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Solar panel certifications and testing

Last updated 6/2/2020

solar panels on house

Solar panel modules go through stringent testing prior to being introduced to the market. These tests, which can last for multiple months, are critical to determining the quality and performance of panels under particular environmental stresses, as well as confirming they meet mandated safety requirements. 

As solar installations become more popular, an increasing number of state and local regulatory bodies are beginning to require that solar equipment hold specific certifications in order to be connected to the electrical grid. Additionally, some solar incentive programs require that any installations participating in the program use equipment that passes particular quality assurance tests.

Below are some of the most common solar panel testing standards and certifications found across solar panel spec sheets.

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IEC: International Electrotechnical Commission

The is a nonprofit tasked with establishing international assessment standards for electronic devices, including but not limited to photovoltaic (PV) panels. Importantly, the IEC does not test or certify panels themselves; rather, they establish the standards for other testing facilities to adhere to when evaluating solar panel quality.

IEC 61215: Standards for crystalline silicon terrestrial PV modules

IEC 61215 is one of the fundamental testing standards for residential solar panels. If a solar panel module successfully passes the IEC 61215 standards, it’s completed a number of stress tests and performs well in regards to quality, performance, and safety. 

IEC 61215 standards apply to both monocrystalline and polycrystalline PV modules, which are the most common types of solar panels. The IEC sets different testing standards for other types of solar electric technologies, such as thin-film solar products (IEC 61646). 

monocrystalline vs polycrystalline solar panels

Solar panels that meet IEC 61215 standards are tested on the following and more:

Electrical characteristics (wet leakage current, insulation resistance)

Mechanical load test (wind and snow)

Climate tests (hot spots, UV exposure, humidity-freeze, damp heat, hail impact, outdoor exposure)

IEC 61215 tests also help determine a panel’s performance metrics at standard testing conditions (STC). This includes determining a panel module’s temperature coefficient, open circuit voltage, and maximum power output.

What are Standard Test Conditions (STC)?

When solar panels undergo performance testing, they do so at fixed laboratory conditions, known as Standard Test Conditions (STC). Because these conditions are the same across the industry, one panel’s performance metrics (such as power rating, module efficiency, optimal voltage, etc.) can be more accurately compared against other options on the market.

IEC 61730: Standard for PV module safety

risk of electrical shock from a solar panel

As with any electronic device, solar panels carry the risk of electrical shock if improperly built. That’s where IEC 61730 comes in: this standard address the safety aspects of a solar panel, encompassing both an assessment of the module’s construction and the testing requirements to evaluate electrical, mechanical, thermal, and fire safety. PV modules that successfully pass IEC 61730 tests run a low risk for these types of hazards.

IEC 62716: Ammonia corrosion testing of photovoltaic (PV) modules

ammonia corrosion

With IEC 62716, solar panels undergo testing to determine a module’s resistance to ammonia. While many won’t have to worry about their PV modules being exposed to high concentrations of ammonia, it can be a concern for solar panel systems that are close to farms and livestock. Ammonia corrosion can accelerate degradation in a panel, leading to lower overall production over the lifetime of the system.

IEC 61701: Salt mist corrosion testing

salt mist corrosion

If you’re shopping for solar and live close to the ocean, it’s worth checking to see your prospective solar panels have successfully passed IEC 61701 tests. With these tests, panels undergo a series of salt sprays in a controlled environment. After the sprays, the modules are inspected for physical damage – such as corrosion or delamination– and assessed on their electrical output and overall performance. Panels that successfully pass IEC 61701 tests are suitable for beach-front solar panel systems or systems that will be in close proximity to roads experiencing high levels of salting in the winter.

IEC 60068-2-68: Blowing sand resistance testing

blowing sand testing

Some solar panels go through IEC 60068-2-68 testing to determine how well they hold up in sandy environments like deserts. Frequent exposure to abrasive sand can wear a panel down, leading to physical or mechanical defects over time. If you’re installing solar in an area that sees frequent sand or dust storms, installing a panel that’s successfully passed these tests helps to ensure that your solar panels can withstand such events.

UL: Underwriters Laboratories

Underwriters Laboratories (UL) is a global safety certification company based in the United States. They provide testing services and certifications for many different types of products, including electric appliances, industrial equipment, plastic materials, and more.

UL 1703: Standard for flat-plate PV modules and panels

UL 1703 is an industry standard for both the safety and performance of PV modules. Similarly to IEC 61215 or 61703 testing, panels with this certification are put through simulated climatic and aging tests and have been deemed as safe in regards to mechanical loads, fire, and electrical hazards.

It’s common for an individual solar module to hold certifications for both UL 1703 and IEC 61730; this is because UL 1703 is a mandate for solar panels sold and installed in North America. IEC 61730, on the other hand, is internationally recognized for safety standards and is more widely applicable to the global solar market.

UL 61730: Photovoltaic module safety qualification

UL 61730, a more recent addition to solar panel testing and certifications, combines the testing procedures and standards of UL 1703 with IEC 61730, allowing for complete international approval in regards to a panel module’s safety and performance.

It will become more and more common to see this certification over time - as opposed to both UL and IEC - because it is more cost-effective for manufacturers. In order to complete solar panel testing, manufacturers need to provide multiple solar panel samples. For companies that plan to sell in both North America and international markets, solely partaking in UL 61730 testing reduces the number of panel samples needed, allowing for reductions in testing time and costs. 

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