聚光光伏系统的技术进展

首先介绍了聚光光伏系统的最新状况，包括标准、正在进行的项目和基本技术特点等，然后详细地介绍了聚光光伏系统各个组件的特点和最新发展，包括聚光系统、光伏转换系统和其它部分等，还对聚光系统的成本做了介绍，同时重点就散热器进行了说明，并列举了被动式和主动式散热的实例，最后对聚光光伏系统进行了展望，指出了主要应解决的问题。     

太阳能光伏聚光器技术进展

介绍了太阳能聚光光伏发电系统聚光器的分类、研究现状及国内外光伏聚光器的技术研究进展,指出了光伏聚光器研究中的难点,提出了光伏聚光器的发展方向,并对其发展前景进行了展望.     

聚光光伏发电国内外研究现状

从国内外聚光光伏发电技术的主要研究方向入手,分别介绍了聚光倍率、聚光器、太阳能跟踪方式、冷却与热管理系统4方面的研究现状,展望了太阳能聚光光伏技术的应用前景。     

国际太阳能发电产业现状及发展趋势

首先,描述了全球太阳能资源情况,总结了目前太阳能发电产业取得的成就,对太阳能光伏发电和聚光太阳能发电技术的发展进行了论述,从并网及分布式光伏的融资特点和资产证券化等方面对太阳能发电项目的融资方式进行了分析;其次,分析了太阳能发电产业面临的挑战,剖析了贸易保护主义对太阳能市场投资的影响,分析了太阳能发电对电网的挑战及环保等方面的问题;最后,着重从太阳能与储能相结合、太阳能发电平价上网、光伏在绿色建筑中的应用,以及分布式光伏发电市场情况等方面论述了国际太阳能产业的发展趋势。     

聚光型太阳能光伏遮阳系统应用研究

随着国内能源供需矛盾的日益突出,以太阳能光伏发电为代表的新能源产业将扮演解决能源危机的重要角色.在国内外光伏建筑一体化(BIPV)产业大背景下,研究如何提高太阳能光伏光电转换效率,降低系统成本,将成为未来很长一段时期光伏发电领域的重要课题.叙述了聚光型太阳能光伏技术与聚光型太阳能光伏遮阳系统的概念,分析了聚光型太阳能光...     

应用于聚光型太阳能电池的几种冷却技术

温度是影响太阳能电池光电转换效率的重要因素之一,在设计聚光型太阳能光伏发电系统时,必需考虑电池组件的温度控制.介绍了国内外聚光型太阳能电池的冷却技术研究成果,分析了目前常用的冷却方法,介绍了几种较有前途的新型冷却技术.     

聚光型太阳能光伏光热系统研究进展

聚光型太阳能光伏光热系统(CPV/T)在传统光伏发电系统的基础上增加了聚光系统和光热系统,在通过聚光系统提高光伏效率的同时将系统中多余的热量加以利用,以达到太阳能最大化利用的目的。本文介绍了CPV/T系统的工作原理及其能效影响因素,以直接影响系统太阳能综合利用效率的聚光器技术、光伏电池技术和光伏冷却技术作为分析对象,结合近几年国内外最新研究成果比较了不同类型聚光器、光伏电池以及冷却方式的优劣,列举了常见的光伏余热利用方式。分析认为:CPV/T系统虽然具有更高的太阳能利用率,但应加大对系统尤其是聚光器经济性的分析;考虑在系统中应用叠层光伏电池缓解聚光器带来的系统体积过大问题;新电池开发过程中应更注意光伏电池的温度系数以减少冷却系统的压力,冷却技术在强化散热的同时也应注意热量的收集方法及其与利用途径的有效结合。     

聚光光伏发电技术的研究

聚光光伏发电是新能源生产的先进技术,将其投入到实际发电作业中具有能源战略意义。结合聚光光伏发电项目前景,研究了砷化镓薄膜电池聚光发电系统技术,提出基于GPS系统的远程发电控制技术方案。     

蝶式光伏发电聚光器的研制

通过跟踪聚光的方法,增加太阳光伏电池板的光照强度,使得同样数量的光伏电池板产生更多电能,并大幅度降低光伏发电系统的成本。介绍了一种自动跟踪太阳的蝶式光伏发电聚光器及其聚光参数优化过程,在保证聚光器的机械强度时得到了最佳聚光比。     

