Stability Issues in Microgrids: A Review

Green Energy ◽  
2020 ◽  
pp. 369-409
Author(s):  
Sonam Khurana ◽  
Sheela Tiwari
Keyword(s):  
Stability Issues

Use of Transparent Conductive Oxide Materials with Low Indices of Refraction in Amorphous Silicon-Based Solar Cell Technology

2005 ◽  
Vol 862 ◽  
Author(s):  
Scott J. Jones ◽  
Joachim Doehler ◽  
Tongyu Liu ◽  
David Tsu ◽  
Jeff Steele ◽  
...  
Keyword(s):  
Solar Cell ◽  
Amorphous Silicon ◽  
Transparent Conductive Oxide ◽  
Open Circuit ◽  
Long Term Stability ◽  
Back Reflectors ◽  
Stability Issues ◽  
Silicon Based ◽  
Solar Cell Technology

AbstractNew types of transparent conductive oxides with low indices of refraction have been developed for use in optical stacks for the amorphous silicon (a-Si) solar cell and other thin film applications. The alloys are ZnO based with Si and MgF added to reduce the index of the materials through the creation of SiO2 or MgF2, with n=1.3-1.4, or the addition of voids in the materials. Alloys with 12-14% Si or Mg have indices of refraction at λ=800nm between 1.6 and 1.7. These materials are presently being used in optical stacks to enhance light scattering by Al/multi-layer/ZnO back reflectors in a-Si based solar cells to increase light absorption in the semiconductor layers and increase open circuit currents and boost device efficiencies. In contrast to Ag/ZnO back reflectors which have long term stability issues due to electromigration of Ag, these Al based back reflectors should be stable and usable in manufactured PV products. In this manuscript, structural properties for the materials will be reported as well as the performance of solar cell devices made using these new types of materials.

Determining the Norton’s Equivalent Model of Distribution System with Distributed Generation (DG) for Stability Analysis

2019 ◽  
Vol 12 (2) ◽  
pp. 190-198
Author(s):  
Sunny Katyara ◽  
Lukasz Staszewski ◽  
Faheem Akhtar Chachar
Keyword(s):  
Distributed Generation ◽  
Normal Condition ◽  
Distribution System ◽  
Distribution Networks ◽  
Equivalent Model ◽  
Stability Factor ◽  
Matlab Simulation ◽  
The Stability ◽  
Stability Issues

Background: Since the distribution networks are passive until Distributed Generation (DG) is not being installed into them, the stability issues occur in the distribution system after the integration of DG. Methods: In order to assure the simplicity during the calculations, many approximations have been proposed for finding the system’s parameters i.e. Voltage, active and reactive powers and load angle, more efficiently and accurately. This research presents an algorithm for finding the Norton’s equivalent model of distribution system with DG, considering from receiving end. Norton’s model of distribution system can be determined either from its complete configuration or through an algorithm using system’s voltage and current profiles. The algorithm involves the determination of derivative of apparent power against the current (dS/dIL) of the system. Results: This work also verifies the accuracy of proposed algorithm according to the relative variations in the phase angle of system’s impedance. This research also considers the varying states of distribution system due to switching in and out of DG and therefore Norton’s model needs to be updated accordingly. Conclusion: The efficacy of the proposed algorithm is verified through MATLAB simulation results under two scenarios, (i) normal condition and (ii) faulty condition. During normal condition, the stability factor near to 1 and change in dS/dIL was near to 0 while during fault condition, the stability factor was higher than 1 and the value of dS/dIL was away from 0.

scholarly journals Degradation mechanism of hybrid tin-based perovskite solar cells and the critical role of tin (IV) iodide

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Luis Lanzetta ◽  
Thomas Webb ◽  
Nourdine Zibouche ◽  
Xinxing Liang ◽  
Dong Ding ◽  
...  
Keyword(s):  
Degradation Mechanism ◽  
Critical Role ◽  
Perovskite Solar Cells ◽  
Hole Transport ◽  
Transport Layer ◽  
Environmental Stability ◽  
Hole Transport Layer ◽  
Future Design ◽  
Cyclic Degradation ◽  
Stability Issues

