Functional Analysis of Shewanella, a cross genome comparison.

Energy Technology Data Exchange (ETDEWEB)

Serres, Margrethe H.

2009-05-15

The bacterial genus Shewanella includes a group of highly versatile organisms that have successfully adapted to life in many environments ranging from aquatic (fresh and marine) to sedimentary (lake and marine sediments, subsurface sediments, sea vent). A unique respiratory capability of the Shewanellas, initially observed for Shewanella oneidensis MR-1, is the ability to use metals and metalloids, including radioactive compounds, as electron acceptors. Members of the Shewanella genus have also been shown to degrade environmental pollutants i.e. halogenated compounds, making this group highly applicable for the DOE mission. S. oneidensis MR-1 has in addition been found to utilize a diverse set of nutrients and to have a large set of genes dedicated to regulation and to sensing of the environment. The sequencing of the S. oneidensis MR-1 genome facilitated experimental and bioinformatics analyses by a group of collaborating researchers, the Shewanella Federation. Through the joint effort and with support from Department of Energy S. oneidensis MR-1 has become a model organism of study. Our work has been a functional analysis of S. oneidensis MR-1, both by itself and as part of a comparative study. We have improved the annotation of gene products, assigned metabolic functions, and analyzed protein families present in S. oneidensis MR-1. The data has been applied to analysis of experimental data (i.e. gene expression, proteome) generated for S. oneidensis MR-1. Further, this work has formed the basis for a comparative study of over 20 members of the Shewanella genus. The species and strains selected for genome sequencing represented an evolutionary gradient of DNA relatedness, ranging from close to intermediate, and to distant. The organisms selected have also adapted to a variety of ecological niches. Through our work we have been able to detect and interpret genome similarities and differences between members of the genus. We have in this way contributed to the

Integrated Genome-Based Studies of Shewanella Ecophysiology

Energy Technology Data Exchange (ETDEWEB)

Andrei L. Osterman, Ph.D.

2012-12-17

Integration of bioinformatics and experimental techniques was applied to mapping and characterization of the key components (pathways, enzymes, transporters, regulators) of the core metabolic machinery in Shewanella oneidensis and related species with main focus was on metabolic and regulatory pathways involved in utilization of various carbon and energy sources. Among the main accomplishments reflected in ten joint publications with other participants of Shewanella Federation are: (i) A systems-level reconstruction of carbohydrate utilization pathways in the genus of Shewanella (19 species). This analysis yielded reconstruction of 18 sugar utilization pathways including 10 novel pathway variants and prediction of > 60 novel protein families of enzymes, transporters and regulators involved in these pathways. Selected functional predictions were verified by focused biochemical and genetic experiments. Observed growth phenotypes were consistent with bioinformatic predictions providing strong validation of the technology and (ii) Global genomic reconstruction of transcriptional regulons in 16 Shewanella genomes. The inferred regulatory network includes 82 transcription factors, 8 riboswitches and 6 translational attenuators. Of those, 45 regulons were inferred directly from the genome context analysis, whereas others were propagated from previously characterized regulons in other species. Selected regulatory predictions were experimentally tested. Integration of this analysis with microarray data revealed overall consistency and provided additional layer of interactions between regulons. All the results were captured in the new database RegPrecise, which is a joint development with the LBNL team. A more detailed analysis of the individual subsystems, pathways and regulons in Shewanella spp included bioinfiormatics-based prediction and experimental characterization of: (i) N-Acetylglucosamine catabolic pathway; (ii)Lactate utilization machinery; (iii) Novel Nrt

Integrated Genome-Based Studies of Shewanella Echophysiology

Energy Technology Data Exchange (ETDEWEB)

Margrethe H. Serres

2012-06-29

Shewanella oneidensis MR-1 is a motile, facultative {gamma}-Proteobacterium with remarkable respiratory versatility; it can utilize a range of organic and inorganic compounds as terminal electronacceptors for anaerobic metabolism. The ability to effectively reduce nitrate, S0, polyvalent metals andradionuclides has established MR-1 as an important model dissimilatory metal-reducing microorganism for genome-based investigations of biogeochemical transformation of metals and radionuclides that are of concern to the U.S. Department of Energy (DOE) sites nationwide. Metal-reducing bacteria such as Shewanella also have a highly developed capacity for extracellular transfer of respiratory electrons to solid phase Fe and Mn oxides as well as directly to anode surfaces in microbial fuel cells. More broadly, Shewanellae are recognized free-living microorganisms and members of microbial communities involved in the decomposition of organic matter and the cycling of elements in aquatic and sedimentary systems. To function and compete in environments that are subject to spatial and temporal environmental change, Shewanella must be able to sense and respond to such changes and therefore require relatively robust sensing and regulation systems. The overall goal of this project is to apply the tools of genomics, leveraging the availability of genome sequence for 18 additional strains of Shewanella, to better understand the ecophysiology and speciation of respiratory-versatile members of this important genus. To understand these systems we propose to use genome-based approaches to investigate Shewanella as a system of integrated networks; first describing key cellular subsystems - those involved in signal transduction, regulation, and metabolism - then building towards understanding the function of whole cells and, eventually, cells within populations. As a general approach, this project will employ complimentary "top-down" - bioinformatics-based genome functional predictions, high

Microbial metal reduction by members of the genus Shewanella: novel strategies for anaerobic respiration

International Nuclear Information System (INIS)

Dichristina, Thomas; Bates, David J.; Burns, Justin L.; Dale, Jason R.; Payne, Amanda N.

2006-01-01

Metal-reducing members of the genus Shewanella are important components of the microbial community residing in redox-stratified freshwater and marine environments. Metal-reducing gram-negative bacteria such as Shewanella, however, are presented with a unique physiological challenge: they are required to respire anaerobically on terminal electron acceptors which are either highly insoluble (Fe(III)- and Mn(IV)-oxides) and reduced to soluble end-products or highly soluble (U(VI) and Tc(VII)) and reduced to insoluble end-products. To overcome physiological problems associated with metal solubility, metal-respiring Shewanella are postulated to employ a variety of novel respiratory strategies not found in other gram-negative bacteria which respire on soluble electron acceptors such as O2, NO3 and SO4. The following chapter highlights the latest findings on the molecular mechanism of Fe(III), U(VI) and Tc(VII) reduction by Shewanella, with particular emphasis on electron transport chain physiology.

Removal of U(VI) from aqueous solutions using Shewanella sp. RCRI7, isolated from Qurugoel Lake in Iran

Energy Technology Data Exchange (ETDEWEB)

Abdehvand, Adib Zaheri; Keshtkar, Alireza; Fatemi, Faezeh [Nuclear Science and Technology Research Institute, Tehran (Iran, Islamic Republic of). Nuclear Fuel Cycle Research School; Tarhiz, Vahideh; Hejazi, Mohammad Saeid [Tabriz Univ. of Medical Sciences (Iran, Islamic Republic of). Molecular Medicine Research Center

2017-04-01

Isolation, genotypic and phenotypic characterization of an aqueous bacterium, Shewanella sp RCRI7, from Qurugoel Lake in Iran and uranium removal from aqueous solutions using the isolate is described. Based on 16S rRNA gene sequence analysis and phylogenetic tree, strain RCRI7{sup T} falls into genus Shewanella. Closely related type strains include Shewanella xiamenensis S4{sup T} KJ542801, Shewanella profunda DSM15900{sup T} FR733713, Shewanella putrefaciens LMG 26268{sup T} X81623 and Shewanella oneidensis MR-1{sup T} AE014299. Anaerobic incubation of the bacteria in the presence of U(VI) led to uranium removal from the solution and formation of a black precipitate. Analysis of the precipitate using UV-vis confirmed the reduction of U(VI) to U(IV). The effects of pH, temperature, U(VI) concentration and cell density on uranium removal were elucidated. The maximum uranium removal was 97%. As a conclusion, the findings revealed the ability of the local strain RCRI7 for U(VI) bioreduction as an effective bacterium for uranium immobilization.

Removal of U(VI) from aqueous solutions using Shewanella sp. RCRI7, isolated from Qurugoel Lake in Iran

International Nuclear Information System (INIS)

Abdehvand, Adib Zaheri; Keshtkar, Alireza; Fatemi, Faezeh; Tarhiz, Vahideh; Hejazi, Mohammad Saeid

2017-01-01

Isolation, genotypic and phenotypic characterization of an aqueous bacterium, Shewanella sp RCRI7, from Qurugoel Lake in Iran and uranium removal from aqueous solutions using the isolate is described. Based on 16S rRNA gene sequence analysis and phylogenetic tree, strain RCRI7 T falls into genus Shewanella. Closely related type strains include Shewanella xiamenensis S4 T KJ542801, Shewanella profunda DSM15900 T FR733713, Shewanella putrefaciens LMG 26268 T X81623 and Shewanella oneidensis MR-1 T AE014299. Anaerobic incubation of the bacteria in the presence of U(VI) led to uranium removal from the solution and formation of a black precipitate. Analysis of the precipitate using UV-vis confirmed the reduction of U(VI) to U(IV). The effects of pH, temperature, U(VI) concentration and cell density on uranium removal were elucidated. The maximum uranium removal was 97%. As a conclusion, the findings revealed the ability of the local strain RCRI7 for U(VI) bioreduction as an effective bacterium for uranium immobilization.

The genus Shewanella: from the briny depths below to human pathogen.

Science.gov (United States)

Janda, J Michael; Abbott, Sharon L

2014-11-01

The genus Shewanella is currently composed of more than 50 species that inhabit a range of marine environs and ecosystems. Several members of this genus, including S. oneidensis, have been identified that could potentially play key roles in environmental processes such as bioremediation of toxic elements and heavy metals and serving as microbial fuel cells. In contrast to this beneficial role, shewanellae are increasingly being implicated as human pathogens in persons exposed through occupational or recreational activities to marine niches containing shewanellae. Documented illnesses linked to Shewanella include skin and soft tissue infections, bacteremia, and otitis media. At present, it is unclear exactly how many Shewanella species are truly bona fide human pathogens. Recent advances in the taxonomy and phylogenetic relatedness of members of this genus, however, support the concept that most human infections are caused by a single species, S. algae. Some phylogenetic data further suggest that some current members of the genus are not true Shewanella species sensu stricto. The current review summarizes our present knowledge of the distribution, epidemiology, disease spectrum, and identification of microbial species focusing on a clinical perspective.

Differentiation of Shewanella putrefaciens and Shewanella alga on the basis of whole-cell protein profiles, ribotyping, phenotypic characterization, and 16S rRNA gene sequence analysis

DEFF Research Database (Denmark)

Vogel, Birte Fonnesbech; Jørgensen, K.; Christensen, H.

1997-01-01

Seventy-six presumed Shewanella putrefaciens isolates from fish, oil drillings, and clinical specimens, the type strain of Shewanella putrefaciens (ATCC 8071), the type strain of Shewanella alga (IAM 14159), and the type strain of Shewanella hanedai (ATCC 33224) were compared by several typing...... methods. Numerical analysis of sodium dodecyl sulfate-polyacrylamide gel electrophoresis of whole-cell protein and ribotyping patterns showed that the strains were separated into two distinct clusters with 56% +/- 10% and 40% +/- 14% similarity for whole- cell protein profiling and ribotyping......, respectively. One cluster consisted of 26 isolates with 52 to 55 mol% G + C and included 15 human isolates, mostly clinical specimens, 8 isolates from marine waters, and the type strain of S. alga. This homogeneous cluster of mesophilic, halotolerant strains was by all analyses identical to the recently...

PV Performance Modeling Methods and Practices: Results from the 4th PV Performance Modeling Collaborative Workshop.

Energy Technology Data Exchange (ETDEWEB)

Stein, Joshua [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2017-03-01

In 2014, the IEA PVPS Task 13 added the PVPMC as a formal activity to its technical work plan for 2014-2017. The goal of this activity is to expand the reach of the PVPMC to a broader international audience and help to reduce PV performance modeling uncertainties worldwide. One of the main deliverables of this activity is to host one or more PVPMC workshops outside the US to foster more international participation within this collaborative group. This report reviews the results of the first in a series of these joint IEA PVPS Task 13/PVPMC workshops. The 4th PV Performance Modeling Collaborative Workshop was held in Cologne, Germany at the headquarters of TÜV Rheinland on October 22-23, 2015.

Structures, Compositions, and Activities of Live Shewanella Biofilms Formed on Graphite Electrodes in Electrochemical Flow Cells.

Science.gov (United States)

Kitayama, Miho; Koga, Ryota; Kasai, Takuya; Kouzuma, Atsushi; Watanabe, Kazuya

2017-09-01

An electrochemical flow cell equipped with a graphite working electrode (WE) at the bottom was inoculated with Shewanella oneidensis MR-1 expressing an anaerobic fluorescent protein, and biofilm formation on the WE was observed over time during current generation at WE potentials of +0.4 and 0 V (versus standard hydrogen electrodes), under electrolyte-flow conditions. Electrochemical analyses suggested the presence of unique electron-transfer mechanisms in the +0.4-V biofilm. Microscopic analyses revealed that, in contrast to aerobic biofilms, current-generating biofilm (at +0.4 V) was thin and flat (∼10 μm in thickness), and cells were evenly and densely distributed in the biofilm. In contrast, cells were unevenly distributed in biofilm formed at 0 V. In situ fluorescence staining and biofilm recovery experiments showed that the amounts of extracellular polysaccharides (EPSs) in the +0.4-V biofilm were much smaller than those in the aerobic and 0-V biofilms, suggesting that Shewanella cells suppress the production of EPSs at +0.4 V under flow conditions. We suggest that Shewanella cells perceive electrode potentials and modulate the structure and composition of biofilms to efficiently transfer electrons to electrodes. IMPORTANCE A promising application of microbial fuel cells (MFCs) is to save energy in wastewater treatment. Since current is generated in these MFCs by biofilm microbes under horizontal flows of wastewater, it is important to understand the mechanisms for biofilm formation and current generation under water-flow conditions. Although massive work has been done to analyze the molecular mechanisms for current generation by model exoelectrogenic bacteria, such as Shewanella oneidensis , limited information is available regarding the formation of current-generating biofilms over time under water-flow conditions. The present study developed electrochemical flow cells and used them to examine the electrochemical and structural features of current

Metabolic Flux Analysis of Shewanella spp. Reveals Evolutionary Robustness in Central Carbon Metabolism

Energy Technology Data Exchange (ETDEWEB)

Tang, Yinjie J.; Martin, Hector Garcia; Dehal, Paramvir S.; Deutschbauer, Adam; Llora, Xavier; Meadows, Adam; Arkin, Adam; Keasling, Jay D.

2009-08-19

Shewanella spp. are a group of facultative anaerobic bacteria widely distributed in marine and fresh-water environments. In this study, we profiled the central metabolic fluxes of eight recently sequenced Shewanella species grown under the same condition in minimal med-ium with [3-13C] lactate. Although the tested Shewanella species had slightly different growth rates (0.23-0.29 h31) and produced different amounts of acetate and pyruvate during early exponential growth (pseudo-steady state), the relative intracellular metabolic flux distributions were remarkably similar. This result indicates that Shewanella species share similar regulation in regard to central carbon metabolic fluxes under steady growth conditions: the maintenance of metabolic robustness is not only evident in a single species under genetic perturbations (Fischer and Sauer, 2005; Nat Genet 37(6):636-640), but also observed through evolutionary related microbial species. This remarkable conservation of relative flux profiles through phylogenetic differences prompts us to introduce the concept of metabotype as an alternative scheme to classify microbial fluxomics. On the other hand, Shewanella spp. display flexibility in the relative flux profiles when switching their metabolism from consuming lactate to consuming pyruvate and acetate.

Isolation of Shewanella putrefaciens in an elderly man with subacute intestinal obstruction & appendicitis

Directory of Open Access Journals (Sweden)

Arif Maqsood Ali

2017-01-01

Full Text Available Shewanella is Gram-negative motile bacillus, non fermentative and facultative anaerobe. Its natural habitat is all forms of water and soil, but has also been isolated from fish, dairy products, oils, and carcasses. Often found with microflora of the marine environment. Bacterial infections with Shewanella spp. are rare. The exposure to the marine environment, sea and diary food are considered as a risk factor for Shewanella spp. infection. Clinical infections seen are otitis, soft tissue infection, bacteremia, ear infection, eye infection, infective arthritis, osteomyelitis, infective endocarditis and peritonitis.

Influence of riboflavin on the reduction of radionuclides by Shewanella oneidenis MR-1.

