How can double-sided double-glass N-type monocrystalline solar photovoltaic modules maximize their power generation advantages in scenarios with highly reflective concrete rooftops?
Publish Time: 2025-10-14
With the continuous advancement of photovoltaic technology, double-sided double-glass N-type monocrystalline solar photovoltaic modules, with their high efficiency, long lifespan, and bifacial power generation capabilities, are gradually replacing traditional P-type monofacial modules and becoming the preferred solution for industrial and commercial rooftop power plants. Their power generation potential is particularly amplified in this typical application scenario, concrete rooftops. Concrete floors have a high reflectivity of sunlight, providing a natural advantage for the backside of bifacial modules to receive sunlight. However, truly maximizing power generation gains requires more than relying solely on highly reflective surfaces; coordinated optimization is required across multiple dimensions, including module selection, system design, installation techniques, and operations and maintenance management.1. Leveraging the Intrinsic Advantages of N-Type Technology: High Efficiency and Low DegradationCompared to traditional P-type materials, N-type monocrystalline silicon wafers offer a longer minority carrier lifetime, greater resistance to metal contamination, and lower risk of photo-induced degradation and potential-induced degradation. Bifacial, double-glass N-type modules typically boast an initial conversion efficiency exceeding 23%, with a degradation rate of less than 1% in the first year and an average annual degradation of approximately 0.25%, ensuring continuous high power output over a 30-year lifecycle. This stability translates directly into higher cumulative energy production and lower cost per kilowatt-hour (KWh) over decades of operation in concrete rooftop power plants.2. Utilizing the high reflectivity of concrete floors to enhance backside gainThe core advantage of bifacial modules lies in their ability to absorb reflected light from the ground, surrounding buildings, or mountings, achieving "double-sided power generation." Concrete roofs are typically light gray or white, with a dense and smooth surface that exhibits excellent diffuse reflectivity under direct sunlight. Research has shown that under standard installation conditions, the backside of bifacial modules can contribute 5%–15% additional power generation; with optimized designs, the gain can reach over 20%. Especially in summer, when sunlight is intense and the sun is at a high altitude, the direct frontside light complements the ground-reflected light, significantly improving the smoothness of the power generation curve and peak power throughout the day.3. Optimize Installation Parameters to Maximize Backside IrradianceTo maximize backside gain, a scientifically designed installation plan is essential:Increase the installation height: The higher the distance between the modules and the ground, the wider the area of reflected light received by the backside. It is recommended that the concrete roof support be at least 1 meter above the ground to maximize the angle of backside illumination.Optimize the layout spacing: Avoid shading between the front and rear rows of modules and ensure that reflected light fully reaches the backside of the rear row. Software can be used to simulate shadow distribution at different inclination angles and spacings to select the optimal solution.Use white coating or reflective film: Applying a highly reflective coating or reflective film to a portion of the concrete floor can increase the albedo to over 50%, further enhancing backside gain.Use a transparent backsheet or all-glass structure: Bifacial double-glass modules have no metal backsheet obstruction, resulting in high backside light transmittance. Combined with the high backside responsivity of N-type cells, this results in higher photoelectric conversion efficiency.4. System Integration and Intelligent Operation and MaintenanceMatching a Bifacial Inverter: Select an inverter that supports high input voltage and features multiple MPPT channels to accommodate potential power generation imbalances associated with bifacial modules.Deploy an Irradiance Monitoring System: Install a bifacial irradiator to measure the light intensity on the front and back of the modules, accurately assessing bifacial gain and optimizing O&M strategies.Regular Cleaning and Maintenance: Concrete roofs are prone to dust accumulation, which not only affects front-side power generation but also reduces ground reflectivity. Regularly cleaning the module surface and keeping the ground clean are key to maintaining high power generation efficiency.Double-sided, double-glass N-type monocrystalline solar photovoltaic modules offer unique power generation advantages on highly reflective concrete roofs. By leveraging the high efficiency and low attenuation characteristics of N-type technology, combined with intelligent support design, optimized ground reflectivity, and intelligent system management, they maximize back-side power generation gain, significantly improving overall power generation and return on investment for the power plant.
