International Journal of Photoenergy The latest articles from Hindawi Publishing Corporation © 2015 , Hindawi Publishing Corporation . All rights reserved. Efficacy of the Reactive Oxygen Species Generated by Immobilized TiO2 in the Photocatalytic Degradation of Diclofenac Wed, 27 May 2015 09:54:55 +0000 We report on the photodegradation of diclofenac (DCF) by hydrothermal anatase nanocrystals either free or immobilized in porous silica matrix (TS) in connection to the type and amount of reactive oxygen species (ROS), in order to have deeper insight into their role in the photocatalysis and to provide an effective tool to implement the DCF mineralization. TiO2 and TS exhibit a remarkable efficiency in the DCF abatement, supporting that the utilization of anatase nanoparticles with the highly reactive , , and exposed surfaces can be an effective way for enhancing the photooxidation even of the persistent pollutants. Furthermore, the hydrothermal TiO2, when immobilized in silica matrix, preserves its functional properties, combining high photoactivity with an easy technical use and recovery of the catalyst. The catalysts performances have been related to the presence of OH•, , and species by electron paramagnetic resonance spin-trap technique. The results demonstrated that the ROS concentration increases with the increase of photoactivity and indicated a significant involvement of in the DCF degradation. The efficacy of TiO2 when immobilized on a silica matrix was associated with the high ROS life time and with the presence of singlet oxygen, which contributes to the complete photomineralization of DCF. B. Di Credico, I. R. Bellobono, M. D’Arienzo, D. Fumagalli, M. Redaelli, R. Scotti, and F. Morazzoni Copyright © 2015 B. Di Credico et al. All rights reserved. Coordinated Control of PV Generation and EVs Charging Based on Improved DECell Algorithm Mon, 25 May 2015 14:21:08 +0000 Recently, the coordination of EVs’ charging and renewable energy has become a hot research all around the globe. Considering the requirements of EV owner and the influence of the PV output fluctuation on the power grid, a three-objective optimization model was established by controlling the EVs charging power during charging process. By integrating the meshing method into differential evolution cellular (DECell) genetic algorithm, an improved differential evolution cellular (IDECell) genetic algorithm was presented to solve the multiobjective optimization model. Compared to the NSGA-II and DECell, the IDECell algorithm showed better performance in the convergence and uniform distribution. Furthermore, the IDECell algorithm was applied to obtain the Pareto front of nondominated solutions. Followed by the normalized sorting of the nondominated solutions, the optimal solution was chosen to arrive at the optimized coordinated control strategy of PV generation and EVs charging. Compared to typical charging pattern, the optimized charging pattern could reduce the fluctuations of PV generation output power, satisfy the demand of EVs charging quantity, and save the total charging cost. Guo Zhao, Xueliang Huang, and Hao Qiang Copyright © 2015 Guo Zhao et al. All rights reserved. Effects of Dopant Metal Variation and Material Synthesis Method on the Material Properties of Mixed Metal Ferrites in Yttria Stabilized Zirconia for Solar Thermochemical Fuel Production Mon, 25 May 2015 11:31:22 +0000 Mixed metal ferrites have shown much promise in two-step solar-thermochemical fuel production. Previous work has typically focused on evaluating a particular metal ferrite produced by a particular synthesis process, which makes comparisons between studies performed by independent researchers difficult. A comparative study was undertaken to explore the effects different synthesis methods have on the performance of a particular material during redox cycling using thermogravimetry. This study revealed that materials made via wet chemistry methods and extended periods of high temperature calcination yield better redox performance. Differences in redox performance between materials made via wet chemistry methods were minimal and these demonstrated much better performance than those synthesized via the solid state method. Subsequently, various metal ferrite samples (NiFe2O4, MgFe2O4, CoFe2O4, and MnFe2O4) in yttria stabilized zirconia (8YSZ) were synthesized via coprecipitation and tested to determine the most promising metal ferrite combination. It was determined that 10 wt.