The Comparison on Single Facial, Double Facial, Half Cut, MBB and Stacked Tile Solar Panels

Despite being in an industry adjustment period, investment and financing institutions remain confident in the photovoltaic sector. Recently, a leading domestic securities institution released a technical report analyzing future trends in solar module technology and continues to recommend investors focus on photovoltaic energy.

Single-Side Solar Panel (with double side glass)

Compositional Structure of Double Glass Single-Facial Solar Panel

The double-glass module is made by laminating two tempered glass layers, EVA films, and solar cells using a high-temperature laminator. The layers are arranged as tempered glass, material layers (PVB, PO, EVA, or ionic polymer), a monocrystalline or polycrystalline cell layer, material layers, and another tempered glass layer.

Characteristic Features of Double Glass Single-Facial Solar Panel

Double-glass modules offer better weather resistance and power generation efficiency compared to traditional modules. Their advantages are more pronounced in areas with high humidity, acid rain, or salt fog, such as photovoltaic power stations in agricultural greenhouses or regions with heavy wind and sand.

Unlike single-glass modules, which use an organic backsheet that allows water vapor to penetrate, causing rapid degradation of the EVA resin, double-glass modules have zero water permeability. This reduces power loss, improves efficiency, and decreases the degradation rate by about 0.2%, extending the lifespan by five years to about 30 years.

Double-glass modules have superior wear resistance, insulation, waterproofing, and load-bearing capacity, reducing issues like microcracks and ensuring more stable power generation. Additionally, the fire rating of double-glass modules has improved from C-grade to A-grade.

With larger thermal capacity, double-glass modules heat up more slowly than regular modules and are less affected by temperature fluctuations. The glass and backsheet have a thermal diffusion coefficient difference of over seven times, solving heat dissipation issues and reducing hotspot damage.

The frameless design eliminates the electric field that causes PID, significantly reducing the likelihood of PID degradation.

Due to lower degradation rates, double-glass modules generate about 3% more power, though light transmission is slightly increased, leading to a 1% overall increase in power output.

Pro

The lower degradation rate increases power generation by 3%. Double-glass modules have a 0.2% lower degradation rate than single-glass modules, resulting in a 3% increase in output under the same conditions.

Con

Increased light transmission causes a 2% power loss. The transparent EVA film reduces the light reflected off the back of the cells, leading to lower power generation. Using white EVA for the back side may block the cells, resulting in power loss. Additionally, the absence of the aluminum frame affects the module’s wind resistance and water protection.

Bifacial(Double Side) Solar Panel

Compositional Structure of Double-Facial Solar Panel

The back of a double-facial module uses a similar fine grid of aluminum paste as the front. The backside is covered with a partial aluminum layer, allowing light to pass through unblocked areas and improving power generation. Similar to single-glass double modules, the back of a double-facial module uses glass or a transparent backsheet, enhancing performance and increasing light transmission.

Characteristic Features of Double-Facial Solar Panel

The temperature increase affects the open circuit voltage, short-circuit current, and peak power of silicon solar cells. With double-facial modules, the temperature is 5-9°C lower, reducing power loss.

Double-facial modules can be installed vertically, taking advantage of reflected and scattered light from the environment, making them suitable for installations like fences, solar walls, highway sound barriers, and agricultural greenhouses.

Power gain depends on system design and installation conditions. In optimal settings, double-facial modules can increase output by 15%-20%, and with increased installation height and ground reflectivity, this can reach up to 30%. Using tracking systems can increase this by over 50%.

The back of the panel still uses an aluminum layer that limits light absorption, resulting in 10%-15% lower efficiency than the front. Additionally, increased light transmission on the back causes a 0.2%-0.5% efficiency drop on the front.

With an optimal installation angle, the higher the module is installed, the more reflected light it can capture from the surroundings, increasing power output. The power gain is greater when using tracking equipment or when the background is lighter and reflects more light.

Half-Cut Solar Panel

Compositional Structure of Half-Cut Solar Panel

Half-cut technology involves laser-cutting standard solar cells (156mm x 156mm) into two smaller pieces (156mm x 78mm) and then connecting them in series. The electrical parameters remain consistent with full-size modules through series and parallel connections of half-cells.

Characteristic Features of Half-Cut Solar Panel

In traditional installations, shading from morning and evening sun or dust can cause significant power loss. Half-cut modules reduce shading loss in vertical arrays while improving bracket and land use.

By reducing internal current and losses, half-cut modules operate at a lower temperature (around 1.6°C), significantly reducing the risk of hot spots and improving overall reliability.

Cutting cells in half reduces current by half, reducing resistance loss to 25% of its original value, leading to a 5-10W power gain (+2%-4%).

Half-cut modules generate 0.672% more power compared to regular modules, translating to about 1.88W more output under the same conditions.

Multi-Busbar (MBB) Solar Panel

Compositional Structure of MBB Solar Panel

Multi-busbar (MBB) technology improves the performance of solar cells by increasing the number of busbars, thus reducing shading and resistance. MBB technology has become more popular due to lower manufacturing costs, larger wafer sizes, and improved screen printing techniques.

Characteristic Features of MBB Solar Panel

With increased busbar density, MBB panels perform better under stress from microcracks or broken cells, maintaining good power generation.

With more busbars, the current collection ability improves, lowering the temperature and enhancing long-term performance, with power gains of 5-10W.

While narrower busbars increase series resistance, the overall effect of more busbars reduces power losses, improving efficiency.

With thinner busbars, the shading area is minimized, increasing the effective light absorption area and improving energy capture.

Stacked Tile Solar Panel

Compositional Structure of Stacked Tile Solar Panel

The stacked tile module cuts cells into 4-5 small pieces and connects them through edge regions, which are designed as main busbars. This design minimizes gaps between cells and eliminates the need for traditional busbars, improving efficiency and reducing power loss.

Characteristic Features of Stacked Tile Solar Panel

Due to its unique arrangement, the stacked tile module reduces the impact of welding resistance on power generation, preventing hotspot effects and improving crack resistance during transport and installation.

Stacked tile modules perform better in partially shaded areas, making them ideal for high-latitude, land-intensive, and distributed projects.

The stacked design allows for 13% more cells, resulting in 18.5% power gain and higher efficiency compared to traditional modules.

The busbar-free design reduces shading, improving overall power output.