With the development and integration of green buildings and renewable energy, BIPV (Building Integrated Photovoltaics) is becoming an important trend in modern building energy-saving design. BIPV not only assumes the functions of traditional building materials such as exterior walls, roofs, and shading systems, but also seamlessly integrates photovoltaic power generation functions into it, realizing "power generation is building". Among the many component structure designs, "double-glass design" (double-layer tempered glass structure) is gaining more and more attention. So, does BIPV solar module support double-glass design? What are the advantages and challenges of double-glass BIPV? This article will answer you in detail.
1. Introduction to BIPV solar modules
BIPV solar modules are different from traditional rooftop photovoltaics. They are both building materials and power generation equipment. Common BIPV application scenarios include:
Building facade glass curtain wall
Roof tiles/glass ceiling
Awnings, sun rooms
Building atriums or light belts
Skylights and ventilation panels
The design of BIPV must not only meet electrical performance (such as power generation efficiency and system stability), but also meet multiple standards such as building safety, structural strength, aesthetics, and lighting performance. Therefore, the reliability and compatibility of the component structure are particularly critical.
2. What is "double glass design"?
"Double glass module" refers to the structure in which solar cells are encapsulated between two pieces of tempered glass, replacing the structure of one layer of glass + one layer of backplane in traditional photovoltaic modules. Its typical structure is:
Front tempered glass (usually 3.2mm thick)
EVA/PVB encapsulation film
Solar cells (monocrystalline silicon, polycrystalline silicon, thin film, etc.)
EVA/PVB encapsulation film
Back tempered glass
Double glass modules were initially used in large-scale ground photovoltaic power stations, but with technological advances, their application in BIPV has gradually expanded.
3. Do BIPV solar modules support double glass design?
The answer is: fully support, and even in some scenarios, double glass structure is more recommended.
At present, more and more BIPV modules use double glass encapsulation, especially in the following types:
Translucent BIPV modules: used in scenes such as skylights, skylights or curtain walls, and the light transmittance can be controlled according to project requirements.
Colored BIPV curtain wall system: through double glass encapsulation, add colored glaze, nano coating or interlayer design to improve the decorativeness and appearance consistency.
Projects with high weather resistance requirements: such as building structures in high altitude, high humidity, and high salt fog environments, double-glass modules can withstand the test better.
4. The main advantages of BIPV double-glass modules
High strength and durability
The double-glass design gives the modules stronger mechanical strength and impact resistance. The two layers of tempered glass improve the overall rigidity, are not easy to deform, and can withstand higher wind pressure, snow load and other harsh climates, especially suitable for high-rise buildings and extreme environmental areas.
Longer service life
Double-glass modules are more tightly encapsulated, which can effectively block the entry of corrosive factors such as water vapor and oxygen, reduce EVA aging and cell cracking, and extend the power generation life, which can reach an average of more than 30 years.
Higher fire protection level
Compared with traditional backplane materials, glass has higher flame retardancy. Double-glass BIPV modules can meet the fire protection requirements of B1 or even A, and are an ideal choice for high-rise curtain wall buildings.
Good light transmittance (optional)
Double-glass BIPV modules support customized light-transmitting areas (such as cell-free design, patterned cloth, translucent silicon wafers), and are widely used in places where lighting and aesthetic requirements coexist, such as commercial centers, subway entrances and exits, bus shelters, etc.
More environmentally friendly and recyclable
Glass is an environmentally friendly material. The double-glass structure is easier to recycle than the fluorine-containing backboard material, which is in line with the development direction of green buildings and low-carbon economy.
5. Comparison with single-glass modules
First of all, in terms of structural strength, the double-glass module has a stronger structure, higher impact resistance and overall rigidity; while the single-glass module has a relatively low structural strength due to the soft backboard material.
In terms of service life, double-glass modules usually have a stable service life of more than 30 years, while the service life of single-glass modules is generally between 20 and 25 years, with a significant gap.
In terms of fire resistance, the double-glass structure uses two layers of tempered glass, which can meet the A-level flame retardant standard, and performs better than the single-glass module with an organic backboard, which generally can only meet the B-level or lower fire resistance requirements.
In terms of waterproof and moisture-proof capabilities, double-glass modules are more tightly packaged and have a higher protection level, which can more effectively block the infiltration of water vapor and oxygen; while single-glass modules have a certain risk of water seepage in long-term use, especially when the frame or backplane is poorly sealed.
From a cost perspective, the manufacturing process of double-glass modules is more complicated and the material cost is higher, so the overall cost is slightly higher than that of single-glass modules; while the cost of the single-glass backplane solution is lower, which is more suitable for projects with limited budgets or low performance requirements.
In terms of weight, double-glass modules are naturally heavier than single-glass modules because they use two pieces of glass, so they require a stronger support structure or a higher building load-bearing design during installation; on the contrary, single-glass modules are lighter and suitable for some lightweight structural roofs or curtain walls with strict load restrictions.
Finally, regarding application flexibility, although double-glass modules have more comprehensive performance, their weight and thickness have certain requirements for installation conditions, so the scope of application is slightly limited; while single-glass modules are lighter and more adaptable, and the installation scenarios are more flexible and changeable.
6. Examples of scenarios suitable for using double-glass BIPV modules
Office building glass curtain wall: Use double-glass BIPV to achieve both lighting and power generation, and improve the green level of the building.
Ceiling of commercial complexes: High durability and aesthetic design meet the needs of high-end buildings.
Building roofs in high-humidity areas (such as coastal cities): Double-glass structures provide higher sealing and corrosion resistance.
Atrium corridors of schools or public facilities: Use translucent double-glass modules to achieve comfortable lighting and clean energy use.
Entrance and exit ceilings of airports and high-speed rail stations: Must meet safety, fire prevention, light transmission and green energy requirements at the same time.
7. Design and selection recommendations for BIPV double-glass modules
Determine the light transmittance according to the purpose of the project: You can choose a variety of light transmission solutions such as full transparency, translucent, opaque, etc.
Pay attention to the matching of thickness and weight: Especially when installed on structures such as facades and glass skylights, the bearing capacity needs to be calculated.
Reasonably design the frame and support structure: Some BIPVs adopt a frameless design, which requires strengthening support and sealing.
Choose reliable manufacturers and packaging technology: The quality of high-quality EVA/PVB film and tempered glass directly affects the lifespan and performance.
BIPV is not just "power-generating glass" or "power-generating roof", it also represents an important trend in the development of green buildings, energy conservation and emission reduction, and smart cities. As a reliable, beautiful and safe packaging solution, double-glass structure is becoming a new standard for BIPV module design. Although double-glass BIPV modules have a slightly higher initial investment, their long life, low maintenance, excellent weather resistance and environmental protection advantages make their comprehensive cost-effectiveness in modern buildings increasingly high.
Therefore, BIPV solar modules not only fully support double-glass design, but also perform excellently in practical applications. They are an ideal choice for high-end buildings to achieve "green + aesthetics + energy".
If you are planning a BIPV project, please feel free to contact us for professional support. We not only provide selection suggestions for double-glass modules of various specifications, but also tailor-made installation solutions based on your building structure, usage scenarios, climate environment and other factors.
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Wuxi Fgnex Technology Co., Ltd.