- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Enhancing optical absorption in visible light of ZnO co-doped with europium and promethium by first principles study through modified Becke and Johnson potential scheme
摘要： By using first-principle calculations we studied the electronic, optical and magnetic properties of ZnO co-doped with Eu and Pm. In this calculation, we used Wien2k code based on Full potential linearized augmented plane waves (FP-LAPW) method with the modified Becke-Johnson (mBJ) approximation. This correction gives good band gap compared to experimental band gap. The introduction of Eu and Pm codoping leads to an increase in the band gap. Electrons can transit easily from the valence band to the conduction band, which results in an enhancement of visible light absorption in a wider absorption range. Absorption spectra reach a high value in visible and infrared light regions. With the significance of the obtained results, the studied compounds may potentially find spintronic and optoelectronic applications.
关键词： transmittance,Zinc Oxide,density functional theory,band gap,spintronics,Rare Earth,magnetic properties,absorption,modified Becke-Johnson,photovoltaic
更新于2025-09-10 09:29:36
-
Optimal Hybrid Neuro-fuzzy Based Controller Using MOGA for Photovoltaic (PV) Battery Charging System
摘要： This paper proposes an optimal hybrid neuro-fuzzy/fuzzy controller based on maximum power point tracking (MPPT) technique and voltage regulation for photovoltaic lead-acid battery charging system through the constant current and constant voltage (CC-CV) charge, denoted by NFC-CC/FLC-CV. The parameter optimization of NFC and FLC, including rule selection, based on multi-objective genetic algorithm (MOGA) is applied to the NFC-CC design to improve the tracking accuracy while reducing complexity. By means of genetic optimization, the number of fuzzy rules can be greatly reduced by 50%. In addition, GA is applied to the FLC-CV design to increase voltage regulation (VR) accuracy. After satisfying the stability condition through the solutions determined by MOGA and GA, the performances of controllers under rapidly-changing weather are evaluated tradeoff by several creteria, including transient response, stabilized accuracy, charging time, and energy utilization and charging ef?ciency. As results, the proposed controller outperforms the other existing controllers with the fastest rise time without overshoot, the highest MPPT and VR accuracy with negligible oscillations, a 12-23% reduction in charging time, and an increase of 5-15% and 1-6% in energy utilization and charging ef?ciency. Furthermore, it provides superior results in terms of computational complexity by achieving the minimum number of multiplications and system parameters, and high reliability with the lowest Akaike information criterion (AIC).
关键词： MPPT,neuro-fuzzy,Fuzzy logic,MOGA,photovoltaic charging system
更新于2025-09-10 09:29:36
-
Drivers, barriers and enablers to end-of-life management of solar photovoltaic and battery energy storage systems: A systematic literature review
摘要： Distributed solar photovoltaic (PV) systems are a low-cost form of renewable energy technology that has had an exponential rate of uptake globally in the last decade. However, little attention has been paid to the potential environmental and human health related impacts associated with PV systems, if not managed properly at the end-of-life (EoL). Rare materials such as ruthenium, gallium, indium, and tellurium are essential components in PV panels, while battery energy storage systems (BESS) are composed of various chemistries (i.e. lithium-ion, lead acid, nickel cadmium, salt water, and flow batteries). An appropriate EoL management strategy for solar photovoltaic systems (i.e. PV modules, BESS) is necessary, not only to prevent and/or mitigate future environmental problems but also to reduce demand on rare earth materials. Drawn from a portfolio of 191 papers collected from Scopus and Web of Science databases between 2000 and 2018 (by 30 June 2018), a systematic quantitative literature review on solar energy systems EoL studies was conducted to examine the temporal trend of current research as well as methodological and geographical distributions of the published articles. Research has been concentrated within Europe, some parts of Asia, and North America, with experimental and modelling/simulation methods being mostly applied. The focus of this study was to compile and synthesise reported drivers, barriers, and enablers to EoL management of PV panels and BESS in the context of the circular economy. A conceptual framework is proposed to facilitate the transition of current PV system material flows and supply chain management practices to circular economy concepts. This paper also presents a future research agenda.
