透明背板材料的可靠性研究

p-PERC+、n-PERT等结构的高效太阳电池的转换效率持续提升,双面化的结构设计在各类高效太阳电池和光伏组件中得以规模化普及应用。双面发电技术大幅降低了度电成本,可双面发电的光伏组件已经成为行业发展的大趋势。对于双面光伏组件的PID问题,可使用抗PID的增强型POE胶膜封装来解决,背面封装主要是使用玻璃或透明背板材料,但背面封装材料的长期可靠性仍需要进行验证。对比分析了透明PVF薄膜、PVDF薄膜、超耐候氟涂层膜等氟保护层材料的优劣,对耐紫外、耐湿热、UV+DH同步老化等性能进行对比,选择出性能更可靠的原材料及透明背板材料,并提供了高可靠性的透明背板封装解决方案。     

不同因素对各类型晶体硅光伏组件温度系数的影响研究

以7种不同类型的晶体硅光伏组件作为研究对象,通过温度系数测量实验,针对光伏组件老化、太阳电池技术、太阳电池尺寸、光伏组件类型等因素对晶体硅光伏组件温度系数的影响进行了分析研究。首先研究了常规老化多晶硅光伏组件的温度系数,然后探讨了双面单晶硅光伏组件温度系数测试方法的具体要求,最后对比分析了采用不同太阳电池技术和尺寸封装的不同类型单晶硅光伏组件的温度系数。研究结果表明：1)在光伏电站现场使用过的常规老化多晶硅光伏组件的温度系数依然保持稳定;2)使用门框内表面为黑色的瞬态太阳光模拟器对双面单晶硅光伏组件进行温度系数测试时,可以不必对光伏组件背部进行遮挡;3)并串结构的半片单晶硅光伏组件的温度系数与太阳电池尺寸、单面或双面发电无直接关系;4)PERC、TOPCon单晶硅光伏组件的温度系数虽然存在一定的差异,但总体来看差异不大。     

背板与玻璃的导热差异对组件发电量的影响分析

以背板的散热性能为切入点,通过背板的散热性能测试和组件户外温度追踪,进行背板散热的性能研究。研究结果表明,单玻光伏组件与双玻光伏组件户外监测时,两者温度差异较小,温度造成的发电量增益小于0.5%。     

高辐照度对高效光伏组件性能影响的研究

研究了高辐照度下的光谱辐照度分布及其与太阳电池的匹配性,通过测试辐照前后太阳电池的光电转换效率、外量子效率(EQE)、反射率、栅线形貌,对比分析了高辐照度、超高辐照度与标准辐照度对高效太阳电池性能影响的差异,并通过与光伏组件户外数据关联分析高辐照度对光伏组件性能的影响。研究结果显示：太阳电池在经受高辐照后,短路电流的下降幅度较为明显,而其下降主要是因为栅线氧化及钝化效果变差引起的复合损失;高辐照环境下最优的光伏组件类型建议选择n型双玻半片光伏组件。评估高效光伏组件在不同环境下的性能,有助于保证光伏组件成品性能的稳定可靠。     

光伏组件综合序列加速老化测试方法综述

国际电工委员会(IEC)标准中的环境类可靠性测试的元素单一且不够充分,无法真实地反映户外实际运行光伏组件的长期耐候性和可靠性,因此需要进行综合序列加速老化测试。对国内外已经开展的一些针对室内加速老化测试的研究进行了综述,讨论了光伏组件综合序列加速老化测试的必要性,老化测试条件的确定、组合方式,以及室内加速老化测试结果和光伏组件现场运行情况的一致性等内容,并指出在制定综合序列加速老化测试方法时需要注意的问题。研究结果表明：综合序列加速老化测试方法不是将单一环境因素的可靠性测试任意组合,而应当结合实际的气候数据,并通过比较不同的老化测试条件来确定;综合序列加速老化测试中的不同环境因素的前后顺序对测试结果也存在很大影响;综合序列加速老化测试结果与光伏组件实际户外运行结果的一致性非常重要。研究结果可为光伏组件的可靠性测试研究和发展提供参考。     

