Life cycle assessment of high‐concentration photovoltaic systems

The environmental profiles of photovoltaic (PV) systems are becoming better as materials are used more efficiently in their production, and overall system performance improves. Our analysis details the material and energy inventories in the life cycle of high‐concentration PV systems, and, based on measured field‐performances, evaluates their energy payback times, life cycle greenhouse gas emissions, and usage of land and water. Although operating high‐concentration PV systems require considerable maintenance, their life cycle environmental burden is much lower than that of the flat‐plate c‐Si systems operating in the same high‐insolation regions. The estimated energy payback times of the Amonix 7700 PV system in operation at Phoenix, AZ, is only 0.9 year, and its estimated greenhouse gas emissions are 27 g CO₂‐eq./kWh over 30 years, or approximately 16 g CO₂‐eq./kWh over 50 years. Copyright © 2012 John Wiley & Sons, Ltd.     

Life prediction of HCPV under thermal cycling test condition

High-concentration photovoltaic (HCPV) module is subject to larger thermal stress due to its more severe temperature fluctuation in real operating conditions. In the thermal cycling test, excessive thermal stress might occur at the peripheral solder layer. For the large area bonding structure, thermal-induced stress is the main cause for cracks. Crack growth is expected to start from the edges of the solder layer and progress to the center. The shrinkage of the bonding area increases the junction temperature of solar cells and reduces the energy-conversion efficiency of the HCPV module. In this study, the stress/strain behavior of the HCPV module under thermal cycling test is analyzed using finite element analysis software, ANSYS®. Results indicate that the von Mises creep strain distribution at the solder layer’s edge is independent of the package’s dimensions. The lifetime of HCPV with uniform solder layer could be predicted by assuming that the crack propagation rate is constant during solder layer degradation. Furthermore, lifetime of tilted HCPV module could be predicted by compensating the variation of thickness of solder layer during crack propagation.     

两种用于HCPV/T的水冷换热器传热特性的对比实验研究

本文对两种适用于高倍聚光发电供热（HCPV/T）系统的多槽道和微通道水冷换热器进行了实验研究。利用模拟热源模拟了HCPV/T系统中光伏电池工作时的热流密度,分别研究了流量、壁面温度和输入电压对两种换热器传热特性的影响,并利用传热学理论对两种换热器的特点进行分析,获得了两种换热器努赛尔数Nu与雷诺数Re的拟合经验公式。实验结果表明,微通道换热器在低流量下有较强的换热能力,但在高流量下,换热能力无法随流量增大继续提高;多槽道换热器在低流量下换热能力不佳,但在高流量下仍可随流量增大继续提高。     

高聚光光伏发电系统和常规晶硅发电系统的对比实验

介绍了鄂尔多斯某产业园区安装高聚光光伏发电系统进行实地发电测试,通过对系统运行的跟踪、日照辐射强度和环境气温的检测以及对气候变化的观测,获取了大量的数据,并与晶硅平板发电系统作对比,结果显示具有很强的竞争优势。     

1MW高倍聚光光伏发电并网系统的设计

本文选云南石林地区为电站场址,通过对高倍聚光光伏组件选择、光伏阵列运行方式选择、光伏阵列设计及布置方案、并网逆变器选型等光伏发电系统构成方面进行了研究设计.分析得出该电站的理论年发电量为170.07万kWh,具有良好的经济效益和环保效益.     

高能流密度下太阳能密集光伏组件射流冲击冷却特性

针对高能流密度下密集阵列光伏组件的冷却控温问题,采用模块化阵列射流冲击装置实现电池控温。基于Fluent软件对密排光伏组件阵列射流冲击换热进行数值模拟,研究不同射流孔径、冲击间距比与射流孔长径比等关键参数对其电池冷却的影响特性,综合分析了质量流量和能流密度变化对其冷却效果和所获电能的影响规律。结果表明冲击间距比对电池的换热效果存在最优值,在本文范围内h3/d=4.5时换热效果最佳,但随着孔径的增大其换热均匀性有所下降;射流孔高度增大,换热效果和电池表面温度均匀性均降低;随着电池表面聚焦能量增加,其发电功率将成比例增加,而电池温度仅有小幅度升高;随着质量流量的合理增加,电池温度大幅度降低,且所产生的压降功耗基本不变。该文工作能为高倍聚光密集阵列光伏组件的高效均匀控温设计提供基础。     

Assessing the potential of concentrating solar photovoltaic generation in Brazil with satellite-derived direct normal irradiation

With the declining costs of flat plate and concentrating photovoltaic (PV) systems, solar PV generation in many sunny regions in Brazil will eventually become cost competitive with conventional and centralized power generation. Detailed knowledge of the local solar radiation resource becomes critical in assisting on the choice of the technology most suited for large-scale solar electricity generation. When assessing the energy generation potential of non-concentrating, fixed flat plate versus concentrating PV, sites with high levels of direct normal irradiation (DNI) can result in cost-competitive electricity generation with the use of high concentrating photovoltaic systems (HCPV). In large countries, where the transmission and distribution infrastructure costs and associated losses typical of centralized generation must be taken into account, the distributed nature of solar radiation should be perceived as a valuable asset. In this work we assess the potential of HCPV energy generation using satellite-derived DNI data for Brazil, a large and sunny country with a continental surface of 8.5 million km². The methodology used in the study involved the analysis of global horizontal, latitude-tilt, and direct normal solar irradiation data resulting from the Solar and Wind Energy Resource Assessment (SWERA) Project, and an estimate of the resulting electricity production potential, based on a review of HCPV generators operating at other sites. The satellite-derived solar irradiation data, with 10 km × 10 km spatial resolution, were analysed over the whole country, in order to identify the regions where HCPV might present a considerable advantage over fixed plate PV on an annual energy generation basis. Our results show that there is a considerable fraction of the national territory where the direct normal solar irradiation resource is up to 20% higher than the latitude-tilt irradiation availability. Furthermore, these sites are located in the most industrially-developed region of the country, and indicate that with the declining costs of this technology, distributed multi-megawatt HCPV can be a good choice of technology for solar energy generation at these sites in the near future.     

Energetic,economic, and environmental (3 E) performances of high concentrated photovoltaic large scale installations: Focus on spatial analysis of Morocco

Producing electricity from a renewable source is a major challenge in Morocco nowadays and high concentrated photovoltaic (HCPV) is becoming an attractive solution to ensure clean energy generation due to its high efficiency. The aim of this paper is to estimate the « Energetic, economic, and environmental » performances of large scale HCPV power plants in the major Moroccan climatic zones and to compare their feasibility to PV plants. The mathematical model for estimating the energetic, economic, and environmental performances of large scale HCPV plants is shown, sensitivity and comparison analysis are exhibited. Another goal of the paper is the optimization of the performances of the algorithm through the study of the effect of different parameters. Our major finding is that the large scale HCPV plants are more competitive than PV plants in Errachidia climatic zone where the (capacity factor, LCOE) take the values (26.07%,8.57c$/kWh). Moreover, the capacity factor of large scale HCPV power plants is the most sensitive to the temperature coefficient while the (LCOE_nominal, LCOE_real, NPV) are the most sensitive to the analysis period. The quantity of CO₂ mitigated reaches a maximal value in the Errachidia zone with 2.59 × 10⁵ tons of carbon per year avoided, and the cost of carbon gained there is estimated to be 10.4 M$. Innovative GIS maps of energetic, economic, and environmental performances of large scale HCPV power plants for all Morocco are given.