Fairbrother Andrew, Boyd Matthew, Lyu Yadong, Avenet Julien, Illich Peter, Wang Yu, Kempe Michael, Dougherty Brian, Bruckman Laura, Gu Xiaohong
Engineering Laboratory, National Institute of Standards and Technology (NIST), Gaithersburg, MD 20899, USA.
SDLE Research Center, Materials Science & Engineering, Case Western Reserve University, Cleveland, OH 44106, USA.
Sol Energy. 2018 Mar;163. doi: 10.1016/j.solener.2018.01.072.
There are relatively few field studies on the degradation of non-fluoropolymer-based backsheets, and understanding their in-field behavior is critical for further development of such products. In this study, backsheet degradation of modules with one of these new types of backsheets (polyethylene naphthalate (PEN)-based) was documented at a four-year old utility-scale array located in Maryland (USA). Visual inspection, colorimetry, glossimetry, and Fourier-transform infrared spectroscopy (FTIR) revealed highly varied properties depending on module position within the array. Specifically, modules near the edge of the array and with higher mounting elevations underwent greater amounts of backsheet degradation, as indicated by yellowing and gloss-loss. The reason for these unique degradation patterns were differential backside exposure conditions, especially of ultraviolet light. This was strongly influenced by the array design, including array structural and environmental factors, such as module spacing and ground cover, respectively. Within the array, no clear link between backsheet degradation and module output or safety has been identified. However, such a relationship may be expected to become more pronounced with time, affecting system lifetime and ultimately the levelized cost of electricity (LCOE). The observed phenomena have implications for both backsheet product development and array design, especially for modules that utilize newer classes of non-fluoropolymer-based backsheets which are typically more susceptible to environmental degradation.
关于非氟聚合物基背板降解的实地研究相对较少，了解它们在实际使用中的行为对于此类产品的进一步开发至关重要。在本研究中，对位于美国马里兰州一个使用这类新型背板（聚萘二甲酸乙二醇酯（PEN）基）之一的四年期公用事业规模阵列中的组件背板降解情况进行了记录。目视检查、比色法、光泽度测量和傅里叶变换红外光谱（FTIR）显示，根据阵列中组件的位置不同，背板性能差异很大。具体而言，阵列边缘附近且安装高度较高的组件背板降解程度更大，表现为发黄和光泽度损失。这些独特降解模式的原因是背板背面暴露条件不同，尤其是紫外线照射情况。这受到阵列设计的强烈影响，阵列设计分别包括阵列结构和环境因素，如组件间距和地面覆盖情况。在阵列内部，尚未发现背板降解与组件输出或安全性之间存在明确联系。然而，预计随着时间推移这种关系会变得更加明显，从而影响系统寿命并最终影响平准化度电成本（LCOE）。观察到的现象对背板产品开发和阵列设计都有影响，特别是对于使用通常更易受环境降解影响的新型非氟聚合物基背板的组件。
