硅太阳电池降温保效的方法分析

太阳电池工作时,温度是影响电池转换效率的重要因素之一。硅太阳电池温度特性决定着当温度升高时,电池输出功率降低:电池温度每升高1 K,功率输出减少0.4%~0.5%,效率同比下降0.08%~0.1%。本文以硅太阳电池组件为例,按照导出热量方式的不同,将硅太阳电池冷却分为空气冷却、水冷却、制冷工质冷却、混合冷却等四种方式。着重介绍了几种国内外硅太阳电池的冷却技术、方法的研究成果,说明各种方法、技术的工作原理,并加以对比,得出结论:分频冷却技术从原理上讲冷却效果较好。文末展望了未来几种新型冷却技术。     

晶硅太阳电池组件年输出性能的数值模拟

通过对实际过程的分析,建立了一套可描述一年中任意时刻晶硅太阳电池组件的电输出和温度特性的数学模型.对比验证实验证明了该文模型的可靠性:模型计算结果与实测结果吻合较好,能够正确反映出电池组件电输出和温度在实际气象条件下的变化趋势,温度的最大瞬时误差为19.0%,全天总电量输出的误差仅为1.4%.以北京地区作为算例,采用近二十年实测气象数据的统计值代人计算,结果表明随着安装倾角口的变化,北京地区单位峰瓦晶硅电池组件的年输出电量为0.95～1.11kWh,并在β=40°时出现最大值.月输出电量具体分布情况为夏季5～7月份占全年总输出电量的38%,冬季11～1月份约占14%,同时电池组件在夏季时的转换效率要低于冬季.     

新产品

<正>Sun Power高效太阳电池板日前,Sun Power推出了SunPower E19系列太阳电池板。E19系列太阳电池组件的特点是面积大,太阳电池全背接触,增加了3%的接收面积,空间利用率高,从而提高了组件效率。此外,E19采用特殊的抗反射涂层,提高了太阳电池的接收面积,可以捕捉更多的散射光,提高了太阳电池的光电转换效率。E19     

中空玻璃式太阳电池组件的热性能研究

对中空玻璃式太阳电池组件的热性能进行了研究,对影响太阳电池温度的各因素进行了分析,建立了一个一维模型对试验结果进行了说明.结果表明,中空玻璃式太阳电池组件的散热性能较差,其内部太阳电池温度高于常规组件.在组件结构方面,影响太阳电池温度的各因素的重要性从高到低依次为:太阳电池与玻璃接触的紧密程度,太阳电池固定的位置,间隔条的宽度,组件所采用的玻璃的厚度.外界环境对太阳电池温度有重要影响,最主要的是风速的影响,其次是地面辐射的影响.     

CdTe薄膜太阳电池及组件的产业化进展与应用方向分析

对CdTe薄膜太阳电池的理论研究和产业化的进展与展望进行重点阐述，概括了此类太阳电池未来的研究重点，并对CdTe薄膜光伏组件在“双碳”目标下的应用情况进行分析探讨。结果显示：1)经过几十年的发展，截至2022年5月，CdTe薄膜太阳电池实验室最高光电转换效率仍为2016年得到的22.1%，与其理论最大光电转换效率(32%)相比还有很大的突破空间；2)未来CdTe薄膜太阳电池性能提升的关键将是进行有效p型掺杂、提高CdTe薄膜载流子寿命、通过制备欧姆接触电极提高开路电压，从而改善CdTe薄膜太阳电池的性能。以期该研究可为中国加快CdTe薄膜太阳电池及组件产业化发展提供参考方向。     

转换效率9.6／%的大面积非晶硅太阳电池

日本三洋电机公司功能材料研究所的大西及桑野,最近研制出转换效率为9.6％的10cm正方形集成结构非晶硅太阳电池。这是目前世界上大面积非晶硅太阳电池达到的最高转换效率(他们曾在1cm正方形非晶硅太阳电池上达到11.7％的效率)。该电池结构示于图1,电池特性列于表1。为了提高电池效率,他们首先分析了电池能量的     

