Practical Realization of a Hybrid Solution for Photovoltaic and Photothermal Conversion

In this paper, an idea and a realization of a hybrid Operational solar system is presented and practically verified discussed on the base of the performance and efficiency results, is confirmed. solution for photovoltaic and photothermal conversion is presented. by the series of experiments. Improvements of the construction are The synergy effect ofphotothermal and photovoltaic part cooperation

Optimal Sizing of Solar/Wind Hybrid Off-Grid Microgrids Using an Enhanced Genetic Algorithm

This paper presents a method for optimal sizing of an off-grid hybrid microgrid (MG) system in order to achieve a certain load demand. The hybrid MG is made of a solar photovoltaic (PV) system, wind turbine (TW) and energy storage system (ESS). The reliability of the MG system is modeled based on the loss of power supply probability (SPSP). For optimization, an enhanced Genetic Algorithm (GA) is used to minimize the total cost of the system over a 20-year period, while satisfying some reliability and operation constraints. A case study addressing optimal sizing of an off-grid hybrid microgrid in Nigeria is discussed. The result is compared with results obtained from the Brute Force and standard GA methods.

Performance Analysis of a Rooftop Hybrid Connected Solar PV System

In the present work,a 5-kW hybrid PV solar system was installed on the roof of a house in Diyala,Iraq(33.77°N,45.14°E elevation 44 m).The system consists of two strings,where each string consists of nine polycrystalline PV modules with 355 Wp in series,and the two strings are in parallel.The energy storage system(ESS)consists of two parallel strings,each with four 12 V and 150 Ah tubular deep cycle batteries in series.A hybrid inverter of 5 kW rated power was operated in different modes.The results showed that May’s monthly energy consumption was about 822.9 and 1085 kWh,respectively.The percentage distribution of the DC energy produced was about 1%system energy losses,27.9%was used to charge the ESS,34.3%was used to feed the grid,and the remaining 37.64%was used to share the load.The energy percentage sharing the load was 16.67%from ESS,33.33%from the PV system,and 50%purchased.The average daily reference,array,and final yields were 6.07,4.327,and 3.991 h/day,respectively.The average array and load efficiencies were 12.3%and 92.24%,with the performance ratio at 65.4%.

A switchable concentrating photovoltaic/concentrating solar power(CPV/CSP)hybrid system for flexible electricity/thermal generation

Due to the intermittency and indeterminacy of solar irradiance,balancing energy supply and load demand remains a challenge.This paper proposed a switchable hybrid system that combines concentrating photovoltaic/concentrating solar power(CPV/CSP)technology with thermal energy storage(TES)to achieve flexible electricity and thermal generation by adjusting the incident solar flux of photovoltaic(PV).The hybrid system can directly transfer surplus solar energy into high-quality heat for storage using a rotatable PV/heat receiver.The simulated results demonstrated that the hybrid system effectively improves power generation,optimally utilizes TES capacity,and reduces the levelized cost of electricity(LCOE).Over a selected seven-day period,the single-junction(1J)Ga As solar cells used in the hybrid system sustainably satisfied the load demand for more than five days without grid supplement,outperforming the CSP plant by an additional two days.The hybrid system utilizing the 1J Ga As with the base configuration of solar multiple(SM)of 1.26 and TES capacity of 5 h improved the annual power production and renewable penetration(RP)by 20.8%and 24.8%compared with the conventional CSP plant,respectively.The hybrid plant with monosilicon and a configuration of SM(1.8),PV ratio(1),and TES capacity(6 h)achieved an optimal LCOE of11.52$ct/k Wh and RP of 75.5%,which is 8.8%lower and 12.1%higher than the CSP plant,respectively.

基于EnergyPlus和Jeplus+EA联合模拟的建筑围护结构及光储系统协同优化研究

建筑本体和可再生能源系统的协同作用对于降低建筑碳排放具有重要意义.以北京某办公建筑为例,基于NSGA-Ⅱ的优化算法,以运行阶段碳排放和生命周期成本为目标函数,以热舒适为约束条件,利用EnergyPlus和Jeplus+EA软件进行联合仿真,开展建筑围护结构和光储系统的协同优化研究.结果表明:配置光储系统可较大程度降低建筑电网购电量及运行阶段碳排放,虽然生命周期成本会略有增加,但其减碳效果,大于单纯依靠围护结构性能提升的传统做法;尽可能利用建筑空间配置光伏对减少碳排放及生命周期成本都是有利的;通过软件联合模拟可实现建筑围护结构和光储系统的协同优化,且较于各自独立优化,能取得更好的设计方案.

