光伏支架成本及选型分析

以长沙地区为例，对采用不同类型光伏支架时光伏电站的占地面积、发电量、运行成本、平准化度电成本(LCOE)进行了分析，并分析了不同场景下适用的光伏支架类型。分析结果显示：1)从发电量差异系数来看，双轴跟踪式光伏支架的发电量差异系数最高，单轴跟踪式光伏支架的次之，固定式光伏支架的最低。2) LCOE从低到高依次为：水平单轴跟踪式光伏支架<固定式光伏支架<垂直单轴跟踪式光伏支架<斜单轴跟踪式光伏支架<双轴跟踪式光伏支架。3)当光伏电站项目以经济性最优为考量标准时，建议选择平单轴跟踪式光伏支架。4)当光伏电站项目以装机容量最大为考量标准时，建议选择固定式光伏支架。本研究方法适用于中国各个地区光伏电站的光伏支架成本及选型分析。     

光谱响应对光伏电站发电量的影响分析

通过对单、多晶硅太阳电池的光谱响应与量子效率,以及格尔木地区太阳光谱的测试分析,同时结合光伏电站单、多晶硅光伏组件发电量的统计数据,分析了光谱响应对光伏电站发电量的影响,提出了光伏组件设备选型的要求。     

光伏组件选型对光伏系统发电量的影响

深入研究了不同种类光伏组件在不同天气条件下的发电特性以及相同种类不同厂家光伏组件的发电特性。实验结果表明不同种类太阳电池在不同季节的发电特性存在明显差异。晶体硅和CIGS(铜铟镓硒)电池冬季发电量明显高于硅薄膜电池,最多可多发电10%左右;随时间推移,三者之间的差异先逐渐减小后增加,到夏季硅薄膜反超多晶硅和CIGS,最多可多发电20%左右。同时,结合光辐照度、温度、湿度等天气资料,测试结果表明:晶体硅和CIGS更适合辐照量高、温度低、湿度小的中国北部地区;硅薄膜在辐照度不高、温度高、湿度大的中国南部大部分地区具有更高发电量。     

光伏电站内不同光伏支架形式数量占比的研究

光伏支架形式不同时会对土建工程量、电气工程量等产生一定影响。针对位于不同太阳能资源区的光伏电站,在光伏电站总装机容量不变的情况下,根据固定式与平单轴跟踪式光伏支架数量占比的变化趋势,对光伏电站全寿命周期内2种光伏支架形式在不同数量占比下的光伏电站初始投资额与25年平均发电量的增益值及增幅进行计算,并得出对应的光伏电站发电量及土建工程量、电气工程量等的变化趋势;最后得出在不同太阳能资源区光伏电站全寿命周期内全资财务内部收益率(税后)较优(大于等于8%)时平单轴跟踪式光伏支架的数量占比范围,为工程建设的最经济性投资提供参考依据。     

温度对屋顶分布式光伏系统发电效率的影响分析

提高发电效率是光伏模块进一步大规模应用的关键。温度是影响光伏模块发电效率的重要因素之一,尤其对屋顶分布式光伏系统而言。基于某屋顶分布式光伏电站运行数据,分析了温度对光伏模块发电效率的影响。通过建立多元线性回归模型探讨了环境温度与电池板发电效率的关系,并提出了一种拟合度较高的理论发电量计算模型。该模型可用于计算电站的应发电量和相应的损失发电量,以便综合考虑收益与成本,判断是否采取适当的降温措施。     

非晶硅与晶硅太阳电池在太阳能光伏发电应用中热性能的研究

对在北京地区屋面上固定角度安装(目前光伏发电应用中最常见的安装形式)的非晶硅和多晶硅太阳电池组件进行了近二年的数据采集,纪录了北京地区温度数据和太阳电池阵列的实际发电量,分析了它们各自的特点,为用户更为关心的户外使用情况提供了参考依据;认为如果仅从温度特性考虑,是否采用非晶硅替代晶体硅电池在不同地区应有不同考虑,如果再考虑到人们普遍认为的非晶硅电池没有解决的稳定性问题,表面玻璃的非钢化、效率低等其它问题,非晶硅的使用应慎重,不应盲从.同时在使用中不论何种电池都不应忽视组件的通风问题.     