基于红外图像的太阳能光伏阵列故障分析

依据处于不同工作状态下太阳电池间存在明显温差这一特性,提出了基于红外图像分析的太阳能光伏阵列工作状态自动分析与识别的方案。该方案首先对光伏阵列的红外图像进行预处理与分析,提取可能的故障区域及区域的特征信息,综合考虑环境温度、照度、风力等环境因素的影响,采用信息融合与模糊推理的方法,实现了对光伏阵列中太阳电池工作状态的自动识别。研究结果表明,该方案能够准确地对运行于光伏系统中组件的正常、遮挡、老化损坏状态进行识别。     

n型TOPCon-PERT双面太阳电池发电特性分析

随着将隧穿氧化层钝化接触(TOPCon)技术应用在n型钝化发射极背表面全扩散(PERT)太阳电池上,电池效率得到了进一步提升,n型TOPCon-PERT太阳电池因具有少子寿命高、无光致衰减及功率温度系数小等优点,已成为当前太阳电池技术研究的热点之一。通过对比叠加TOPCon技术前、后n型PERT双面太阳电池的量子效率,并根据p型PERC双面光伏组件、n型PERT双面光伏组件及n型TOPCon-PERT双面光伏组件的户外发电特性及衰减率等实测数据,验证了n型TOPCon-PERT双面太阳电池的发电量增益。     

基于石墨烯提升光伏组件散热性能实验研究

采用新型石墨烯材料用于光伏组件背板散热,以提高光伏组件能量转换效率。在硅太阳电池组件基础上分别设计并制作普通石墨烯薄膜组件以及石墨烯肋片复合结构组件,建立2种石墨烯光伏组件的热力学模型,搭建石墨烯组件散热性能测试平台进行实验研究,此外进行组件室外光伏电站的性能测试。实验结果表明,添加石墨烯及肋片能增强光伏组件散热性能和提高组件输出功率;在室内模拟的晴天气象条件及辐照度高的情况下,石墨烯肋片复合组件的散热性能提升较为显著。通过室外测试,石墨烯肋片复合组件的功率及发电量相比于普通光伏组件分别提高0.5%～1.15%和0.97%。     

镀膜玻璃对光伏组件户外输出性能的影响

通过对使用3M减反镀膜液的镀膜玻璃封装光伏组件及常规钢化玻璃封装光伏组件进行长期的户外功率跟踪测试后发现,使用3M减反镀膜液的镀膜玻璃在光伏组件户外长期使用过程中的功率增益要远高于在STC测试条件下的功率增益,并对其在光伏组件户外使用过程带来额外增益的机理进行了分析和探讨。同时,对减反涂层的机械性能及老化性能进行了研究。     

局部阴影下光伏组件的Matlab/Simulink仿真模拟与特性分析

针对局部阴影遮挡条件对光伏组件输出特性的影响进行仿真分析。建立改进的双二极管太阳电池数学模型,模型中二极管D2的反向饱和电流I02采用电池材料自身性能参数进行计算,模型除二极管的理想因子n1、n2是经验值,无需估计任何值。仿真模型以建立的双二极管太阳电池数学模型为基础,通过Matlab/Simulink对双二极管太阳电池进行建模。以双二极管太阳电池模型为基础,建立适用于局部阴影下光伏组件的电气模型,从而避免构建光伏组件过程中繁杂的数学建模工作。利用该模型对不同局部阴影条件下的太阳电池和光伏组件进行仿真模拟,并对仿真数据进行对比分析。分析结果表明,局部阴影的数量和分布均匀性不同,对光伏组件输出特性的影响也有所不同。     

单面和双面单晶硅光伏组件的发电性能实证

针对p型PERC单面单晶硅光伏组件和n型双面单晶硅光伏组件,利用光伏组件户外实证测试系统,分析了2016年12月15日～2018年7月20日期间,上海市嘉定区某屋顶的地面采用白板背景时双面和单面组件,以及水泥背景时双面组件的等效发电时长,并对白板背景和水泥背景时双面组件较单面组件的发电量增益情况进行了分析;计算了组件的PR值;分析了阴天和晴天时组件最大输出功率与组件背板温度、太阳辐照度和环境温度的关系;最后对比了单面和双面组件运行13个月后的衰减值。该实证结果为单面和双面组件的户外实证发电性能提供了数据支撑,并对双面组件较单面组件的发电量增益情况进行了有效证明。     