关键词： battery energy storage system,recycling,solar panel,photovoltaic,end-of-life management,circular economy
更新于2025-09-10 09:29:36
-
Economic and Resilience Benefit Analysis of Incorporating Battery Storage to Photovoltaic Array Generation
摘要： Power systems with photovoltaic (PV) arrays combined with battery backup storage are becoming increasingly used because of their capability of working in power island mode, especially during grid outages. The problem is to decide the optimal battery sizes for PV + battery systems with given solar array sizes, from both power supply reliability and economical perspectives. An optimization method based on the simulation of system operation during grid interruption is developed to investigate the effects of battery size on system output reliability level of meeting load demand with minimum cost. Case studies are conducted for validation according to actual solar irradiation data, load profiles and realistic power interruption statistics. Sensitivity analysis is also performed to explore how system total cost affects islanding capability of a PV + battery system to supply energy to facilities. The finding shows that the decline of battery price not only reduces the lowest system total cost but also improves islanded system generation reliability. The proposed methodology for optimizing battery capacity added to PV array systems can make them grid-outage resilient and economically viable, which can be utilized as a decision-making tool for future PV + battery system expansion.
关键词： Resilient power systems,Resilience,Photovoltaic power island system,Battery backup systems,System design optimization,Solar power storage
更新于2025-09-10 09:29:36
-
Evaluation of color changes in PV modules using reflectance measurements
摘要： The main objective of this paper is to investigate the possibility of evaluating the color changes in real photovoltaic modules from re?ectance measurements. To accomplish this main objective, the work has been organized into three main axis: (1). Exploring the possibility of using simpli?ed instrumentation and techniques for the measurement of color parameters in solar cells. (2). Identifying a simple parameter as an indicator of solar module color appearance and (3). Exploring the possibility of correlating that parameter with solar module degradation. It is explored the use of re?ectance and related magnitude Yellowness Index (YI) as an indicator of photovoltaic (PV) solar module surface color change and degradation. While spectrometric quantities as transmittance have been used as a measurement of separated encapsulant and backsheet characteristics, in the present paper re?ectance of the surface of real PV solar mono and polycrystalline modules are analyzed. With the objective of verifying the applicability of such measurements in real PV installations, the correctness of using simpli?ed measurement geometries and portable spectrometers is tested. It is found that 45°/45° and hemispheric re?ectance supply similar results. Consequently portable ?ber optic spectrometers and simple ?ber optic probes with their holders can be used. We found that 45°/45° and hemispheric re?ectance with their associated Yellowness Index can be used indistinctly in the cases analyzed as a good indicator of super?cial color changes. We have also concluded that Yellowness Index is a good indicator of changes in appearance in PV modules. It is observed an increase of Yellowness Index with ultraviolet dose supplied to a solar module and a reduction in its maximum power.
关键词： Re?ectance,Degradation,Yellowness index,Photovoltaic
更新于2025-09-10 09:29:36
-
Disentangling the Electron and Hole Dynamics in Janus CdSe/PbSe Nanocrystals through Variable Pump Transient Absorption Spectroscopy
摘要： CdSe/PbSe Janus hetero-nanocrystals (HNCs) represent an interesting system where structurally immiscible CdSe and PbSe co-exist in a single structure with intermixed electronic states. Here, we have investigated the carrier dynamics in Janus CdSe/PbSe HNCs through ultrafast transient absorption spectroscopy by selectively exciting either the CdSe or the PbSe domains. Upon excitation of the CdSe domain sub-picosecond hole transfer to the hybrid interfacial PbSe states were identified. On the other hand, the transfer of hot electron from PbSe to CdSe was evident upon creation of hot electrons in PbSe domain without exciting the CdSe domain. The photo-excited hot hole also gets transferred to the hybrid interfacial states in sub-ps time (~1ps) bleaching the corresponding transition. The decay of the localized hole was found to be much slower compared to the electron which can be beneficial for carrier extraction and multiexciton generation. The finding of hot electron transfer in a single structure and slow decay of holes can thus prove to be advantageous for future design of photovoltaic devices.