% CoFe2O4 in 8YSZ produced the highest and most consistent yields of O2 and CO. By testing the effects of synthesis methods and dopants in a consistent fashion, those aspects of ferrite preparation which are most significant can be revealed. More importantly, these insights can guide future efforts in developing the next generation of thermochemical fuel production materials. Jeffrey Leonard, Nichole Reyes, Kyle M. Allen, Kelvin Randhir, Like Li, Nick AuYeung, Jeremy Grunewald, Nathan Rhodes, Michael Bobek, and James F. Klausner Copyright © 2015 Jeffrey Leonard et al. All rights reserved. The Synergistic Effect of Thermal Collectors Rotation in relation to Their Energy Efficiency and Stagnation Compared with the Static Thermal System in the Conditions of Central Europe Mon, 25 May 2015 09:36:39 +0000 The presented paper deals with the issue of the efficient use of solar energy potential gained from thermal panels via tracking the Sun’s trajectory. Based on long-term measurements of the selected parameters, the efficiency of the installed system in relation to the ecliptic was evaluated in the static regime as well as in a rotary regime. In the comparison of rotary and fixed system of the collectors the presented results show an increase of the effectiveness of rotary one during the period of the day. On closer view the increase is not constant. During the day it varies: the most significant increase is in the afternoon, while the time from 10:30 a.m. to 1:00 p.m. the effectiveness of both systems almost identical. The utilisation of the rotary system as a suitable instrument for the elimination of the system stagnation was also evaluated. Miroslav Rimar, Marcel Fedak, Michal Hatala, and Peter Smeringai Copyright © 2015 Miroslav Rimar et al. All rights reserved. Enhanced Photoreduction Activity of Carbon Dioxide over Co3O4/CeO2 Catalysts under Visible Light Irradiation Thu, 21 May 2015 07:50:40 +0000 A series of new two semiconductor catalysts, Co3O4/CeO2, were prepared by glycine-nitrate combustion method for photocatalytic reduction of carbon dioxide to produce methanol and ethanol under visible light ( nm) irradiation. The catalysts were characterized by BET, UV-vis spectra, XRD, SEM, PL, and XPS and the results indicated that the catalyst with 5 wt.% of Co3O4 has the highest yield among all kinds of tests with the methanol yield of 1.52 μmol·g−1·h−1 and the ethanol yield of 4.75 μmol·g−1·h−1, which are about 2.34 and 1.71 times as large as those of CeO2. However, methanol and ethanol can hardly be detected for Co3O4 under the same condition because of its too narrow band gap. The improvement of the photoreduction activity of Co3O4 doped CeO2 was caused by the separation of electron-hole pairs of Co3O4/CeO2 and charge transfer between Co3O4 and CeO2, mimicking the Z-scheme in photosynthesis. Ying Huang, Chang-Feng Yan, Chang-Qing Guo, and Shi-Lin Huang Copyright © 2015 Ying Huang et al. All rights reserved. Enhanced Photocatalytic Activity of BiOBr/ZnO Heterojunction Semiconductors Prepared by Facile Hydrothermal Method Wed, 13 May 2015 09:33:35 +0000 Hexagonal wurtzite pure ZnO and BiOBr-ZnO composites were synthesized by facile hydrothermal method. The amount of BiOBr as dopant was adjusted from 5 wt.% to 75 wt.%, and correspondingly the morphologies and crystal structures of the as-prepared composites were measured and discussed. Specifically, according to XRD patterns and SEM images, the main crystalline structure of ZnO was not destroyed after doping, but growth of ZnO crystals was inhibited by doping BiOBr. Meanwhile, the optical properties of the composites were measured by the diffuse reflectance spectra (DRS). The band gap of composites was also calculated using the classical Tauc equation and it was found to be around 3.0 eV. In the test of photocatalytic activation, the ZnO-BiOBr photocatalysts exhibited high photocatalytic efficiencies in the degradation of Rhodamine B (RhB) under visible-light irradiation. It was ascribed to not only the small size of crystalline, but also the reduction in the recombination rate of the photogenerated carriers for the enhancement effect of p-n heterojunction. This work sheds light on improving the photocatalytic performance by establishing the heterojunction and contributes to the development of a commercially competitive photocatalyst. Xiangchao Meng, Lingyun Jiang, Weiwen Wang, and Zisheng Zhang Copyright © 2015 Xiangchao Meng et al. All rights reserved. Analysis of Power Loss for Crystalline Silicon Solar Module during the Course of Encapsulation Mon, 27 Apr 2015 13:00:05 +0000 During the course of solar module encapsulation, the output power of crystalline silicon solar module is less than the sum of the maximum output power of the constituents because of power loss. So it is very important to investigate the power loss caused by encapsulation