Science.gov (United States)

Cherkouk, Andrea; Law, Gareth T W; Rizoulis, Athanasios; Law, Katie; Renshaw, Joanna C; Morris, Katherine; Livens, Francis R; Lloyd, Jonathan R

2016-03-28

Uranium (as UO2(2+)), technetium (as TcO4(-)) and neptunium (as NpO2(+)) are highly mobile radionuclides that can be reduced enzymatically by a range of anaerobic and facultatively anaerobic microorganisms, including Shewanella oneidensis MR-1, to poorly soluble species. The redox chemistry of Pu is more complicated, but the dominant oxidation state in most environments is highly insoluble Pu(IV), which can be reduced to Pu(III) which has a potentially increased solubility which could enhance migration of Pu in the environment. Recently it was shown that flavins (riboflavin and flavin mononucleotide (FMN)) secreted by Shewanella oneidensis MR-1 can act as electron shuttles, promoting anoxic growth coupled to the accelerated reduction of poorly-crystalline Fe(III) oxides. Here, we studied the role of riboflavin in mediating the reduction of radionuclides in cultures of Shewanella oneidensis MR-1. Our results demonstrate that the addition of 10 μM riboflavin enhances the reduction rate of Tc(VII) to Tc(IV), Pu(IV) to Pu(III) and to a lesser extent, Np(V) to Np(IV), but has no significant influence on the reduction rate of U(VI) by Shewanella oneidensis MR-1. Thus riboflavin can act as an extracellular electron shuttle to enhance rates of Tc(VII), Np(V) and Pu(IV) reduction, and may therefore play a role in controlling the oxidation state of key redox active actinides and fission products in natural and engineered environments. These results also suggest that the addition of riboflavin could be used to accelerate the bioremediation of radionuclide-contaminated environments.

Shewanella putrefaciens infective endocarditis

Directory of Open Access Journals (Sweden)

Jonathan Constant

2014-11-01

Full Text Available Shewanella putrefaciens rarely causes infection in humans. In the last few decades a growing number of cases have been described. The following report outlines the case of a 40-year-old immunocompetent white man with S. putrefaciens infective endocarditis. This is the first known case of infective endocarditis due to an apparently monomicrobial S. putrefaciens infection, and the second known case of S. putrefaciens-related infective endocarditis worldwide.

Redox sensing within the genus Shewanella

NARCIS (Netherlands)

Harris, Howard W.; Sánchez-Andrea, Irene; McLean, Jeffrey S.; Salas, Everett C.; Tran, William; El-Naggar, Mohamed Y.; Nealson, Kenneth H.

2018-01-01

A novel bacterial behavior called congregation was recently described in Shewanella oneidensis MR-1 as the accumulation of cells around insoluble electron acceptors (IEA). It is the result of a series of "run-and-reversal" events enabled by modulation of swimming speed and direction. The model

Characterization of lead nanoparticles formed by Shewanella sp. KR-12

Energy Technology Data Exchange (ETDEWEB)

Liu, Chien-Liang; Yen, Jui-Hung, E-mail: sonny@ntu.edu.tw [National Taiwan University, Department of Agricultural Chemistry (China)

2016-01-15

The bacterial strain KR-12 was isolated from river sediment in northeast Taiwan. 16S rRNA gene sequencing revealed that it belongs to the genus Shewanella. The strain can accumulate lead (Pb) and form Pb nanoparticles (PbNPs) on exposure to Pb(NO{sub 3}){sub 2} and sodium formate in HEPES buffer. On transmission electron microscopy (TEM), the KR-12-formed PbNPs were spherical in shape and ranged from 3 to 8 nm. The PbNPs formed a line or curved pattern on bacteria. In addition, one or more pilus-like structures elongated from the bacteria. In contrast, Shewanella oneidensis MR-1 and other bacteria could not form PbNPs pattern or pilus-like structure under the same conditions. High-resolution TEM combined with energy-dispersive X-ray spectroscopy demonstrated that these PbNPs primarily contained Pb and had an amorphous structure. This is the first report of the biosynthesis of PbNPs by a Shewanella species.

Estimates of abundance and diversity of Shewanella genus in natural and engineered aqueous environments with newly designed primers.

Science.gov (United States)

Li, Bing-Bing; Cheng, Yuan-Yuan; Fan, Yang-Yang; Liu, Dong-Feng; Fang, Cai-Yun; Wu, Chao; Li, Wen-Wei; Yang, Zong-Chuang; Yu, Han-Qing

2018-05-12

Shewanella species have a diverse respiratory ability and wide distribution in environments and play an important role in bioremediation and the biogeochemical cycles of elements. Primers with more accuracy and broader coverage are required with consideration of the increasing number of Shewanella species and evaluation of their roles in various environments. In this work, a new primer set of 640F/815R was developed to quantify the abundance of Shewanella species in natural and engineered environments. In silico tools for primer evaluation, quantitative polymerase chain reaction (qPCR) and clone library results showed that 640F/815R had a higher specificity and coverage than the previous primers in quantitative analysis of Shewanella. Another newly developed primer pair of 211F/815cR was also adopted to analyze the Shewanella diversity and demonstrated to be the best candidate in terms of specificity and coverage. We detected more Shewanella-related species in freshwater environments and found them to be substantially different from those in marine environments. Abundance and diversity of Shewanella species in wastewater treatment plants were largely affected by the process and operating conditions. Overall, this study suggests that investigations of abundance and diversity of Shewanella in various environments are of great importance to evaluate their ecophysiology and potential ecological roles. Copyright © 2018 Elsevier B.V. All rights reserved.

Current trends of human infections and antibiotic resistance of the genus Shewanella.

Science.gov (United States)

Yousfi, K; Bekal, S; Usongo, V; Touati, A

2017-08-01

Shewanella spp. are commonly known as environmental bacteria and are most frequently isolated from aquatic areas. Currently, diseases syndromes and multidrug resistance have increasingly been reported in the genus Shewanella. Some species are associated with various infections, such as skin and soft tissue infections, as well as bacteremia. Generally, these bacteria are opportunistic and mostly affect people with an impaired immune system. This genus is also a probable vehicle and progenitor of antibiotic resistance genes. In fact, several resistance genes and mobile genetic elements have been identified in some resistant species isolated from environmental or clinical settings. These genes confer resistance to different antibiotic classes, including those used in therapies such as β-lactams and quinolones, and are generally located on the chromosome. Recently, a multidrug-resistant (MDR) plasmid harboring several drug resistance genes associated with transposons and integrons has been identified in Shewanella xiamenensis. These antibiotic resistance genes can circulate in the environment and contribute to the emergence of antibiotic resistance. This review describes different aspects of Shewanella, focusing on the infections caused by this genus, as well as their role in the propagation of antibiotic resistance via mobile genetic elements.

Distribution of Shewanella putrefaciens and Desulfovibrio vulgaris in ...

African Journals Online (AJOL)

Distribution of Shewanella putrefaciens and Desulfovibrio vulgaris in sulphidogenic biofilms of industrial cooling water systems determined by fluorescent in situ hybridisation. Elise S McLeod, Raynard MacDonald, Volker S. Brozel ...

Shewanella alga bacteremia in two patients with lower leg ulcers

DEFF Research Database (Denmark)

Domínguez, H.; Vogel, Birte Fonnesbech; Gram, Lone

1996-01-01

of infection. Both patients survived; however, one of them had extensive myonecrosis, while the other patient had an uncomplicated course. The strains were initially believed to be Shewanella putrefaciens on the basis of key characteristics and results of the API 20NE identification system (bioMerieux, Marcy l......The first Danish cases of Shewanella alga bacteremia in two patients with chronic lower leg ulcers are reported. Both patients were admitted to the hospital during the same month of a very warm summer and had been exposed to the same marine environment, thereby suggesting the same source...

PV power plants

Energy Technology Data Exchange (ETDEWEB)

NONE

2012-07-01

Within the international seminar of the Ostbayerisches Technologie-Transfer-Institut e.V. (OTTI) at 11th June, 2012 in Munich (Federal Republic of Germany), the following lectures were held: (1) Technical due diligence (Dietmar Obst); (2) Certification / rating system for large PV plants (Robert Pfatischer); (3) O and M requirements (Lars Rulf); (4) IR photography for large scale systems (Bernhard Weinreich); (5) New market models for PV systems - direct marketing and sales of PV electricity (Martin Schneider); (6) Needs and benefits for plant certification for grid connection and operation (Christoph Luetke-Lengerich); (7) Lare volume module testing / Screening in the field and workshop (Semir Merzoug); (8) Dismantling costs of large scale PV plants (Siegfried Schimpf).

Building Integrated PV and PV/Hybrid Products - The PV:BONUS Experience: Preprint

Energy Technology Data Exchange (ETDEWEB)

Thomas, H.; Pierce, L. K.

2001-10-01

Presented at the 2001 NCPV Program Review Meeting: Successes and lessons learned from PV:BONUS (Building Opportunities in the United States in PV). This program has funded the development of PV or PV/hybrid products for building applications.

Molecular characterization and bioactivity profile of the tropical sponge-associated bacterium Shewanella algae VCDB

Science.gov (United States)

Rachanamol, R. S.; Lipton, A. P.; Thankamani, V.; Sarika, A. R.; Selvin, J.

2014-06-01

The pigmented, rod-shaped, Gram-negative, motile bacteria isolated from marine sponge Callyspongia diffusa exhibiting bioactivity was characterized as Shewanella algae (GenBank: KC623651). The 16S rRNA gene sequence-based phylogenetic analysis showed its similarity with the member of Shewanella and placed in a separate cluster with the recognized bacteria S. algae (PSB-05 FJ86678) with which it showed 99.0 % sequence similarity. Growth of the strain was optimum at temperature 30 °C, pH 8.0 in the presence of 2.0-4.0 % of NaCl. High antibiotic activity against microbes such as Escherichia coli (MTCC 40), S. typhii (MTCC 98), P. vulgaris (MTCC 426), V. fluvialis, V. anguillarum, E. cloacae, and L. lactis was recorded. The growth of fungal pathogens such as Aspergillus niger, Aspergillus fumigatus, Saccharomyces cerevisiae, and Colletotrichum gloeosporioides was effectively controlled.

PV-CAD: an integrated tool for designing PV facades; PV-CAD - Ein integriertes Werkzeug zur Auslegung von PV-Fassaden

Energy Technology Data Exchange (ETDEWEB)

Giese, H.; Viotto, M. [Inst. fuer Solare Energieversorgungstechnik (ISET) e.V., Kassel (Germany); Esser, M.; Pukrop, D. [Univ. Oldenburg (Germany). Abt. Energie- und Halbleiterforschung; Stellbogen, D. [Zentrum fuer Sonnenergie- und Wasserstoff-Forschung, Stuttgart (Germany)

1997-12-31

PV-CAD provides PV system planners with a practice-oriented tool for an efficient design of PV facades. Being compatible with the standard programmes of the architects` and electrical engineering sectors it can be used on already existing systems and allows the user to draw on previously acquired knowedge. Its open interfaces permit the integration of further design tools. PV CAD works under Microsoft Windows for which it has the necessary graphic user interface. Its compliance to PC standards opens up a wide range of applications and permits its use also on inexpensive computers. Thanks to its promotion by the Federal Ministry for Education, Science, Research, and Technology under the research project ``Computer programmes for the design of photovoltaic facades`` PV-CAD is available at a moderate price. PV-CAD permits an efficient planning of solar facades and therefore has the potential to stimulate the use of PV on buildings. (orig.) [Deutsch] Mit PV-CAD steht dem Anlagenplaner ein anwendungsorientiertes Werkzeug zur Verfuegung, das eine rationelle Auslegung von PV-Fassaden ermoeglicht. Die Kompatibilitaet zu Standardprogrammen aus dem Architektur- und Elektrosektor erlaubt die Nutzung bereits vorhandener Systeme und damit erworbener Kenntnisse. Offene Schnittstellen gestatten die Einbindung weiterer Entwurfswerkzeuge. PV-CAD arbeitet unter Microsoft-Windows und verfuegt ueber die entsprechende grafische Benutzerschnittstelle. Die Kompatibilitaet zum PC-Standard eroeffnet eine sehr breite Anwenderbasis und ermoeglicht den Einsatz des Programms auch auf preiswerten Rechnern. Aufgrund der Foerderung durch das Bundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie im Rahmen des Forschungsprojekts `Rechnerprogramm zur Auslegung von Photovoltaik-Fassaden` steht PV-CAD preiswert zur Verfuegung. PV-CAD ermoeglicht eine effiziente Planung von Solarfassaden und kann daher dem PV-Einsatz in Gebaeuden weitere Impulse geben. (orig.)

PV-WEB: internet-based PV information tool

International Nuclear Information System (INIS)

Cowley, P.

2003-01-01

This report gives details of a project to create a web-based information system on photovoltaic (PV) systems for the British PV Association (PV-UK) for use by decision makers in government, the utilities, and the housing and construction sectors. The project, which aims to provide an easily accessible tool for UK companies, promote PV technology, increase competitiveness, and identify market opportunities, is described. The design of the web site and its implementation and the evolution are discussed, along with the maintenance of the site by PV-UK and the opportunities offered to PV-UK Members

PV-WEB: internet-based PV information tool

Energy Technology Data Exchange (ETDEWEB)

Cowley, P

2003-07-01

This report gives details of a project to create a web-based information system on photovoltaic (PV) systems for the British PV Association (PV-UK) for use by decision makers in government, the utilities, and the housing and construction sectors. The project, which aims to provide an easily accessible tool for UK companies, promote PV technology, increase competitiveness, and identify market opportunities, is described. The design of the web site and its implementation and the evolution are discussed, along with the maintenance of the site by PV-UK and the opportunities offered to PV-UK Members.

PV-Developer. A Concept Paper. Version 4.0

International Nuclear Information System (INIS)

2001-10-01

The market for Photovoltaic Energy systems is developing very rapidly with annual growth rates in the range of 20-40%. The growth creates new business opportunities for project development. The markets are immature and the competitiveness of PV is increasing, whereby it is important to develop the business concept within the next few years if the long-term aim is to become a major player in the field of PV-project development. Like in the field of wind energy, which has grown to a large-scale business area within the last decade, the long-term perspectives of photovoltaic energy will depend upon the market development, interest groups and stake holders. The solar power developers might be catalysts for high growth rates like in the wind energy field. The concern for global warming leads the international energy policies in favour of renewable energy incentives followed by the technological development of PV-equipment, which constantly improves the cost level of PV-produced electricity. The markets for PV-systems are geographically widespread and the way to implement systems goes to a large extent via financing from international governmental as well as non-governmental lateral and bilateral aid organisations. Lead times to develop projects are counted in years, and the time from the first project idea to the final commissioning of the installed plants might take 3-5 years. More specific studies of market segments and business opportunities, development of market penetration and design of strategy must be carried out. Organisation seems to be a major issue as the complexity of the projects and the project location in 3rd world countries as well as in the industrialised countries combined with high proportion of donor funding will require a high level of organisation and coordination. In general a detailed study should be made in order to create a business plan. The business plan must contain budgets, volume estimates, sensitivity analyses, organisational proposals

A Rare Case of Pneumonia Caused by Shewanella putrefaciens

Directory of Open Access Journals (Sweden)

Rajshree Patel

2012-01-01

Full Text Available Shewanella putrefaciens is a gram-negative, nonfermentative, oxidase positive, motile bacillus that produces hydrogen sulphide. It is found widely in the nature especially in marine environments. In some very rare cases Shewanella putrefaciens can be a human pathogen. It can produce a wide variety of clinical syndromes including bacteremia as well as skin and soft tissue infections. However, pneumonia due to S. putrefaciens is rare; there are a total of 4 reported cases in the literature. We present a case of 63-year-old male who was presented to emergency room status after cardiac arrest, fell into sea water face down. On the second day of hospitalization, he was diagnosed to have pneumonia based on the clinical, radiological, and laboratory findings. Empirical antibiotic treatment with vancomycin and piperacillin/tazobactam combination was initiated. Gram-stained smear of endotracheal aspirate yielded gram-negative bacteria, and the isolate grown from endotracheal aspirate culture was identified as S. putrefaciens by Biomerieux API 20 NE technique. On review of the literature and according to culture and sensitivity results, therapy in our patient was changed to cefepime. Patient’s pneumonia improved with treatment with cefepime. We believe that our patient developed pneumonia evidently caused by S. putrefaciens, after near drowning in sea water. The pneumonia resolved after treatment with cefepime.

U.S. Residential Photovoltaic (PV) System Prices, Q4 2013 Benchmarks: Cash Purchase, Fair Market Value, and Prepaid Lease Transaction Prices

Energy Technology Data Exchange (ETDEWEB)

Davidson, C.; James, T. L.; Margolis, R.; Fu, R.; Feldman, D.

2014-10-01

The price of photovoltaic (PV) systems in the United States (i.e., the cost to the system owner) has dropped precipitously in recent years, led by substantial reductions in global PV module prices. This report provides a Q4 2013 update for residential PV systems, based on an objective methodology that closely approximates the book value of a PV system. Several cases are benchmarked to represent common variation in business models, labor rates, and module choice. We estimate a weighted-average cash purchase price of $3.29/W for modeled standard-efficiency, polycrystalline-silicon residential PV systems installed in the United States. This is a 46% decline from the 2013-dollar-adjusted price reported in the Q4 2010 benchmark report. In addition, this report frames the cash purchase price in the context of key price metrics relevant to the continually evolving landscape of third-party-owned PV systems by benchmarking the minimum sustainable lease price and the fair market value of residential PV systems.