关键词： carrier dynamics,ultrafast transient absorption spectroscopy,CdSe/PbSe Janus hetero-nanocrystals,photovoltaic devices,hot electron transfer
更新于2025-09-10 09:29:36
-
Developed and STM implementation of modified P&O MPPT technique for a PV system over sun
摘要： The non-linearity of photovoltaic systems and the change in maximum power point with a level of insolation and temperature complicates the tracking of the maximum power point. Several maximum power point tracker methods have been proposed and implemented in literature. The paper studies a modified perturb and observe (P&O) approach for a photovoltaic system in order to extract the maximum power point with more precision, fast speed and avoid the problems caused by the classic P&O method under the change of climatic conditions. This work is tested with a resistive load powered by a photovoltaic generator via a DC/DC converter. These methods are implemented with STM32F4 microcontroller running environment MATLAB/SIMULINK, using a computer incorporating a card DS1104 for visualization. The simulations and experimental results show that the proposed algorithm offers a fast response with smaller stationary oscillations compared to conventional methods.
关键词： photovoltaic generator (PVG),perturb and observe (P&O),maximum power point (MPP),Modified perturb and observe (MP&O),Maximum Power Point Tracking (MPPT)
更新于2025-09-10 09:29:36
-
Introducing Four 1,1-Dicyanomethylene-3-Indanone (IC) End-capped Groups as an Alternative Strategy for the Design of Small Molecular Nonfullerene Acceptors
摘要： Linear A-D-A or A-π-D-π-A architectures are predominant in the design of promising non-fullerene acceptors (NFAs), which promoted the rapid progress of organic solar cells (OSCs). However, utilization of four electron-accepting units (A) to construct four-armed NFAs is rarely reported and the relationship of structure-properties-performance is unclear. In this study, we designed and synthesized a novel acceptor (A401) with (AA)-π-D-π-(AA) configuration, where four 1,1-dicyanomethylene-3-indanone (IC) groups were used as the end-capped segments. When A401 was paired with a classic p-type polymer PBDB-T, a power conversion efficiency (PCE) of 7.54% could be achieved, which was much higher than that of the reported two-armed analogue of DC-IDT2T (3.93%). The improved photovoltaic performance of A401 should be ascribed to the high electron-affinity. Our results indicate introducing more end-capped electron-accepting units is a simple and effective alternative strategy for the design of promising NFAs. Our conceptualized molecular architecture will encourage further research of high-performance multi-armed NFAs.
关键词： photovoltaic performance,electron-affinity,electron-accepting units,organic solar cells,non-fullerene acceptors
更新于2025-09-10 09:29:36
-
Solar Water Pump
摘要： Solar powered water pumping systems have become the interest of many people in the recent years. Acknowledging that nature has provided a bounty of energy which can be converted into electrical energy has created innovative ways of discovering materials that can be used to make a system that supports turning heat into electricity. In this regard, the paper presented different concepts that relate to how the whole energy creation process is done and discusses useful ways of turning heat into useful energy. Furthermore, the recommendations dictate that while advancements in the technology are given attention, the issue of the investment cost and how it will thrive in the market is still a question. Nevertheless, many developing and developed countries continue to express interest in this area, and most are actively using and exploring how solar power can be used in other ways. Photovoltaic systems which are used to pump water for people, livestock and plants are an important move for technology and use of solar energy. Pumping water system using this PV technology has shown that is simple and that it does not require a lot of maintenance. In this regard, the idea gained the interest of farmers whose main concern is providing sufficient water not only for themselves but also for their plants and crops and livestock. The only major difference to this is that the system relies on solar energy as a power source for the pumps.
关键词： Energy,Direct Current (DC),Photovoltaic Energy,Electric Power Plant,Array,Photovoltaic (PV) System,Displaced or Volumetric Pump,Energy Consumption
更新于2025-09-09 09:28:46
-
Preface: Two dimensional (2D) hybrid organic-inorganic perovskites
摘要： 2D hybrid organic-inorganic perovskites (HOIPs) have been intensively investigated over the past 30 years before the rise of photovoltaic 3D hybrid perovskites. Along with the increasing research interest on 2D materials, they have attracted much attention. On the one hand, 2D hybrid perovskites possess much improved photo- and chemical stability over their 3D counterparts. On the other hand, the delicate interplay of multiple atomic bonding forces in the crystal lattice enables them to exhibit extraordinary properties that traditional inorganic 2D materials are unable to show. More importantly, the chemical and structural diversity of 2D HOIPs offers greater opportunities to fine-tune and engineer properties and functionalities compared with their 3D counterparts.
关键词： chemical and structural diversity,atomic bonding forces,photo- and chemical stability,2D hybrid organic-inorganic perovskites,photovoltaic
更新于2025-09-09 09:28:46