materials and module production process. In this paper, the power loss of crystalline silicon solar module is investigated by experiments systematically for the first time. It is found that the power loss is mainly caused by the resistance of ribbon and mismatch of solar cells; the total power loss is as high as 3.93% for solar module composed of 72 cells (125 mm × 125 mm) connected in series. Analyzing and reducing the power losses are beneficial to optimizing encapsulation process for the solar module. The results presented in this study give out a direction to decreasing power loss and optimizing encapsulation process of crystalline silicon solar module. Hong Yang, He Wang, Dingyue Cao, Dangmin Sun, and Xiaobao Ju Copyright © 2015 Hong Yang et al. All rights reserved. Solar Cells: From Sunlight into Electricity Mon, 27 Apr 2015 09:53:05 +0000 Serap Günes, M. S. A. Abdel-Mottaleb, Harald Hoppe, and Daniel Ayuk Mbi Egbe Copyright © 2015 Serap Günes et al. All rights reserved. Influence of Substrate on Crystal Orientation of Large-Grained Si Thin Films Formed by Metal-Induced Crystallization Thu, 23 Apr 2015 14:20:57 +0000 Producing large-grained polycrystalline Si (poly-Si) film on glass substrates coated with conducting layers is essential for fabricating Si thin-film solar cells with high efficiency and low cost. We investigated how the choice of conducting underlayer affected the poly-Si layer formed on it by low-temperature (500°C) Al-induced crystallization (AIC). The crystal orientation of the resulting poly-Si layer strongly depended on the underlayer material: (100) was preferred for Al-doped-ZnO (AZO) and indium-tin-oxide (ITO); (111) was preferred for TiN. This result suggests Si heterogeneously nucleated on the underlayer. The average grain size of the poly-Si layer reached nearly 20 µm for the AZO and ITO samples and no less than 60 µm for the TiN sample. Thus, properly electing the underlayer material is essential in AIC and allows large-grained Si films to be formed at low temperatures with a set crystal orientation. These highly oriented Si layers with large grains appear promising for use as seed layers for Si light-absorption layers as well as for advanced functional materials. Kaoru Toko, Mitsuki Nakata, Atsushi Okada, Masato Sasase, Noritaka Usami, and Takashi Suemasu Copyright © 2015 Kaoru Toko et al. All rights reserved. Heterovalent Cation Substitutional and Interstitial Doping in Semiconductor Sensitizers for Quantum Dot Cosensitized Solar Cell Thu, 23 Apr 2015 07:53:19 +0000 Doped films of TiO2/PbS/CdS have been prepared by successive ionic layer adsorption and reaction (SILAR) method. Bi- and Ag-doped-PbS quantum dot (QD) were produced by admixing Bi3+ or Ag+ during deposition and the existing forms of the doping element in PbS QD were analyzed. The results show that Bi3+ entered the cube space of PbS as donor yielding interstitial doping Bi-doped-PbS QD, while Ag+ replaced Pb2+ of PbS as acceptor yielding substitutional doping Ag-doped-PbS QD. The novel Bi-doped-PbS/CdS and Ag-doped-PbS/CdS quantum dot cosensitized solar cell (QDCSC) were fabricated and power conversion efficiency (PCE) of 2.4% and 2.2% was achieved, respectively, under full sun illumination. Ningning Zhang, Xiaoping Zou, and Yanyan Gao Copyright © 2015 Ningning Zhang et al. All rights reserved. Homogenized Poly(3-hexylthiophene)/Methanofullerene Film by Addition of End-Functionalized Compatibilizer and Its Application to Polymer Solar Cells Thu, 23 Apr 2015 06:53:31 +0000 A uniformed poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) blended film prepared by using spin-coating process is achieved by addition of 10% hydroxyl group end-functionalized P3HT (HOC-P3HT-COH) as a compatibilizer. Ratio of P3HT/PCBM on a spin-coated film has been improved from 1 : 1.22 on the edge and 1 : 0.85 in the center of substrate (substrate size, 2 cm × 3 cm) to 1 : 1.03 on the edge and 1 : 0.94 in the center for P3HT/HOC-P3HT-COH/PCBM film (1 : 0.1 : 1). Homogeneous and reproducible polymer solar cell with an average of 3.71% power conversion efficiency under AM1.5G irradiation is fabricated with 10% HOC-P3HT-COH in P3HT/PCBM layer. Ping-Tsung Huang, Yi-Hao Chen, Bo-Yu Lin, and Wei-Ping Chuang Copyright © 2015 Ping-Tsung Huang et al. All rights reserved. Influence of Surface Morphology on the Effective Lifetime and Performance of Silicon Heterojunction Solar Cell Thu, 23 Apr 2015 06:48:49 +0000 Different etching times are used to etch silicon wafers. Effects of surface morphology on wafer minority carrier lifetime, passivation quality, and heterojunction solar cell (HJ) performance are investigated. The numbers of mountains and