Biological characteristics and pathogenicity of a highly pathogenic Shewanella marisflavi infected sea cucumber (Apostichopus uaponicus)

Science.gov (United States)

Shewanella marisflavi isolate AP629 was characterized as a novel pathogen of sea cucumber. The LD50 values (14 days) in sea cucumber and swordtail fish were 3.89 × 106 and 4.85 × 104 CFU g-1 body weight, respectively. Studies on S. marisflavi had been conducted, including morphology, physiological a...

Ablating ErbB4 in PV neurons attenuates synaptic and cognitive deficits in an animal model of Alzheimer's disease.

Science.gov (United States)

Zhang, Heng; Zhang, Ling; Zhou, Dongming; He, Xiao; Wang, Dongpi; Pan, Hongyu; Zhang, Xiaoqin; Mei, Yufei; Qian, Qi; Zheng, Tingting; Jones, Frank E; Sun, Binggui

2017-10-01

Accumulation of amyloid β (Aβ) induces neuronal, synaptic, and cognitive deficits in patients and animal models of Alzheimer's disease (AD). The underlying mechanisms, however, remain to be fully elucidated. In the present study, we found that Aβ interacted with ErbB4, a member of the receptor tyrosine kinase family and mainly expressed in GABAergic interneurons. Deleting ErbB4 in parvalbumin-expressing neurons (PV neurons) significantly attenuated oligomeric Aβ-induced suppression of long term potentiation (LTP). Furthermore, specific ablation of ErbB4 in PV neurons via Cre/loxP system greatly improved spatial memory and synaptic plasticity in the hippocampus of hAPP-J20 mice. The deposition of Aβ detected by 3D6 and Thioflavin S staining and the proteolytic processing of hAPP analyzed by western blotting were not affected in the hippocampus of hAPP-J20 mice by deleting ErbB4 in PV neurons. Our data suggested that ErbB4 in PV neurons mediated Aβ-induced synaptic and cognitive dysfunctions without affecting Aβ levels. Copyright © 2017 Elsevier Inc. All rights reserved.

Identification of Shewanella baltica as the most important H2S-producing species during iced storage of Danish marine fish.

Science.gov (United States)

Fonnesbech Vogel, Birte; Venkateswaran, Kasthuri; Satomi, Masataka; Gram, Lone

2005-11-01

Shewanella putrefaciens has been considered the main spoilage bacteria of low-temperature stored marine seafood. However, psychrotropic Shewanella have been reclassified during recent years, and the purpose of the present study was to determine whether any of the new Shewanella species are important in fish spoilage. More than 500 H2S-producing strains were isolated from iced stored marine fish (cod, plaice, and flounder) caught in the Baltic Sea during winter or summer time. All strains were identified as Shewanella species by phenotypic tests. Different Shewanella species were present on newly caught fish. During the warm summer months the mesophilic human pathogenic S. algae dominated the H2S-producing bacterial population. After iced storage, a shift in the Shewanella species was found, and most of the H2S-producing strains were identified as S. baltica. The 16S rRNA gene sequence analysis confirmed the identification of these two major groups. Several isolates could only be identified to the genus Shewanella level and were separated into two subgroups with low (44%) and high (47%) G+C mol%. The low G+C% group was isolated during winter months, whereas the high G+C% group was isolated on fish caught during summer and only during the first few days of iced storage. Phenotypically, these strains were different from the type strains of S. putrefaciens, S. oneidensis, S. colwelliana, and S. affinis, but the high G+C% group clustered close to S. colwelliana by 16S rRNA gene sequence comparison. The low G+C% group may constitute a new species. S. baltica, and the low G+C% group of Shewanella spp. strains grew well in cod juice at 0 degrees C, but three high G+C Shewanella spp. were unable to grow at 0 degrees C. In conclusion, the spoilage reactions of iced Danish marine fish remain unchanged (i.e., trimethylamine-N-oxide reduction and H2S production); however, the main H2S-producing organism was identified as S. baltica.

PV and PV/hybrid products for buildings

Energy Technology Data Exchange (ETDEWEB)

Thomas, H. P.; Hayter, S. J.; Martin, R. L., Pierce, L. K.

2000-05-15

Residential, commercial, and industrial buildings combined are the largest consumers of electricity in the United States and represent a significant opportunity for photovoltaic (PV) and PV/hybrid systems. The U.S. Department of Energy (DOE) is conducting a phased research and product development program, Building Opportunities in the United States for Photovoltaics (PV:BONUS), focused on this market sector. The purpose of the program is to develop technologies and foster business arrangements integrating cost-effective PV or hybrid products into buildings. The first phase was completed in 1996 and a second solicitation, PV:BONUS2, was initiated during 1997. These projects are resulting in a variety of building-integrated products. This paper summarizes the recent progress of the seven firms and collaborative teams currently participating in PV:BONUS2 and outlines planned work for the final phase of their work.

Potential for luxS related signalling in marine bacteria and production of autoinducer-2 in the genus Shewanella

Directory of Open Access Journals (Sweden)

Wagner-Döbler Irene

2008-01-01

Full Text Available Abstract Background The autoinducer-2 (AI-2 group of signalling molecules are produced by both Gram positive and Gram negative bacteria as the by-product of a metabolic transformation carried out by the LuxS enzyme. They are the only non species-specific quorum sensing compounds presently known in bacteria. The luxS gene coding for the AI-2 synthase enzyme was found in many important pathogens. Here, we surveyed its occurrence in a collection of 165 marine isolates belonging to abundant marine phyla using conserved degenerated PCR primers and sequencing of selected positive bands to determine if the presence of the luxS gene is phylogenetically conserved or dependent on the habitat. Results The luxS gene was not present in any of the Alphaproteobacteria (n = 71 and Bacteroidetes strains (n = 29 tested; by contrast, these bacteria harboured the sahH gene, coding for an alternative enzyme for the detoxification of S-adenosylhomocysteine (SAH in the activated methyl cycle. Within the Gammaproteobacteria (n = 76, luxS was found in all Shewanella, Vibrio and Alteromonas isolates and some Pseudoalteromonas and Halomonas species, while sahH was detected in Psychrobacter strains. A number of Gammaproteobacteria (n = 27 appeared to have neither the luxS nor the sahH gene. We then studied the production of AI-2 in the genus Shewanella using the Vibrio harveyi bioassay. All ten species of Shewanella tested produced a pronounced peak of AI-2 towards the end of the exponential growth phase in several media investigated. The maximum of AI-2 activity was different in each Shewanella species, ranging from 4% to 46% of the positive control. Conclusion The data are consistent with those of fully sequenced bacterial genomes and show that the potential for luxS related signalling is dependent on phylogenetic affiliation rather than ecological niche and is largest in certain groups of Gammaproteobacteria in the marine environment. This is the first report on AI-2

Comparative genomic reconstruction of transcriptional networks controlling central metabolism in the Shewanella genus

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Kovaleva Galina

2011-06-01

Full Text Available Abstract Background Genome-scale prediction of gene regulation and reconstruction of transcriptional regulatory networks in bacteria is one of the critical tasks of modern genomics. The Shewanella genus is comprised of metabolically versatile gamma-proteobacteria, whose lifestyles and natural environments are substantially different from Escherichia coli and other model bacterial species. The comparative genomics approaches and computational identification of regulatory sites are useful for the in silico reconstruction of transcriptional regulatory networks in bacteria. Results To explore conservation and variations in the Shewanella transcriptional networks we analyzed the repertoire of transcription factors and performed genomics-based reconstruction and comparative analysis of regulons in 16 Shewanella genomes. The inferred regulatory network includes 82 transcription factors and their DNA binding sites, 8 riboswitches and 6 translational attenuators. Forty five regulons were newly inferred from the genome context analysis, whereas others were propagated from previously characterized regulons in the Enterobacteria and Pseudomonas spp.. Multiple variations in regulatory strategies between the Shewanella spp. and E. coli include regulon contraction and expansion (as in the case of PdhR, HexR, FadR, numerous cases of recruiting non-orthologous regulators to control equivalent pathways (e.g. PsrA for fatty acid degradation and, conversely, orthologous regulators to control distinct pathways (e.g. TyrR, ArgR, Crp. Conclusions We tentatively defined the first reference collection of ~100 transcriptional regulons in 16 Shewanella genomes. The resulting regulatory network contains ~600 regulated genes per genome that are mostly involved in metabolism of carbohydrates, amino acids, fatty acids, vitamins, metals, and stress responses. Several reconstructed regulons including NagR for N-acetylglucosamine catabolism were experimentally validated in S

Identification and characterization of new designer drug 4-fluoro-PV9 and α-PHP in the seized materials.

Science.gov (United States)

Majchrzak, Milena; Rojkiewicz, Marcin; Celiński, Rafał; Kuś, Piotr; Sajewicz, Mieczysław

In this study, we present identification and physicochemical characterization of new cathinone derivatives, 4-fluoro-PV9 and already known α-PHP in seized materials. Although the disclosure of α-PHP from an illegal product had been reported and characterized to some extent, the data on α-PHP are also presented together with those of 4-fluoro-PV9. The data of characterization for the two compounds were obtained by high-performance liquid chromatography (HPLC)-mass spectrometry and HPLC-diode array detection, electrospray ionization/ion trap mass spectrometry in MS 2 and MS 3 modes, gas chromatography-mass spectrometry, thermogravimetric analysis, differential scanning calorimetry, Fourier transform infrared spectroscopy, ultraviolet-visible spectroscopy, and nuclear magnetic resonance spectroscopy. To our knowledge, this is the first report for identification and detailed characterization of 4-fluoro-PV9 circulated on the illegal drug market.

Projecting of PV facades in consideration of PV-specific operating conditions; Besonderheiten bei der Projektierung von Photovoltaik-Fassadenanlagen

Energy Technology Data Exchange (ETDEWEB)

Decker, B.; Grimmig, B.; Mencke, D. [Institut fuer Solarenergieforschung GmbH Hameln/Emmerthal (ISFH), Emmerthal (Germany). Gruppe Photovoltaik-Systeme; Stellbogen, D. [Zentrum fuer Sonnenenergie- und Wasserstoff-Forschung Baden-Wuerttemberg (ZSW), Stuttgart (Germany). Fachgebiet Photovoltaische Anlagentechnik

1998-02-01

PV facades can provide several additional functions such as weather protection, thermal insulation, daylighting or sun protection. On the other hand, specific operating conditions for PV facades must be taken into account when selecting components and designing the system. Depending on ventilation conditions, there is a large range of maximum module temperatures. South-oriented PV facades receive about 30% less yearly irradiation than an optimally inclined PV generator, hence reflection losses are approximately 4% higher. The maximum of yearly irradiation lies only in the 400-600 W/m{sup 2} range. Surrounding buildings and/or vegetation can impair performance of the PV-facades. For a south-oriented PV facade an annual yield in the range of 470-560 kwh/kW{sub p}.a has been prodicted which was verified by operating results of eight PV facades. (orig.) [Deutsch] Photovoltaik (PV) Fassaden ermoeglichen neben der Stromerzeugung zusaetzliche Funktionen wie Wetterschutz bzw. Waermedaemmung des Gebaeudes oder Tageslichtnutzung bzw. Sonnenschutz der Innenraeume. Allerdings muessen fassadenspezifische Betriebsbedingungen, bei der Komponentenauswahl und Systemauslegung beruecksichtigt werden. Unterschiedliche Hinterlueftungsbedingungen fuehren zu einer grossen Bandbreite der maximalen Modultemperatur. PV-Suedfassaden empfangen etwa 30% weniger Jahreseinstrahlung als ein optimal geneigter PV-Generator. Die Haelfte der jaehrlichen Einstrahlung trifft mit Einfallswinkeln groesser 50 auf die vertikal angeordneten Module wodurch die Reflexionsverluste um ca. 4% hoeher sind. Das Maximum der Jahreseinstrahlung liegt nur um 400-600 W/m{sup 2} und erreicht selten Werte ueber 800 W/m{sup 2}. Umliegende Gebaeude oder Vegetation koennen zu Teilabschattungen des Generators fuehren. Fuer eine vertikale PV-Suedfassade wird ein Jahresenergieertrag in Hoehe von 470-560 kWh/kW{sub p}.a prognostiziert, der anhand der Betriebsergebnisse von acht PV-Fassadenanlagen verifiziert werden konnte

Molecular underpinnings of nitrite effect on CymA-dependent respiration in Shewanella oneidensis

Directory of Open Access Journals (Sweden)

Miao Jin

2016-07-01

Full Text Available Shewanella exhibit a remarkable versatility of respiration, with a diverse array of electron acceptors (EAs. In environments where these bacteria thrive, multiple EAs are usually present. However, we know little about strategies by which these EAs and their interaction affect ecophysiology of Shewanella. In this study, we demonstrate in the model strain, Shewanella oneidensis MR-1, that nitrite, not through nitric oxide to which it may convert, inhibits respiration of fumarate, and probably many other EAs whose reduction depends on quinol dehydrogenase CymA. This is achieved via the repression of cyclic adenosine monophosphate (cAMP production, a second messenger required for activation of cAMP-receptor protein (Crp which plays a primary role in regulation of respiration. If nitrite is not promptly removed, intracellular cAMP levels drop, and this impairs Crp activity. As a result, the production of nitrite reductase NrfA, CymA, and fumarate reductase FccA is substantially reduced. In contrast, nitrite can be simultaneously respired with trimethylamine N-oxide, resulting in enhanced biomass.

Impacts of PV Array Sizing on PV Inverter Lifetime and Reliability

DEFF Research Database (Denmark)

Sangwongwanich, Ariya; Yang, Yongheng; Sera, Dezso

2017-01-01

. However, oversizing the PV array will increase the loading of PV inverters, which may have undesired influence on the PV inverter lifetime and reliability. In that case, it may result in a negative impact on the overall PV energy cost, due to the increased maintenance for the PV inverters. This paper...... evaluates the lifetime of PV inverters considering the PV array sizing and installation sites, e.g., Denmark and Arizona. The results reveal that the PV array sizing has a considerable impact on the PV inverter lifetime and reliability, especially in Denmark, where the average solar irradiance level...

Impacts of PV Array Sizing on PV Inverter Lifetime and Reliability

OpenAIRE

Sangwongwanich, Ariya; Yang, Yongheng; Sera, Dezso; Blaabjerg, Frede

2017-01-01

In order to enable a more wide-scale utilization of PV systems, the cost of PV energy has to be comparable with other energy sources. Oversizing the PV array is one common approach to reduce the cost of PV energy, since it increases the PV energy yield during low solar irradiance conditions. However, oversizing the PV array will increase the loading of PV inverters, which may have undesired influence on the PV inverter lifetime and reliability. In that case, it may result in a negative impact...

Reaction of common bean lines to Xanthomonas axonopodis pv. phaseoli and Curtobacterium flaccumfaciens pv. flaccumfaciens

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Tamires Ribeiro

2016-12-01

Full Text Available The aim of this study was to evaluate the resistance of 58 common bean lines against common bacterial blight (Xanthomonas axonopodis pv. phaseoli and bacterial wilt (Curtobacterium flaccumfaciens pv. flaccumfaciens. The experimental design consisted of completely randomized blocks, with four replications per pathogen. The results were subjected to variance analysis by the F test at 1% probability. Significant differences between the treatments indicated different resistance levels among the lines against both pathogens. According to the Scott-Knott test, six lines were resistant to Xanthomonas axonopodis pv. phaseoli, 14 moderately resistant, and 38 susceptible. To Curtobacterium flaccumfaciens pv. flaccumfaciens, 11 lines were resistant, 26 moderately resistant and 21 susceptible. Among these, the lines Pr10-3-4/1, Pr10-5-2/1 and Pr10-5- 2/2 of the black bean group and C10-2-4/2 of the Carioca group were resistant to both major bacterial diseases affecting common bean in Brazil.