AbstractTin perovskites have emerged as promising alternatives to toxic lead perovskites in next-generation photovoltaics, but their poor environmental stability remains an obstacle towards more competitive performances. Therefore, a full understanding of their decomposition processes is needed to address these stability issues. Herein, we elucidate the degradation mechanism of 2D/3D tin perovskite films based on (PEA)0.2(FA)0.8SnI3 (where PEA is phenylethylammonium and FA is formamidinium). We show that SnI4, a product of the oxygen-induced degradation of tin perovskite, quickly evolves into iodine via the combined action of moisture and oxygen. We identify iodine as a highly aggressive species that can further oxidise the perovskite to more SnI4, establishing a cyclic degradation mechanism. Perovskite stability is then observed to strongly depend on the hole transport layer chosen as the substrate, which is exploited to tackle film degradation. These key insights will enable the future design and optimisation of stable tin-based perovskite optoelectronics.

scholarly journals Tailings facility disclosures reveal stability risks

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Daniel M. Franks ◽  
Martin Stringer ◽  
Luis A. Torres-Cruz ◽  
Elaine Baker ◽  
Rick Valenta ◽  
...  
Keyword(s):  
Information Disclosure ◽  
Significant Risk ◽  
Construction Method ◽  
Facility Management ◽  
Alternative Technologies ◽  
Construction Methods ◽  
Comprehensive Survey ◽  
Engineering Standards ◽  
The Right ◽  
Stability Issues

AbstractTailings facility failures represent a significant risk to the environment and communities globally, but until now little data was available on the global distribution of risks and characteristics of facilities to ensure proper governance. We conducted a survey and compiled a database with information on tailings facilities disclosed by extractive companies at the request of institutional investors. Despite limitations in the data, this information disclosure request represents the most comprehensive survey of tailings facilities ever undertaken. The compiled dataset includes 1743 tailings facilities and provides insights into a range of topics including construction method, stability, consequence of failure, stored volume, and the rate of uptake of alternative technologies to dewater tailings and reduce geotechnical risk. Our analysis reveals that 10 per cent of tailings facilities reported notable stability concerns or failure to be confirmed or certified as stable at some point in their history, with distinct trends according to construction method, governance, age, height, volume and seismic hazard. Controversy has surrounded the safety of tailings facilities, most notably upstream facilities, for many years but in the absence of definitive empirical data differentiating the risks of different facility types, upstream facilities have continued to be used widely by the industry and a consensus has emerged that upstream facilities can theoretically be built safely under the right circumstances. Our findings reveal that in practice active upstream facilities report a higher incidence of stability issues (18.3%) than other facility types, and that this elevated risk persists even when these facilities are built in high governance settings. In-pit/natural landform and dry-stack facilities report lower incidence of stability issues, though the rate of stability issues is significant by engineering standards (> 2 per cent) across all construction methods, highlighting the universal importance of careful facility management and governance. The insights reported here can assist the global governance of tailings facility stability risks.

Approaching stability challenges for flow cytometry in a regulated bioanalytical environment

Bioanalysis ◽  
2019 ◽  
Vol 11 (20) ◽  
pp. 1845-1858 ◽  
Author(s):  
Anamica Muruganandham ◽  
Carolyne Dumont ◽  
Kuiyi Xing
Keyword(s):  
Flow Cytometry ◽  
Critical Parameter ◽  
Storage Period ◽  
Reliable Data ◽  
Clinical Samples ◽  
Sample Collection ◽  
Testing Laboratory ◽  
Stability Parameters ◽  
Stability Issues ◽  
Limited Period

Stability of samples for flow cytometry is a critical parameter since storage period of samples is restricted to only a limited period after collection. For most studies, clinical samples have to be shipped to a testing laboratory, in contrast to preclinical samples, which can be analyzed on-site or off-site. Therefore, evaluating stability is critical to provide flexibility on testing of samples to obtain reliable data. A wide variety of factors contributes to establishing stability from sample collection through acquisition. We provided suggestions for experimental and stability parameters to be taken into consideration when designing a flow cytometry method. The case studies presented represent how certain stability issues were overcome to perform flow cytometry assays in a regulated bioanalytical environment.

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