Blog Archives - Brij Encapsulants (India)

September 27, 2021

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A considerable research and evolution in solar photovoltaic have led to sheer price depletions and productive improvements all over the supply chain. When this combined with subsidy inputs from government administration, has led to an enormous growth of this industry.

As per the latest MNRE report, module manufacturing presently perches at just over 2500 MW and is assured to augment further to meet the growing demand. However, the investment you made in solar would be long-term, compensating for 8 years or more. Thus, it is essential to prolong durability, trustworthiness and make particular cost-effectiveness of this investment.

With the experience of more than 20 years in the EVA processing field, Brij has a story of supporting this industry by building high-quality solar cell Encapsulants.

PV Module Basics

Though looks simple, a crystalline module is a combination of massive engineered materials operating together in pair to tackle energy. Therefore, every element used acts on its quality, longevity and plays an essential factor. One such element is the Ethylene Vinyl Acetate (EVA) Encapsulant.

A PV module is assessed by its electrical performance and its annual degradation, and product lifetime. Thus, an affordable module might appear to be a catchy option today but could be jammed with inferiority elements leading to a short lifetime and low return on investments.

Now you might be thinking of what happens when a solar panel is safeguarded with a less quality Encapsulant? It may lead to different defects like yellowing of module surface, electrical framework, water influx and stratification.

Quality Assurance And Test Standards

Product testing can be defined as the form of quality control in composure to product research and development. Though it is considered the most unvaried and extravagant research and development stage, it is still assertive.

The typical tests for ascertaining the quality of various module elements, especially EVA, are broadly varied and sometimes enigmatic.

Now let’s discuss some of the tests typically used to establish the EVA Encapsulant films.

1.Encapsulant tests

Mostly, all of the tests can be executed on the shop floor systematically to ensure consistency.

a)Peel Strength (Adhesion test)

Adherence of EVA to granule is the crucial element to the endurance of a module throughout its functional lifetime. Low absorption is a good indicator of expired EVA or disclosure to moisture during transit or even unsuitable laminating conditions. EN 1895 & ASTM D1876 test standards can be followed to determine the peel strength promptly.

b)Gel Content Test (Crosslinking Ratio)

The gel content of EVA is a measure of the degree of crosslinking of the polymer. Lower gel content desires a lower degree of crosslinking, which endangers the long term mechanical righteousness of the module. ASTM D-2765 test standards can be deserved to determine the gel content precisely. Differences of the same are often used to imprecise the gel content values at the shop floor level.

c)Thermal Shrinkage

EVA films have a fundamental inclination to reduce when heated at lamination temperatures. Reduction is usually caused due to process that induces stresses during the building of EVA films. Therefore, it is essential to use it else it might lead to breakage of solar cells, stumble of strings, amongst other stability issues. In general, 2% or fewer shrinkage levels are permissible and are considered as not laminating problems.

2.Module Tests

EVA is an essential component of a solar module, and thus it is critical to evaluate its impact on module lifespan. Now let’s discuss some of the tests that can be performed at the module level which may impact the quality of Encapsulant film:

a)Accelerated Aging

Other testing bodies have formulated several laboratory tests to envisage module output and condition at the end of life to recreate the external environment and facilitate the moderate natural aging process.

Let’s have a look at some tests that are important to the EVA Encapsulant:

Damp heat test

Determination of the ability of the module to resist the effects of long-term disclosure to humidity and heat is one of the vital aspects of this test. The test contains a systematized procedure according to IEC 61215 wherein the module is subjected to 85°C, 85% relative humidity for 1000 hrs.

UV Testing

EVA is delicate to UV radiation and undergoes degradation on its continuous exposure. Therefore, it is essential to confirm if this indignity rate is well under the specified limits to ensure long-term stability. While making the UV testing, the module is exposed to 15 kWh/m2 UV light within 280nm to 320nm and 5kWh/m2 in 320 to 385nm spectrum at a temperature of 60°C.

Thermal Cycling

In actual structure, solar modules, particularly in cold weather, resist temperature changes and, at times, from zero to 30-40 degrees in a single day. It may also lead to thermal exhaustion due to continuous enlargement and contraction of elements. IEC61215 tests this by exposing the modules to 200 cycles between -40°C to 85°C, with the cycle time not exceeding 6 hours.