Cold adaptation of the mononuclear molybdoenzyme periplasmic nitrate reductase from the Antarctic bacterium Shewanella gelidimarina

Energy Technology Data Exchange (ETDEWEB)

Simpson, Philippa J.L. [School of Chemistry, University of Sydney, New South Wales 2006 (Australia); Codd, Rachel, E-mail: rachel.codd@sydney.edu.au [School of Chemistry, University of Sydney, New South Wales 2006 (Australia); School of Medical Sciences (Pharmacology) and Bosch Institute, University of New South Wales, New South Wales 2006 (Australia)

2011-11-04

Highlights: Black-Right-Pointing-Pointer Cold-adapted phenotype of NapA from the Antarctic bacterium Shewanella gelidimarina. Black-Right-Pointing-Pointer Protein homology model of NapA from S. gelidimarina and mesophilic homologue. Black-Right-Pointing-Pointer Six amino acid residues identified as lead candidates governing NapA cold adaptation. Black-Right-Pointing-Pointer Molecular-level understanding of designing cool-temperature in situ oxyanion sensors. -- Abstract: The reduction of nitrate to nitrite is catalysed in bacteria by periplasmic nitrate reductase (Nap) which describes a system of variable protein subunits encoded by the nap operon. Nitrate reduction occurs in the NapA subunit, which contains a bis-molybdopterin guanine dinucleotide (Mo-MGD) cofactor and one [4Fe-4S] iron-sulfur cluster. The activity of periplasmic nitrate reductase (Nap) isolated as native protein from the cold-adapted (psychrophilic) Antarctic bacterium Shewanella gelidimarina (Nap{sub Sgel}) and middle-temperature adapted (mesophilic) Shewanella putrefaciens (Nap{sub Sput}) was examined at varied temperature. Irreversible deactivation of Nap{sub Sgel} and Nap{sub Sput} occurred at 54.5 and 65 Degree-Sign C, respectively. When Nap{sub Sgel} was preincubated at 21-70 Degree-Sign C for 30 min, the room-temperature nitrate reductase activity was maximal and invariant between 21 and 54 Degree-Sign C, which suggested that Nap{sub Sgel} was poised for optimal catalysis at modest temperatures and, unlike Nap{sub Sput}, did not benefit from thermally-induced refolding. At 20 Degree-Sign C, Nap{sub Sgel} reduced selenate at 16% of the rate of nitrate reduction. Nap{sub Sput} did not reduce selenate. Sequence alignment showed 46 amino acid residue substitutions in Nap{sub Sgel} that were conserved in NapA from mesophilic Shewanella, Rhodobacter and Escherichia species and could be associated with the Nap{sub Sgel} cold-adapted phenotype. Protein homology modeling of Nap{sub Sgel} using a

Cold adaptation of the mononuclear molybdoenzyme periplasmic nitrate reductase from the Antarctic bacterium Shewanella gelidimarina

International Nuclear Information System (INIS)

Simpson, Philippa J.L.; Codd, Rachel

2011-01-01

Highlights: ► Cold-adapted phenotype of NapA from the Antarctic bacterium Shewanella gelidimarina. ► Protein homology model of NapA from S. gelidimarina and mesophilic homologue. ► Six amino acid residues identified as lead candidates governing NapA cold adaptation. ► Molecular-level understanding of designing cool-temperature in situ oxyanion sensors. -- Abstract: The reduction of nitrate to nitrite is catalysed in bacteria by periplasmic nitrate reductase (Nap) which describes a system of variable protein subunits encoded by the nap operon. Nitrate reduction occurs in the NapA subunit, which contains a bis-molybdopterin guanine dinucleotide (Mo–MGD) cofactor and one [4Fe–4S] iron–sulfur cluster. The activity of periplasmic nitrate reductase (Nap) isolated as native protein from the cold-adapted (psychrophilic) Antarctic bacterium Shewanella gelidimarina (Nap Sgel ) and middle-temperature adapted (mesophilic) Shewanella putrefaciens (Nap Sput ) was examined at varied temperature. Irreversible deactivation of Nap Sgel and Nap Sput occurred at 54.5 and 65 °C, respectively. When Nap Sgel was preincubated at 21–70 °C for 30 min, the room-temperature nitrate reductase activity was maximal and invariant between 21 and 54 °C, which suggested that Nap Sgel was poised for optimal catalysis at modest temperatures and, unlike Nap Sput , did not benefit from thermally-induced refolding. At 20 °C, Nap Sgel reduced selenate at 16% of the rate of nitrate reduction. Nap Sput did not reduce selenate. Sequence alignment showed 46 amino acid residue substitutions in Nap Sgel that were conserved in NapA from mesophilic Shewanella, Rhodobacter and Escherichia species and could be associated with the Nap Sgel cold-adapted phenotype. Protein homology modeling of Nap Sgel using a mesophilic template with 66% amino acid identity showed the majority of substitutions occurred at the protein surface distal to the Mo–MGD cofactor. Two mesophilic ↔ psychrophilic

A rare case of Shewanella putrefaciens bacteremia in a patient of road traffic accident

Directory of Open Access Journals (Sweden)

Ritesh Ranjan

2017-01-01

Full Text Available Shewanella putrefaciens rarely causes human infection. These are mostly found in environment and food stuffs. Shewanella are often found in mixed culture. It has been implicated in cellulitis, otitis media, and septicemia. It may be found in respiratory tract, urine, feces, and pleural fluid. There is no definite guideline for therapeutic option. In general, these are susceptible to various antimicrobial agents but are often resistant to penicillin and cephalothin. We report a rare case of bacteremia by S. putrefaciens in a patient of head injury with polytrauma after a road traffic accident.

Integrated genome-based studies of Shewanella ecophysiology

Energy Technology Data Exchange (ETDEWEB)

Segre Daniel; Beg Qasim

2012-02-14

This project was a component of the Shewanella Federation and, as such, contributed to the overall goal of applying the genomic tools to better understand eco-physiology and speciation of respiratory-versatile members of Shewanella genus. Our role at Boston University was to perform bioreactor and high throughput gene expression microarrays, and combine dynamic flux balance modeling with experimentally obtained transcriptional and gene expression datasets from different growth conditions. In the first part of project, we designed the S. oneidensis microarray probes for Affymetrix Inc. (based in California), then we identified the pathways of carbon utilization in the metal-reducing marine bacterium Shewanella oneidensis MR-1, using our newly designed high-density oligonucleotide Affymetrix microarray on Shewanella cells grown with various carbon sources. Next, using a combination of experimental and computational approaches, we built algorithm and methods to integrate the transcriptional and metabolic regulatory networks of S. oneidensis. Specifically, we combined mRNA microarray and metabolite measurements with statistical inference and dynamic flux balance analysis (dFBA) to study the transcriptional response of S. oneidensis MR-1 as it passes through exponential, stationary, and transition phases. By measuring time-dependent mRNA expression levels during batch growth of S. oneidensis MR-1 under two radically different nutrient compositions (minimal lactate and nutritionally rich LB medium), we obtain detailed snapshots of the regulatory strategies used by this bacterium to cope with gradually changing nutrient availability. In addition to traditional clustering, which provides a first indication of major regulatory trends and transcription factors activities, we developed and implemented a new computational approach for Dynamic Detection of Transcriptional Triggers (D2T2). This new method allows us to infer a putative topology of transcriptional dependencies

Shewanella algae in acute gastroenteritis

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S Dey

2015-01-01

Full Text Available Shewanella algae is an emerging bacteria rarely implicated as a human pathogen. Previously reported cases of S. algae have mainly been associated with direct contact with seawater. Here we report the isolation of S. algae as the sole etiological agent from a patient suffering from acute gastroenteritis with bloody diarrhoea. The bacterium was identified by automated identification system and 16S rRNA gene sequence analysis. Our report highlights the importance of looking for the relatively rare aetiological agents in clinical samples that does not yield common pathogens. It also underscores the usefulness of automated systems in identification of rare pathogens.

PV potential and potential PV rent in European regions

DEFF Research Database (Denmark)

Hansen, Anders Chr.; Thorn, Paul

2013-01-01

The paper provides a GIS based model for assessing the potentials of photovoltaic electricity in Europe by NUTS 2 regions. The location specific energy potential per PV-­‐panel area is estimated based on observations of solar irradiation, conversion efficiency, levelised costs and the social value...... of PV-­‐electricity. Combined with the potential density of PV-­‐panel area based on land cover and environental restrictions, the PV energy potential and the potential PV ressource rent is calculated. These calculations enbable the model to estimate the regional patterns at NUTS 2 level...

Distribution and Genetic Characteristics of SXT/R391 Integrative Conjugative Elements in Shewanella spp. From China

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Yujie Fang

2018-05-01

Full Text Available The genus Shewanella consists of facultatively anaerobic Gram-negative bacteria, which are regarded as potential agents of food contamination and opportunistic human pathogens. Information about the distribution and genetic characteristics of SXT/R391 integrative conjugative elements (ICEs in Shewanella species is limited. Here, 91 Shewanella strains collected from diverse samples in China were studied for the presence of SXT/R391 ICEs. Three positive strains, classified as Shewanella upenei, were obtained from patients and water from a local mill. In light of their close clonal relationships and high sequence similarity, a representative ICE was selected and designated ICESupCHN110003. The BLASTn searches against GenBank showed that ICEVchBan5 was most closely related to ICESupCHN110003, with the coverage of 76% and identity of 99%. The phylogenetic tree of concatenated core genes demonstrated that ICESupCHN110003 formed a distinct branch outside the cluster comprising ICEValA056-1, ICEPmiCHN2410, and ICEPmiChn1. Comparison of the genetic structures revealed that ICESupCHN110003 encoded uncommon genes in hotspots, such as specific type III restriction-modification system, conferring adaptive functions to the host. Based on the low coverage in the sequence analysis, independent clade in the phylogenetic tree, and unique inserted fragments in hotspots, ICESupCHN110003 represented a novel SXT/R391 element, which widened the list of ICEs. Furthermore, the antibiotic resistance genes floR, strA, strB, and sul2 in ICESupCHN110003 and resistance to multiple drugs of the positive isolates were detected. A cross-species transfer capability of the SXT/R391 ICEs was also discovered. In summary, it is necessary to reinforce continuous surveillance of SXT/R391 ICEs in the genus Shewanella.

PV-hybrid and mini-grid

Energy Technology Data Exchange (ETDEWEB)

NONE

2010-07-01

Within the 5th European PV-hybrid and mini-grid conference 29th and 30th April, 2010 in Tarragona (Spain) the following lectures were held: (1) Overview of IEA PVPS Task 11 PV-hybrid systems within mini grids; (2) Photovoltaic revolution for deployment in developing countries; (3) Legal and financial conditions for the sustainable operation of mini-grids; (4) EU instruments to promote renewable energies in developing countries; (5) PV hybridization of diesel electricity generators: Conditions of profitability and examples in differential power and storage size ranges; (6) Education suit of designing PV hybrid systems; (7) Sustainable renewable energy projects for intelligent rural electrification in Laos, Cambodia and Vietnam; (8) Techno-economic feasibility of energy supply of remote villages in Palestine by PV systems, diesel generators and electric grid (Case studies: Emnazeil and Atouf villages); (9) Technical, economical and sustainability considerations of a solar PV mini grid as a tool for rural electrification in Uganda; (10) Can we rate inverters for rural electrification on the basis of energy efficiency?; (11) Test procedures for MPPT charge controllers characterization; (12) Energy storage for mini-grid stabilization; (13) Redox flow batteries - Already an alternative storage solution for hybrid PV mini-grids?; (14) Control methods for PV hybrid mini-grids; (15) Partial AC-coupling in mini-grids; (15) Normative issues of small wind turbines in PV hybrid systems; (16) Communication solutions for PV hybrid systems; (17) Towards flexible control and communication of mini-grids; (18) PV/methanol fuel cell hybrid system for powering a highway security variable message board; (19) Polygeneration smartgrids: A solution for the supply of electricity, potable water and hydrogen as fuel for transportation in remote Areas; (20) Implementation of the Bronsbergen micro grid using FACDS; (21) A revisited approach for the design of PV wind hybrid systems; (22

Interband cascade (IC) photovoltaic (PV) architecture for PV devices

Science.gov (United States)

Yang, Rui Q.; Tian, Zhaobing; Mishima, Tetsuya D.; Santos, Michael B.; Johnson, Matthew B.; Klem, John F.

2015-10-20

A photovoltaic (PV) device, comprising a PV interband cascade (IC) stage, wherein the IC PV stage comprises an absorption region with a band gap, the absorption region configured to absorb photons, an intraband transport region configured to act as a hole barrier, and an interband tunneling region configured to act as an electron barrier. An IC PV architecture for a photovoltaic device, the IC PV architecture comprising an absorption region, an intraband transport region coupled to the absorption region, and an interband tunneling region coupled to the intraband transport region and to the adjacent absorption region, wherein the absorption region, the intraband transport region, and the interband tunneling region are positioned such that electrons will flow from the absorption region to the intraband transport region to the interband tunneling region.

Comparative Genomics Analysis and Phenotypic Characterization of Shewanella putrefaciens W3-18-1: Anaerobic Respiration, Bacterial Microcompartments, and Lateral Flagella

International Nuclear Information System (INIS)

Qiu, D.; Tu, Q.; He, Zhili; Zhou, Jizhong

2010-01-01

Respiratory versatility and psychrophily are the hallmarks of Shewanella. The ability to utilize a wide range of electron acceptors for respiration is due to the large number of c-type cytochrome genes present in the genome of Shewanella strains. More recently the dissimilatory metal reduction of Shewanella species has been extensively and intensively studied for potential applications in the bioremediation of radioactive wastes of groundwater and subsurface environments. Multiple Shewanella genome sequences are now available in the public databases (Fredrickson et al., 2008). Most of the sequenced Shewanella strains were isolated from marine environments and this genus was believed to be of marine origin (Hau and Gralnick, 2007). However, the well-characterized model strain, S. oneidensis MR-1, was isolated from the freshwater lake sediment of Lake Oneida, New York (Myers and Nealson, 1988) and similar bacteria have also been isolated from other freshwater environments (Venkateswaran et al., 1999). Here we comparatively analyzed the genome sequence and physiological characteristics of S. putrefaciens W3-18-1 and S. oneidensis MR-1, isolated from the marine and freshwater lake sediments, respectively. The anaerobic respirations, carbon source utilization, and cell motility have been experimentally investigated. Large scale horizontal gene transfers have been revealed and the genetic divergence between these two strains was considered to be critical to the bacterial adaptation to specific habitats, freshwater or marine sediments.

An Analysis of Open World PvP in LOTRO's PvMP as a Case Study for PvP Games

Directory of Open Access Journals (Sweden)

Toh Weimin

2014-11-01

Full Text Available This article focuses on the analysis of emergent gameplay, based on a case study of the author's subjective gameplay experience of Player versus Monster Player (PvMP in The Lord of the Rings Online (LOTRO. The argument presented here is that although there is a core system of Player versus Player (PvP which LOTRO shares with other online games, each type of online game has a specific kind of PvP system which attracts players to engage in the gameplay. For instance, the open world sandbox type of PvP attracts certain players to play in LOTRO's PvMP. One of the main aims of this study is thus to investigate some of the core systems of PvP gameplay in open world sandbox PvP. In this article, LOTRO is shown to offer unique opportunities for studying emergent gameplay in open world games, with particular relevance to PvP studies. Two of the core systems of PvP discussed include the design of the simple gameplay rules to support emergent gameplay, and the community's attitudes towards player's behaviours. The types of emergent gameplay discussed include free play versus negotiated fair play, the players' utilisation of strategies in open world PvP to support collaborative and competitive gameplay, and the changing dynamics of open ended gameplay. It is hoped that the analysis provided in this article would form the­ basis of future work on a more general framework for understanding PvP in other online games.

Fire resistant PV shingle assembly

Science.gov (United States)

Lenox, Carl J.

2012-10-02

A fire resistant PV shingle assembly includes a PV assembly, including PV body, a fire shield and a connection member connecting the fire shield below the PV body, and a support and inter-engagement assembly. The support and inter-engagement assembly is mounted to the PV assembly and comprises a vertical support element, supporting the PV assembly above a support surface, an upper interlock element, positioned towards the upper PV edge, and a lower interlock element, positioned towards the lower PV edge. The upper interlock element of one PV shingle assembly is inter-engageable with the lower interlock element of an adjacent PV shingle assembly. In some embodiments the PV shingle assembly may comprise a ventilation path below the PV body. The PV body may be slidably mounted to the connection member to facilitate removal of the PV body.

PV/T slates - Laboratory measurements; PV/T-Schiefer. Labormessungen

Energy Technology Data Exchange (ETDEWEB)

Kropf, S.

2003-07-01

This comprehensive, illustrated report for the Swiss Federal Office of Energy (SFOE) is one a series of five reports dealing with increasing the overall efficiency of photovoltaic (PV) installations by also using the heat collected by the dark-coloured PV panels. The work reported on addresses open questions on the use of the heat and its optimal use. This report deals with an experimental outdoor set-up and reviews in-situ measurements made on a prototype of a ventilated PV-tile system (PV/T-Slates). The report describes the configuration and construction of the experimental PV-tiled roof and the measurement system used to measure its electrical and thermal performance. The results of the measurements made are presented in detail in graphical form. The influence of various factors such as air-slit width and mounting angle are discussed.

Plasmodium vivax Tryptophan Rich Antigen PvTRAg36.6 Interacts with PvETRAMP and PvTRAg56.6 Interacts with PvMSP7 during Erythrocytic Stages of the Parasite.

