The U.S. solar energy industry is experiencing a significant upturn, thanks to the Inflation Reduction Act and local incentives. As domestic production expands, promising new job opportunities and strengthening supply chains, it is crucial to address the longevity of solar panels. With warranties lasting 25 years or more, we need to ask ourselves: How can we ensure that solar panels will endure for such a lengthy lifespan?

International standards play a vital role in guaranteeing the safety and effectiveness of solar panels. The International Electrotechnical Commission (IEC), a global organization that sets standards for electrical and electronic technologies, has developed several key standards in this regard. For instance, IEC 61730 focuses on the safety requirements of solar panels, specifying design qualifications, construction requirements, and testing procedures. IEC 61215 outlines criteria for design qualification, ensuring panels are safe, reliable, and suitable for their intended use. Additionally, IEC 61701 assesses the resistance of solar panels to salt mist corrosion, prevalent in coastal or marine environments.

While these standards are essential for minimum safety and reliability, they are not designed to validate performance over the full warranty period.

Extended Durability Testing

To provide confidence in long-term reliability and durability, solar panels undergo extensive additional environmental stress tests. These tests subject panels to harsh conditions that accelerate chemical and physical mechanisms leading to performance degradation.

Due to the complexity of panel performance, a comprehensive suite of tests is necessary. Over time, a consensus has emerged regarding exposure times, stress levels, and sequences required for testing protocols. Independent third-party laboratories conduct these tests as part of “Product Qualification Programs.” Manufacturers undergo these tests to assure customers of the quality and reliability of their panels.

The Product Qualification Programs include various environmental stress tests. The Damp Heat test exposes panels to high temperatures (185°F) and humidity (85%) for 2000 hours, assessing resistance to moisture ingress and suitability for hot and humid climates. Thermal Cycling involves exposing panels to temperature cycles between -40°F and +185°F to stress the electrical interconnects and simulate hot and dry climates like the U.S. southwest. Mechanical Stress tests simulate typical snow load conditions and wind events by applying static and dynamic loads to panels. Backsheet Testing examines the external layer’s durability against exposure to UV, thermal cycling, and damp heat. Hail Testing evaluates panels’ ability to resist physical damage from hailstones of different sizes and speeds. Lastly, Potential-Induced Degradation (PID) Testing assesses panels’ resistance to power loss caused by voltage potential between cells and the frame.

Image courtesy of PVEL LLC

After each testing sequence, panels are evaluated for performance and safety. Severe degradation indicates potential flaws in design, materials, or manufacturing. While not mandatory, many solar panels on the market have successfully endured these harsh conditions, bolstering consumer confidence in their quality and longevity.

By adhering to international standards and rigorous testing protocols, top-tier solar panel manufacturers aim to exceed warranty expectations and provide the best levelized cost of energy. These efforts contribute to the growth of the solar energy industry and offer consumers reliable and durable options for a sustainable future.

The U.S. solar energy industry is entering an exciting phase, fueled by legislation and incentives. As manufacturers expand production, it is essential to address the durability of solar panels. Though warranties promise decades of flawless operation, international standards and rigorous testing protocols provide confidence in their longevity. Tests designed to simulate harsh environmental conditions ensure panels meet quality and reliability expectations. While not yet mandatory, many solar panels on the market have successfully passed these tests, further enhancing consumer trust. Through these efforts, solar panel manufacturers contribute to the industry’s growth and offer North American consumers sustainable and dependable energy solutions.