A review of concentrated photovoltaic-thermal(CPVT) hybrid solar systems with waste heat recovery(WHR)

In conventional photovoltaic(PV) systems, a large portion of solar energy is dissipated as waste heat since the generating efficiency is usually less than 30%. As the dissipated heat can be recovered for various applications, the wasted heat recovery concentrator PV/thermal(WHR CPVT) hybrid systems have been developed. They can provide both electricity and usable heat by combining thermal systems with concentrator PV(CPV) module, which dramatically improves the overall conversion efficiency of solar energy.This paper systematically and comprehensively reviews the research and development of WHR CPVT systems. WHR CPVT systems with innovative design configurations, different theoretical evaluation models and experimental test processes for several implementations are presented in an integrated manner. We aim to provide a global point of view on the research trends, market potential, technical obstacles, and the future work which is required in the development of WHR CPVT technology. Possibly, it will offer a generic guide to the investigators who are interested in the study of WHR CPVT systems.

Optical analysis of a hybrid solar concentrating Photovoltaic /Thermal (CPV/T) system with beam splitting technique

A novel hybrid solar concentrating Photovoltaic/Thermal (CPV/T) system with beam splitting technique is presented. In this system, a beam splitter is used to separate the concentrated solar radiation into two parts: one for the PV power generation and the other for thermal utility. The solar concentrator is a flat Fresnel-type concentrator with glass mirror reflectors. It can concentrate solar radiation onto solar cells with high uniformity, which is beneficial to improving the efficiency of solar cells. The thermal receiver is separated to the solar cells, and therefore, the thermal fluid can be heated to a relatively high temperature and does not affect the performance of solar cells. A dimensionless model was developed for the performance analysis of the concentrating system. The effects of the main parameters on the performance of the concentrator were analyzed. The beam splitter with coating materials Nb2O3 /SiO2 was designed by using the needle optimization technique, which can reflect about 71% of the undesired radiation for silicon cell(1.1m < 3m) to the thermal receiver for thermal utility. The performance of this CPV/T system was also theoretically analyzed.

High-Performance Perovskite Quantum Dot Solar Cells Enabled by Incorporation with Dimensionally Engineered Organic Semiconductor

Perovskite quantum dots(PQDs)have been considered promising and effective photovoltaic absorber due to their superior optoelectronic properties and inherent material merits combining perovskites and QDs.However,they exhibit low moisture stability at room humidity(20-30%)owing to many surface defect sites generated by inefficient ligand exchange process.These surface traps must be re-passivated to improve both charge transport ability and moisture stability.To address this issue,PQD-organic semiconductor hybrid solar cells with suitable electrical properties and functional groups might dramatically improve the charge extraction and defect passivation.Conventional organic semiconductors are typically low-dimensional(1D and 2D)and prone to excessive self-aggregation,which limits chemical interaction with PQDs.In this work,we designed a new 3D star-shaped semiconducting material(Star-TrCN)to enhance the compatibility with PQDs.The robust bonding with Star-TrCN and PQDs is demonstrated by theoretical modeling and experimental validation.The Star-TrCN-PQD hybrid films show improved cubic-phase stability of CsPbI_(3)-PQDs via reduced surface trap states and suppressed moisture penetration.As a result,the resultant devices not only achieve remarkable device stability over 1000 h at 20-30%relative humidity,but also boost power conversion efficiency up to 16.0%via forming a cascade energy band structure.

Lanthanide-based downshifting layers tested in a solar car race

The mismatch between the AM1.5G spectrum and the photovoltaic (PV) cells absorption is one of the most limiting factors for PV performance.To overcome this constraint through the enhancement of solar energy harvesting,luminescent downshifting (LDS) layers are very promising to shape the incident sunlight and,thus,we report here the use of Tb^3+- and Eu^3+-doped organic-inorganic hybrid materials as LDS layers on Si PV cells.Electrical measurements on the PV cell,done before and after the deposition of the LDS layers,confirm the positive effect of the coatings on the cell’s performance in the UV spectral region.The maximum delivered power and the maximum absolute external quantum efficiency increased 14% and 27%,respectively.Moreover,a solar powered car race was organized in which the small vehicle containing the coated PV cells presented a relative increase of 9% in the velocity,when compared to that with the uncoated one.

