The backside power gain of double-sided double-glass n-type monocrystalline solar photovoltaic modules is one of their core advantages. Its performance is influenced by the interaction of multiple factors, primarily four dimensions: surface reflectivity, module mounting geometry, environmental compatibility, and system design synergy.
Surface reflectivity is the fundamental physical condition that determines backside power generation. The module's backside generates secondary power by capturing solar radiation reflected from the ground. Therefore, surface reflectivity directly affects energy capture efficiency. Light-colored, highly reflective materials such as white gravel, highly reflective aluminum sheets, or painted surfaces can increase reflectivity to 30%-80%, significantly enhancing backside radiation input. Dark soil, vegetation, or asphalt pavement, on the other hand, typically have reflectivity below 20%, limiting gain. Furthermore, the wavelength distribution and spectral matching of reflected light also influence cell conversion efficiency. For example, in snowy environments, the high reflectivity and broad spectral characteristics of ice and snow can increase backside power generation by 20%-30%, but attention should be paid to module design to prevent snow accumulation.
Module mounting geometry optimizes power generation efficiency by regulating radiation uniformity. Mounting height is a key variable. When the module height exceeds 0.7 meters above the ground, backside irradiance uniformity significantly improves, reaching saturation at a height of 1.2 meters. Mounting too high increases structural costs and wind load risks, while too low can result in ground shadowing. The mounting angle should be optimized based on local latitude and the sun's path. In low latitudes, a lower tilt angle can expand the range of ground-reflected light received; in high latitudes, a larger tilt angle is required to match the sun's altitude. Array spacing improves backside irradiance by reducing shadow interference from front-row modules, but this requires a balance between land use efficiency and power generation density.
Suitability for environmental conditions plays a decisive role in long-term power generation stability. Regarding temperature coefficient, N-type monocrystalline cells have a lower negative temperature coefficient than P-type cells, resulting in less degradation in high-temperature environments, maintaining their backside power generation efficiency advantage. Humidity and corrosive environments can accelerate the aging of double-glass module frames and wiring, requiring IP68 protection and weather-resistant materials to ensure long-term reliability. In rainy and cloudy areas with a high proportion of diffuse light, bifacial modules can utilize ambient reflected light to maintain power generation, offering superior gain stability compared to monofacial modules. Dust, snow, and other coverings reduce ground reflectivity, requiring automated cleaning systems or high-angle designs to mitigate their impact.
System design synergy unlocks power generation potential through electrical matching and structural optimization. DC-side output current increases with backside gain, necessitating the use of high-current inverters or string-based solutions to minimize power loss. In terms of wiring, straight-line wiring can reduce current mismatch between strings, increasing power generation by 5%-10% compared to traditional C-type wiring. The support structure must balance backside unobstructed access and wind load resistance. While single-axis tracking systems can increase frontside power generation, they may reduce backside gain due to support obstruction, necessitating simulation-based trajectory optimization.
Material properties and process control provide the foundation for power generation gain. N-type monocrystalline cells typically achieve a bifaciality of 80%-90%, exceeding the 60%-70% of P-type PERC, directly boosting backside power generation potential. The double-glass structure utilizes low-iron glass and POE film to reduce light decay and moisture vapor transmission, guaranteeing a 25-year power warranty. Sealing the module edges and waterproofing the junction box reduce power loss due to environmental corrosion.
In practical applications, scenario-based design is essential to maximize power generation gains. In desert power plants, using highly reflective sand and a 1.2-meter installation height can increase bifacial module power generation by 15%-20%. In distributed rooftop projects, combining white waterproofing membrane with a 30° tilt angle can achieve a 10%-15% backside gain. At the system level, optimizing module selection and installation parameters using LCOE models can reduce the cost per kilowatt-hour (KWH) of double-sided double-glass n-type monocrystalline solar photovoltaic modules by 8%-12% compared to monofacial modules, highlighting their economic advantages.