Humidity Freeze

The humidity freeze test regulates the capability of the module to resist changes in temperature in fuggy conditions. It evaluates the access of moisture through several layers of solar panels. Under it involves 10 cycles of disclosure to 85°C at 85% RH for the first 20 hrs and -40°C without RH control for the next 4 hours. It is one of the major port tests and examines the quality of adhesion.

b)PID Testing

In recent times, MW scale insertions have propelled the voltage limits of more than 800V leading high potential gradient between the solar cells and the streak frame. There might be changes where the gradient is highly negative, making the leakage current from the module frame to the cell. It may result in impurities from the top glass surface through EVA into the solar cell. In this test, the module is put to a temperature of 60°C with 85% humidity under 1000V load for 96 hours.

Conclusion

Thus, we hope you understand the different test standards used in Solar EVA Encapsulation sheets. A substantial encapsulant needs rigorous quality control, consistent compositions and utilization of the best raw materials.

Even a minute decline of the possessions of the encapsulant extension will weaken the electrical output of the module that is of vital importance to providing a 25 to 30-year working life of a solar module. Moreover, a supreme EVA film should enchant high boom strength, adequate gel content, low abatement and should resist the module tests and harsh environmental conditions with ease.

Brij is the first Indian company to manufacture EVA Encapsulation Films and is the leader in manufacturing IEC 61215 qualified films in the nation. Through constant research and development, in-house testing laboratory, and stringent quality checks, Brij makes sure that each square meter of EVA manufactured encapsulates the modules for 25 years and a lifetime.

July 26, 2021

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Solar panel lamination secures the endurance of the solar cells as they need the capacity to resist open exposure irrespective of the climatic impact factors for a more extended lifespan period. Good solar panels will withstand for more than 25 years, increasing the return on invested capital for the user with annual gassed-up.

The encapsulation of solar cells through lamination is an essential step in
solar PV module manufacturing. The lamination procedure captures solar cells in between multiple substrate layers, including protective layers. These layers are stated as “lay-up”, and this technique has been effectively employed for decades.

The module laminators stick to a three-step process for appropriate liquefy and healing of the capsulate (EVA) and achieving a high-quality lamination.

laminator

It includes:

Warming of the segment lay-up to requisite condition to execute the EVA cross-linking step.
Producing a vacuum to detach the air and keep away from bubble formation.
Execution of pressure to make certain a standard surface contact and adherence between the different layers of the PV module.

THE PROCESS

The basic processes are further classified into the following as mentioned below:

1.Lay up

In this process, a cold PV module lay up into a laminator. The material first goes into a lay up of glass, then coat it with an EVA sheet to enhance the durability and performance of solar panels.

Once it is coated with one layer of EVA, it goes into photovoltaic cells arranged in configuration. Then again, it is covered with an EVA sheet layer and reaches the backsheet that is the outermost layer of the PV module.

2.Pin lift

The lift pin system provides accurate thermal control during the lamination process. Because of the comparatively high-temperature difference of 100°C between the heating plate and the PV module lay-up, while inserted, a 3-4 mm thick glass is observed.

The flat-bed laminator is furnished with pins to keep away from the glass bending and attain equivalent warming outline. These pins enable lifting the PV module lay-up for 5mm from the heating plate, making the lay-up more pleasant and homogenous.

3.Vacuum–Upper chamber

The vacuum chamber is a process used for encapsulating worldly PV modules. The lower chamber of the laminator is shifted to detach the air and steer clear of the bubble formation.

These can also be used to evaluate the production of the applications for manufacturing operations. The schedule of implementing a vacuum and the tariff of eviction were obtained to enhance the process.

Even if the pressure is reduced at high pressure in the earlier stages leads to vital outgassing of the accompaniments in the EVA. Whereas applying the vacuum too late might result in air insertion, which leads to unwanted bubble generation.

4.Pin Release

Once the module attained an equivalent temperature in the glass plate and crossed the intersection of the EVA softening point (60°C-80°C), the PV module is compressed on the warming plate by liberating the pins. It will also initiate the actual EVA cross-linking process.

5.Vent–Upper chamber

It is one of the best methods to implement solar panels. While discharging the upper chamber, a refined contact and heat shift occurs between the element lay-up and the heating plate.

In this situation, while giving high pressure, the utmost care must be taken of the exact extent and rate. It will also lead to the cell-swimming phenomenon.