屋顶型聚光光伏系统

介绍屋顶型聚光光伏系统的技术原理,对国内外相关企业的研究进展进行描述和归纳,从技术、政策、市场的可行性对该类产品进行分析和论述。     

A comprehensive study of dense-array concentrator photovoltaic system using non-imaging planar concentrator

A special modeling method using Simulink has been developed to analyze the electrical performance of dense-array concentrator photovoltaic (CPV) system. To optimize the performance of CPV system, we have adopted computational modeling method to design the best configuration of dense-array layout specially tailored for flux distribution profile of solar concentrator. It is an expeditious, efficient and cost effective approach to optimize any dense-array configuration for any solar concentrator. A prototype of non-imaging planar concentrator (NIPC) was chosen in this study for verifying the effectiveness of this method. Mismatch effects in dense array solar cells caused by non-uniform irradiance as well as sun-tracking error normally happens at the peripheral of the array. It is a crucial drawback that affects the electrical performance of CPV systems because maximum output power of the array is considerably reduced when a current–voltage (I–V) curve has many mismatch steps and thus leads to lower fill factor (FF) and conversion efficiency. The modeling method is validated by assembling, installing and field testing on an optimized configuration of solar cells with the NIPC prototype to achieve a conversion efficiency of 34.18%. The measured results are in close agreement with simulated results with a less than 3% deviation in maximum output power.     

具有均匀照度的高倍太阳能聚光器

利用非成像光学方法,设计了适用于聚光光伏系统的高倍聚光器。为了提高电池表面的照度均匀性,在设计中引入匀光器,并综合优化容忍角和光通过率等关键参数。设计完成的带有匀光器的TIR-R(Total Internal Reflection-Refraction)太阳能聚光器,可使电池表面光照最大强度不大于平均值的2倍,容忍角达到1.53°,聚光倍数为1256倍。仿真表明,太阳光发散角可改善光照均匀性,而聚光器材料色散则主要造成容忍角减小。     

Design and analysis of a CPV/T solar receiver with volumetric absorption combined spectral splitter

Spectral beam splitting is a promising technology to achieve the maximum electrical and thermal outputs from concentrating photovoltaic/thermal (CPV/T) systems simultaneously. In this article, a novel CPV/T receiver is proposed by incorporating a fluid based filter together with a solid absorptive filter. The geometry of the receiver is developed for a designed linear flat mirror concentrator. According to the optical transmittance of both fluid based filters and solid absorptive filters, as well as their corresponding merit functions, four fluid filters and two solid filters are determined to be the candidates of the combined filter for the silicon concentrator solar cell. Then, a complete solar radiation propagation process from concentrator to the designed CPV/T receiver is simulated using ray tracing software-LightTools. The results show that the surface illumination uniformity of the PV module filtered by each combined filter under the linear flat mirror concentrator is higher than 96%. Using 5 g/L CoSO₄ solution and HB650 as the combined filter, 33.67% of the concentrated light can be directed to the PV module with the remainder collected by the filter as thermal energy and the silicon CPV cells can convert 27.06% of this energy into electrical power. This contributes to the fact that 92.43% of the light striking the PV module is within 650-1100 nm, which is the spectral response range of the cell can work efficiently. The total efficiency of 49.88% can be achieved with such a filter and the electrical efficiency is 9.1% with respect to the total incident power on the receiver.     

Thermal management of concentrator photovoltaic systems using nano-enhanced phase change materials-based heat sink

Temperature regulation of concentrator photovoltaic systems is essential in reducing operating temperatures with higher system performance. A new nano-enhanced phase change material, with multi-cavity heat sinks, integrated with a concentrator photovoltaic (CPV) system is developed. The multi-cavity heat sink includes a single-, triple-, and quintuple-cavity configuration in both parallel and series pattern filled with n-octadecane PCM and graphene nanoparticle additives with 2% and 5 wt%. Numerical simulations are performed using the developed two-dimensional model for photovoltaic layers integrated with the nano-enhanced phase change material-based heat sink. The predicted results are compared with the available numerical results and measurements. Results indicate that increasing the number of parallel cavities, along with weight fraction of nanoparticles, significantly improves the thermal conductivity, and consequently attains better performance for the CPV system. Using a parallel quintuple-cavity configuration, with 5 wt% NPCM, achieves maximum reduction in the solar cell mean temperature along with the best temperature uniformity compared to other configurations. At a concentration ratio of 20, the thermal efficiency is 65%, the electrical efficiency is about 10%, and the output electrical power of the system is 235 W per m width of the cell. On the contrary, using a series pattern of the heat sink has an unfavorable effect on the mean solar cell temperature, as well as on electrical efficiency and thermal performance of the CPV system. The obtained result can assist in identifying the best possible design of the heat sink in addition to the most appropriate selection of PCM and nanoparticle additives.     