valleys, defined as turning points, on wafer surfaces are used to explain the minority carrier lifetime variations. For a wafer with a smaller amount of turning points, hydrogenated amorphous silicon (a-Si:H) passivation quality can be comparable to ideal iodine-ethanol solution passivation. If the wafer has a notable amount of turning points, the carrier lifetime decreases as the a-Si:H layer will not be able to be well-deposited on turning points. Furthermore, the PC1D simulation indicates that an optimal device conversion efficiency of 21.94% can be achieved at an etching time of 60 min, where a best combination of short-circuit current and open-circuit voltage is obtained. Shui-Yang Lien, Yun-Shao Cho, Yan Shao, Chia-Hsun Hsu, Chia-Chi Tsou, Wei Yan, Pin Han, and Dong-Sing Wuu Copyright © 2015 Shui-Yang Lien et al. All rights reserved. Optimization of Solar Module Encapsulant Lamination by Optical Constant Determination of Ethylene-Vinyl Acetate Thu, 23 Apr 2015 06:38:30 +0000 This investigation elucidates the physical properties of ethylene-vinyl acetate (EVA) used in the lamination process of module encapsulation and the module performance from the optical transmission to the photoelectric power. In module encapsulation, the effects of the lamination parameters on the module performance, transmittance, and stack adhesion have been considered as they were found to influence the reliability of the module. The determination of the optical constants of EVA may serve as a nondestructive analytical method for optimizing the module encapsulation, on the basis of its effects on the optical transmittance, gel content, peel strength, and performance power. Bing-Mau Chen, Cheng-Yu Peng, Ju-Lu Cho, and Glen Andrew Porter Copyright © 2015 Bing-Mau Chen et al. All rights reserved. Development and Prospect of Nanoarchitectured Solar Cells Thu, 23 Apr 2015 06:24:58 +0000 This paper gives an overview of the development and prospect of nanotechnologies utilized in the solar cell applications. Even though it is not clearly pointed out, nanostructures indeed have been used in the fabrication of conventional solar cells for a long time. However, in those circumstances, only very limited benefits of nanostructures have been used to improve cell performance. During the last decade, the development of the photovoltaic device theory and nanofabrication technology enables studies of more complex nanostructured solar cells with higher conversion efficiency and lower production cost. The fundamental principles and important features of these advanced solar cell designs are systematically reviewed and summarized in this paper, with a focus on the function and role of nanostructures and the key factors affecting device performance. Among various nanostructures, special attention is given to those relying on quantum effect. Bo Zhang, Wenxu Xie, and Yong Xiang Copyright © 2015 Bo Zhang et al. All rights reserved. Synthesis, Analysis, and Testing of BiOBr-Bi2WO6 Photocatalytic Heterojunction Semiconductors Mon, 20 Apr 2015 14:26:44 +0000 In photocatalysis, the recombination of electron-hole pairs is generally regarded as one of its most serious drawbacks. The synthesis of various composites with heterojunction structures has increasingly shed light on preventing this recombination. In this work, a BiOBr-Bi2WO6 photocatalytic heterojunction semiconductor was synthesized by the facile hydrothermal method and applied in the photocatalytic degradation process. It was determined that both reaction time and temperature significantly affected the crystal structure and morphologies of the photocatalysts. BiOBr (50 at%)-Bi2WO6 composites were prepared under optimum synthesis conditions (120°C for 6 h) and by theoretically analyzing the DRS results, it was determined that they possessed the suitable band gap (2.61 eV) to be stimulated by visible-light irradiation. The photocatalytic activities of the as-prepared photocatalysts were evaluated by the degradation of Rhodamine B (RhB) under visible-light irradiation. The experimental conditions, including initial concentration, pH, and catalyst dosage, were explored and the photocatalysts in this system were proven stable enough to be reused for several runs. Moreover, the interpreted mechanism of the heterojunction enhancement effect proved that the synthesis of a heterojunction structure provided an effective method to decrease the recombination rate of the electron-hole pairs, thereby improving the photocatalytic activity. Xiangchao Meng and Zisheng Zhang Copyright © 2015 Xiangchao Meng and Zisheng Zhang. All rights reserved. Design of Incremental Conductance Sliding Mode MPPT Control Applied by Integrated