非晶硅与晶硅太阳电池发电比较分析

采用实验测量装置对非晶硅太阳电池组件和单晶硅太阳电池组件的日均发电量进行测试对比,并对非晶硅的温度系数、I-V曲线特性及低光强下的吸收特性进行了分析。结果显示:非晶硅太阳电池板的发电效能优于单晶硅太阳电池板。     

局部阴影遮挡的太阳电池组件输出特性实验研究

结合太阳电池双二极管与雪崩击穿效应数学模型,设计太阳电池组件遮挡实验,并对组件性能进行实际测试。分别在有、无旁通二极管两种情况下,分析比较单片太阳电池小比例(1%～10%)、大比例(10%～100%)遮挡及多片电池阴影遮挡的太阳电池组件输出的I-V及P-V特性曲线。结果表明,有、无旁通二极管情况下,组件单片电池被遮挡1%～10%,整个组件输出功率下降比例均不超过2%,同一串电池片之间可允许存在小的功率差异或表面辐照强度差异(<5%)。同组件无旁通二极管多个电池遮挡实验显示,电池出现热斑效应时会被反向击穿,实验组件击穿电压约15V,为避免热斑损害,组件中应对少于15/0.6=25片串联电池并联一个旁通二极管。     

太阳能路灯工作原理

太阳能路灯的工作原理是：白天太阳能路灯在智能控制器的控制下,太阳能电池板经过太阳光的照射,吸收太阳能光并转换成电能。白天太阳电池组件向蓄电池组充电。     

光伏窗口

● 日立推出高效染料增感太阳电池大面积组件 图 1 东京消息,日立开发的色素增感有机太阳电池的光电转换效率已经赶上非晶硅太阳电池。日立在3月17～19日东 京Big Sight转 换 中 心 的 “nano tech2004”纳米技术展览会上展示了这种太阳电池的大型组件。该单元组件由4块电池连接起来,边长约10cm ,实验室光电转换效率为9.3%,在同类电池中最高。这种电池是由有机染料沉积在TiO 层上, 2这是由涂层方法形成的多孔层,涂在带有透明电极的玻璃 基片 上 ,其间 植 入 正 负 金 属 电 极 , 相 距10μm 。电极之间充满碘溶液。当有…     

PV/T太阳能光伏光热系统关键参数影响特性研究

利用PV/T太阳能光伏光热系统实验平台针对空气质量流量、太阳辐照强度、环境温度和大气降尘 4种影响系统性能的关键工况参数进行了实验研究。结果表明:在实验设定的流量范围内,PV/T系统的光热和光电效率都随着空气质量流量增大而稳步上升;太阳辐照强度增大时,系统输出电功率随之增大,光热效率变化较小,光电效率有一定程度的降低;环境温度在一定范围内时,系统的输出电功率和集热效率都随着环境温度的增大而增大,而当环境温度超过一定值后,系统的光伏模块受面板温度升高的影响光电转换效率呈下降趋势;随着积尘密度的增大,玻璃盖板的透射率减小,一个月的积尘量会导致系统光电效率和输出电功率分别下降17.84%和18.25%,若以光电效率衰减20%为界限,清洁周期为5周左右。     

The effect of temperature on the power drop in crystalline silicon solar cells

The influence of temperature and wavelength on electrical parameters of crystalline silicon solar cell and a solar module are presented. At the experimental stand a thick copper plate protected the solar cell from overheating, the plate working as a radiation heat sink, or also as the cell temperature stabilizer during heating it up to 80°C. A decrease of the output power (−0.65%/K), of the fill-factor (−0.2%/K) and of the conversion efficiency (−0.08%/K) of the PV module with the temperature increase has been observed. The spectral characteristic of the open-circuit voltage of the single-crystalline silicon solar cell is also presented. It is shown that the radiation-rate coefficient of the short-circuit current-limit of the solar cell at 28°C is 1.2%/(mW/cm²).     

