- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
[IEEE 2018 2nd International Conference on Energy Conservation and Efficiency (ICECE) - Lahore, Pakistan (2018.10.16-2018.10.17)] 2018 2nd International Conference on Energy Conservation and Efficiency (ICECE) - Performance Analysis of First Grid Connected PV Power Plant in Subtropical Climate of Pakistan
摘要： With the increasing penetration of both grid connected and standalone photovoltaic (PV) systems in Pakistan to cater the shortfall of energy, it is necessary to determine the performance and durability of already installed PV systems in different climates of country. This work aims to analyze the performance of first grid connected PV power plant located in Islamabad, Pakistan. The performance degradation of PV plants primarily depends on PV modules type (technology and design), regional climatic factors and field operating conditions. In this paper, performance ratio (PR) and degradation rate have been calculated from meteorological and performance data of plant to investigate the energy efficiency and modules quality over the course of operational years. Temperature losses due to module operating temperature were also estimated that primarily contribute to overall energy losses. This evaluation is of paramount importance for estimating the cost effect of the performance, identification of the underlying performance degradation and energy losses mechanisms, that help investors to choose climate specific modules technology and design for future plants and also to make efficient scheduling for preventive maintenance.
关键词： Photovoltaic (PV) system,performance index (PI),energy losses,climatic factors,degradation rate analysis,performance ratio (PR)
更新于2025-09-23 15:22:29
-
A Novel Wide-Bandgap Small Molecule Donor for High Efficiency All-Small-Molecule Organic Solar Cells with Small Non-Radiative Energy Losses
摘要： All-small-molecule organic solar cells (SM-OSCs) have attracted considerable attention owing to the merits of small molecules, such as easy purification, well-defined chemical structure and less batch-to-batch variation. To achieve high-performance SM-OSCs, the rational design of well-matched donor and acceptor materials to reduce energy losses is extremely essential. In this work, we developed a novel wide-bandgap small molecule donor, namely BTTzR, by firstly introducing the thiazolo[5,4-d]thiazole (TTz) unit as the building block. The optimized SM-OSCs based on BTTzR and Y6 exhibited an outstanding power conversion efficiency (PCE) of 13.9%. More importantly, the devices demonstrated very small non-radiative energy losses of 0.18 eV, which are similar to that of inorganic counterparts. This work indicates that BTTzR is a promising small molecule donor material for high-performance SM-OSCs application and provides a new sight of material design to reduce the non-radiative energy losses in the OSCs.
关键词： small molecule donor,organic solar cells,energy losses,wide-bandgap,high efficiency
更新于2025-09-23 15:21:01
-
Toward Efficient Triple-Junction Polymer Solar Cells through Rational Selection of Middle Cells
摘要： The photon energy losses of polymer solar cells (PSCs) routinely drag their experimental power conversion efficiencies (PCEs) far below the theoretical limits. We report herein efficient triple-junction PSCs (TJ-PSCs) with mitigated energy losses through rational selection of subcells. We reveal that avoiding strong photon competition between the front and middle cells is critical in balancing the absorption rate among subcells with realistic layer thicknesses. Efficient TJ-PSCs are achieved by stacking a front cell of PBDB-T-2F:PC71BM, a middle cell of PBDB-T:HF-TCIC, and a rear cell of PTB7-Th: IEICO-4F in series and connecting them with two functional interconnection layers. A PCE of 13.09% is obtained from champion devices, representing one of the best TJ-PSCs among the reported studies. It accounts for a 35% improvement in efficiency over those of single-junction PSCs with the same absorption range, which is mainly attributed to the reduced nonabsorbing and thermalization losses of TJ-PSCs.