一种反射聚光的双面光伏发电装置的设计研究

目前双面光伏电池发展迅速,但是双面光伏电池组件的背面光线差,发电效率低.为了提高双面光伏电池组件的发电量,通过对平面镜反射聚光原理的分析,得出了光线反射强度的变化规律.采用双平面镜反射光叠加后,光伏板倾角从0°增大到60°时,两镜总反射光强度系数从1.12增大到1.71,平均发电量可提高1倍以上.据此设计了一种双平面镜...     

单抛物反射面聚光光伏系统的性能研究

为了提高常规光伏电池组件利用率,该文采用单抛物反射面建立了聚光光伏系统,并与常规平板系统对比,进行了性能研究.该系统利用控制机构,根据太阳高度角决定单抛物反射面是否立起工作,对太阳辐射低倍率聚光,避免了聚光后辐照度过高,表面温度升高也较小.对比常规平板系统,夏至附近短路电流提高了约12.6%,开路电压提高了约0.5%;冬至附近,短路电流提高了约36.4%,开路电压提高了约1.4%.另一方面,夏至附近不聚光的最高辐照度为842W/m2,冬至附近聚光的最高辐照度为834W/m2,不会损伤光伏电池组件,可采用普通多晶硅光伏电池组件,且不需要冷却系统.研究表明,采用该系统能以较小的成本获得以上受益,发掘了常规光伏电池组件应用潜力,为进一步提高光伏发电系统的性价比提供了方法.     

上海地区各种光伏组件户外发电性能比较和衰减原因分析

主要利用中国科学院上海微系统与信息技术研究所嘉定园区配置的光伏组件户外测试系统,针对各种光伏组件(类型包括:多晶硅、n型单面和双面、PERC单晶硅和多晶硅、12栅单晶硅、HIT单面和双面、CIGS组件、CdTe组件)在上海地区的应用,于2016年6月1日～2018年7月20日开展了户外实证监测。首先通过室内标定对比了各种光伏组件的衰减,然后利用户外实证发电量对比了各种光伏组件的户外发电性能,进而分析了各种光伏组件的衰减原因。     

冷却剂流量对聚光型太阳能光伏系统效率的影响

针对聚光型太阳能光伏电池工作中温度升高会导致发电效率降低的问题,在太阳能模组上铺设有机工质循环管路对光伏电池进行冷却,通过冷凝器对管内有机工质吸收的热量进行收集利用,构建聚光型太阳能光伏/光热综合利用系统。建立传热模型,计算不同日照强度下模组的输出效率并与实验数据进行对比。实验结果表明:发电效率随日照强度的增加先增加后减小;对光伏电池进行冷却可提升系统输出效率;太阳能光伏发电及散热量利用效率合计可达60%。     

Simulation model for sizing of stand-alone solar PV system with interconnected array

Solar PV arrays made of interconnected modules are comparatively less susceptible to shadow problem and power degradation resulting from the aging of solar cells. This paper presents a simulation model for the sizing of stand-alone solar PV systems with interconnected arrays. It considers the electricity generation in the array and its storage in the battery bank serving the fluctuating load demand. The loss of power supply probability (LPSP) is used to connote the risk of not satisfying the load demand. The non-tracking (e.g., fixed and tilted) and single-axis tracking aperture arrays having cross-connected modules of single crystalline silicon solar cells in a (6×6) modular configuration are considered. The simulation results are illustrated with the help of a numerical example wherein the load demand is assumed to follow uniform probabilistic distribution. For a given load, the numbers of solar PV modules and batteries corresponding to zero values of LPSP on diurnal basis during the year round cycle of operation are presented. The results corresponding to the surplus and deficit of energy as a function of LPSP are also presented and discussed to assess the engineering design trade offs in the system components.Furthermore, a simple cost analysis has also been carried out, which indicates that for Delhi the stand-alone solar PV systems with fixed and tilted aperture arrays are better option than those with single-axis tracking aperture (with north–south oriented tracking axis) arrays.     