Directory of Open Access Journals (Sweden)

Kriti Tyagi

Full Text Available Plasmodium vivax is most wide spread and a neglected malaria parasite. There is a lack of information on parasite biology of this species. Genome of this parasite encodes for the largest number of tryptophan-rich proteins belonging to 'Pv-fam-a' family and some of them are potential drug/vaccine targets but their functional role(s largely remains unexplored. Using bacterial and yeast two hybrid systems, we have identified the interacting partners for two of the P. vivax tryptophan-rich antigens called PvTRAg36.6 and PvTRAg56.2. The PvTRAg36.6 interacts with early transcribed membrane protein (ETRAMP of P.vivax. It is apically localized in merozoites but in early stages it is seen in parasite periphery suggesting its likely involvement in parasitophorous vacuole membrane (PVM development or maintenance. On the other hand, PvTRAg56.2 interacts with P.vivax merozoite surface protein7 (PvMSP7 and is localized on merozoite surface. Co-localization of PvTRAg56.2 with PvMSP1 and its molecular interaction with PvMSP7 probably suggest that, PvTRAg56.2 is part of MSP-complex, and might assist or stabilize the protein complex at the merozoite surface. In conclusion, the PvTRAg proteins have different sub cellular localizations and specific associated functions during intra-erythrocytic developmental cycle.

Plasmodium vivax Tryptophan Rich Antigen PvTRAg36.6 Interacts with PvETRAMP and PvTRAg56.6 Interacts with PvMSP7 during Erythrocytic Stages of the Parasite

Science.gov (United States)

Tyagi, Kriti; Hossain, Mohammad Enayet; Thakur, Vandana; Aggarwal, Praveen; Malhotra, Pawan; Mohmmed, Asif; Sharma, Yagya Dutta

2016-01-01

Plasmodium vivax is most wide spread and a neglected malaria parasite. There is a lack of information on parasite biology of this species. Genome of this parasite encodes for the largest number of tryptophan-rich proteins belonging to ‘Pv-fam-a’ family and some of them are potential drug/vaccine targets but their functional role(s) largely remains unexplored. Using bacterial and yeast two hybrid systems, we have identified the interacting partners for two of the P. vivax tryptophan-rich antigens called PvTRAg36.6 and PvTRAg56.2. The PvTRAg36.6 interacts with early transcribed membrane protein (ETRAMP) of P.vivax. It is apically localized in merozoites but in early stages it is seen in parasite periphery suggesting its likely involvement in parasitophorous vacuole membrane (PVM) development or maintenance. On the other hand, PvTRAg56.2 interacts with P.vivax merozoite surface protein7 (PvMSP7) and is localized on merozoite surface. Co-localization of PvTRAg56.2 with PvMSP1 and its molecular interaction with PvMSP7 probably suggest that, PvTRAg56.2 is part of MSP-complex, and might assist or stabilize the protein complex at the merozoite surface. In conclusion, the PvTRAg proteins have different sub cellular localizations and specific associated functions during intra-erythrocytic developmental cycle. PMID:26954579

Final Technical Report - Photovoltaics for You (PV4You) Program

Energy Technology Data Exchange (ETDEWEB)

Weissman, J. M. [Interstate Renewable Energy Council (IREC), New York, NY (United States); Sherwood, L. [Interstate Renewable Energy Council (IREC), New York, NY (United States); Pulaski, J. [Interstate Renewable Energy Council (IREC), New York, NY (United States); Cook, C. [Interstate Renewable Energy Council (IREC), New York, NY (United States); Kalland, S. [Interstate Renewable Energy Council (IREC), New York, NY (United States); Haynes, J. [Interstate Renewable Energy Council (IREC), New York, NY (United States)

2005-08-14

In September 2000, the Interstate Renewable Energy Council (IREC) began its 5-year work on contract # DE-FGO3-00SF22116, the Photovoltaics for You (PV4You) Project. The objective was to develop and distribute information on photovoltaics and to educate key stakeholder groups including state government agencies, local government offices, consumer representative agencies, school officials and students, and Million Solar Roofs Partnerships. In addition, the project was to identify barriers to the deployment of photovoltaics and implement strategies to overcome them. Information dissemination and education was accomplished by publishing newsletters; creating a base of information, guides, and models on the www.irecusa.org and the www.millionsolarroofs.org web sites; convening workshops and seminars; engaging multiple stakeholders; and widening the solar network to include new consumers and decision makers. Two major web sites were maintained throughout the project cycle. The www.irecusa.org web site housed dedicated pages for Connecting to the Grid, Schools Going Solar, Community Outreach, and Certification & Training. The www.millionsolarroofs.org web site was created to serve the MSR Partnerships with news, interviews, key documents, and resource material. Through the course of this grant, the Interstate Renewable Energy Council has been supporting the Department of Energy's solar energy program goals by providing the Department with expertise services for their network of city, state, and community stakeholders. IREC has been the leading force at the state and federal levels regarding net metering and interconnection policy for photovoltaic systems. The principal goal and benefit of the interconnection and net metering work is to lower both barriers and cost for the installation of PV. IREC typically plays a leadership role among small generator stakeholders and has come to be relied upon for its expertise by industry and regulators. IREC also took a leadership

Whole-genome sequencing reveals that Shewanella haliotis Kim et al. 2007 can be considered a later heterotypic synonym of Shewanella algae Simidu et al. 1990.

Science.gov (United States)

Szeinbaum, Nadia; Kellum, Cailin E; Glass, Jennifer B; Janda, J Michael; DiChristina, Thomas J

2018-04-01

Previously, experimental DNA-DNA hybridization (DDH) between Shewanellahaliotis JCM 14758 T and Shewanellaalgae JCM 21037 T had suggested that the two strains could be considered different species, despite minimal phenotypic differences. The recent isolation of Shewanella sp. MN-01, with 99 % 16S rRNA gene identity to S. algae and S. haliotis, revealed a potential taxonomic problem between these two species. In this study, we reassessed the nomenclature of S. haliotis and S. algae using available whole-genome sequences. The whole-genome sequence of S. haliotis JCM 14758 T and ten S. algae strains showed ≥97.7 % average nucleotide identity and >78.9 % digital DDH, clearly above the recommended species thresholds. According to the rules of priority and in view of the results obtained, S. haliotis is to be considered a later heterotypic synonym of S. algae. Because the whole-genome sequence of Shewanella sp. strain MN-01 shares >99 % ANI with S. algae JCM 14758 T , it can be confidently identified as S. algae.

Shewanella putrefaciens adhesion and biofilm formation on food processing surfaces

DEFF Research Database (Denmark)

Bagge, Dorthe; Hjelm, M.; Johansen, C.

2001-01-01

Laboratory model systems were developed for studying Shewanella putrefaciens adhesion and biofilm formation under batch and flow conditions. S. putrefaciens plays a major role in food spoilage and may cause microbially induced corrosion on steel surfaces. S. putrefaciens bacteria suspended in buf...... from surfaces, and indirect conductometry and found this combination sufficient to quantify bacteria on surfaces...

The PV market

International Nuclear Information System (INIS)

Hammond, B.

1992-01-01

This paper forecasts the photovoltaic (PV) market growth for the 1990s. Ten years of PV history are reviewed and used to establish market trends in terms of average selling price (ASP) and kilowatts shipped by market segment. The market is segmented into indoor consumer, stand-alone, and grid-connected applications. Indoor consumer presently represents a saturated market and is fairly predictable. The stand-alone market (i.e. not connected to the utility grid) is fairly stable and predictable. The utility PV market however is highly dependent on a number of market factors such as the cost of conventional energy the cost of PV systems utility acceptance of PV and regulatory controls. Government and institutional regulations, environmental issues, and OPEC and Middle East politics will have the greatest impact on the cost of conventional fuels. Private and federal investment in PV technology development could have a significant impact on the cost of PV systems. Forecasts are provided through the year 2000 for indoor consumer stand-alone and utility markets

Growth of the facultative anaerobe Shewanella putrefaciens by elemental sulfur reduction

Science.gov (United States)

Moser, D. P.; Nealson, K. H.

1996-01-01

The growth of bacteria by dissimilatory elemental sulfur reduction is generally associated with obligate anaerobes and thermophiles in particular. Here we describe the sulfur-dependent growth of the facultatively anaerobic mesophile Shewanella putrefaciens. Six of nine representative S. putrefaciens isolates from a variety of environments proved able to grow by sulfur reduction, and strain MR-1 was chosen for further study. Growth was monitored in a minimal medium (usually with 0.05% Casamino Acids added as a growth stimulant) containing 30 mM lactate and limiting concentrations of elemental sulfur. When mechanisms were provided for the removal of the metabolic end product, H2S, measurable growth was obtained at sulfur concentrations of from 2 to 30 mM. Initial doubling times were ca. 1.5 h and substrate independent over the range of sulfur concentrations tested. In the cultures with the highest sulfur concentrations, cell numbers increased by greater than 400-fold after 48 h, reaching a maximum density of 6.8 x 10(8) cells ml-1. Yields were determined as total cell carbon and ranged from 1.7 to 5.9 g of C mol of S(0) consumed-1 in the presence of the amino acid supplement and from 0.9 to 3.4 g of C mol of S(0-1) in its absence. Several lines of evidence indicate that cell-to-sulfur contact is not required for growth. Approaches for the culture of sulfur-metabolizing bacteria and potential ecological implications of sulfur reduction in Shewanella-like heterotrophs are discussed.

Building brighter PV business

International Nuclear Information System (INIS)

Hacker, R.

2002-01-01

The current status and future prospects of the UK market for solar photovoltaic (PV) electricity are briefly discussed. Through the Department of Trade and Industry (DTI), the UK Government has supported research and development (R and D) into PV for a number of years. This programme has now been extended to demonstrating PV systems on houses. Phase 2 - the domestic field trial programme - aims to monitor the performance of individual systems and the impact on a cluster of systems on the electricity network. New funding had allowed a trebling of the size of this programme, which involves both private developers and housing associations. The DTI is also working to promote PV on commercial buildings, eg the installation of BP Solar PV systems at BP petrol stations. The PV industry in the UK is technically strong and is working to overcome the barriers in the UK to greater uptake of the technology (including cost, conservatism, legal requirements and metering practices). Improvements are expected in a number of recent initiatives in the electricity industry to boost PV use and the PV industry is lobbying for PV to be included in the Enhanced Capital Allowances (ECA) scheme

On the Impact of Partial Shading on PV Output Power

DEFF Research Database (Denmark)

Sera, Dezso; Baghzouz, Yahia

2008-01-01

clarifies the mechanism of partial PV shading on a number of PV cells connected in series and/or parallel with and without bypass diodes. The analysis is presented in simple terms and can be useful to someone who wishes to determine the impact of some shading geometry on a PV system. The analysis...... is illustrated by measurements on a commercial 70 W panel, and a 14.4 kW PV array....

Building opportunities in the U.S. for PV (PV:BONUS): A progress report

International Nuclear Information System (INIS)

Taylor, R.W.

1994-01-01

Five contract teams are developing photovoltaic (PV) products that will have a significant impact on building-integrated PV systems. The product lines that these teams are pursuing include roofing materials, building facade materials, PV integrated into modular homes, ac-PV modules, and utility-dispatchable PV systems. The objective of these efforts is to develop product and market opportunities that can provide for the introduction of PV into the buildings market sector at higher allowable installed systems costs than conventional ground- or roof-mounted systems. Each of the teams has a unique approach, and synergistic opportunities among teams are beginning to emerge. This paper reviews the product and market development efforts of these teams and describes the links between the product efforts and parallel analytical work to develop PV as a demand-side management option

Variations of PV Panel Performance Installed over a Vegetated Roof and a Conventional Black Roof

Directory of Open Access Journals (Sweden)

Mohammed J. Alshayeb

2018-05-01

Full Text Available The total worldwide photovoltaic (PV capacity has been growing from about 1 GW at the beginning of the twenty-first century to over 300 GW in 2016 and is expected to reach 740 GW by 2022. PV panel efficiency is reported by PV manufacturers based on laboratory testing under Standard Testing Condition with a specific temperature of 25 °C and solar irradiation of 1000 W/m2. This research investigated the thermal interactions between the building roof surface and PV panels by examining the differences in PV panel temperature and energy output for those installed over a green roof (PV-Green and those installed over a black roof (PV-Black. A year-long experimental study was conducted over the roof of an educational building with roof mounted PV panels with a system capacity of 4.3 kW to measure PV underside surface temperature (PV-UST, ambient air temperature between PV panel and building roof (PV-AT, and PV energy production (PV-EP. The results show that during the summer the PV-Green consistently recorded lower PV-UST and PV-AT temperatures and more PV-EP than PV-Black. The average hourly PV-EP difference was about 0.045 kWh while the maximum PV-EP difference was about 0.075 kWh, which represents roughly a 3.3% and 5.3% increase in PV-EP. For the entire study period, EP-Green produced 19.4 kWh more energy, which represents 1.4% more than EP-Black.

High Pressure Reduction of Selenite by Shewanella oneidensis MR-1

Science.gov (United States)

Picard, A.; Daniel, I.; Testemale, D.; Letard, I.; Bleuet, P.; Cardon, H.; Oger, P.

2007-12-01

High-pressure biotopes comprise cold deep-sea environments, hydrothermal vents, and deep subsurface or deep-sea sediments. The latter are less studied, due to the technical difficulties to sample at great depths without contamination. Nevertheless, microbial sulfate reduction and methanogenesis have been found to be spatially distributed in deep deep-sea sediments (1), and sulfate reduction has been shown to be actually more efficient under high hydrostatic pressure (HHP) in some sediments (2). Sulfate-reducing bacteria obtained from the Japan Sea are characterized by an increased sulfide production under pressure (3,4). Unfortunately, investigations of microbial metabolic activity as a function of pressure are extremely scarce due to the experimental difficulty of such measurements at high hydrostatic pressure. We were able to measure the reduction of selenite Se(IV) by Shewanella oneidensis MR-1 as a function of pressure, to 150 MPa using two different high-pressure reactors that allow in situ X-ray spectroscopy measurements on a synchrotron source. A first series of measurements was carried out in a low-pressure Diamond Anvil Cell (DAC) of our own design (5) at ID22 beamline at ESRF (European Synchrotron Radiation Facility); a second one was performed in an autoclave (6) at the BM30B beamline at ESRF. Selenite reduction by strain MR-17 was monitored from ambient pressure to 150 MPa over 25 hours at 30 deg C by XANES spectroscopy (X-ray Analysis of Near Edge Structure). Spectra were recorded hourly in order to quantify the evolution of the oxidation state of selenium with time. Stationary-phase bacteria were inoculated at a high concentration into fresh growth medium containing 5 or 10 M of sodium selenite and 20 mM sodium lactate. Kinetic parameters of the Se (IV) reduction by Shewanella oneidensis strain MR-1 could be extracted from the data, as a function of pressure. They show 1) that the rate constant k of the reaction is decreased by a half at high pressure

Towards structural studies of the old yellow enzyme homologue SYE4 from Shewanella oneidensis and its complexes at atomic resolution

International Nuclear Information System (INIS)

Elegheert, Jonathan; Hemel, Debbie van den; Dix, Ina; Stout, Jan; Van Beeumen, Jozef; Brigé, Ann; Savvides, Savvas N.

2009-01-01

Of the four old yellow enzyme homologues found in S. oneidensis, SYE4 is the homologue most implicated in resistance to oxidative stress. SYE4 was recombinantly expressed in Escherichia coli, purified and crystallized using the hanging-drop vapour-diffusion method. Shewanella oneidensis is an environmentally versatile Gram-negative γ-proteobacterium that is endowed with an unusually large proteome of redox proteins. Of the four old yellow enzyme (OYE) homologues found in S. oneidensis, SYE4 is the homologue most implicated in resistance to oxidative stress. SYE4 was recombinantly expressed in Escherichia coli, purified and crystallized using the hanging-drop vapour-diffusion method. The crystals belonged to the orthorhombic space group P2 1 2 1 2 1 and were moderately pseudo-merohedrally twinned, emulating a P422 metric symmetry. The native crystals of SYE4 were of exceptional diffraction quality and provided complete data to 1.10 Å resolution using synchrotron radiation, while crystals of the reduced enzyme and of the enzyme in complex with a wide range of ligands typically led to high-quality complete data sets to 1.30–1.60 Å resolution, thus providing a rare opportunity to dissect the structure–function relationships of a good-sized enzyme (40 kDa) at true atomic resolution. Here, the attainment of a number of experimental milestones in the crystallographic studies of SYE4 and its complexes are reported, including isolation of the elusive hydride–Meisenheimer complex

PV ready roofing systems

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-07-01

The integration of PV technology into roofs of houses has become very popular in the United States, Japan, Germany and The Netherlands. There could be a considerable market in the UK for these systems, given the large number of houses that are projected to be built in the next 10 years, and taking account of increased awareness of energy issues. A significant proportion of the market share of annual installed PV is for solar PV systems installed into homes (currently 15%), this is expected to rise to 23% (900MW) by 2010. The grid connected roof and building mounted facade systems represent the fastest growing market for PV systems in Europe. In conclusion, therefore, innovative approached for fixing PV technology onto roofs have been identified for both domestic roofs and for the commercial sector. With reference to production methodologies within the roofing industry, both approaches should be capable of being designed with PV-ready connections suitable for fixing PV modules at a later date. This will help overcome the key barriers of cost of installation, skills required and the lack of retrofit potential. Based on the results of this project, Sustainable Energy together with PV Systems are keen to take forward the full research and development of PV-ready systems for both the domestic and commercial sectors.