Photovoltaic and Proton Exchange Membrane Fuel Cell System under Various Operating Conditions for BLDC Motor Sun, 19 Apr 2015 17:04:12 +0000 This paper proposes an integrated photovoltaic (PV) and proton exchange membrane fuel cell (PEMFC) system for continuous energy harvesting under various operating conditions for use with a brushless DC motor. The proposed scheme is based on the incremental conductance (IncCond) algorithm combined with the sliding mode technique. Under changing atmospheric conditions, the energy conversion efficiency of a PV array is very low, leading to significant power losses. Consequently, increasing efficiency by means of maximum power point tracking (MPPT) is particularly important. To manage such a hybrid system, control strategies need to be established to achieve the aim of the distributed system. Firstly, a Matlab/Simulink based model of the PV and PEMFC is developed and validated, as well as the incremental conductance sliding (ICS) MPPT technique; then, different MPPT algorithms are employed to control the PV array under nonuniform temperature and insolation conditions, to study these algorithms effectiveness under various operating conditions. Conventional techniques are easy to implement but produce oscillations at MPP. Compared to these techniques, the proposed technique is more efficient; it produces less oscillation at MPP in the steady state and provides more precise tracking. Jehun Hahm, Hyoseok Kang, Jaeho Baek, Heejin Lee, and Mignon Park Copyright © 2015 Jehun Hahm et al. All rights reserved. Technoeconomical Assessment of Optimum Design for Photovoltaic Water Pumping System for Rural Area in Oman Thu, 16 Apr 2015 13:22:16 +0000 Photovoltaic (PV) systems have been used globally for a long time to supply electricity for water pumping system for irrigation. System cost drops down with time since PV technology, efficiency, and design methodology have been improved and cost of wattage drops dramatically in the last decade. In the present paper optimum PV system design for water pumping system has been proposed for Oman. Intuitive and numerical methods were used to design the system. HOMER software as a numerical method was used to design the system to come up with optimum design for Oman. Also, REPS.OM software has been used to find the optimum design based on hourly meteorological data. The daily solar energy in Sohar was found to be 6.182 kWh/m2·day. However, it is found that the system annual yield factor is 2024.66 kWh/kWp. Furthermore, the capacity factor was found to be 23.05%, which is promising. The cost of energy and system capital cost has been compared with that of diesel generator and systems in literature. The comparison shows that the cost of energy is 0.180, 0.309, and 0.790 USD/kWh for PV-REPS.OM, PV-HOMER, and diesel systems, respectively, which sound that PV water pumping systems are promising in Oman. Hussein A. Kazem, Ali H. A. Al-Waeli, Atma H. K. Al-Kabi, and Asma Al-Mamari Copyright © 2015 Hussein A. Kazem et al. All rights reserved. Sb2S3 Quantum-Dot Sensitized Solar Cells with Silicon Nanowire Photoelectrode Tue, 07 Apr 2015 12:55:55 +0000 We propose a novel quantum-dot sensitized solar cell (QDSSC) structure that employs a quantum dot/semiconductor silicon (QD/Si) coaxial nanorod array to replace the conventional dye/TiO2/TCO photoelectrode. We replaced the backlight input mode with top-side illumination and used a quantum dot to replace dye as the light-absorbing material. Photon-excited photoelectrons can be effectively transported to each silicon nanorod and conveyed to the counter electrode. We use two-stage metal-assisted etching (MAE) to fabricate the micro-nano hybrid structure on a silicon substrate. We then use the chemical bath deposition (CBD) method to synthesize a Sb2S3 quantum dot on the surface of each silicon nanorod to form the photoelectrode for the quantum dot/semiconductor silicon coaxial nanorod array. We use a xenon lamp to simulate AM 1.5 G (1000 W/m2) sunlight. Then, we investigate the influence of different silicon nanorod arrays and CBD deposition times on the photoelectric conversion efficiency. When an NH (N-type with high resistance) silicon substrate is used, the QD/Si coaxial nanorod array synthesized by three runs of Sb2S3 deposition shows the highest photoelectric conversion efficiency of 0.253%. The corresponding short-circuit current density, open-circuit voltage, and fill factor are 5.19 mA/cm2, 0.24 V, and 20.33%, respectively. You-Da Hsieh, Ming-Way Lee, and Gou-Jen Wang Copyright © 2015 You-Da Hsieh et al. All rights reserved. Characterization of Organic Thin Film Solar Cells of PCDTBT : PC71BM Prepared