Analysis of transmitted optical spectrum enabling accelerated testing of multijunction concentrating photovoltaic designs
Analysis of transmitted optical spectrum enabling accelerated testing of multijunction concentrating photovoltaic designs
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DOI：
10.1117/1.3530092
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发表时间：
2011
影响因子：
1.3
通讯作者：
David C. Miller;M. Kempe;C. Kennedy;S. Kurtz
中科院分区：
文献类型：
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作者：
David C. Miller;M. Kempe;C. Kennedy;S. Kurtz
集中式光伏(CPV)技术最近因其可扩展性和预期的低水平电力成本而受到人们的关注。然而，CPV系统中使用的封装材料的可靠性还没有得到很好的确定。例如，目前对CPV模块的合格测试仅包括实时紫外线(UV)暴露，即尚未开发出加速UV测试的方法。为了更好地定义CPV系统固有的应力，评估了通过典型光学系统传输的紫外和红外光谱。光学元件的测量用于评估预期的光学性能和量化破坏性的光学暴露。确定了候选材料(包括PMMA、钠钙玻璃、硼硅酸盐玻璃和石英折射器)、组件(包括银和铝反射器)和封装剂(包括EVA、离聚体、PDMS、PPMS、聚烯烃和PVB)的光学性能(透射率、折射率、反射率和吸收率)。使用假设的作用光谱计算了典型光学系统的激活光谱，以比较传递到细胞封装的紫外线辐射的预期破坏剂量。剂量和流量分析确定了红外相对于紫外线照射对CPV系统的重要性。由于紫外光的衰减度通常更高，封装内的紫外线剂量可能不会大大超过未集中的全球太阳条件，但热负荷几乎与几何浓度成正比。相对于先前对晶体硅电池技术的分析，这里的分析是针对III-V多结技术进行的。新的方面还包括其他材料(如TPU封装)和其他组件(通过玻璃镜片上的有机硅透射率、减反射涂层和用于反射系统的前玻璃，以及电池的反射)。
Concentrating photovoltaic (CPV) technology has recently gained interest based on its scalability and expected low levelized cost of electricity. The reliability of encapsulation materials used in CPV systems, however, is not well established. For example, the present qualification test for CPV modules includes only real-time ultraviolet (UV) exposure, i.e., methods for accelerated UV testing have not yet been developed. To better define the stress inherent to CPV systems, the UV and infrared spectra transmitted through representative optical systems were evaluated. Measurements of optical components are used to assess expected optical performance and quantify damaging optical exposure. Optical properties (transmittance, refractive index, reflectance, and absorptance) of candidate materials (including PMMA, soda-lime glass, borosilicate glass, and quartz refractors), components (including Ag- and Al-enabled reflectors), and encapsulants (including EVA, ionomer, PDMS, PPMS, polyolefin, and PVB) were identified. The activation spectrum was calculated for the representative optical systems using an assumed action spectrum to compare the expected damaging dose of UV radiation delivered to the cell encapsulation. The dose and flux analysis identifies the significance of IR relative to UV exposure for CPV systems. Because UV light is typically more highly attenuated, the UV dose within the encapsulation may not greatly exceed the unconcentrated global solar condition, but the thermal load scales nearly directly with the geometric concentration. Relative to a previous analysis for crystalline silicon cell technology, the analysis here is performed for III-V multijunction technology. Novel aspects here also include additional materials (such as TPU encapsulation) and additional components (transmission through silicone on glass lenses, antireflective coatings, and the front glass used with reflective systems, as well as reflection off of the cell).