Occasionally, Potential Induced Degradation can occur on solar products produced by certain Chinese manufacturers. This occurs when the module’s voltage potential and leakage current drive ion mobility within the module, specifically when this occurs between the semiconductor material and other elements of the module, such as the frame or the glass. This action, typically brought on by high levels of humidity and high temperatures, causes the module’s power to degrade, often resulting in the loss of up to forty percent of the panel’s power.
To fix this issue, manufactures need to improve the insulation on the module, as to prevent the painful effects of excessive temperatures and humidity levels. However, according to an article recently completed by Renesola’s website, which interviewed Dr. Hou Ruzhong, R&D director of Renesola, some Chinese manufacturers pay very little attention to this concern. That is not the case for Renesola, Hou asserts, as the company has made researching the problem a priority.
There are other issues in the production as well. A problem entitled Snail Trail, in which the solar cell grid discolors, allows moisture to transmit through the backsheet, EVA and solar cell. Through this, the backsheet will turn yellow, if the front of the EVA lets UV rays transmit. There is also an issue with resistance to wind and snow, with the frames and glass not being made to withstand harsh weather conditions, resulting in micro cracks along the structure. According to Hou, thinning the thickness of the aluminum is often pursued as it cut costs in production. However, costs should not be the priority, in Hou’s opinion, as long-term exposure to all of these elements results in degradation in the solar output of the product.
In the case of Renesola, the company is working very hard to not fall to these shortcomings. In the PVEL test for 2014, in which more than ten companies participated and were tested in varying categories, Renesola scored very successfully, achieving top performance ranking in Dynamic Mechanical Load and Damp Heat, in which the company’s products won the top ranking. Renesola came in second in the Potential Induced Degradation category and fifth in the Humidity Freeze category.