Output variation of photovoltaic modules with environmental factors — II: seasonal variation

This study investigated how seasonal changes in cell temperature and spectral solar radiation effect the seasonal variation in photovoltaic (PV) module conversion efficieny for CdS–CdTe and two-layer tandem-amorphous silicon (for simplicity referred to as CdS and 2L A Si, respectively). First, using the measured data, the ratio of the spectral solar radiation available for solar cell utilization to the global solar radiation (denoted hereafter as “available spectral ratio”), the mean cell temperature, and the conversion efficiency for each month were obtained, and seasonal variations were analyzed. Mean cell temperature and available spectral ratio seasonal changes were found to be 9% for CdS and 16% for 2L A Si.The CdS conversion efficiency increased during summer by 7%, whereas 2L A Si exhibited a more substantial 14% variation. During summer, although the spectral ratio available to CdS increases, the conversion efficiency does not increase by the same amount, because of an increase in cell temperature. Similarly, although 2L A Si, experienced a much greater increase in available spectral ratio and had a better overall performance, there was still only a 2% variation, because of the cell temperature increases.If the basic characteristics of solar cell output for various types are compared with the variation in environmental factors, such as irradiance, cell temperature and spectral solar radiation, it is possible to calculate the precise output of a solar cell. Accordingly, it is possible to evaluate the seasonal variation in conversion efficiency for each solar cell type and utilize this information to optimize the PV power system.     

无盖板型水冷式PV/T模块光电/光热综合性能实验研究

无盖板PV/T组件相比于盖板式PV/T组件有更高的光电转换效率,在电能输出方面的优势明显。基于此,提出一种无盖板型水冷式PV/T模块,并搭建由光伏对比模块、水冷式PV/T模块以及无冷却水循环的PV/T对比模块构成的实验平台开展对比实验,研究温度、流量对无盖板PV/T模块电、热转换效率的影响。结果表明,在水冷作用下,PV/T模块的光伏组件温度显著降低,与PV/T对比模块相比发电效率提升11.54%;环境平均温度为21.7 ℃、平均辐照度650 W/m²的测试条件下,流量0.12 m³/h时模块的电效率为17.44%,热效率为19.80%,综合效率达到65.69%,考虑到循环泵消耗的电能,表面积1.93 m²的水冷式PV/T模块全天可存储有效能3.72 MJ。     

光伏光热一体化组件性能实验探究与分析

通过搭建PV/T一体化组件性能测试实验台,测试在不同进口水温、不同一体化组件倾角和不同流量时PV/T一体化组件的热、电效率。结果表明,在进口水温30℃工况下一体化组件拥有最优的热效率值和输出电功率值,其日总热效率为35.97%,对应的输出电功率范围为29.40~30.51 W;45°倾角放置的一体化组件可接收到较多的太阳辐照度,且具有最优的光热性能,对应的日总热效率为32.65%;流量85 L/h工况下一体化组件拥有最优的热效率值,对应的日总热效率值为25.89%,串联50Ω电阻时组件的输出电功率随流量的增大而增大,但变化较小,流量120 L/h工况下一体化组件拥有最优的输出电功率值,对应的输出电功率值范围为24.02~29.19 W。     

On the investigation of photovoltaic output power reduction due to dust accumulation and weather conditions

Certain environmental conditions such as accumulation of dust and change in weather conditions affect the amount of solar radiation received by photovoltaic (PV) panel surfaces and thus have a significant effect on panel efficiency. This study conducted an experimental investigation in Surabaya, Indonesia, on the effect of these factors on output PV power reduction from the surface of a PV module. The module was exposed to outside weather conditions and connected to a measurement system developed using a rule-based model to identify different environmental conditions. The rule-based model, a clear sky solar irradiance model that included solar position, and a PV temperature model were then used to estimate the PV output power, and tests were also conducted using an ARM Cortex-M4 microcontroller STM32F407 as a standalone digital controller equipped with voltage, current, temperature, and humidity sensors to measure real time PV output power. In this system, humidity was monitored to identify dusty, cloudy, and rainy conditions. Validated test results demonstrate that the prediction error of PV power output based on the model is 3.6% compared to field measurements under clean surface conditions. The effects of dust accumulation and weather conditions on PV panel power output were then analyzed after one to four weeks of exposure. Results revealed that two weeks of dust accumulation caused a PV power output reduction of 10.8% in an average relative humidity of 52.24%. Results of the experiment under rainy conditions revealed a decrease in PV output power of more than 40% in average relative humidity of 76.32%, and a decrease in output power during cloudy conditions of more than 45% in an average relative humidity of 60.45% was observed. This study reveals that local environmental conditions, i.e., dust, rain, and partial cloud, significantly reduce PV power output.     