Sensorless PV Array Diagnostic Method for Residential PV Systems

DEFF Research Database (Denmark)

Sera, Dezso; Spataru, Sergiu; Mathe, Laszlo

2011-01-01

This work proposes a temperature and irradiance sensorless diagnostic method suitable for small residential PV installations, focusing on detection of partial shadows. The method works by detection of failures in crystalline silicone PV arrays by concomitant monitoring of some of their key...

Identification of Shewanella baltica as the most important H2S-producing species during iced storage of danish marine fish

DEFF Research Database (Denmark)

Vogel, Birte Fonnesbech; Venkateswaran, K.; Satomi, M.

2005-01-01

are important in fish spoilage. More than 500 H2S-producing strains were isolated from iced stored marine fish (cod, plaice, and flounder) caught in the Baltic Sea during winter or summer time. All strains were identified as Shewanella species by phenotypic tests. Different Shewanella species were present...... unchanged (i.e., trimethylamine-N-oxide reduction and H2S production); however, the main H2S-producing organism was identified as S. baltica....

City and County Solar PV Training Program, Module 2: Screening and Identifying PV Projects

Energy Technology Data Exchange (ETDEWEB)

Elgqvist, Emma M [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

2018-04-09

When screening and identifying PV projects, cities and counties should understand the different factors that impact the technical and economic potential of a PV project, the steps of the PV screening process, and how to use REopt Lite to screen a site for PV and storage project potential.

Modelling PV modules' performance in Sahelian climates

Energy Technology Data Exchange (ETDEWEB)

Diarra, D.C.; Akuffo, F.O. [Kwame Nkrumah Univ. of Science and Technology, Kumasi (Ghana). Dept. of Mechanical Engineering

2003-08-01

This paper describes the development of a thermo-optical model designed to evaluate the temperature of a photovoltaic (PV) module in an effort to design a cost-effective cooling system for PV modules operating under high ambient temperatures. The power output of a PV module is greatly reduced when its temperature rises. This loss in efficiency is particularly significant in Sahelian regions where PV modules are subjected to high solar radiation intensities and high ambient temperatures. The newly developed thermo-optical model confirms that most of the heat in a PV module is generated in the solar cell. The results of the analysis include: the optical absorption, reflection and transmission of the solar radiation incident on the module; the temperature distribution in the module; and, the heat transfer through the top and bottom of the module. At incidence angles of 60 degrees, approximately three-quarters of the heat is generated in the solar cell. The optical efficiency is 88.44 per cent at normal incidence angle and 82.48 per cent when the incidence angle is 60 degrees. It was determined that the cooling system should be located as close as possible to the solar cell in order to increase the thermal heat flow from the cell. 4 refs., 3 tabs., 4 figs.

Contribution of Extracellular Polymeric Substances from Shewanella sp. HRCR-1 Biofilms to U(VI) Immobilization

Energy Technology Data Exchange (ETDEWEB)

Cao, Bin; Ahmed, B.; Kennedy, David W.; Wang, Zheming; Shi, Liang; Marshall, Matthew J.; Fredrickson, Jim K.; Isern, Nancy G.; Majors, Paul D.; Beyenal, Haluk

2011-06-05

The goal of this study was to quantify the contribution of extracellular polymeric substances (EPS) in U(VI) immobilization by Shewanella sp. HRCR-1. Through comparison of U(VI) immobilization using cells with bound EPS (bEPS) and cells without EPS, we showed that i) bEPS from Shewanella sp. HRCR-1 biofilms contributed significantly to U(VI) immobilization, especially at low initial U(VI) concentrations, through both sorption and reduction; ii) bEPS could be considered as a functional extension of the cells for U(VI) immobilization and they likely play more important roles at initial U(VI) concentrations; and iii) U(VI) reduction efficiency was found to be dependent upon initial U(VI) concentration and the efficiency decreased at lower concentrations. To quantify relative contribution of sorption and reduction in U(VI) immobilization by EPS fractions, we isolated loosely associated EPS (laEPS) and bEPS from Shewanella sp. HRCR-1 biofilms grown in a hollow fiber membrane biofilm reactor and tested their reactivity with U(V). We found that, when in reduced form, the isolated cell-free EPS fractions could reduce U(VI). Polysaccharides in the EPS likely contributed to U(VI) sorption and dominated reactivity of laEPS while redox active components (e.g., outer membrane c-type cytochromes), especially in bEPS, might facilitate U(VI) reduction.

Contribution of extracellular polymeric substances from Shewanella sp. HRCR-1 biofilms to U(VI) immobilization.

Science.gov (United States)

Cao, Bin; Ahmed, Bulbul; Kennedy, David W; Wang, Zheming; Shi, Liang; Marshall, Matthew J; Fredrickson, Jim K; Isern, Nancy G; Majors, Paul D; Beyenal, Haluk

2011-07-01

The goal of this study was to quantify the contribution of extracellular polymeric substances (EPS) to U(VI) immobilization by Shewanella sp. HRCR-1. Through comparison of U(VI) immobilization using cells with bound EPS (bEPS) and cells with minimal EPS, we show that (i) bEPS from Shewanella sp. HRCR-1 biofilms contribute significantly to U(VI) immobilization, especially at low initial U(VI) concentrations, through both sorption and reduction; (ii) bEPS can be considered a functional extension of the cells for U(VI) immobilization and they likely play more important roles at lower initial U(VI) concentrations; and (iii) the U(VI) reduction efficiency is dependent upon the initial U(VI) concentration and decreases at lower concentrations. To quantify the relative contributions of sorption and reduction to U(VI) immobilization by EPS fractions, we isolated loosely associated EPS (laEPS) and bEPS from Shewanella sp. HRCR-1 biofilms grown in a hollow fiber membrane biofilm reactor and tested their reactivity with U(VI). We found that, when reduced, the isolated cell-free EPS fractions could reduce U(VI). Polysaccharides in the EPS likely contributed to U(VI) sorption and dominated the reactivity of laEPS, while redox active components (e.g., outer membrane c-type cytochromes), especially in bEPS, possibly facilitated U(VI) reduction.

Performance analysis of PV panel under varying surface temperature

Directory of Open Access Journals (Sweden)

Kumar Tripathi Abhishek

2018-01-01

Full Text Available The surface temperature of PV panel has an adverse impact on its performance. The several electrical parameters of PV panel, such as open circuit voltage, short circuit current, power output and fill factor depends on the surface temperature of PV panel. In the present study, an experimental work was carried out to investigate the influence of PV panel surface temperature on its electrical parameters. The results obtained from this experimental study show a significant reduction in the performance of PV panel with an increase in panel surface temperature. A 5W PV panel experienced a 0.4% decrease in open circuit voltage for every 1°C increase in panel surface temperature. Similarly, there was 0.6% and 0.32% decrease in maximum power output and in fill factor, respectively, for every 1°C increase in panel surface temperature. On the other hand, the short circuit current increases with the increase in surface temperature at the rate of 0.09%/°C.

PV Obelisk - Information system with photovoltaics; PV-Obelisk Orientierungssystem mit Photovoltaik

Energy Technology Data Exchange (ETDEWEB)

Ruoss, D.; Rasmussen, J.

2004-07-01

This final report for the Swiss Federal Office of Energy (SFOE) describes the development of an information system powered by a photovoltaic (PV) array. As an innovative approach, the 'PV-Obelisk' project is the combination of PV with a multi-functional pillar made of natural stone in an aesthetic way. The PV modules serve both as a power supply and as a design element. Two initial prototypes led the way to a third, optimised consumer configuration that was planned to guarantee maximum user frequency. Test operation in front of the 'Heidiland' motor way restaurant confirmed the market analyses made and delivered the expected results. The product, whose three LCD displays are updated via a mobile telephony-based text-message system, proved its technical reliability and showed a high user frequency. Because of the high overall energy consumption, PV power can only partially contribute to the energy supply needed. Various compromises in the technical and aesthetic areas are discussed that were made for the sake of product acceptance in the market. The range of application areas for such a 'PV Obelisk' are discussed and the need for early co-ordination with urban planners is stressed.

Passive cooling of standalone flat PV module with cotton wick structures

International Nuclear Information System (INIS)

Chandrasekar, M.; Suresh, S.; Senthilkumar, T.; Ganesh karthikeyan, M.

2013-01-01

Highlights: • A simple passive cooling system is developed for standalone flat PV modules. • 30% Reduction in module temperature is observed with developed cooling system. • 15.61% Increase in output power of PV module is found with developed cooling system. • Module efficiency is increased by 1.4% with cooling arrangement. • Lower thermal degradation due to narrow range of temperature characteristics. - Abstract: In common, PV module converts only 4–17% of the incoming solar radiation into electricity. Thus more than 50% of the incident solar energy is converted as heat and the temperature of PV module is increased. The increase in module temperature in turn decreases the electrical yield and efficiency of the module with a permanent structural damage of the module due to prolonged period of thermal stress (also known as thermal degradation of the module). An effective way of improving efficiency and reducing the rate of thermal degradation of a PV module is to reduce the operating temperature of PV module. This can be achieved by cooling the PV module during operation. Hence in the present work, a simple passive cooling system with cotton wick structures is developed for standalone flat PV modules. The thermal and electrical performance of flat PV module with cooling system consisting of cotton wick structures in combination with water, Al 2 O 3 /water nanofluid and CuO/water nanofluid are investigated experimentally. The experimental results are also compared with the thermal and electrical performance of flat PV module without cooling system

Novel Methods to Determine Feeder Locational PV Hosting Capacity and PV Impact Signatures

Energy Technology Data Exchange (ETDEWEB)

Reno, Matthew J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Coogan, Kyle [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Seuss, John [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Broderick, Robert Joseph [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2017-05-01

Often PV hosting capacity analysis is performed for a limited number of distribution feeders. For medium - voltage distribution feeders, previous results generally analyze less than 20 feeders, and then the results are extrapolated out to similar types of feeders. Previous hosting capacity research has often focused on determining a single value for the hosting capacity for the entire feeder, whereas this research expands previous hosting capacity work to investigate all the regions of the feeder that may allow many different hosting capacity values wit h an idea called locational hosting capacity (LHC)to determine the largest PV size that can be interconnected at different locations (buses) on the study feeders. This report discusses novel methods for analyzing PV interconnections with advanced simulati on methods. The focus is feeder and location - specific impacts of PV that determine the locational PV hosting capacity. Feeder PV impact signature are used to more precisely determine the local maximum hosting capacity of individual areas of the feeder. T he feeder signature provides improved interconnection screening with certain zones that show the risk of impact to the distribution feeder from PV interconnections.

Energy balance of the global photovoltaic (PV) industry--is the PV industry a net electricity producer?

Science.gov (United States)

Dale, Michael; Benson, Sally M

2013-04-02

A combination of declining costs and policy measures motivated by greenhouse gas (GHG) emissions reduction and energy security have driven rapid growth in the global installed capacity of solar photovoltaics (PV). This paper develops a number of unique data sets, namely the following: calculation of distribution of global capacity factor for PV deployment; meta-analysis of energy consumption in PV system manufacture and deployment; and documentation of reduction in energetic costs of PV system production. These data are used as input into a new net energy analysis of the global PV industry, as opposed to device level analysis. In addition, the paper introduces a new concept: a model tracking energetic costs of manufacturing and installing PV systems, including balance of system (BOS) components. The model is used to forecast electrical energy requirements to scale up the PV industry and determine the electricity balance of the global PV industry to 2020. Results suggest that the industry was a net consumer of electricity as recently as 2010. However, there is a >50% that in 2012 the PV industry is a net electricity provider and will "pay back" the electrical energy required for its early growth before 2020. Further reducing energetic costs of PV deployment will enable more rapid growth of the PV industry. There is also great potential to increase the capacity factor of PV deployment. These conclusions have a number of implications for R&D and deployment, including the following: monitoring of the energy embodied within PV systems; designing more efficient and durable systems; and deploying PV systems in locations that will achieve high capacity factors.

Phylogenetic Analysis of Shewanella Strains by DNA Relatedness Derived from Whole Genome Microarray DNA-DNA Hybridization and Comparisons with Other Methods

International Nuclear Information System (INIS)

Wu, Liyou; Yi, T.Y.; Van Nostrand, Joy; Zhou, Jizhong

2010-01-01

Phylogenetic analyses were done for the Shewanella strains isolated from Baltic Sea (38 strains), US DOE Hanford Uranium bioremediation site (Hanford Reach of the Columbia River (HRCR), 11 strains), Pacific Ocean and Hawaiian sediments (8 strains), and strains from other resources (16 strains) with three out group strains, Rhodopseudomonas palustris, Clostridium cellulolyticum, and Thermoanaerobacter ethanolicus X514, using DNA relatedness derived from WCGA-based DNA-DNA hybridizations, sequence similarities of 16S rRNA gene and gyrB gene, and sequence similarities of 6 loci of Shewanella genome selected from a shared gene list of the Shewanella strains with whole genome sequenced based on the average nucleotide identity of them (ANI). The phylogenetic trees based on 16S rRNA and gyrB gene sequences, and DNA relatedness derived from WCGA hybridizations of the tested Shewanella strains share exactly the same sub-clusters with very few exceptions, in which the strains were basically grouped by species. However, the phylogenetic analysis based on DNA relatedness derived from WCGA hybridizations dramatically increased the differentiation resolution at species and strains level within Shewanella genus. When the tree based on DNA relatedness derived from WCGA hybridizations was compared to the tree based on the combined sequences of the selected functional genes (6 loci), we found that the resolutions of both methods are similar, but the clustering of the tree based on DNA relatedness derived from WMGA hybridizations was clearer. These results indicate that WCGA-based DNA-DNA hybridization is an idea alternative of conventional DNA-DNA hybridization methods and it is superior to the phylogenetics methods based on sequence similarities of single genes. Detailed analysis is being performed for the re-classification of the strains examined.

Phylogenetic Analysis of Shewanella Strains by DNA Relatedness Derived from Whole Genome Microarray DNA-DNA Hybridization and Comparison with Other Methods

Energy Technology Data Exchange (ETDEWEB)

Wu, Liyou; Yi, T. Y.; Van Nostrand, Joy; Zhou, Jizhong

2010-05-17

Phylogenetic analyses were done for the Shewanella strains isolated from Baltic Sea (38 strains), US DOE Hanford Uranium bioremediation site [Hanford Reach of the Columbia River (HRCR), 11 strains], Pacific Ocean and Hawaiian sediments (8 strains), and strains from other resources (16 strains) with three out group strains, Rhodopseudomonas palustris, Clostridium cellulolyticum, and Thermoanaerobacter ethanolicus X514, using DNA relatedness derived from WCGA-based DNA-DNA hybridizations, sequence similarities of 16S rRNA gene and gyrB gene, and sequence similarities of 6 loci of Shewanella genome selected from a shared gene list of the Shewanella strains with whole genome sequenced based on the average nucleotide identity of them (ANI). The phylogenetic trees based on 16S rRNA and gyrB gene sequences, and DNA relatedness derived from WCGA hybridizations of the tested Shewanella strains share exactly the same sub-clusters with very few exceptions, in which the strains were basically grouped by species. However, the phylogenetic analysis based on DNA relatedness derived from WCGA hybridizations dramatically increased the differentiation resolution at species and strains level within Shewanella genus. When the tree based on DNA relatedness derived from WCGA hybridizations was compared to the tree based on the combined sequences of the selected functional genes (6 loci), we found that the resolutions of both methods are similar, but the clustering of the tree based on DNA relatedness derived from WMGA hybridizations was clearer. These results indicate that WCGA-based DNA-DNA hybridization is an idea alternative of conventional DNA-DNA hybridization methods and it is superior to the phylogenetics methods based on sequence similarities of single genes. Detailed analysis is being performed for the re-classification of the strains examined.

PV Thermal systems: PV panels supplying renewable electricity and heat

NARCIS (Netherlands)

Helden, van W.G.J.; Zolingen, van R.J.C.; Zondag, H.A.