新型双轴跟踪光伏发电技术

  [目的]  为了克服传统光伏发电能源利用率低、经济性差的问题,特别是水面光伏固定困难,需探索一种新型的双轴跟踪光伏发电技术。  [方法]  新型地面和水面双轴跟踪光伏发电技术,在类似于塔吊的钢桁架构成的、以固定圆心做极其缓慢转动的大圆盘上布置平单轴光伏阵列。从光伏阵列布置入手,分析了新型双轴跟踪在土地资源占用和能源利用率的特点,进而对该新型系统较传统光伏发电系统的发电量增加和成本增量作技术经济性分析。  [结果]  新型双轴跟踪技术节约土地资料,为传统双轴跟踪式占地面积50%左右,提高单位面积能源利用率。增加发电量,双轴跟踪式相较于固定式增加35%～45%,水面光伏再增加6%～15%。电能输出更加平稳,双轴跟踪式光伏发电很快进入平稳期,电能输出更加平稳。提高了经济性,新型双轴跟踪,所有光伏板同步转动,只需要一个方位角和一个高度角检测装置,方位角跟踪也只需要一套驱动装置;高度角跟踪可以分区域集中供电驱动,相对节省成本。技术经济指标更优,特别是相较于传统水面光伏有明显改善。运营维护方便,采用龙门吊门型架结构,在等间距的钢桁架上前后、左右、上下移动方便进行检修和清洗。  [结论]  提出的新型双轴跟踪系统在经济性、电源输出平稳性和运维简易性上有巨大优势,通过分析对比可以看出该系统具有很强的推广前景。     

双面光伏组件背面无遮挡时的发电量研究

针对以常规方式安装双面光伏组件时组件背面存在一定遮挡会影响其发电量这一情况,通过对双面光伏组件分别安装于固定式光伏支架、平单轴跟踪光伏支架时组件背面有、无遮挡,以及背景反射率不同时双面光伏组件的发电量情况进行分析,结果发现,在双面光伏组件背面无遮挡的前提下,当采用平单轴跟踪光伏支架且地面背景为白色时,双面光伏组件的发电...     

非晶硅太阳能光伏/光热空气集热器性能对比实验研究

文章设计了新型非晶硅太阳能PV/T空气集热器,该空气集热器能够解决传统太阳能PV/T热水器在高温波动情况下,晶硅电池热应力大的问题,同时避免了冬季管道发生霜冻的现象。文章通过实验对比,分析了非晶硅太阳能PV/T空气集热器、单独非晶硅光伏电池和传统太阳能空气集热器的能量效率和[火用]效率的差异。分析结果表明:非晶硅太阳能PV/T空气集热器的平均热效率为45.70%,比传统太阳能空气集热器的平均热效率降低了约25.88%;当空气质量流量增大至0.048 kg/s时,非晶硅太阳能PV/T空气集热器中的非晶硅光伏电池的平均电效率高于单独非晶硅光伏电池,它们的平均电效率分别为4.70%,4.54%;非晶硅太阳能PV/T空气集热器的总[火用]效率高于传统太阳能空气集热器的热[火用]效率和单独非晶硅光伏电池的电[火用]效率,非晶硅太阳能PV/T空气集热器总[火用]效率最大值为7.14%。文章的分析结果为非晶硅太阳能PV/T空气集热器的推广提供了参考。     

异质结光伏组件的发电效果研究

为研究异质结光伏组件的实际发电效果,收集某光伏发电站近两年的发电量数据,得到单块组件的月均发电量.通过对比分析,验证该异质结光伏组件相对于多晶光伏组件在发电效率方面的优越性,且与理论增益相符.通过计算冬夏两季的月均发电量和月均辐照度,证明相比多晶光伏组件,温度升高对该异质结光伏组件的功率影响更小,与理论上异质结光伏组件...     