The performance analysis and evaluation of C‐PV/T aided power generation system

In this paper, a novel solar aided power generation (SAPG) hybrid system based on the structural characteristics of coal‐fired power generation is established. In this system, the extraction steam of No.8 low pressure heater is replaced by the hot water coming from a concentration‐photovoltaic/thermal (C‐PV/T) module. The extraction steam returns into the steam turbine to do work, which increases the output power. And the electricity from the parallel C‐PV/T module goes directly into the power grid, which increases the generated power. The C‐PV/T module coupled with coal‐fired power generation improves the solar energy efficiency and provides hot water. As a case study, the economic calculation is performed with actual operation data extracted from a 600‐MW coal‐fired unit. The results show that the total efficiency increased by 1.3%, the coal fuel consumption is lowered by 11 g/kW·h, and the investment recovery period is approximately 7 years. This study offers a theoretical support to the engineering demonstration.     

Temperature and wind speed impact on the efficiency of PV installations. Experience obtained from outdoor measurements in Greece

Although efficiency of photovoltaic (PV) modules is usually specified under standard test conditions (STC), their operation under real field conditions is of great importance for obtaining accurate prediction of their efficiency and power output. The PV conversion process, on top of the instantaneous solar radiation, depends also on the modules' temperature. Module temperature is in turn influenced by climate conditions as well as by the technical characteristics of the PV panels. Taking into consideration the extended theoretical background in the field so far, the current study is focused on the investigation of the temperature variation effect on the operation of commercial PV applications based on in-situ measurements at varying weather conditions. Particularly, one year outdoor data for two existing commercial (m-Si) PV systems operated in South Greece, i.e. an unventilated building-integrated (81 kW_p) one and an open rack mounted (150 kW_p) one, were collected and evaluated. The examined PV systems were equipped with back surface temperature sensors in order to determine module and ambient temperatures, while real wind speed measurements were also obtained for assessing the dominant effect of local wind speed on the PVs' thermal loss mechanisms. According to the results obtained, the efficiency (or power) temperature coefficient has been found negative, taking absolute values between 0.30%/°C and 0.45%/°C, with the lower values corresponding to the ventilated free-standing frames.     

Performance evaluation of water and air based PVT solar collector for hydrogen production application

This study aims to investigate the performance of the Photovoltaic Thermal (PVT) collector based hydrogen production system. For this purpose, a solar assisted water splitting system is fabricated. This system comprises the array of photovoltaic (PV) cells with 0.303 m² surface area, a spiral flow thermal collector with 12.7 mm outer diameter, 10.26 mm internal diameter, 10 m length copper tube and Hoffman voltameter. The results have been taken for three different mass flow rates (0.008, 0.01 and 0.011 kg/s) and compared with the reference PV module. This study results clearly show that the collector outlet temperature, output voltage and output power increase as the flow rate increases and the PV module temperature decreases with an increase of flow rate. The maximum thermal and electrical efficiency of 33.8% and 8.5% are observed for water based PVT solar collector with 0.011 kg/s flow rate at 12.00. It is also noted that the hydrogen yield rate increases significantly with an increase in flow rate. The highest hydrogen yields of 17.1 ml/min are obtained at a fluid flow rate of 0.011 kg/sec at 12.00.     

Insolation-oriented model of photovoltaic module using Matlab/Simulink

This paper presents a novel model of photovoltaic (PV) module which is implemented and analyzed using Matlab/Simulink software package. Taking the effect of sunlight irradiance on the cell temperature, the proposed model takes ambient temperature as reference input and uses the solar insolation as a unique varying parameter. The cell temperature is then explicitly affected by the sunlight intensity. The output current and power characteristics are simulated and analyzed using the proposed PV model. The model verification has been confirmed through an experimental measurement. The impact of solar irradiation on cell temperature makes the output characteristic more practical. In addition, the insolation-oriented PV model enables the dynamics of PV power system to be analyzed and optimized more easily by applying the environmental parameters of ambient temperature and solar irradiance.