power attenuation; concurrently, EVA is prone to yellowing in the light and heat environment, which lowers the light transmittance and results in the module’s overall power loss.
The processing is too difficult, the film lip is easy to hang, and the overall price of POE particles is more expensive than that of EVA. POE’s disadvantages include its low polarity, which causes the polar additive solvent to precipitate to the surface of the film during processing, making it smooth and easy to shift. According to common consensus, the following variables will cause the fraction of POE particles in the application of film particles to increase during the next several years:
1. N-type battery: While the upper limit of photoelectric conversion efficiency for P-type batteries is currently close to 24.5%, it is higher for N-type batteries; the boron-oxygen complex doped in P-type batteries’ silicon wafers will cause the potential decay to speed up, and N-type batteries mixed with scale will perform better against attenuation. N-type cells have a PID effect that is more sensitive to the light-receiving surface. After the light is restored, N-type components with significant PID attenuation will likewise sustain permanent harm. Therefore, selecting POE film for packaging can lower the module’s total water vapor transmission rate and increase the module’s useful life. As a result, encouraging the use of N-type batteries can boost POE.
2. Battery power on a large scale: In recent years, the power of various battery component types has substantially improved, and heat generation has grown. The demands for electrical performance will be increased.
3. The reduction in cover glass thickness and the rise in double-glass components: According to CPIA statistics, there are now three primary grades of glass thickness: 2.5mm, 2.8mm, and 3.2mm; of these, the market share of 2.5mm glass cover plates is 32%. By 2025, it’s anticipated that the percentage would reach about 50%. The performance requirements for packaging materials will rise as glass becomes thinner, and POE offers strong mechanical strength and toughness.
