Solar Panel Structure Explained | Photovoltaic Module Components

A solar panel (also called a photovoltaic module) is the core unit that converts sunlight into usable electricity ⚡. Its design is like a carefully engineered “sandwich” structure 🥪, where multiple functional layers are laminated together. This ensures long-term durability and high efficiency even under harsh outdoor conditions such as strong sunlight 🌤, heavy rain 🌧, sandstorms 🌪, snow load ❄, and temperature variations 🌡.

1. Front Layer – Glass Panel 🪟

• Function: Protects solar cells from hail ❄, dust storms 🌬, rain ☔, and snow weight. Must have high light transmittance (>91.5%) so sunlight reaches the cells.

• Material: Low-iron tempered glass (3.2 mm or 2.0 mm). Ultra-clear glass reduces absorption, and tempering provides strength & safety.
  
  
  

2. Upper Encapsulation Film 🔗

• Function: Bonds tempered glass to solar cells, ensuring insulation, cushioning, and resistance to moisture 💧 and oxygen 🫧.

• Material: EVA film (most common), or alternatives like POE / PVB.
  

3. Core Unit – Solar Cells ☀️🔋

• Function: The heart of a solar panel ❤️. Solar cells use the photovoltaic effect to convert sunlight into DC electricity ⚡.

• Material & Structure: Mostly silicon-based cells (mono or poly). Today, N-type monocrystalline cells dominate the market. Thin-film cells (CdTe, CIGS, a-Si) are also used.
  
  
  

📊 Types of Solar Cells

💡 Notes:

• Mono & poly dominate the market.

• Efficiency depends on cell quality + encapsulation + environment.

• Mono panels usually last longer (25+ years).

4. Lower Encapsulation Film 🛡

• Function: Bonds solar cells to the backsheet, providing sealing and insulation.

• Material: EVA or POE.
  
  

5. Backsheet / Rear Glass 🔲

• Function: Protects from UV ☀, moisture 💧, oxygen, and mechanical stress. Provides structural support.

• Material: 2.0 mm / 1.6 mm glass or composite polymer. Some have reflective coatings to bounce light back → more power output ⚡.
  
  
  

6. Frame 🖼

• Function: Aluminum frame gives mechanical strength, grounding ⚡, and easier installation 🔧.

• Material: Anodized aluminum alloy – lightweight, durable, corrosion-resistant. Some modules are frameless.
  
  
  

7. Junction Box 📦

• Function: Electrical hub of the solar module. Connects with MC4 cables and houses bypass diodes ➡ allowing current to flow even if part of the panel is shaded 🌳 or damaged. Prevents hot-spot effect 🔥.

• Material: Engineering plastic shell with copper parts and diodes.
  
  
  

8. Sealant & Potting Compounds 🧴

• Function: Sealants keep panels waterproof 💦, dustproof 🌀, and insulated. Potting compounds protect electronic parts inside junction boxes.

• Material:

  • Silicone sealants → great weather resistance 🌤.

  • Thermal potting gel → heat dissipation 🌡 + long-term durability.
    

✅ Conclusion

A solar panel’s structure is not just simple glass and cells—it’s a carefully designed multi-layer system 🥪 ensuring high efficiency ⚡, durability 🛡, and long-term stability (25+ years).

When choosing between monocrystalline vs polycrystalline solar panels, consider:
👉 Efficiency ⚡
👉 Cost 💰
👉 Durability ⏳
👉 Warranty 📜

By understanding the components of solar panels, both homeowners 🏡 and businesses 🏭 can make better decisions when investing in solar energy systems, ensuring sustainable, renewable, and cost-effective power 🌍.