跟踪式光伏发电系统研究

根据某地实测的太阳辐射数据,仿真比较了配备有单轴跟踪和双轴跟踪等4种跟踪控制的光伏发电系统与固定式光伏发电系统的太阳辐射利用率。并在此基础上对4种跟踪系统的跟踪角控制规律及跟踪控制方式进行了详细的分析,得出倾纬度角单轴跟踪系统控制规律最为简单,算法实施更为实用的结论。同时,也在理论上证明了采用步进式控制方式的跟踪系统能够在保持较高太阳辐射利用率情况下简化控制系统设计,有利于工程设计及应用。     

Assessing the performance of a building integrated BP c-Si PV system

In this study, the performance, yield and characteristics of a 16 year old photovoltaic (PV) system installation have been investigated. The technology, BP Saturn modules which were steel-blue polycrystalline silicon cells are no longer in production. A bespoke monitoring system has been designed to monitor the characteristics of 6 refurbished strings, of 18 modules connected in series. The total output of the system is configured to 6.5 kWp (series to parallel configuration). In addition to experimental results, the performance ratio (PR) of known values was simulated using PVSyst, a simulation software package. From calculations using experimental values, the PV system showed approximately 10% inferior power outputs to what would have been expected as standard test conditions. However, efficiency values in comparison to standard test conditions and the performance ratio (∼75% from PVSyst simulations) over the past decade have remained practically the same. This output though very relevant to the possible performance and stability of aging cells, requires additional parametric studies to develop a more robust argument. The result presented in this paper is part of an on-going investigation into PV system aging effects.     

Performance modeling and investigation of fixed, single and dual-axis tracking photovoltaic panel in Monastir city, Tunisia

Presented in this paper was an overview on research works on solar radiation basics and photovoltaic generation. Also, a complete PV modeling and investigation on the effect of using multi-axes sun-tracking systems on the electrical generation was carried out to evaluate its performance using the case study of the Monastir city, Tunisia. The effects of azimuth and tilt angles on the output power of a photovoltaic module were investigated. The instantaneous increments of the output power generated by a photovoltaic module mounted on a single and dual-axis tracking system relative to a traditional fixed panel were estimated. The results show that the yearly optimal tilt angle of a fixed panel faced due to the south is close to 0.9 times Monastir latitude. The gain made by the module mounted on a single-axis tracking panel relative to a traditional fixed panel was analyzed. The monthly increments of the gain are more noticeable for two critical periods which correspond to those surrounding the summer and the winter solstice dates. It reaches the value of 10.34% and 15% in the summer and winter solstice periods, respectively. However, the yearly gain relative to a fixed panel installed with the yearly optimal tilt angle is 5.76%. In some applications, covering loads at early morning or late afternoon hours and in order to more optimize the solar systems exploitation suggest the adjustment of the PV panel orientation to azimuth angles different from the south direction by using a dual-axis tracking installation. The gain made by this recommendation relative to a traditional fixed panel is evaluated. This gain reaches 30% and 44% respectively in the winter and summer solstice days.     

Polar coordinated fuzzy controller based real-time maximum-power point control of photovoltaic system

It is crucial to improve the photovoltaic (PV) system efficiency and to develop the reliability of PV generation control systems. There are two ways to increase the efficiency of PV power generation system. The first is to develop materials offering high conversion efficiency at low cost. The second is to operate PV systems optimally. However, the PV system can be optimally operated only at a specific output voltage and its output power fluctuates under intermittent weather conditions. Moreover, it is very difficult to test the performance of a maximum-power point tracking (MPPT) controller under the same weather condition during the development process and also the field testing is costly and time consuming. This paper presents a novel real-time simulation technique of PV generation system by using dSPACE real-time interface system. The proposed system includes Artificial Neural Network (ANN) and fuzzy logic controller scheme using polar information. This type of fuzzy logic rules is implemented for the first time to operate the PV module at optimum operating point. ANN is utilized to determine the optimum operating voltage for monocrystalline silicon, thin-film cadmium telluride and triple junction amorphous silicon solar cells. The verification of availability and stability of the proposed system through the real-time simulator shows that the proposed system can respond accurately for different scenarios and different solar cell technologies.