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In photovoltaic module manufacturing, the choice of encapsulation materials plays a vital role in determining module performance, lifespan, and reliability. Recently, with advancements in technology and changing market demands, POE (Polyolefin Elastomer) has emerged as a favored encapsulation material for many companies. This article explores the differences between EVA (Ethylene Vinyl Acetate) and POE, and why POE is gaining popularity in the photovoltaic industry.

Key Differences Between EVA and POE

1. Chemical Stability

   • EVA: EVA has been the mainstream encapsulation material due to its excellent adhesion and optical transparency. However, its main drawback lies in the presence of acetate groups, which are prone to hydrolysis in high-temperature and high-humidity conditions, leading to delamination or acetic acid formation, potentially reducing module lifespan.
   • POE: POE, being a non-polar material, offers superior resistance to moisture ingress and chemical stability. Even in harsh environments, POE demonstrates better performance, effectively reducing the risk of PID (Potential Induced Degradation).

2. Transparency and UV Resistance

   • EVA: While highly transparent, EVA may yellow over time under UV exposure, negatively impacting the module’s power output.
   • POE: POE provides excellent optical properties and superior UV resistance, maintaining long-term module performance without yellowing.

3. Mechanical Properties

   • EVA: While flexible, EVA has lower mechanical strength and durability compared to POE.
   • POE: POE exhibits higher mechanical strength and elastic modulus, providing better protection for solar cells, particularly with large-size, high-power cells.

4. Encapsulation Compatibility

   • EVA: Best suited for traditional vacuum lamination processes.
   • POE: Compatible with new co-extrusion encapsulation processes and can be combined with EVA to leverage the strengths of both materials, enhancing encapsulation performance.

Why Are More Companies Choosing POE?

1. Improved Module Longevity
   POE’s superior moisture resistance and PID prevention make it ideal for challenging environments such as coastal solar farms or tropical regions. These settings demand robust encapsulation materials, and POE meets these requirements effectively.

2. Adaptation to High-Power Module Trends
   With the industry’s shift toward higher power and larger-size cells, mechanical performance requirements for encapsulation materials have risen. POE’s high strength and elasticity better protect large-size cells, reducing risks during encapsulation and transport.

3. Lower System Costs Over Time
   Modules encapsulated with POE exhibit lower degradation rates, leading to higher energy output and extended service life, thereby reducing the system’s levelized cost of electricity (LCOE).

4. Regulatory and Market Drivers
   Markets like Europe and the U.S. have stricter standards for module reliability, including requirements for PID resistance and moisture protection. POE’s properties align with these stringent demands, making it an advantageous choice for global market entry.

Future Prospects for EVA and POE

Despite POE’s advantages, its higher cost and more complex processing compared to EVA remain challenges. However, as raw material prices decrease and encapsulation technologies advance, POE’s market share is expected to grow. Hybrid solutions combining EVA and POE are also becoming increasingly popular to balance performance and cost.

Conclusion

EVA and POE are both essential encapsulation materials, each with its own strengths and weaknesses. However, POE’s superior chemical stability, UV resistance, and mechanical properties position it as a rising star in the photovoltaic industry. With the growing emphasis on module reliability and the trend toward high-power systems, POE’s applications are set to expand further.

At SpolarPV, we are committed to leading photovoltaic technology advancements by embracing innovative encapsulation materials to deliver efficient and reliable solar solutions to our customers.