Quality by SolarWorld

How we manufacture the highest quality solar panels

A higher standard of quality

At SolarWorld, our solar technologies are different because we’re different. This difference is demonstrated every day by our high quality standards, which go beyond quality assurance to elevate solar to unprecedented standards.

Our commitment to quality has powered our success for more than three decades. Unlike manufacturers of disposable electronics like cell phones and laptops, we create sophisticated solar technologies designed to produce clean energy for at least 25 years—even in some of the harshest weather conditions like blizzards, high winds, hail and coastal sea spray.

From inception to installation, we meticulously control and sustainably execute every step of the solar panel manufacturing process. The result is maximum, cost-effective performance from every SolarWorld panel, every time.

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Explore how we do it

Solar panel testing lab

We test, test and test again to deliver the industry's most reliable panels

High temperatures. Biting frost. Heavy storms. Blowing sand. Dense snow loads. SolarWorld specialists thoroughly test materials, prototypes and finished solar panels using climate chamber, electrical, mechanical and UV tests. This ensures optimal performance and durability—and maximizes return on your solar investment.

In fact, our testing goes far beyond the most stringent U.S. and international standards, including the International Electrotechnical Commission (IEC) and the International Organization for Standardization (ISO), producing the best solar panels in the industry.

Every panel must satisfy our strict performance and safety criteria—with NO exceptions.

Solar panel hail impact quality testHail impact test. Replicates a natural hail storm by dropping a 1.1-pound, one-inch steel ball onto solar panels from a height of 13 feet. Then we repeat this up to 20 times in the same place on at least 11 different points of impacts.

Solar panel breakage quality testPanel breakage test. Subjects our panels to brutal impacts by heavy or hard objects to ensure stability and break-resistance. Occasionally hard objects fall onto roofs and we conduct these test to ensure that our roof-mounted solar system will withstand these impacts. For good measure, we also drop a 99-pound, lead-filled sack from a height of four feet onto the middle of vertically positioned solar panels up to three times

Solar panel inclined plane quality testInclined plane test. Tests the effects of snow load on the lower edge of our solar panels, which simulates real-world conditions since sliding snow and ice apply pressure to the lower part of the frame. Other companies typically test evenly distributed snow load on a horizontal panel, even though installations almost always parallel the slope of a roof.

Solar panel salt spray quality testSalt spray test. Makes sure our panels are ideally suited for coastal areas and salty air by exposing the solar panel to a salt mist mixture and then storing it under humid conditions to simulate coastal conditions. We voluntarily submit our panels for this optional test to guarantee maximum performance and further demonstrate our commitment to quality.

Solar panel hemispheric lighting quality testHemispheric lighting test. Simulates authentic light and temperature conditions to make sure our panels deliver optimal performance in the real world—which includes changing weather patterns.

Solar panel mechanical load quality testMechanical load test. Ensures our panels withstand extreme weather conditions, including excessive wind pressure, wind suction and snow load. Alternating pressure and suction are applied up to 1.2 million times using both static and dynamic forces, far exceeding IEC standards.

Solar panel UV light aging quality testUV light aging test. Guarantees excellent results from our solar panels even in some of the brightest spots on the planet. We simulate 25 years of intense UV radiation, including 1300 kWh/m2 in normal conditions and up to 3000 kWh/m2 in desert conditions, which far exceeds IEC test standards.

Solar panel climate chamber quality testClimate chamber test. Puts our solar panels through extreme temperature fluctuations in order to emulate 25 years of weather changes. In the climate chamber, the modules withstand temperatures as low as -40 degrees Celsius to as high as 85 degrees Celsius. We repeat this cycle 9,125 times versus the mere 200 cycles required by the IEC

Solar panel peel quality testField installation and peel tests. Tests performance by exposing our solar panels to real wind and weather conditions in varying climate zones—not just contrived laboratory conditions. In field tests, data consistently shows our panels perform well above 100 percent of predicted models. At the same time, peel tests confirm the superior reliability of our sheet-to-glass and inter-sheet connections, which is a key contributor to the long lifespan of SolarWorld panels.

Solar panel hot spot quality testElectrical and hotspot tests. Assures optimal insulation and electrical safety in both wet and dry conditions in a broad range of temperatures. Electroluminescence measurements identify otherwise undetectable micro-cracks or contact breaks while thermography cameras search for “hot spots,” which can occur when cells lie in a shadow and heat up as a result of residual electricity, ultimately damaging the panel over time.