by Different Mixing Ratio and Effect of Hole Transport Layer Tue, 07 Apr 2015 12:51:23 +0000 The organic thin film solar cells (OTFSCs) have been successfully fabricated using PCDTBT : PC71BM with different mixing ratios (1 : 1 to 1 : 8) and the influence of hole transport layer thickness (PEDOT : PSS). The active layers with different mixing ratios of PCDTBT : PC71BM have been fabricated using o-dichlorobenzene (o-DCB). The surface morphology of the active layers and PEDOT : PSS layer with different thicknesses were characterized by AFM analysis. Here, we report that the OTFSCs with high performance have been optimized with 1 : 4 ratios of PCDTBT : PC71BM. The power conversion efficiency (PCE = 5.17%) of the solar cells was significantly improved by changing thickness of PEDOT : PSS layer. The thickness of the PEDOT : PSS layer was found to be of significant importance; the thickness of the PEDOT : PSS layer at 45 nm (higher spin speed 5000 rpm) shows higher short circuit current density () and lower series resistance () and higher PCE. Vijay Srinivasan Murugesan, Shusuke Ono, Norio Tsuda, Jun Yamada, Paik-Kyun Shin, and Shizuyasu Ochiai Copyright © 2015 Vijay Srinivasan Murugesan et al. All rights reserved. Prediction of a New Phase of CuxS near Stoichiometric Composition Sun, 05 Apr 2015 11:33:10 +0000 Cu2S is known to be a promising solar absorber material due to its suitable band gap and the abundance of its constituent elements. Cu2S is known to have complex phase structures depending on the concentration of Cu vacancies. Its instability of phases is due to favorable formation of Cu vacancies and the mobility of Cu atoms within the crystal. Understanding its phase structures is of crucial important for its application as solar absorber material. In this paper, we have predicted a new crystal phase of copper sulfide (CuxS) around chemical composition of by utilizing crystal database search and density functional theory. We have shown that this new crystal phase of CuxS is more favorable than low chalcocite structure even at stoichiometric composition of . However, Cu vacancy formation probability was found to be higher in this new phase than the low chalcocite structure. Prashant Khatri and Muhammad N. Huda Copyright © 2015 Prashant Khatri and Muhammad N. Huda. All rights reserved. Phototreatment of Water by Organic Photosensitizers and Comparison with Inorganic Semiconductors Sun, 05 Apr 2015 07:18:21 +0000 Phototreatment of water is drawing the attention of many as a promising alternative to replace methods like chlorination, ozonization, and other oxidation processes, used in current disinfection methods limiting harmful side-products and by-products that can cause damage to the fauna and flora. Porphyrins, phthalocyanines, and other related organic dyes are well known for their use in photodynamic therapy (PDT). These photosensitizers cause cell death by generating reactive oxygen species (ROS) especially singlet oxygen in the presence of light. Such molecules are also being explored for photodynamically treating microbial infections, killing of unwanted pathogens in the environment, and oxidation of chemical pollutants. The process of photosensitisation (phototreatment) can be applied for obtaining clean, microbe-free water, thus exploiting the versatile properties of photosensitizers. This review collects the various attempts carried out for phototreatment of water using organic photosensitizers. For comparison, some reports of semiconductors (especially TiO2) used in photocatalytic treatment of water are also mentioned. Merlyn Thandu, Clara Comuzzi, and Daniele Goi Copyright © 2015 Merlyn Thandu et al. All rights reserved. Formation of Silicon Carbide Using Volcanic Ash as Starting Material and Concentrated Sunlight as Energy Resource Mon, 30 Mar 2015 06:18:03 +0000 SiC was formed using volcanic ash as starting material and concentrated sunlight as energy resource. The solar furnace was composed of two parts: Fresnel lens and reacting furnace. The reacting furnace was composed of a cylindrical vacuum chamber and quartz glass plate functioning to guide the concentrated sunlight into the furnace and was placed at the focal point of the Fresnel lens. The sample was made from the mixture of silica formed from volcanic ash and graphite and placed in the carbon crucible inside the reacting furnace. The temperature in the carbon crucible reached more than 1500°C. After the reaction using concentrated light, β-SiC was formed. The weight % of formed SiC was 90.5%. Kensuke Nishioka, Junki Komori, Kouji Maeda, Yasuyuki Ota, Hiroshi Kaneko, and Kosei Sato Copyright © 2015 Kensuke Nishioka et al. All rights