关键词： polymer solar cells,photon energy losses,power conversion efficiencies,nonfullerene acceptors,triple-junction
更新于2025-09-23 15:21:01
-
Shading, Dusting and Incorrect Positioning of Photovoltaic Modules as Important Factors in Performance Reduction
摘要： The amount of solar radiation reaching the front cover of a photovoltaic module is crucial for its performance. A number of factors must be taken into account at the design stage of the solar installation, which will ensure maximum utilization of the potential arising from the location. During the operation of a photovoltaic installation, it is necessary to limit the shading of the modules caused by both dust and shadowing by trees or other objects. The article presents an analysis of the impact of the radiation reaching the surface of the radiation module on the e?ciency obtained. Each of the analyzed aspects is important for obtaining the greatest amount of energy in speci?c geographical conditions. Modules contaminated by settling dust will be less e?cient than those without deposits. The results of experimental studies of this e?ect are presented, depending on the amount of impurities, including their origins and morphologies. In practice, it is impossible to completely eliminate shadowing caused by trees, uneven terrain, other buildings, chimneys, or satellite dishes, and so on, which limits the energy of solar radiation reaching the modules. An analysis of partial shading for the generated power was also carried out. An important way for maximizing the incoming radiation is the correct positioning of the modules relative to the sun. It is considered optimal to position the modules relative to the light source, that is, the sun, so that the rays fall perpendicular to the surfaces of the modules. Any deviation in the direction of the rays results in a loss in the form of a decrease in the available power of the module. The most bene?cial option would be to use sun-tracking systems, but they represent an additional investment cost, and their installations require additional space and maintenance. Therefore, the principle was adopted that stationary systems should be oriented to the south, using the optimal angle of inclination of the module surface appropriate for the location. This article presents the dependence of the decrease in obtained power on the angle of deviation from the optimal one.
关键词： energy losses,photovoltaic module,shading,maximum power generation,dusting,optimal orientation
更新于2025-09-23 15:21:01
-
Optimization Study of Parasitic Energy Losses in Photovoltaic System with Dual-Axis Solar Tracker Located at Different Latitudes
摘要： Despite the sun-tracking system maximising the annual yield of solar power generation, the inevitable parasitic energy losses from the sun-tracking mechanism related to range of motion should be considered. This paper presents a systematic approach to investigate the annual accumulated parasitic energy losses in photovoltaic (PV) or concentrator photovoltaic (CPV) system installed in a dual-axis solar tracker located at various locations with latitudes ranging from 45°N to 45°S. This approach allows the engineers to evaluate and to optimize the PV/CPV system performance by determining the least parasitic energy loss in the cases of fixed and non-fixed stow positions. The results show that the solar tracker with non-fixed stow position always has lower annual accumulated parasitic energy losses as compared to that of fixed stow position located in different latitudes.
关键词： Concentrator photovoltaic system,Photovoltaic system,Dual-axis solar tracker,Azimuth-elevation tracking,General sun-tracking formula,Parasitic energy losses
更新于2025-09-12 10:27:22
-
Small energy loss and high open circuit voltage in conventional structure polymer solar cells with the mixture thin films of polyethylenimine ethoxylated and TiOX as the electron extraction layer and Ag as the cathode
摘要： One of the challenges facing the fabrication of high-performance conventional structure polymer solar cells (PSCs) is the development of new interface materials that have better air stability and charge carrier collection and transport ability. In this study, the mixture thin films of polyethylenimine ethoxylated (PEIE) and TiOX are developed as the electron extraction layer (EEL) and Ag as the cathode for the application in PSCs, replacing the Ca/Al composite cathode. Ultraviolet photoelectron spectroscopy (UPS) and space-charge-limited current (SCLC) measurements demonstrate that PEIE:TiOX/Ag shows appropriate energy levels, substantially reduced barrier potential, weakened charge carrier recombination and enhanced electron mobility. As a result, the PEIE:TiOX-based PSCs demonstrate not only an enhanced power conversion efficiency (PCE) of 10.94% but also the photovoltaic performance insensitive to the storage time, yielding an aged PCE that is 92% of the fresh PCE. This result can be further explained by the dependence of the charge carrier mobility on storage time. Our work suggests exploiting the PEIE:TiOX/Ag composite thin films as the composite cathode replacing Ca/Al thin films for successfully enhancing the photovoltaic performance and improving the stability of PSCs.
关键词： Energy losses,Barrier potential,Charge carrier recombination
更新于2025-09-12 10:27:22
-
Efficient Organic Solar Cells with a High Open‐Circuit Voltage of 1.34 V
摘要： One of the most important challenges that hinders the power conversion efficiencies (PCEs) of organic solar cells (OSCs) is the modest open-circuit voltages (VOC) due to large energy losses. The large driving force during for charge generation and the non-radiative recombination are the main causes of energy losses. To maximize the VOC of OSCs, herein, we modulate the end-groups and design a non-fullerene acceptor ITCCM-O, which shows a bandgap of 2.0 eV. By blending a polymer donor named J52, the device demonstrates a PCE of 5.5% with an outstanding VOC of 1.34 V, which is the highest value for single-junction OSCs over 5% PCEs. The high VOC is benefited from 1) the negligible driving force for charge transfer, and 2) the suppressed non-radiative recombination loss, as low as 0.22 V.
关键词： energy losses,high voltage,non-fullerene acceptors
更新于2025-09-11 14:15:04