In bifacial solar power generation scenarios, light leakage from the edges of special-shaped photovoltaic module glass directly impacts power generation efficiency and system reliability. A solution requires comprehensive breakthroughs in four dimensions: material optimization, structural design, packaging technology, and system adaptation. The curved surface of special-shaped photovoltaic module glass causes light to refract or scatter at the edges, causing some light to escape directly without being absorbed by the cell, resulting in light leakage. This phenomenon is particularly prominent in bifacial solar power generation scenarios, as the backside glass must both transmit and reflect light. Inadequate edge sealing or optical design can exacerbate light leakage, reducing overall energy conversion efficiency.
Taking advantage of the curved surface characteristics of special-shaped photovoltaic module glass, specialized high-transmittance, low-iron-content photovoltaic glass must be developed. This type of glass reduces absorption and loss of light during transmission. By optimizing the curvature radius of the curved transition zone, light is more evenly projected onto the cell surface. For example, an asymmetric curved design can bring the incident angle of light at the edges closer to the cell's optimal absorption range, thereby reducing light leakage. In addition, polishing the glass edges can reduce light scattering at the microscopic level, further improving light utilization efficiency.
The encapsulation process is a key step in addressing edge light leakage. Traditional double-glass modules use transparent EVA film, which prevents light leakage between the cells from being reflected back into the module, resulting in power loss. For special-shaped photovoltaic module glass, white EVA or POE film is used as the rear encapsulation material. White film's high reflectivity redirects edge light leakage toward the cells, while its excellent insulation properties reduce the risk of PID degradation. During the lamination process, precise temperature and pressure parameters must be controlled to ensure that there are no bubbles or delamination between the film, glass, and cells, preventing edge light leakage caused by encapsulation defects.
The edge sealing design of special-shaped photovoltaic module glass must balance waterproofness and optical performance. Traditional aluminum frames are gradually being phased out due to weight and cost concerns, replaced by butyl tape or silicone sealing solutions. These materials form a flexible sealing layer that adapts to the curved surface of special-shaped glass, while also blocking moisture and oxygen intrusion and preventing increased light leakage caused by hydrolysis of the EVA film. Furthermore, reflective coatings or microstructures can be added to the edge areas to reflect escaping light back into the module, creating secondary absorption and further improving power generation efficiency.
For system adaptation, special-shaped photovoltaic module glass must work in conjunction with a tracking mount or intelligent cleaning system. The tracking mount dynamically adjusts the module angle based on the sun's position, ensuring that light always strikes the cells at the optimal angle of incidence, reducing edge light leakage. The intelligent cleaning system regularly removes dust and dirt from the glass surface, preventing localized hot spots and light leakage caused by shading. For example, in high-humidity environments such as agricultural greenhouses or tidal flat power stations, the cleaning system can effectively prevent condensation on the glass edges, reducing the risk of light leakage caused by water permeability.
Edge light leakage in special-shaped photovoltaic module glass also requires standardized testing and certification systems. The industry needs to develop specialized testing standards for special-shaped modules, simulating extreme operating conditions such as multi-directional combined loads, high temperature, and high humidity, to verify the module's ability to control light leakage over long-term operation.
The light leakage problem at the edges of special-shaped photovoltaic module glass in bifacial power generation scenarios requires a closed-loop solution through material innovation, process optimization, system adaptation, and standard certification. In the future, with breakthroughs in technologies such as transparent backsheets and highly reflective films, light leakage control for special-shaped modules will become even more refined, providing efficient and reliable energy solutions for complex scenarios such as building-integrated photovoltaics and agricultural photovoltaics.