Powertrain control of a solar photovoltaic-battery powered hybrid electric vehicle

This paper proposes a powertrain controller for a solar photovoltaic battery powered hybrid electric vehicle (HEV). The main objective of the proposed controller is to ensure better battery management, load regulation, and maximum power extraction whenever possible from the photovoltaic panels. The powertrain controller consists of two levels of controllers named lower level controllers and a high-level control algorithm. The lower level controllers are designed to perform individual tasks such as maximum power point tracking, battery charging, and load regulation. The perturb and observe based maximum power point tracking algorithm is used for extracting maximum power from solar photovoltaic panels while the battery charging controller is designed using a PI controller. A high-level control algorithm is then designed to switch between the lower level controllers based on different operating conditions such as high state of charge, low state of charge, maximum battery current, and heavy load by respecting the constraints formulated. The developed algorithm is evaluated using theoretical simula-tion and experimental studies. The simulation and experimental results are presented to validate the proposed technique.

Influence of Internal and External Parameters in Temperature of Hybrid PV/T Water Collector

The combination of photovoltaic system with a thermal to form the hybrid PVT （photovoltaic thermal）, which together will generate electricity and heat. This energy depends on the input that is to say the energy of solar radiation, temperature and speed wind and output which is the operating temperature of the system. This production also depends on the mode of heat removal. The authors present in this article; a study by a numerical simulation of the thermal behavior of a prototype hybrid sensor through the development of an energy balance that involves heat exchange between the different components of the hybrid sensor, and it will allow us to study the influence of internal and external parameters on the temperature variation in the different layers of the prototype PV/T studied.

考虑光热光伏混合电站内外双重电压安全的两阶段无功优化控制

针对实际运行的大规模光热光伏混合电站并网后面临的“内忧外患”电压问题,既受电站内部节点电压状态的影响,也受外部电网系统静态电压稳定状态的影响,提出一种考虑光热光伏混合电站内外双重电压安全的两阶段无功优化控制方法。首先,通过静态电压稳定裕度、节点电压均衡度和无功储备裕度3种指标表征混合电站电压安全状态。然后,结合小时级长时间尺度的光伏出力预测信息,在第I阶段实施有载变压器和电容器慢速调整。针对分钟级短时间尺度内的光伏出力波动,以混合电站内的光伏发电单元、光热发电单元和静止同步补偿器为第II阶段的优化控制对象,实现快速精细化电压调节。所提方法能有效避免全站设备频繁参与优化调整,从而提高控制效率。最后,通过测试系统验证分析结果表明:通过两阶段无功控制协调,所提方法能够抑制光伏出力的波动冲击,有效降低站内电压安全越限和失稳风险。

反向传播神经网络及其改进算法用于光伏MPPT的研究

研究了反向传播神经网络(BPNN)、粒子群优化反向传播神经网络(PSO-BPNN)、萤火虫优化反向传播神经网络(FA-BPNN),以及斐波那契优化反向传播神经网络(IM-FSM-BPNN)用于光伏组件在局部阴影下最大功率点的跟踪,以及上述算法在太阳能无人机中飞行光伏发电跟踪。结果首先表明,局部阴影下,IM-FSM-BPNN功率预测精度最低,跟踪时间最长,鲁棒性差,原因是控制参数多,依赖参数初始值。FA-BPNN功率预测精度最高且鲁棒性较好,原因是在训练过程中有效避免梯度消失的问题。其次,在样本数据量增加和太阳能无人机的应用中,发现FA-BPNN的预测效果好和IM-FSM-BPNN的局限性。最后,探讨了参数变化对预测结果的影响。IM-FSM-BPNN、PSO-BPNN和FA-BPNN较BPNN更适用于多样本数据预测,IM-FSM-BPNN相较于其他3种算法更适用于较小的学习率,4种算法的平均跟踪时间和功率平均预测精度随隐含层节点数震荡。

