Do larger photovoltaic modules have less durability?

Technological innovations continue to be the main driver of the solar industry's rapid growth, and now the industry has entered a new era in which large modules are increasingly dominant.

The quest for lower levelized cost of energy (LCOE) and balance sheet cost (BOS) and technological advances have made large modules, especially modules with 210 mm and 182 mm cells, the preferred choice of customers.

According to data from the China Photovoltaic Industry Association, the above-mentioned large modules together accounted for 82.8% of the photovoltaic sector in 2022 and this percentage is expected to reach 93.2% in 2023.

Photovoltaic plants can have their balance of system (BOS) and LCOE costs significantly reduced using large modules. As a result, the speed at which high-power modules are gaining market share makes this trend inevitable.

Some rumors have been floating in the market lately, implying that modules of size 2384 x 1303 mm, consisting of 132 210 mm half-cell solar cells, given that they are larger than the modules of size 2278 x 1134 mm of 144 cells of 182 mm, 40% to 60% are more likely to deform under the same load condition, increasing the risk of microcracks and reducing the level of reliability.

Could this be the truth?

To verify the validity of such statements, Risen Energy carried out tests in a laboratory certified by the National Conformity Assessment Accreditation Service of China.

During the tests, in terms of deformation, a Titan 132 cell 210 mm double glass module was compared with a 144 cell 182 mm double glass module, both with an aluminum structure.

For the tests, the same installation was used, without a beam and with fixing by the four outer holes, assembled under load conditions.

Test results showed that compared to the 182mm 144-cell module, the 210mm 132-cell module demonstrated 1% less deformation on the short side and 4% more deformation in the center of the glass.

The electroluminescence (EL) test revealed that no microcracks occurred when installed without a beam with fixation through the four outer holes under a load of 3600 Pa (front side).

At the same time, Risen Energy carried out a second test during which a 132-cell 210mm double-glass Titan cell module with a steel frame was compared with a 144-cell 182mm double-glass module with an aluminum frame. , using the same type of installation, without beam and with fixation by the four outer holes under a load of 3600 Pa (front side).

The test results showed that compared to the 182 mm cell module, the larger size module (132 cells of 210 mm) with steel frame demonstrated 53% less deformation on the short side and 15% less deformation in the center of the glass, without microcracks revealed after the EL test.

Against facts there are no arguments

The results of the two tests show that there is no particular difference in deformation between the 210mm 132-cell module and the 182mm 144-cell module when both have an aluminum frame.

In this same test, the largest module, with 210 mm cells, had significantly less deformation when it has a steel structure.

The yield limit (σ), or elasticity limit, is the parameter that determines the maximum stress that a material can withstand without undergoing plastic deformation. All deformations caused by pressures that do not exceed σ are elastic deformations, also known as recoverable deformations.

These deformations do not damage the structure of the material, since only pressures that exceed the yield limit (σ) can cause destructive plastic deformations.

It is normal for modules to experience different degrees of deformation under different loads, but evaluating a module's load capacity and reliability simply by observing its deformations is not considered a rigorous or scientifically valid approach. In short, it is simply wrong to state that the larger a module is, the more deformations it must have.

It is generally true that the larger and longer an object is, the more likely it is to deform, however this can be fully controlled through appropriate design.

For example, a piece of steel will sink when placed in water, but may float if it is designed to be a boat. Photovoltaic modules are all created under a rigorous development process during which materials and design cannot be finalized until rigorous, detailed validation and testing is completed.

This approach was rigorously followed throughout the design and development phases of the Risen Energy 210mm series.

With shipments exceeding 25 GW since its launch in 2019, the series has been widely used in a variety of application scenarios worldwide, including large-scale photovoltaic plants, industrial and commercial rooftops, as well as residential rooftops, while receiving time, praise from both domestic and foreign customers for its excellent performance.

The opinions and information expressed are the sole responsibility of the author and do not necessarily represent the official position of Canal Solar.