Double glass photovoltaic modules and ordinary photovoltaic modules primarily differ in their construction and durability.

1. Glass Layers:
   • Double Glass Modules: These modules have a layer of glass on both the front and back sides of the solar cells. The front glass typically has an anti-reflective coating to maximize light absorption and minimize reflections.
   • Ordinary Modules: Ordinary modules usually have a glass front cover only, with the rear side exposed to the environment. The backside is often covered with a polymer backsheet for protection.
2. Durability:
   • Double Glass Modules: Double glass modules are known for their enhanced durability and resistance to environmental factors such as moisture, humidity, and temperature fluctuations. Because both sides are glass, they are less susceptible to physical damage, such as hail or impact.
   • Ordinary Modules: Ordinary modules are generally less durable than double glass modules because they have a polymer backsheet that can degrade over time, especially in harsh weather conditions.
3. Longevity:
   • Double Glass Modules: Due to their improved resistance to environmental factors, double glass modules tend to have a longer lifespan compared to ordinary modules. They are less prone to delamination and moisture ingress, which can affect the performance of ordinary modules over time.
4. Performance:
   • Double Glass Modules: Double glass modules may have slightly better performance characteristics because the rear glass layer can reflect some of the light back into the solar cells, increasing overall efficiency.
   • Ordinary Modules: While still efficient, ordinary modules may experience some energy loss due to the reflection and absorption of light by the polymer backsheet.
5. Weight:
   • Double Glass Modules: Double glass modules are generally heavier than ordinary modules because they have glass on both sides.
   • Ordinary Modules: Ordinary modules are lighter due to the use of a polymer backsheet.
6. Cost:
   • Double Glass Modules: Double glass modules are often more expensive to manufacture and purchase compared to ordinary modules due to the additional glass layer and specialized sealing techniques required.
7. Application:
   • Double Glass Modules: These modules are preferred in applications where durability, longevity, and resistance to environmental factors are crucial, such as in coastal areas, deserts, or regions with extreme weather conditions.
   • Ordinary Modules: Ordinary modules are suitable for most residential and commercial solar installations where cost is a more significant factor, and environmental conditions are less severe.

The choice between double glass and ordinary modules depends on the specific needs of the solar installation, the budget, and the environmental conditions of the location where they will be deployed. Double glass modules are often considered a premium option for applications that require extra durability and longevity, while ordinary modules remain a cost-effective choice for standard solar installations.