Introduction of IEC Standard Testing for Photovoltaic Solar Panels

Solar panel testing and certifications

Like other types of electronics, solar panel modules go through rigorous testing before installation. These tests are critical to determining the quality and performance of panels under particular environmental stresses, as well as confirming they meet mandated safety requirements. In this article, we’ll review the most common testing and certifications for solar panels on the market today.

Why is solar panel testing important?

Solar panel testing is key to assuring both the quality and safety of a module. Photovoltaic Solar Panels have a long lifespan: properly built and installed equipment should generate usable electricity for more than 25 years. Given the longevity of your investment, you want to make sure that any equipment on your roof will perform well and operate safely on your roof.

With solar becoming more and more popular each day, many states, local governments, and utility companies have come out with new mandates that require any grid-tied solar equipment to hold specific certifications. The same holds true for some solar incentive programs; if you’re participating in a state-funded incentive program, don’t be surprised if they have certain testing or certification requirements for your chosen equipment.

Common solar panel testing & certification standards

While reviewing a solar panel spec sheet, you’ll likely notice a bunch of acronyms and random numbers listed under safety and rating certifications – what do these mean? Below are some of the most common solar panel testing standards and certifications to look for when comparing solar panels:

IEC: International Electrotechnical Commission
The IEC is a nonprofit that establishes international assessment standards for a bunch of electronic devices, including photovoltaic (PV) panels. Importantly, the IEC does not test or certify panels themselves – 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 core testing standards for residential solar panels. If a solar panel module successfully meets IEC 61215 standards, that means it completed a number of stress tests and performed 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).

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 test conditions (STC), including 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 compared apples-to-apples against other available options.

IEC 61730: Standard for PV module safety
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
Do you live on or close by to a farm? If so, keep an eye out for IEC 62716 – this is a test to determine a module’s resistance to ammonia. While most people don’t have to worry about their high concentrations of ammonia exposure with their PV modules, it can be a concern if you install your solar panel system close to farms and livestock. Ammonia corrosion can accelerate degradation in a panel, leading to lower overall electricity production over the lifetime of your system.

IEC 61701: Salt mist corrosion testing
If you’re lucky enough to be installing solar panels on a beach house, 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, testers inspect the modules for physical damage – such as corrosion or delamination– and assess their electrical output and overall performance. Panels that successfully pass IEC 61701 tests are definitely a suitable choice 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
Some solar panels go through IEC 60068-2-68 testing to determine how well they hold up in sandy desert environments. 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, try choosing a panel that successfully passed these tests to maximize the durability of your system.

UL: Underwriters Laboratories
Outside of IEC, the other most common acronym you’ll see on a spec sheet related to solar panel testing is UL. This stands for Underwriters Laboratories (UL), 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 attesting to both the safety and performance of solar panel modules. Similarly to IEC 61215 or 61703 tests, panels with this certification go through simulated climatic and aging tests and have been deemed as safe in regards to mechanical loads, fire, and electrical hazards.

You may find that a solar panel spec sheet lists both UL 1703 and IEC 61730 under safety certifications; this is pretty typical for any solar panel sold worldwide. 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 often the more cost-effective option 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 completing UL 61730 testing reduces the number of panel samples needed, allowing for reductions in testing time and costs.