reserved. Investigation of Photovoltaic Assisted Misting System Application for Arbor Refreshment Thu, 26 Mar 2015 12:20:42 +0000 In this study, for the first time in the literature, solar assisted cooler with misting system established on an arbor with an area of 24 m2 and georeferenced in Elazig (38.6775° N, 39.1707° E), Turkey, is presented. Here, we present a system that reduces interior temperature of the arbor while increasing humidity. Also, the system generates required electricity with a solar photovoltaic module to power pressurized water pump through an inverter and stores it in a battery for use when there is no sunlight. The model of the photovoltaic module was implemented using a Matlab program. As a result of being an uncomplicated system, return on investment for the system is 3.7 years. Hikmet Esen and Omer Tuna Copyright © 2015 Hikmet Esen and Omer Tuna. All rights reserved. An Adaptive Photovoltaic Topology to Overcome Shading Effect in PV Systems Wed, 25 Mar 2015 08:37:28 +0000 Shading in photovoltaic systems can cause many undesired effects. When shading occurs, the power generated from the PV system is much less than nominal power, increasing the electrical mismatching losses between PV system components. Active research to address this power loss focuses on static and adaptive systems. This paper addresses an adaptive system solution and proposes a new method to adaptively overcome losses due to shading during low radiation conditions. In addition, a statistical analysis for choosing the most feasible and efficient configuration for the system size is presented. The proposed system has been validated under shade conditions in a simulation and prototype experiment. The experiments are conducted using a PV system consisting of 10 PV modules located at the Petroleum Institute in the United Arab Emirates. The proposed system is shown to minimize the shading losses of the PV array in real time by an average of 100% under simulated conditions and 84% in practical experiments. Mohamed Amer Chaaban, Lana El Chaar, and Mahmoud Alahmad Copyright © 2015 Mohamed Amer Chaaban et al. All rights reserved. A New Energy Management Technique for PV/Wind/Grid Renewable Energy System Wed, 25 Mar 2015 06:21:09 +0000 An intelligent energy management system (IEMS) for maintaining the energy sustainability in renewable energy systems (RES) is introduced here. It consists of wind and photovoltaic (PV) solar panels are established and used to test the proposed IEMS. Since the wind and solar sources are not reliable in terms of sustainability and power quality, a management system is required for supplying the load power demand. The power generated by RES is collected on a common DC bus as a renewable green power pool to be used for supplying power to loads. The renewable DC power bus is operated in a way that there is always a base power available for permanent loads. Then the additional power requirement is supplied from either wind or PV or both depending upon the availability of these power sources. The decision about operating these systems is given by an IEMS with fuzzy logic decision maker proposed in this study. Using the generated and required power information from the wind/PV and load sides, the fuzzy reasoning based IEMS determines the amount of power to be supplied from each or both sources. Besides, the IEMS tracks the maximum power operating point of the wind energy system. Onur Ozdal Mengi and Ismail Hakki Altas Copyright © 2015 Onur Ozdal Mengi and Ismail Hakki Altas. All rights reserved. Synergetic Enhancement of Device Efficiency in Poly(3-hexylthiophene-2,5-diyl)/[6,6]-phenyl C61 Butyric Acid Methyl Ester Bulk Heterojunction Solar Cells by Glycerol Addition in the Active Layer Tue, 24 Mar 2015 13:43:27 +0000 Poly(3-hexylthiophene-2,5-diyl)(P3HT):[6,6]-phenyl-C61-butyric acid methyl ester (PC60BM) is the widely used active layer for the bulk heterojunction solar cells. Annealing is essential for P3HT:PC60BM active layer, since it facilitates the creation of better network for the transfer of the charge carriers. However, the PC60BM in the active layer can crystallize excessively during annealing treatments and disrupt the favorable morphology by forming crystallites in micrometer ranges, thus reducing device efficiency. In this paper we used glycerol as an additive in the active layer. Due to high boiling point of glycerol, it makes slow drying of the active layer possible during the annealing. It thus gives enough time to both electron donor (P3HT) and electron acceptor (PC60BM) components of the active layer to self-organize and also restrict the crystal overgrowth of PC60BM. Further, the glycerol