The risk of power loss in crystalline silicon based photovoltaic modules due to micro-cracks

Micro-cracks in wafer based silicon solar cell modules are nowadays identified by a human observer with the electroluminescence (EL) method. However, the essential question of how the micro-cracks affect the PV module performance has yet to be answered. We experimentally analyze the direct impact of micro-cracks on the module power and the consequences after artificial aging. We show that the immediate effect of micro-cracks on the module power is small, whereas the presence of micro-cracks is potentially crucial for the performance of the module after artificial ageing. This confirms the necessity to develop the means of quantifying the risk of power loss in PV modules with cracked solar cells in their lifetime, in order to enable manufacturers to discard defective modules with high risk of failure while keeping modules with uncritical micro-cracks. As a first step towards risk estimation we develop an upper bound for the potential power loss of PV modules due to micro-cracks in the solar cells. This is done by simulating the impact of inactive solar cell fragments on the power of a common PV module type and PV array. We show that the largest inactive cell area of a double string protected by a bypass diode is most relevant for the power loss of the PV module. A solar cell with micro-cracks, which separate a part of less than 8% of the cell area, results in no power loss in a PV module or a PV module array for all practical cases. In between approximately 12 and 50% of inactive area of a single cell in the PV module the power loss increases nearly linearly from zero to the power of one double string.     

光伏组件PID失效与DH失效的微观分析研究

对电势诱导衰减(potential induced degradation,PID)测试和湿热(damp heat,DH)测试后失效的光伏组件进行破拆,根据电致发光(electroluminescence,EL)测试结果,选取EL图像显示的不同明、暗区域(正常区域、异常区域)的太阳电池作为测试样品,并对其表面进行扫描电...     

Impact of environment factors on solar cell parameters of a-Si∥μc-Si photovoltaic modules

The behavior of amorphous silicon∥micro crystalline silicon (a-Si∥μc-Si) tandem-type photovoltaic (PV) module is complex because the output current is limited by the lower current component cell. Also, the outdoor behaviors are not fully understood. The impact of environment factors on solar cell parameters of a-Si∥μc-Si PV module was quantitatively analyzed and the module was compared with other silicon-based PV modules (single crystalline silicon (sc-Si) and amorphous silicon (a-Si)). The contour maps of solar cell parameters were constructed as a function of irradiance and module temperature. The contour map of a-Si∥μc-Si PV modules is similar to that of a-Si modules. The results imply that output characteristics of a-Si∥μc-Si PV modules are mainly influenced by the a-Si top cell. Furthermore, the efficiency of a-Si∥μc-Si PV modules was compared other solar cell parameters and the contour map of efficiency is similar to that of fill factor.     

Impact of spectral irradiance distribution and temperature on the outdoor performance of amorphous Si photovoltaic modules

Performance of photovoltaic (PV) modules is evaluated under the standard test condition, which rarely meets actual outdoor conditions. Environmental conditions greatly affect the output energy of PV modules. The impact of environmental factors, especially solar spectrum distribution and module temperature, on the outdoor performance of amorphous Si (a-Si) and multicrystalline Si (mc-Si) PV modules is characterized. The results show that the output energy of a-Si modules mainly depends on spectrum distribution and is higher under blue-rich spectrum. In contrast, the output energy of mc-Si module is sensitive to module temperature but not to spectrum distribution.     