2004-01-01

With PV Thermal panels sunlight is converted into electricity and heat simultaneously. Per unit area the total efficiency of a PVT panel is higher than the sum of the efficiencies of separate PV panels and solar thermal collectors. During the last 20 years research into PVT techniques and concepts

PV-HYBRID and MINI-GRID. Proceedings

Energy Technology Data Exchange (ETDEWEB)

NONE

2006-07-01

Within the 3rd European Conference at the Centre de Congres in Aix en Provence (France) between 11th and 12th May, 2006, the following lessons were held: (1) Small electric networks: European drivers and projects for the integration of RES and DG into the electricity grids of the future (Manuel Sanchez-Jimenez); (2) PV hybrid system within mini grids - IEA PVPS programme (Meuch Konraf); (3) Renewables for the developing world (Alvaro Ponce Plaza); (4) Rural electicity supply using photovoltaic / - Diesel hybrid systems: Attractive for investors in the renewable energy sector? (Andreas Hahn); (5) Economic analysis of stand-alone and grid-connected photovoltaic systems under current tariff structure of Taiwan (Yaw-Juen Wang); (6) Using wind-PV-diesel hybrid system for electrification of remote village in Western Libya (N.M. Kreama); (7) Venezuela's renewable energy program for small towns and rural areas ''Sembrando Luz'' (Jorge Torres); (8) AeroSmart5, the professional, sysem-compatible small-scale wind energy converter will be tested in field tests (Fabian Jochem); (9) Lifetime, test procedures and recommendations for optimal operating strategies for lead-acid-batteries in renewable energy systems - A survey on results from European projects from the 5th framework programme (Rudi Kaiser); (10) Prototype of a reversible fuel cell system for autonomous power supplies (Tom Smolinska); (11) Interconnection management in microgrids (Michel Vandenbergh); (12) Control strategy for a small-scale stand-alone power system based on renewable energy and hydrogen (Harald Miland); (13) Standard renewable electricity supply for people in rural areas - mini-grids in western provinces of China (Michael Wollny); (14) The Brava island a ''100% renewable energy'' project (Jean-Christian Marcel); (15) Breakthrough to a new era of PV-hybrid systems with the help of standardised components communication? (Michael Mueller); (16) Standardized

Simulation of Power Produced by a Building Added PV System in Indonesia using virtual reality

NARCIS (Netherlands)

Veldhuis, A.J.; Reinders, Angelina H.M.E.

2014-01-01

In this study a PV system will be simulated using virtual reality software for PV system simulations -called VR4PV - to show the effectiveness of the modelling of PV systems on buildings which are placed in the tropics. The PV system used for this study has been installed in Papua, Indonesia and

EcPV2 DNA in equine genital squamous cell carcinomas and normal genital mucosa.

Science.gov (United States)

Bogaert, Lies; Willemsen, Anouk; Vanderstraeten, Eva; Bracho, Maria A; De Baere, Cindy; Bravo, Ignacio G; Martens, Ann

2012-07-06

Squamous cell carcinoma (SCC) represents the most common genital malignant tumor in horses. Similar to humans, papillomaviruses (PVs) have been proposed as etiological agents and recently Equine papillomavirus type 2 (EcPV2) has been identified in a subset of genital SCCs. The goals of this study were (1) to determine the prevalence of EcPV2 DNA in tissue samples from equine genital SCCs, penile intraepithelial neoplasia (PIN) and penile papillomas, using EcPV2-specific PCR, (2) to examine the prevalence of latent EcPV2 infection in healthy genital mucosa and (3) to determine genetic variability within EcPV2 and to disentangle phylogenetic relationships of EcPV2 among PVs. EcPV2 DNA was detected in all but one penile SCC (15/16), in all PIN lesions (8/8) and penile papillomas (4/4). Additionally, EcPV2 DNA was demonstrated in one of two metastasized lymph nodes, one contact metastasis in the mouth, two vaginal and one anal lesion. In healthy horses, EcPV2 DNA was detected in 10% (4/39) of penile swabs but in none of vulvovaginal swabs (0/20). This study confirms the presence of EcPV2 DNA in equine genital SCCs and shows its involvement in anal lesions, a lymph node and contact metastases. Latent EcPV2 presence was also shown in normal male genital mucosa. We found that different EcPV2 variants cocirculate among horses and that EcPV2 is related to the Delta+Zeta PVs and is only a very distant relative of high-risk human PVs causing genital cancer. Thus, similar viral tropism and similar malignant outcome of the infection do not imply close evolutionary relationship. Copyright © 2012 Elsevier B.V. All rights reserved.

Comparison of three different methods of perturbing the potential vorticity field in mesoscale forecasts of Mediterranean heavy precipitation events: PV-gradient, PV-adjoint and PV-satellite

Science.gov (United States)

Vich, M.; Romero, R.; Richard, E.; Arbogast, P.; Maynard, K.

2010-09-01

Heavy precipitation events occur regularly in the western Mediterranean region. These events often have a high impact on the society due to economic and personal losses. The improvement of the mesoscale numerical forecasts of these events can be used to prevent or minimize their impact on the society. In previous studies, two ensemble prediction systems (EPSs) based on perturbing the model initial and boundary conditions were developed and tested for a collection of high-impact MEDEX cyclonic episodes. These EPSs perturb the initial and boundary potential vorticity (PV) field through a PV inversion algorithm. This technique ensures modifications of all the meteorological fields without compromising the mass-wind balance. One EPS introduces the perturbations along the zones of the three-dimensional PV structure presenting the local most intense values and gradients of the field (a semi-objective choice, PV-gradient), while the other perturbs the PV field over the MM5 adjoint model calculated sensitivity zones (an objective method, PV-adjoint). The PV perturbations are set from a PV error climatology (PVEC) that characterizes typical PV errors in the ECMWF forecasts, both in intensity and displacement. This intensity and displacement perturbation of the PV field is chosen randomly, while its location is given by the perturbation zones defined in each ensemble generation method. Encouraged by the good results obtained by these two EPSs that perturb the PV field, a new approach based on a manual perturbation of the PV field has been tested and compared with the previous results. This technique uses the satellite water vapor (WV) observations to guide the correction of initial PV structures. The correction of the PV field intents to improve the match between the PV distribution and the WV image, taking advantage of the relation between dark and bright features of WV images and PV anomalies, under some assumptions. Afterwards, the PV inversion algorithm is applied to run

Photovoltaics for Buildings Cutting-Edge PV

International Nuclear Information System (INIS)

Hayter, S. J.; Martin, R. L.

1998-01-01

Photovoltaic (PV) technology development for building-integrated applications (commonly called PV for Buildings) is one of the fastest growing areas in the PV industry. Buildings represent a huge potential market for photovoltaics because they consume approximately two-thirds of the electricity consumed in the US. The PV and buildings industries are beginning to work together to address issues including building codes and standards, integration, after-market servicing, education, and building energy efficiency. One of the most notable programs to encourage development of new PV-for-buildings products is the PV:BONUS program, supported by the US Department of Energy. Demand for these products from building designers has escalated since the program was initiated in 1993. This paper presents a range of PV-for-buildings issues and products that are currently influencing today's PV and buildings markets

Global PV Market Development

International Nuclear Information System (INIS)

Schmidt, F.

2009-01-01

The dawn of 2009 saw several events which caused major turbulence in the global photovoltaic industry. In 2008 the Spanish PV market grew beyond all expectations and even outranked Germany as the world's number one market. However, the promotion scheme was modified and a market cap was introduced in 2009, cutting back the maximum capacity to be installed to about the level of 2007. In addition, the industry is facing an oversupply of PV modules and a harsh recession which is significantly affecting the traditionally strong PV markets. International photovoltaic companies are challenged by a changing market situation: all of a sudden, competition has increased significantly, pushing the customer to the fore. As a result, a consolidation process is expected within the PV industry worldwide. However, the story is not all negative. In the U.S., the election of Barack Obama may be seen as the starting signal for a massive expansion in PV, likely to bring the country to first place globally within the next five years. Furthermore, different markets and market segments are being opened up - especially in Europe - thanks to the gradual arrival of generation parity and new PV support mechanisms. EuPD Research has observed and studied international PV markets since its foundation. The information included in the presentation is based on a wide range of quantitative and qualitative studies that EuPD Research has conducted in the key markets since 2002. Florian Schmidt, EuPD Research's Head of Product Management, will give an overview of the global PV market and how it is developing in this crucial year 2009. Aspects such as technology development, production capacities and the demand side will be included, with a special emphasis on the European PV markets. So far Chinese PV companies have often benefited from the booming PV markets in Europe, above all Germany and Spain. Due to the lack of domestic market, the Chinese industry strongly depends on the export and is

SunShot 2030 for Photovoltaics (PV): Envisioning a Low-Cost PV Future

Energy Technology Data Exchange (ETDEWEB)

Cole, Wesley J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Frew, Bethany A [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Gagnon, Pieter J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Richards, James [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Sun, Yinong [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Zuboy, Jarrett; Woodhouse, Michael A [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Margolis, Robert M [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

2017-10-01

This presentation summarizes the findings from the report 'SunShot 2030 for Photovoltaics (PV): Envisioning a Low-cost PV Future.' This presentation was given as a webinar on September 26, 2017.

Economic PV - a shift in thinking

International Nuclear Information System (INIS)

Maycock, P.

1999-01-01

This article argues that photovoltaic (PV) technology is already economically viable contrary to current opinion. A table of world PV module shipments for 1990 to 1998 by market sector is presented, and use of PV modules in consumer electronics such as calculators, battery trickle chargers, and garden lights; in communications and signals (eg. microwave repeaters, cellular communication); and in the residential sector in fluorescent lights, radios etc. are discussed. The early adopters of PV technology, and the value placed on PV devices by consumers are considered. Details of PV manufacturing costs for 1997, and forecasts for 2000 and 2010 are tabulated

Multiple approaches towards decolorization and reuse of a textile dye (VB-B) by a marine bacterium Shewanella decolorationis

Digital Repository Service at National Institute of Oceanography (India)

SatheeshBabu, S.; Mohandass, C.; VijayRaj, A.S.; Rajasabapathy, R.; Dhale, M.A.

stream_size 41279 stream_content_type text/plain stream_name Water_Air_Soil_Pollut_224_1500a.pdf.txt stream_source_info Water_Air_Soil_Pollut_224_1500a.pdf.txt Content-Encoding UTF-8 Content-Type text/plain; charset=UTF-8...     1    Author version: Water Air Soil Pollut., vol.224(4); 2013; 1500 Multiple approaches towards decolorization and reuse of a textile dye (VB-B) by a marine bacterium Shewanella decolorationis S. Satheesh Babu, C.Mohandass*, A.S.Vijay Raj, R...

PV module mounting method and mounting assembly

Science.gov (United States)

Lenox, Carl J.S.; Johnson, Kurt M.

2013-04-23

A method for mounting PV modules to a deck includes selecting PV module layout pattern so that adjacent PV module edges are spaced apart. PV mounting and support assemblies are secured to the deck according to the layout pattern using fasteners extending into the deck. The PV modules are placed on the PV mounting and support assemblies. Retaining elements are located over and secured against the upper peripheral edge surfaces of the PV modules so to secure them to the deck with the peripheral edges of the PV modules spaced apart from the deck. In some examples a PV module mounting assembly, for use on a shingled deck, comprises flashing, a base mountable on the flashing, a deck-penetrating fastener engageable with the base and securable to the deck so to secure the flashing and the base to the shingled deck, and PV module mounting hardware securable to the base.

40 CFR 180.1261 - Xanthomonas campestris pv. vesicatoria and Pseudomonas syringae pv. tomato specific Bacteriophages.

Science.gov (United States)

2010-07-01

... and Pseudomonas syringae pv. tomato specific Bacteriophages. 180.1261 Section 180.1261 Protection of.... vesicatoria and Pseudomonas syringae pv. tomato specific Bacteriophages. An exemption from the requirement of... syringae pv. tomato specific bacteriophages in or on pepper and tomato. [74 FR 26536, June 3, 2009] ...

Prospects for PV: a learning curve analysis

International Nuclear Information System (INIS)

Zwaan, Bob van der; Rabi, A.

2003-01-01

This article gives an overview of the current state-of-the-art of photovoltaic electricity technology, and addresses its potential for cost reductions over the first few decades of the 21st century. Current PV production cost ranges are presented, both in terms of capacity installation and electricity generation, of single crystalline silicon, multi-crystalline silicon, amorphous silicon and other thin film technologies. Possible decreases of these costs are assessed, as expected according to the learning-curve methodology. We also estimate how much PV could gain if external costs (due to environmental and health damage) of energy were internalised, for example by an energy tax. Our conclusions are that, (1) mainly due its high costs, PV electricity is unlikely to play a major role in global energy supply and carbon emissions abatement before 2020, (2) extrapolating learning curves observed in the past, one can expect its costs to decrease significantly over the coming years, so that a considerable PV electricity share world-wide could materialise after 2020, (3) niche-market applications, e.g. using stand-alone systems in remote areas, are crucial for continuing 'the ride along the learning curve', (4) damage costs of conventional (fossil) power sources are considerable, and their internalisation would improve the competitiveness of PV, although probably not enough to close the current cost gap. (author)

The marine bacteria Shewanella frigidimarina NCIMB400 upregulates the type VI secretion system during early biofilm formation.

Science.gov (United States)

Linares, Denis; Jean, Natacha; Van Overtvelt, Perrine; Ouidir, Tassadit; Hardouin, Julie; Blache, Yves; Molmeret, Maëlle

2016-02-01

Shewanella sp. are facultative anaerobic Gram-negative bacteria, extensively studied for their electron transfer ability. Shewanella frigidimarina has been detected and isolated from marine environments, and in particular, from biofilms. However, its ability to adhere to surfaces and form a biofilm is poorly understood. In this study, we show that the ability to adhere and to form a biofilm of S. frigidimarina NCIMB400 is significantly higher than that of Shewanella oneidensis in our conditions. We also show that this strain forms a biofilm in artificial seawater, whereas in Luria-Bertani, this capacity is reduced. To identify proteins involved in early biofilm formation, a proteomic analysis of sessile versus planktonic membrane-enriched fractions allowed the identification of several components of the same type VI secretion system gene cluster: putative Hcp1 and ImpB proteins as well as a forkhead-associated domain-containing protein. The upregulation of Hcp1 a marker of active translocation has been confirmed using quantitative reverse transcription polymerase chain reaction. Our data demonstrated the presence of a single and complete type VI secretion system in S. frigidimarina NCIMB400 genome, upregulated in sessile compared with planktonic conditions. The fact that three proteins including the secreted protein Hcp1 have been identified may suggest that this type VI secretion system is functional. © 2015 Society for Applied Microbiology and John Wiley & Sons Ltd.

Numerical study of PV/T-SAHP system

Institute of Scientific and Technical Information of China (English)

Gang PEI; Jie JI; Ke-liang LIU; Han-feng HE; Ai-guo JIANG

2008-01-01

In order to utilize solar energy effectively and to achieve a higher electrical efficiency by limiting the operating temperature of the photovoltaic (PV) panel, a novel photovoltaic/thermal solar-assisted heat pump (PV/T-SAHP) system was proposed and constructed. The hybrid solar system generates electricity and thermal energy simultaneously. A distributed parameters model of the PV/T-SAHP system was developed and applied to analyze the system dynamic performance in terms of PV action, photothermal action and Rankine cycle processes. The simulation results indicated that the coefficient of performance (COP) of the proposed PV/T-SAHP can be much better than that of the conventional heat pump. Both PV-efficiency and photothermic efficiency have been improved considerably. The results also showed that the performance of this PV/T-SAHP system was strongly influenced by the evaporator area, tube pitch and tilt angle of the PV/T evaporator, which are the key factors in PV/T-SAHP system optimization and PV/T evaporator design.

Power Electronic System for Multi-MW PV sites

DEFF Research Database (Denmark)

Paasch, Kasper

in Sønderborg (DK) was implemented. A total of 17 PV-inverters have been monitored during a period exceeding one year and the recorded data constitutes the basis of this investigation. A part of the 2.1 MW PV plant was reconfigured to emulate the behavior of a central-inverter and solar panels distributed over...... a distance of 160 m. In parallel a string based inverter configuration was established with solar panels at the same locations. An analysis of irradiation data recorded during the test period showed that non-uniform irradiance due to moving clouds is expected to influence the PV plants for less than 4.......4%. A portable IV-scanning instrument for the fast long term characterization of solar panels was developed as part of the project. Each second a sweep of the IV-characteristics of a solar panel is performed and the result stored for later analysis. The instrument is based on an active load, is optimized...

Design optimization of grid-connected PV inverters

DEFF Research Database (Denmark)

Koutroulis, Eftichios; Blaabjerg, Frede

2011-01-01

The DC/AC inverters are the key elements in grid-connected PV energy production systems. In this paper, new design optimization techniques focused on transformerless (very high efficiency) PV inverters are proposed. They have been developed based on an analysis of the deficiencies of the current......, state-of-the-art PV inverters design technology, which limits the amount of PV energy supplied into the electric grid. The influences of the electric grid regulations and standards and the PV array operational characteristics on the design of grid-connected PV inverters have also been considered....... The simulation results verify that the proposed optimization techniques enable the maximization of the PV energy injected into the electric grid by the optimized PV installation....

