Embedding materials in solar modules – an often underestimated success factor
- 17 hours ago
- 3 min read
When it comes to solar modules, the focus is often on the solar cells or their efficiency. An equally crucial component is frequently overlooked: the encapsulation materials. They play a central role in the mechanical stability, cell protection, and long-term performance of a module.
Functions of embedding materials
The encapsulating material in solar modules is located between the front glass, solar cells, and the back glass. It performs several essential functions:
Mechanical fixing of the solar cells
Protection against environmental influences such as moisture, dust and temperature fluctuations
Electrical insulation of the cells
High light transmission to minimize optical losses
Long-term stability over a module lifetime of 30 years and more
EVA - the proven industry standard
Ethylene vinyl acetate (EVA) is the most widely used embedding material worldwide and has been considered the standard solution in the industry for years.
Typical properties of EVA are:
High light transmission
Good mechanical stability
Easy processing in the lamination process
Cost-efficient and widely available
EVA should not be categorically dismissed. With suitable material quality, optimized lamination parameters, and appropriate operating conditions, EVA can be a very reliable and durable embedding solution. Particularly in moderate climates and with proven module designs, EVA remains a technically and economically viable choice.
At the same time, EVA can be more susceptible to moisture ingress or aging processes under unfavorable operating conditions, which can lead to performance losses in the long term.
POE - increased durability for demanding applications
Polyolefin elastomer (POE) is gaining in importance, especially in high-quality and durable module solutions.
Advantages of POE include:
Very low water vapor permeability
Improved protection against potential-induced degradation (PID)
Higher chemical and thermal stability
SOLYCO uses POE
POE is particularly suitable for modules that are operated under demanding conditions, such as:
In regions with high humidity
Near the coast
At high system voltages
Disadvantages currently include higher material costs and more demanding processing compared to EVA.
Hybrid solutions - balanced material concepts
Combinations of EVA, POE, and EVA (EPE) are increasingly being used. These material combinations aim to:
To utilize the good processability of EVA
At the same time, to integrate the protective effect of POE
To achieve a balanced ratio of performance, reliability and cost.
Furthermore, asymmetrical material concepts are also employed. For example, POE or an EPE structure can be used on the front of a module to ensure increased protection against moisture, UV radiation, and PID, while EVA is deliberately used on the back. This concept makes it possible to selectively utilize the advantages of both materials where they offer the greatest added value, without unnecessarily compromising cost-effectiveness or process stability.
Crosslinking and lamination process - a crucial quality factor
Regardless of the embedding material chosen, cross-linking during the lamination process is a key factor influencing module quality. Both EVA and POE must achieve a defined degree of cross-linking to ensure their mechanical, electrical, and chemical properties remain stable over the long term.
The following should be noted:
EVA and POE differ significantly in their optimal lamination temperatures.
The required holding times in the laminator also vary depending on the material.
Hybrid or asymmetric concepts require particularly precise process control.
Inadequately selected lamination parameters can lead to incomplete crosslinking, accelerated aging, adhesion problems, or long-term reliability risks. Therefore, careful coordination of temperature, pressure, and time is a crucial factor for quality, especially when working with material combinations.
Comparison of advantages and disadvantages
embedding material | Advantages | Disadvantages |
EVA (ethylene-vinyl acetate) | • High light transmission • Proven industry standard • Good mechanical stability • Easy processing • Cost-efficient | • Higher water vapor permeability • More susceptible to chemical aging • Less protection against PID compared to POE |
POE (Polyolefin Elastomer) | • Very low water vapor permeability • High protection against PID • Very good thermal and chemical stability • Particularly suitable for demanding environments | • Higher material costs • More demanding processing • Lower market penetration than EVA |
Hybrid solutions (EVA/POE) | • Combination of good workability and high protective effect • Flexibly adaptable to modular design • Balanced ratio between performance and cost | • More complex material selection • Dependence on precise process control • Quality strongly depends on the specific material concept |
Conclusion: Embedding materials are a crucial factor for SOLYCO.
While EVA remains widely used, high-performance modules are increasingly relying on POE or hybrid solutions to meet higher demands for reliability and lifespan.
Through targeted material combinations and precisely coordinated crosslinking in the lamination process, SOLYCO can optimally utilize the respective strengths of EVA and POE.
For our product development, the targeted selection of high-quality embedding materials is an essential component in order to develop durable, safe and high-performance SOLYCO premium solar modules.