Difference in the outdoor performance of bulk and thin-film silicon-based photovoltaic modules

Differences in the outdoor performances of bulk (multi- and single-crystalline Si) and thin-film (amorphous Si(a-Si), a-Si/micro-crystalline Si and a-Si/a-SiGe/a-SiGe) photovoltaic (PV) modules are analyzed. The influence of module temperature and solar spectrum distribution on the PV output is clarified. The PV outputs almost only depend on module temperature in bulk-type Si PV modules while that depend both module temperature and spectrum distribution in thin-film ones. Also, the PV outputs of the bulk-type Si PV modules at most frequent condition at outdoor are lower than that at the standard test condition; in contrast, it was the other way round for thin-film ones.     

Solar cell junction temperature measurement of PV module

The present study develops a simple non-destructive method to measure the solar cell junction temperature of PV module. The PV module was put in the environmental chamber with precise temperature control to keep the solar PV module as well as the cell junction in thermal equilibrium with the chamber. The open-circuit voltage of PV module V_oc is then measured using a short pulse of solar irradiation provided by a solar simulator. Repeating the measurements at different environment temperature (40-80 °C) and solar irradiation S (200-1000 W/m²), the correlation between the open-circuit voltage V_oc , the junction temperature T_j , and solar irradiation S is derived.The fundamental correlation of the PV module is utilized for on-site monitoring of solar cell junction temperature using the measured V_oc and S at a short time instant with open circuit. The junction temperature T_j is then determined using the measured S and V_oc through the fundamental correlation. The outdoor test results show that the junction temperature measured using the present method, T_jo, is more accurate. The maximum error using the average surface temperature T_ave as the junction temperature is 4.8 °C underestimation; while the maximum error using the present method is 1.3 °C underestimation.     

Producer responsibility and recycling solar photovoltaic modules

Rapid expansion of the solar photovoltaic (PV) industry is quickly causing solar to play a growing importance in the energy mix of the world. Over the full life cycle, although to a smaller degree than traditional energy sources, PV also creates solid waste. This paper examines the potential need for PV recycling policies by analyzing existing recycling protocols for the five major types of commercialized PV materials. The amount of recoverable semiconductor material and glass in a 1 m² area solar module for the five types of cells is quantified both physically and the profit potential of recycling is determined. The cost of landfill disposal of the whole solar module, including the glass and semiconductor was also determined for each type of solar module. It was found that the economic motivation to recycle most PV modules is unfavorable without appropriate policies. Results are discussed on the need to regulate for appropriate energy and environmental policy in the PV manufacturing industry particularly for PV containing hazardous materials. The results demonstrate the need to encourage producer responsibility not only in the PV manufacturing sector but also in the entire energy industry.     

A new integrated single‐diode solar cell model for photovoltaic power prediction with experimental validation under real outdoor conditions

The output power prediction by a photovoltaic (PV) system is an important research area for which different techniques have been used. Solar cell modeling is one of the most used methods for power prediction, the accuracy of which strongly depends on the selection of cell parameters. In this study, a new integrated single‐diode solar cell model based on three, four, and five solar cell parameters is developed for the prediction of PV power generation. The experimental validation of the predicted results is done under outdoor climatic conditions for an Indian location. The predicted power by three models is found close to measured values within 4.29% to 4.76% accuracy range. The comparative power estimation analysis by these models shows that the three‐parameter model gives higher accuracy for low solar irradiance values <150 W/m², the four‐parameter model in the range of 150 to 500 W/m², and the five‐parameter model for >500 W/m². The present model is also compared with other models in literature and is found to be more accurate with less percentage error. The overall results also show that the power produced depends on temperature and solar radiation levels at a particular location. Thus, single solar cell model developed can be used with sufficient accuracy for power forecast of PV systems for any location worldwide. The follow‐up research areas are also identified.     

基于太阳能光伏热利用的光伏/热电(PV/TV)建筑一体化试验研究

将太阳能电池板、集热器、热电发电片结合起来,设计并制成了一套光伏/热电(PV/TV)系统,在利用太阳能电池发电的同时,收集热量并利用其发电。在北京地区进行了该系统的室外模拟试验,测试并讨论了该系统在不同结构和不同环境下的性能,探讨该系统在光伏建筑中的应用。试验结果表明,与单纯的光伏发电系统或太阳能热水系统相比,PV/TV系统具有占地面积小、综合效率高等优点。