additive makes the active layer smoother, which may also improve adhesion between the electrode and the active layer. The devices with the pristine active layer showed a power conversion efficiency (PCE) of about 2.1% and, with the addition of 30 vol% of glycerol in the active layer, the PCE value increased to 3%. Bobins Augustine and Tapio Fabritius Copyright © 2015 Bobins Augustine and Tapio Fabritius. All rights reserved. Progress in Photovoltaic Devices and Systems Tue, 24 Mar 2015 07:28:16 +0000 Hongxing Yang, Hui Shen, Tao Xu, and Dimitrios Karamanis Copyright © 2015 Hongxing Yang et al. All rights reserved. Morphological Effect of CNT/Ti Nanocomposite Photoelectrodes Dye-Sensitized Solar Cell on Photovoltaic Performance with Various Annealing Temperatures Thu, 19 Mar 2015 13:51:26 +0000 This research focused on the fabrication of dye-sensitized solar cell based on a photoanode of carbon nanotube/titanium dioxide (CNT/TiO2) nanocomposite photoanode synthesized through acid-catalyzed sol-gel method. The results show the improvement of the chemical and electrical properties of the solar cells annealed at different temperatures. The CNT/TiO2 colloidal solution was synthesized using titanium tetraisopropoxide and CNT/2-propanol solution. The thin films were doctor-bladed on a fluorine tin oxide glass before being annealed at 550, 650, and 750°C. The field emission scanning electron microscopy morphological images show that the thin films were homogenously distributed and maintained their spherical structures. The X-ray diffraction patterns show that the films consisted of anatase and rutile phases with large crystallite sizes due to temperature increment. The atomic force microscopy analysis presents the thin film roughness in terms of root mean square roughness. The photovoltaic performance was analyzed using IV curve and electrochemical impedance spectroscopy (EIS). The thin films annealed at 750°C had the highest energy conversion efficiency at 5.23%. The EIS analysis estimated the values of the effective electron lifetime (), effective electron diffusion coefficient, effective electron diffusion (), and effective recombination rate constant (). A large , small , and longer can improve photovoltaic performance efficiency. Mohd Zikri Razali, Huda Abdullah, and Izamarlina Asaahari Copyright © 2015 Mohd Zikri Razali et al. All rights reserved. Application of Extension Theory with Chaotic Signal Synchronization on Detecting Islanding Effect of Photovoltaic Power System Tue, 17 Mar 2015 07:26:01 +0000 The detection of islanding effect is a highly important topic for photovoltaic (PV) power system. The islanding effect occurs when the distributed power source is disconnected from the main supply while the power is still supplied in partial load area, which may injure the set maintenance personnel or damage the equipment. Combining chaotic synchronization and extension theory, this research is to propose a novel detection method to distinguish the occurrence of islanding effect based on nonautonomous Chua’s circuit. To demonstrate the effectiveness of the proposed method, this paper applies PSIM to simulate the PV power system. The experimental results show that the accuracy of the proposed method achieves 98% on islanding effect. Meng-Hui Wang, Mei-Ling Huang, and Kang-Jian Liou Copyright © 2015 Meng-Hui Wang et al. All rights reserved. Effects of CdS Buffer Layers on Photoluminescence Properties of Cu2ZnSnS4 Solar Cells Thu, 12 Mar 2015 11:59:31 +0000 Cu2ZnSnS4 (CZTS) absorber layers grown by sputtering were investigated by photoluminescence before and after the chemical bath deposition of CdS in order to evaluate the possible passivation of point defects by Cd atoms at the absorber/buffer layer interface. According to the literature, a broad emission around 1.21 eV was observed at low temperature under above bandgap excitation of the as-grown CZTS samples. Broad bands at 1.075 eV and 0.85 eV were detected for the first time under below bandgap excitation of the as-grown CZTS samples at low temperature, which were explained in terms of radiative transitions involving point defect-related levels determined in the literature by first-principles calculations. The emissions observed in the as-grown samples were monitored by both above and below bandgap excitations also in standard CZTS solar cells produced on the same layers. The obtained results suggest that, as in the case of Cu(In, Ga)Se2, Cd atoms passivate point defects at the absorber/buffer layer interface also in CZTS. A. Le Donne, S. Marchionna, P. Garattini, R. A. Mereu, M. Acciarri, and S. Binetti Copyright © 2015 A. Le Donne et al. All rights reserved.