Advances in Solar Module Frame Technology: A Comparative Analysis of Materials

When purchasing solar modules, performance and price are the two key factors to consider. The performance of a solar module depends not only on its photovoltaic conversion efficiency but also on the strength and durability of its structure. As a crucial support and protective component, the frame material has a direct impact on the overall performance of the module. Additionally, solar module frames, being high-value auxiliary materials, play a significant role in the module’s total cost structure. For instance, *the commonly used aluminum frame, with its strong mechanical properties, accounts for around 13% of the total module cost—surpassing other auxiliary materials like EVA, glass, backsheets, and solder ribbons—second only to the 55% cost share of the solar cells themselves.

Currently, *aluminum alloy frames dominate the market with a penetration rate exceeding 95%. However, with increasing focus on efficiency and sustainability, the industry is exploring new materials like polyurethane(PU) composites, which offer potential for more efficient, economical, and environmentally friendly module frame solutions.

Aluminum Alloy Frames: The Industry Standard

Aluminum alloy has long been the traditional material for solar module frames due to its excellent combination of strength, corrosion resistance, and ease of manufacturing. The main characteristics of aluminum alloy frames are:

1. Ideal Strength-to-Weight Ratio: Ensures structural stability while minimizing weight.

2. Outstanding Corrosion Resistance: Can withstand diverse and harsh environmental conditions.

3. Good Thermal and Electrical Conductivity: Aids in module heat dissipation and grounding.

4. Highly Recyclable: Meets large-scale production needs and aligns with sustainability goals.

Despite these advantages, aluminum alloy production is energy-intensive, and the fluctuating prices of raw materials pose challenges for cost control. As sustainability becomes a growing concern, the search for alternative materials has gained momentum.

Exploring Alternative Frame Materials

To address the limitations of aluminum frames, the industry has been exploring various innovative frame materials. Below are some noteworthy alternatives:

1. Frameless Double-Glass Modules

Frameless double-glass modules eliminate the traditional frame and rely on two layers of tempered glass to encapsulate the solar cells. In theory, this design reduces material usage and lowers costs. However, practical applications have revealed several challenges:

   - Insufficient Structural Rigidity: Susceptible to deformation under external forces.

   - Poor Sealing: Increases the risk of moisture ingress.

   - Complex Installation: Raises installation costs and technical complexity.

These drawbacks have restricted the widespread adoption of frameless double-glass modules in the market.

2. Rubber Clip-On Frames

Rubber clip-on frames aim to leverage the elasticity and sealing properties of rubber to enhance waterproofing and ease of installation. However, the lifespan of rubber materials is generally shorter than that of the module itself, along with its vulnerability to extreme temperatures. Furthermore, environmental concerns surrounding the recyclability of rubber products limit the appeal of this solution within the industry.

3. Steel Frames

Steel frames offer extremely high strength and rigidity, making them suitable for certain specialized applications. However, their heavy weight increases transportation and installation costs. Additionally, steel requires special anti-corrosion treatments, complicating the manufacturing process. As a result, steel frames are typically used in projects that demand exceptional strength, rather than in conventional photovoltaic systems.

Emerging Material: Polyurethane(PU) Composite Frames

In recent years, polyurethane composites have gained attention as a promising alternative for solar module frames. Polyurethane (commonly abbreviated as PU), also known as polycarbamate or polyurethanes, is a type of polymer characterized by urethane units in its main chain.

This polymer material combines the elasticity of rubber with the strength and processing efficiency of plastics, making it highly adaptable across a wide range of industries. PU’s versatility spans across several key applications, including plastics, rubber, foam, fibers, coatings, adhesives, and functional polymers. Some of the key benefits include:

1. Lightweight: Approximately 20% lighter than aluminum, reducing transportation and installation costs.

2. Superior Corrosion Resistance: Particularly suitable for highly corrosive environments such as coastal areas.

3. Lower Energy Consumption: Significantly reduced energy usage and carbon emissions during production.

4. High Design Flexibility: Allows for customizable properties such as strength and elasticity.

Despite these advantages, polyurethane composite frames are still relatively new in the industry and have yet to achieve widespread adoption. Additionally, the lack of a comprehensive recycling system presents a challenge for future development. Nevertheless, the material's potential cannot be overlooked, and with further market penetration and data accumulation, polyurethane composites could see broader acceptance.

Conclusion and Outlook

The evolution of solar module frame technology reflects the photovoltaic industry's continuous pursuit of improved efficiency, cost-effectiveness, and sustainability. While aluminum alloy remains the industry standard due to its excellent all-around performance, emerging solutions like polyurethane composite frames are pushing the boundaries toward lighter, more corrosion-resistant, and lower-energy alternatives.

An ideal solar module frame should balance high strength and low weight, offer excellent durability and corrosion resistance, and be both cost-competitive and environmentally friendly. As advancements in materials science and manufacturing techniques continue, we can expect breakthroughs in frame technology that will further enhance the performance, reliability, and economic viability of solar modules, driving the solar industry towards a more efficient and greener future.

*Data source: According to the report issued by the "China Composites Industry Association," https://www.ccia.xin/xingyebaogao/1582.html