Quality in production

The more sunlight your solar panels capture, the more sunlight they convert into clean, efficient energy. SolarWorld solar panels are designed detail by detail to capture as much of the sun’s rays as possible. Our solar panels are widely recognized as the industry standard in quality—testament to the stringent quality checks we perform during every second of the manufacturing process.

Solar panel automated manufacturing processResearch and Development. SolarWorld’s R&D team is comprised of some of the sharpest minds in solar. This is where solar research and development excellence—and our dreams for a new panel or technology—begin.

Full Automation. Our sophisticated, fully automated manufacturing process moves cells through our factory lines using state-of-the-art vacuum handling systems. This means our solar cells remain pristine—and untouched by human hands until final inspection. This automation is crucial to apply the precise amount of pressure to the 2,016 soldering points in each module which cannot be replicated by hand.

Manufacturing Execution System (MES). Combined with our statistical process control, MES precisely determines a module’s power level to ensure that the power rating on the nameplate is the minimum amount of power the solar module will produce. In fact, our modules routinely outperform the nameplate rating.


Quality process at-a-glance

Quality in production

Quality materials

At SolarWorld, the highest-quality solar panels begin with the highest-quality materials. It’s not easy to be selected as a SolarWorld supplier—or to maintain this distinction. Our quality assurance agreements require proof of manufacturing quality and environmental standards. We even audit our suppliers’ factories, and visually inspect every component that arrives at our production plant.

Materials that do not meet our standards do not continue into production. It’s that simple.

Solar manufacturing quality assuranceSafety glass. We meticulously inspect our thick, low-iron glass for any damage that could impact solar performance, including warping, perpendicularity, dimensions, edge finish, crystalline inclusions and bubbles. A special anti-reflection coating further maximizes efficiency and yield.

Backsheet. Few suppliers in the world can meet our high criteria for backsheet and EVA, which are critical for the long-term durability of solar panels—especially when exposed to extreme weather conditions and UV irradiation. Our standards are so high that out of over 80 backsheets and EVA tested, only 8 met our requirements.

SolarWorld solar cell quality assurance testingSolar Cells. As the most integral component of any solar panel, we don’t trust the production of solar cells to anyone else. We manufacture every solar cell we use, transforming high-quality crystalline silicon wafers into high-performing solar cells.

  • Every solar cell is carefully inspected for possible damage and tested for specific tension and efficiency—only the highest quality solar cells continue into production.
  • Cells are classified according to color and power level, which enhances the solar panel's appearance and ensures the highest power delivery – a step that is skipped by most other manufacturers.
  • Cells are then connected using five-busbar or three-busbar automated robotics technology.

Junction box. SolarWorld’s compact yet robust junction boxes are welded to contacts for superior endurance. Heat is efficiently dissipated to safely maintain an ideal temperature while fused connections ensure optimum safety at peak mechanical and thermal loads. At the same time, high-quality silicone protects against corrosion and mechanical loads.

Frames. SolarWorld frames support our solar panels with exceptional stability to easily withstand high loads, such as avalanching snow or hurricane-force winds. Our aluminum frames and cast-aluminum corner keys are assembled at our fully automated framing station, creating a joint that will not loosen over time. They are then filled with two-component silicone to ensure an extremely stable laminate-to-frame connection.

Plus-sorting. After framing, the performance of every SolarWorld panel is flashed with a light spectrum at an angle of 90 degrees to test electrical safety and record actual performance. Using these results, our panels are categorized according to performance—a process we call plus-sorting. Only panels that demonstrate a nominal power performance or higher ever leave our facility.

Product certifications

We believe that superior performance begins with superior quality. This is why SolarWorld solar panels are independently certified by a multitude of agencies and organizations to meet and surpass stringent national and international standards.

These authoritative performance ratings, certifications and standards consistently confirm what we already know: from sourcing the highest quality materials and adopting sophisticated manufacturing processes to engineering custom-designed installations, we demonstrate our commitment to excellence time and again.

We back this commitment with our 25-year linear performance guarantee, the first introduced in the industry, and a 20-year product workmanship guarantee.

Don’t take our word for it. Read all our warranties and certifications.

Our products are manufactured in accordance with third-party validated PAN files:

  • For each of our modules we go a step further than required by having our PAN files validated by independent testing and performance laboratories.