6.Controlled Cooling

A narrow pipe was positioned on the PV module as a coil heat exchanger to provide active cooling. As the set temperature increased, module temperature can be increased or decreased. Studies have proved that module efficiencies with cooling are calculated as 13%, whereas the module without cooling at 10%.

An adequate controlled cooling step guide to an administered stopping of the absolute persuades chemical reactions. It fulfils the lamination cycle enabling the stable PV module prepared for the post-processing steps and testing.

Module lamination is a crucial process step that straightly impacts module reliability and lifespan. While several strategies may be used to reduce bottlenecks in the lamination procedure for abundant production, the PV industry would benefit from the attainability of quick curing synopsis.

As a leading manufacturer of Solar EVA Encapsulants, we at Brij understand this complexity and develop our product with lower rejection rates, higher adhesion strength and controlled cross-linking.

Switch today and experience the ‘Brij Advantage‘.

June 17, 2021

Ethylene Vinyl Acetate is an encapsulant for solar modules or cells. It is a copolymer film that is an essential sealant of photovoltaic solar modules to ensure reliability and performance.

Here the materials attract a lot of attention due to their extensive applications in solar cells. EVA materials encapsulate about 80% of photovoltaic modules. There are many advantages, such as good light transmittance and elasticity, low processing temperature, excellent melt fluidity, and adhesive property. In addition, the price is low, which makes it very suitable as a solar cell encapsulation material.

Along with these points, below are some essential criteria considerations for the selection of EVA Encapsulates

Brij-Encapsulants

January 30, 2021

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Product testing in any industry is a vital role to play product research and development. The process might look easy and simple, but in reality, it is not, the standard tests for determination of the quality of EVA are majorly varied and sometimes ambiguous. Hence the following tests are generally used to define the quality of the EVA encapsulant films.

1.Peel strength (Adhesion test)

Peel Strength testing is a basic mechanical test technique that the peel separation strength of 2 flexible materials adhered or bonded together. It measures adhesion of EVA to the substrate, which is a vital factor indicating the durability and longevity throughout its operational lifetime and guarantees its excellent performance.

Low adhesion force leads to expiring EVA material or exposure to moisture or even improper laminating conditions during manufacturing.

Peel Strength testing is also a vital tool to determine the overall quality of the lamination. Values are between 75 N/cm and 125 N/cm can be used as a reference for quality control.

peel-test

Source

2.Gel Content Test

The objective of the method is to determine the gel content of the EVA. Gel content provides a means of both controlling the process and rating finished product quality.

EVA Gel Content test (known as a Crosslinking ratio measure) is a quality test of solar panel. The gel content of EVA is a degree of crosslinking in the polymer. Lower gel content can indicate a lower degree of crosslinking, which can severely jeopardize the solar module’s long-term mechanical integrity. The EVA Gel Content levels of 70% or higher are recommended for longer lifetime of solar modules.

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Source

Also Read: Why EVA Front Sheets are Important for Solar Module?

3.Thermal Shrinkage

EVA films shrink when they are heated at lamination temperatures. If it is not controlled, it will cause misalignment of strings, breakage of solar cells, and other issues. Shrinkage is generally observed due to process-induced stresses while manufacturing of EVA films.

However, the rule of ‘lower the shrinkage and better the encapsulant’ is not always accurate due to other trade-offs. Globally, shrinkage levels of 2% or less are acceptable and are known to cause no laminating problems.

4.Long Term Encapsulation and Protection

Ethylene-vinyl acetate (EVA) encapsulation materials have attracted a lot of attention due to their extensive solar cells applications. Nearly 80% of photovoltaic (PV) modules are encapsulated by EVA materials.

An observation of slight deterioration of any of the encapsulant properties will lead to impair the electrical output of the module. That is very important to provide a 25 to the 30-year working life of a solar module. Hence a good EVA film should possess high peal strength, low shrinkage, good gel content, and withstand the module tests and harsh environmental conditions with ease.

Brij conducts regular research and development and stays updated with the latest trends and updates to not miss anything productive. Our in-house testing laboratory and stringent quality checks ensure the maximum gain of life span for our products. Contact us today to understand more in details.

December 28, 2020

Solar electric systems are famous renewable energy options due to its low maintenance and long lifetime elements as there are no moving parts, hence the least chance of mechanical failure. Most of the solar electric systems continue to produce power for 30 years or more!