Electrical and thermal performance of silicon concentrator solar cells immersed in dielectric liquids

Direct liquid-immersion cooling of concentrator solar cells was proposed as a solution for receiver thermal management of concentrating photovoltaic (CPV) and hybrid concentrating photovoltaic thermal (CPV-T) systems. De-ionized (DI) water, isopropyl alcohol (IPA), ethyl acetate, and dimethyl silicon oil were selected as potential immersion liquids based on optical transmittance measurement results. Improvements to the electrical performance of silicon CPV cells were observed under a range of concentrations in the candidate dielectric liquids, arising from improved light collection and reduced cell surface recombination losses from surface adsorption of polar molecules. Three-dimensional numerical simulations with the four candidate liquids as the working fluids, exploring the thermal performance of a silicon CPV cell array in a liquid immersion prototype receiver, have been performed. Simulation results show that the direct-immersion cooling approach can maintain low and uniform cell temperature in the designed liquid immersion receiver. The fluid inlet velocity and flow mode, along with the fluid thermal properties, all have a significant influence on the cell array temperature.     

Extended description of tunnel junctions for distributed modeling of concentrator multi-junction solar cells

One of the key components of highly efficient multi-junction concentrator solar cells is the tunnel junction interconnection. In this paper, an improved 3D distributed model is presented that considers real operation regimes in a tunnel junction. This advanced model is able to accurately simulate the operation of the solar cell at high concentrations at which the photogenerated current surpasses the peak current of the tunnel junction. Simulations of dual-junction solar cells were carried out with the improved model to illustrate its capabilities and the results have been correlated with experimental data reported in the literature. These simulations show that, under certain circumstances, the solar cell's short circuit current may be slightly higher than the tunnel junction peak current without showing the characteristic dip in the J-V curve. This behavior is caused by the lateral current spreading toward dark regions, which occurs through the anode/p-barrier of the tunnel junction.     

Three-dimensional simulating of concentrator photovoltaic modules using ray trace and equivalent circuit simulators

A 3-dimensional (3D) simulation for a concentrator photovoltaic (CPV) module using a triple-junction solar cell was developed. By connecting ray-trace simulation for an optics model and 3D equivalent circuit simulation for a triple-junction solar cell, the operating characteristics of a CPV module were calculated. By using the 3D simulation, we considered the influence of tracking error on the CPV module. It was found that maximum output power was not correlated with optical efficiency of the optics system and was strongly dependent on fill factor. We can use this total 3D simulation for the evaluation and optimization of CPV modules.     

Operating characteristics of multijunction solar cells

Multijunction solar cells produced by Spectrolab are the most efficient solar cells in the world, with a record efficiency of over 40%. Cell designs have been modified for high performance in concentrator photovoltaic (CPV) systems with the potential for low-cost, high-volume manufacturing. High-performance CPV cells have been designed, tested, and entered into production for field testing in CPV systems. Performance under variable concentrations and temperatures has been characterized and compared to semiconductor theory. The cell response has been applied to a spectral irradiance model to predict field performance at reference locations. Cell qualification has been completed for the current-generation C1MJ design.     

Non-concentrating and asymmetric compound parabolic concentrating building façade integrated photovoltaics: An experimental comparison

Concentration of solar energy increases the illuminated flux on the photovoltaic (PV) surface thus less PV material is required. A novel asymmetric compound parabolic photovoltaic concentrator has been characterised experimentally with a similar non-concentrating system. Different numbers of PV strings connected within the system have been analysed and a power ratio of 1.62 measured compared to a similar non-concentrating PV panel with the same cell area. The solar to electrical conversion efficiency of 8.6% and 6.8% was achieved for the non-concentrating panel the concentrating system, respectively. The measured average solar cell temperature of the PV in the concentrator system was only 12 °C higher than that of the similar non-concentrating system with same cell area.