太阳能高效光伏热电-复合发电技术现状与展望

能源需求增加和环境污染问题日益严峻,能源结构转型是实现全球可持续发展的必然趋势。太阳能发电得益于其资源丰富、分布广泛、洁净无污染等优点而成为新能源利用的首选,太阳能发电包括太阳能光伏发电(PV)和太阳能光热发电(TE)2种,将光伏电池和热电材料互补集成,建立光伏-热电(PV-TE)复合发电系统成为研究重点。文章简要介绍PV-TE复合发电工作原理,总结近年来国内外PV-TE领域研究现状,包括复合发电方式具体存在的一些关键问题,并对未来发展方向做出展望。

光伏／光热(PVT)系统概况与评价

简要介绍了当前PVT系统的主要类型及其研究概况,分析了不同的PVT系统能源效率评价方法,并比较了PVT系统、PV系统和太阳集热器系统的经济性。通过案例分析,指出了影响PVT系统经济性的重要因素。

一种新型全铝扁盒式PV/T热水系统

将单晶硅光伏电池与全铝扁盒式太阳能热水器集热板通过特殊工艺粘结起来,制成了一套自然循环式光伏光热一体化(PV/T)系统,在利用太阳能发电的同时提供热水。于04年7月-10月在合肥地区进行了室外实验,测试并讨论了该系统以不同水量和不同初始水温运行时的光电光热性能。结果表明,当m/Ac>80kg/m2时,这种PV/T热水系统的发电效率在10.15%左右,热效率在50%左右,光电光热总效率可以达到60%左右,光电光热综合性能效率可以达到70%左右。相对于单纯的光伏系统或自然循环式太阳能热水系统,这种PV/T热水系统具有占地面积小、综合效率高等优点。

离网型户用风光互补发电系统的匹配

以内蒙古苏尼特右旗安装的一套离网型户用风光互补系统为例对系统的风电机组、光伏发电机组及系统的每月日均发电量进行了测试分析。结果表明,系统在风电机组发电量最低的7、8、9月仍能够保证用户需求,向用户稳定供电,不需再增加光伏组件。系统匹配性能良好,设计合理。

采用热管冷却技术的太阳能光伏电–热一体化系统性能分析

太阳能光伏电–热(photovoltaic-thermal,PV-T)一体化系统将光伏组件与太阳能热利用系统组合在一起,具有较高的太阳能综合利用效率。针对热管具有高效传热和均温性能的特点,提出一种采用热管冷却技术的太阳能光伏电-热一体化系统;基于光伏电池板传热过程特点及换热器的传热有效度——传热单元数(ε-NTU)法,对热管式PV-T系统的电池板温度、冷却流体出口温度以及系统电效率和热效率等热电转换性能进行了理论分析和计算。结果表明,热管式PV-T系统的电池温度变化幅度在2.5℃以内,系统电效率和热效率分别达到6.99%～7.46%和51.0%～63.2%。该文提出的理论方法为研究热管式PV-T系统热电转换性能提供了一种新的途径,可用来分析和讨论相关参数对热管式PV-T系统性能的影响。

新型PV/T太阳能利用复合系统的实验研究

为提高PV/T系统太阳能利用率,同时获得可利用的热水和电力,将铝合金背板型单晶硅光伏组件和自行设计制作的不锈钢扁盒式集热板相结合,用导热硅胶加以粘接制成新型光伏光热一体化(PV/T)复合系统,该系统实现了光伏组件与集热板之间良好的粘接性、绝缘性和热传导,并在昆明地区对系统进行测试,分析了系统在不同水箱水容量及不同天气工况下运行的光电光热性能。结果表明,系统在75kg水箱水容量(m)晴天工况下运行效率更高,系统的平均电效率、热效率、综合效率及综合性能效率分别在14%、37%、51%、70.72%左右,与系统在50kg水箱水容量晴天或75kg水箱水容量多云工况下运行相比,综合性能效率约提高了11.86%或2.09%。与独立的光热或光伏系统相比,具有占地面积小、太阳能利用率高、更经济等优势。

太阳能电热联用系统研究进展

首先对太阳能电热联用系统的基本组成形式进行了简要介绍,并对不同的电热联用集热器、热能利用 方式进行了对比分析,接着对电热联用的研究方法和发展现状进行了详细说明,并列举了一些电热联用产品和 示范工程,最后指出了电热联用发展中应解决的问题,并对其发展前景进行了展望。