Hello Solar enthusiasts! If you’re in the process of selecting solar panels for your home or even considering a full solar array for your home setup, this blog post will certainly rekindle those environmentalist sparks within you. As an expert, I bring forward the most recent solar industry conversation–the introduction of large-format modules and the controversy it spans while delving into load testing, certification standards, and critical impacts on the field.
During the RE+ 2023 conference, leading solar companies graced us with their latest, breath-taking innovations in photovoltaics, which promise renewal in cost efficiency. The solar panels presented were larger, slimmer, more powerful than ever witnessed, an unprecedented stride in the solar companies’ relentless pursuit to scalability and affordability. And yet, a closer inspection of these gigantic modules reveals an unexpected detail: their frames are seemingly micro-sized.
Now, scratching at the surface of this curiosity reveals an underlying complexity. Historically, let’s look at the 2- by 1-meter module with a frame height of 50mm. Today we see a module around 55% larger in surface area but with the frame height reduced to as low as 30mm. The surprising fact is such advancements came while maintaining the constant mechanical load ratings. The intricacies of physics apply here too, making it an intriguing matter to delve into.
To trust these large solar panels’ durability, they undergo standard mechanical load tests for certification. The esteemed establishments conducting these certifications like UL 61730-2, IEC 61730, and IEC 61215-2, all play a critical role in adhering to predefined testing procedures. Every solar company prides itself on being compliant with these standards. However, there seems to be a small catch here.
No matter how lab-perfect these panels may seem, the reality of the field is quite different. Real-world loading on the solar panels depends largely on the structure of mounting and project conditions, significantly influenced by wind zones. Diverse tilt angles also add into the equation, increasing wind loading on modules and varying across array locations. Combined with snow impacts, which are usually inverse (higher tilt solar panels shedding more snow), give rise to a wide range of factors impacting module loading in real-world conditions versus laboratory testing.
Now, the real challenge is to navigate through structural design intricacies to fully comprehend the diverse variables affecting module loading. This deep understanding of the load dynamics is especially vital as new generation large-format modules are designed to safety factors near 1.5, allowing them to stay cost-efficient. Consequently, it’s crucial for the designer to understand what the module ratings include and adapt to the market driving the load capacity to its potential maximums, particularly considering backside wind uplift loading.
The ultimate goal is not about laying the blame but understanding these technical issues and guiding stakeholders to deal with these risks efficiently. Here are some tips from my end:
1. Make sure you allocate enough budget and time to each project, especially the smaller ones, to verify key details about module loading and not just for the entire project, but for every location within the project.
2. Perform due diligence with the structure manufacturer to confirm various aspects. For instance, confirm whether the clip and bolt loads for module retention use module clip loads or average row areas. Or that the loading on half the module differs from the other half. Also, double-check whether the module designers have considered the uneven module loading in their designs.
3. Last but not least, make it a point to check and confirm a few things with the solar company about their modules. Check whether the listed mechanical load ratings on the datasheet include the test safety factor. Also, ascertain if the module frame can withstand extra forces that come from uneven loading. And, critically, do ensure the mounting method matches the module certification and can uphold the warranty under project conditions.
In closing, I hope this post helps you in your journeys in welcoming solar energy into your homes. Remember, it is crucial for us to learn and understand the details of solar technology, its pitfalls, and its solutions, all in an effort to make the world a more sustainable place. Expect more exciting posts on the solar industry soon, until then, stay bright and let the sun power your day!
Original Articlehttps://pv-magazine-usa.com/2024/02/14/large-format-solar-modules-and-legacy-assumptions/