A case study of utility PV economics

International Nuclear Information System (INIS)

Wenger, H.; Hoff, T.; Osborn, D.E.

1997-01-01

This paper presents selected results from a detailed study of grid-connected photovoltaic (PV) applications within the service area of the Sacramento Municipal Utility District. The intent is to better understand the economics and markets for grid-connected PV systems in a utility setting. Research results include: Benefits calculations for utility-owned PV systems at transmission and distribution voltages; How the QuickScreen software package can help utilities investigate the viability of distributed PV; Energy production and capacity credit estimates for fixed and tracking PV systems; Economics and rate impacts of net metering residential PV systems; Market potential estimates for residential rooftop PV systems; and Viability and timing of grid-connected PV commercialization paths

Solar PV. Innovators talking; Zon PV. Innovators aan het woord

Energy Technology Data Exchange (ETDEWEB)

NONE

2013-02-15

Qualitative studies have been conducted of the results of completed projects focused on energy innovation, spread over the seven themes of the top sector Energy: Energy saving in industry, Energy conservation in the built environment, Gas, Bio-energy, Smart grids, Offshore Wind, Solar PV. This provides insight into the follow-up activities and lessons of some EOS (Energy Research Subsidy) completed projects with the aim to inspire, connect and strengthen the TKIs (Topconsortia for Knowledge and Innovation) and individual companies and researchers working on energy innovation. This report concerns the research on solar PV [Dutch] Er is een kwalitatief onderzoek uitgevoerd naar de resultaten van afgeronde projecten gericht op energie-innovatie, verdeeld over de zeven thema's van de topsector Energie: Energiebesparing in de industrie; Energiebesparing in de gebouwde omgeving; Gas; Bio-energie; Smart grids; Wind op zee; Zon-pv. Daarmee wordt inzicht gegeven in de vervolgactiviteiten en lessen van een aantal afgesloten EOS-projecten (Energie Onderzoek Subsidie) met het oog op het inspireren, verbinden en versterken van de TKI's (Topconsortia voor Kennis en Innovatie) en individuele bedrijven en onderzoekers die werken aan energie-innovatie. Dit rapport betreft het onderzoek naar zon PV.

Solar PV. Innovators talking; Zon PV. Innovators aan het woord

Energy Technology Data Exchange (ETDEWEB)

NONE

2013-02-15

Qualitative studies have been conducted of the results of completed projects focused on energy innovation, spread over the seven themes of the top sector Energy: Energy saving in industry, Energy conservation in the built environment, Gas, Bio-energy, Smart grids, Offshore Wind, Solar PV. This provides insight into the follow-up activities and lessons of some EOS (Energy Research Subsidy) completed projects with the aim to inspire, connect and strengthen the TKIs (Topconsortia for Knowledge and Innovation) and individual companies and researchers working on energy innovation. This report concerns the research on solar PV [Dutch] Er is een kwalitatief onderzoek uitgevoerd naar de resultaten van afgeronde projecten gericht op energie-innovatie, verdeeld over de zeven thema's van de topsector Energie: Energiebesparing in de industrie; Energiebesparing in de gebouwde omgeving; Gas; Bio-energie; Smart grids; Wind op zee; Zon-pv. Daarmee wordt inzicht gegeven in de vervolgactiviteiten en lessen van een aantal afgesloten EOS-projecten (Energie Onderzoek Subsidie) met het oog op het inspireren, verbinden en versterken van de TKI's (Topconsortia voor Kennis en Innovatie) en individuele bedrijven en onderzoekers die werken aan energie-innovatie. Dit rapport betreft het onderzoek naar zon PV.

Firefighter Safety for PV Systems

DEFF Research Database (Denmark)

Mathe, Laszlo; Sera, Dezso; Spataru, Sergiu

2015-01-01

An important and highly discussed safety issue for photovoltaic (PV) systems is that as long as the PV panels are illuminated, a high voltage is present at the PV string terminals and cables between the string and inverters that is independent of the state of the inverter's dc disconnection switch...

Integrating solar PV (photovoltaics) in utility system operations: Analytical framework and Arizona case study

International Nuclear Information System (INIS)

Wu, Jing; Botterud, Audun; Mills, Andrew; Zhou, Zhi; Hodge, Bri-Mathias; Heaney, Mike

2015-01-01

A systematic framework is proposed to estimate the impact on operating costs due to uncertainty and variability in renewable resources. The framework quantifies the integration costs associated with sub-hourly variability and uncertainty as well as day-ahead forecasting errors in solar PV (photovoltaics) power. A case study illustrates how changes in system operations may affect these costs for a utility in the southwestern United States (Arizona Public Service Company). We conduct an extensive sensitivity analysis under different assumptions about balancing reserves, system flexibility, fuel prices, and forecasting errors. We find that high solar PV penetrations may lead to operational challenges, particularly during low-load and high solar periods. Increased system flexibility is essential for minimizing integration costs and maintaining reliability. In a set of sensitivity cases where such flexibility is provided, in part, by flexible operations of nuclear power plants, the estimated integration costs vary between $1.0 and $4.4/MWh-PV for a PV penetration level of 17%. The integration costs are primarily due to higher needs for hour-ahead balancing reserves to address the increased sub-hourly variability and uncertainty in the PV resource. - Highlights: • We propose an analytical framework to estimate grid integration costs for solar PV. • Increased operating costs from variability and uncertainty in solar PV are computed. • A case study of a utility in Arizona is conducted. • Grid integration costs are found in the $1.0–4.4/MWh range for a 17% PV penetration. • Increased system flexibility is essential for minimizing grid integration costs

Grid integrated distributed PV (GridPV).

Energy Technology Data Exchange (ETDEWEB)

Reno, Matthew J.; Coogan, Kyle

2013-08-01

This manual provides the documentation of the MATLAB toolbox of functions for using OpenDSS to simulate the impact of solar energy on the distribution system. The majority of the functions are useful for interfacing OpenDSS and MATLAB, and they are of generic use for commanding OpenDSS from MATLAB and retrieving information from simulations. A set of functions is also included for modeling PV plant output and setting up the PV plant in the OpenDSS simulation. The toolbox contains functions for modeling the OpenDSS distribution feeder on satellite images with GPS coordinates. Finally, example simulations functions are included to show potential uses of the toolbox functions. Each function in the toolbox is documented with the function use syntax, full description, function input list, function output list, example use, and example output.

PV/T slates - Pilot project in Steinhausen; PV/T-Schiefer. Pilotprojekt Steinhausen

Energy Technology Data Exchange (ETDEWEB)

Kropf, S.

2003-07-01

This comprehensive, illustrated report for the Swiss Federal Office of Energy (SFOE) is one a series of five reports dealing with increasing the overall efficiency of photovoltaic (PV) installations by also using the heat collected by the dark-coloured PV panels. The work reported on addresses open questions on the use of the heat and its optimal use. This report deals with a ventilated PV-tile system (PV/T-Slates) mounted on a garden shed in Steinhausen, Switzerland. The installation provides power and heat to the main house. The report describes the construction and operation of this pilot project and the results of measurements made on its electrical and thermal performance. The results of measurements made are presented in detail in graphical form and compared with the results of simulation. Suggestions are made for the optimisation of the system. Figures are presented on energy production and energy flows in graphical form.

Photovoltaics: PV takes off the UK

International Nuclear Information System (INIS)

Noble, Ray; Gregory, Jenny

2000-01-01

Despite historical ups and downs, there is still ambition to bring increasingly efficient photovoltaic (PV) systems to the market. PV for major remote telecommunications systems is now an established part of the market, many mobile phone systems are powered by PV and there is potential for increased use of home solar systems, especially in developing countries. Over the past few years, building-integrated PV (BIPV) has been on the increase. In 1999, global production from PV exceeded 200 MW and the UK installed capacity was greater than 1 MW. BIPV is a fast growing market and its characteristics and advantages are discussed. PV installations at Nottingham University, Greenwich Pavilion, BP Amoco Sunbury, Baglan Bay, BP filling stations, and Sainsbury's are described

PV-BUK: Operating and maintenance costs of photovoltaic installations; PV-BUK - Betriebs- und Unterhaltskosten von PV-Anlagen - Schlussbericht

Energy Technology Data Exchange (ETDEWEB)

Stettler, S.; Toggweiler, P. [Enecolo AG, Moenchaltorf (Switzerland); Ruoss, D.; Schudel, P. [Envision, Lucerne (Switzerland); Kottmann, A.; Steinle, F. [BE Netz AG, Lucerne (Switzerland)

2008-03-15

This final report elaborated for the Swiss Federal Office of Energy (SFOE) takes a look at the results of a project carried out to determine the costs for facility management, to estimate future cost development and to propose activities for the further reduction of the operation and maintenance costs of photovoltaic systems. Information on the cost situation was collected by literature study, as well as in interviews and surveys with photovoltaic (PV) experts and the owners of PV installations. The discussion of the results at a workshop with about 20 Swiss PV experts is noted. The results are presented and discussed. These show that operating costs per kWh decrease with the size of the PV system. Figures are quoted. The major part of the costs are quoted as being those for spare parts, especially for the inverter. The authors are of the opinion that, in future, costs for facility management will further decrease, as they are partly linked to capital and insurance costs. Potential for optimisation is said to exist in several areas of facility management such as, for example, in system monitoring and fast reaction in the case of malfunctions.

Solar cell junction temperature measurement of PV module

KAUST Repository

Huang, B.J.

2011-02-01

The present study develops a simple non-destructive method to measure the solar cell junction temperature of PV module. The PV module was put in the environmental chamber with precise temperature control to keep the solar PV module as well as the cell junction in thermal equilibrium with the chamber. The open-circuit voltage of PV module Voc is then measured using a short pulse of solar irradiation provided by a solar simulator. Repeating the measurements at different environment temperature (40-80°C) and solar irradiation S (200-1000W/m2), the correlation between the open-circuit voltage Voc, the junction temperature Tj, and solar irradiation S is derived.The fundamental correlation of the PV module is utilized for on-site monitoring of solar cell junction temperature using the measured Voc and S at a short time instant with open circuit. The junction temperature Tj is then determined using the measured S and Voc through the fundamental correlation. The outdoor test results show that the junction temperature measured using the present method, Tjo, is more accurate. The maximum error using the average surface temperature Tave as the junction temperature is 4.8 °C underestimation; while the maximum error using the present method is 1.3 °C underestimation. © 2010 Elsevier Ltd.

Economic perspective of PV electricity in Oman

International Nuclear Information System (INIS)

Al-Badi, A.H.; Albadi, M.H.; Al-Lawati, A.M.; Malik, A.S.

2011-01-01

Solar and wind energies are likely to play an important role in the future energy generation in Oman. This paper utilizes average daily global solar radiation and sunshine duration data of 25 locations in Oman to study the economic prospects of solar energy. The study considers a solar PV power plant of 5-MW at each of the 25 locations. The global solar radiation varies between slightly greater than 4 kWh/m 2 /day at Sur to about 6 kWh/m 2 /day at Marmul while the average value in the 25 locations is more than 5 kWh/m 2 /day. The results show that the renewable energy produced each year from the PV power plant varies between 9000 MWh at Marmul and 6200 MWh at Sur while the mean value is 7700 MWh of all the 25 locations. The capacity factor of PV plant varies between 20% and 14% and the cost of electricity varies between 210 US$/MWh and 304 US$/MWh for the best location to the least attractive location, respectively. The study has also found that the PV energy at the best location is competitive with diesel generation without including the externality costs of diesel. Renewable energy support policies that can be implemented in Oman are also discussed. -- Research highlights: → The global solar radiation values for 25 locations in Oman are obtained using satellite data that are corrected by data from ground stations. → The study considers a solar PV power plant of 5-MW to calculate the capacity factor (CF) and the cost of energy (COE) at each of the 25 locations. → The study has found that the CF of PV plant varies between 20% and 14% and the corresponding COE varies between 210 US$/MWh and 304 US$/MWh for the best location to the least attractive location, respectively. → The study has found that the PV energy at the best location is competitive with diesel generation without including the externality costs of diesel. → Since PV energy is not competitive with fossil fuel-based generation in most locations renewable energy support mechanisms have been

POWERED LED LIGHTING SUPPLIED FROM PV CELLS

Directory of Open Access Journals (Sweden)

Tirshu M.

2011-12-01

Full Text Available The paper deals with practical realization of efficient lighting system based on LED’s of 80W total power mounted on corridor ceiling total length of which is 120m and substitutes existing traditional lighting system consisting of 29 lighting blocks with 4 fluorescent lamps each of them and summary power 2088W. Realized lighting system is supplied from two photovoltaic panels of power 170W. Generated energy by PV cells is accumulated in two accumulators of 75Ah capacity and from battery by means of specialized convertor is applied to lighting system. Additionally, paper present data measured by digital weather station (solar radiation and UV index, which is mounted near of PV cells and comparative analyze of solar energy with real energy generated by PV cells is done. Measured parameters by digital weather station are stored by computer in on-line mode.

Optimization of PV-based energy production by dynamic PV-panel/inverter configuration

DEFF Research Database (Denmark)

Paasch, Kasper; Nymand, Morten; Haase, Frerk

This paper investigates the possible increase in annual energy production of a PV system with more than one MPPT (maximum power point tracker) input channels under Nordic illumination conditions, in case a concept of dynamic switching of the PV panels is used at the inputs of the inverters....

Increased Age-Dependent Risk of Death Associated With lukF-PV-Positive Staphylococcus aureus Bacteremia

DEFF Research Database (Denmark)

Knudsen, Trine A; Skov, Robert; Petersen, Andreas

2016-01-01

BACKGROUND: Panton-Valentine leucocidin is a Staphylococcus aureus virulence factor encoded by lukF-PV and lukS-PV that is infrequent in S aureus bacteremia (SAB), and, therefore, little is known about risk factors and outcome of lukF-PV/lukS-PV-positive SAB. METHODS: This report is a register......-based nationwide observational cohort study. lukF-PV was detected by polymerase chain reaction. Factors associated with the presence of lukF-PV were assessed by logistic regression analysis. Adjusted 30-day hazard ratios of mortality associated with lukF-PV status were computed by Cox proportional hazards...... regression analysis. RESULTS: Of 9490 SAB cases, 129 were lukF-PV-positive (1.4%), representing 14 different clonal complexes. lukF-PV was associated with younger age, absence of comorbidity, and methicillin-resistant S aureus. In unadjusted analysis, mortality associated with lukF-PV-positive SAB...

PV integration into a CSP plant

Science.gov (United States)

Carvajal, Javier López; Barea, Jose M.; Barragan, Jose; Ortega, Carlos

2017-06-01

This paper describes a preliminary techno-economic analysis of the integration of a PV plant into an optimized Parabolic Trough Plant in order to reduce the online consumptions and thus, increase the net electricity injected into the grid. The idea is to assess the feasibility of such project and see what configuration would be the optimal. An extra effort has been made in terms of modelling as the analysis has to be done to the integrated CSP + PV plant instead of analyzing them independently. Two different technologies have been considered for the PV plant, fix and one-axis tracking. Additionally three different scenarios have been considered for the CSP plant auxiliary consumptions as they are essential for determining the optimal PV plant (the higher the auxiliary consumption the higher the optimal PV plant). As could be expected, the results for all cases with PV show an improvement in terms of electricity generation and also in terms of LCOE with respect to the CSP plant. Such improvement is slightly higher with tracking technology for this specific study. Although this exercise has been done to an already designed CSP plant (so only the PV plant had to be optimized), the methodology could be applied for the optimization of an integrated CSP + PV plant during the design phase.

Reduction of Ferrrihydrite and Akaganeite by Shewanella alga (PAH93)

Science.gov (United States)

Jung, M.; Kim, Y.; Lee, Y.; Kwon, K.; Roh, Y.

2009-12-01

Shewanella species are capable of oxidizing diverse organic acids coupled to reducing Fe(III) (oxy)hydroxides to crystalline Fe(II)-containing phases such as magnetite, siderite, and vivianite. The objective of this study was to examine reduction of ferrihydrite and akaganeite as the electron acceptors using various organic acids as the electron donors by Shewanella alga (PAH93) isolated from Yeosu, South Korea. Microbial reduction of akaganeite (40 mM) and ferrihydrite (40 mM) was examined using acetate (10 mM), glucose (10 mM), and lactate (10 mM) as electron donors at room temperature. Ferrozine method was used to analyze both water soluble and HCl soluble Fe(II) concentrations during the microbial Fe(III) reduction. XRD and TEM-EDX analyses were used to characterize biominerals formed by PAH93. PAH93 was completely reduced ferrihydrite to Fe(II), which transformed as siderite (FeCO3). PAH93 was oxidized acetate, glucose, and lactate coupled to reducing akaganeite to magnetite or green rust. Microbial reduction of ferrihydrite resulted in higher soluble Fe(II) concentration (446 - 498 mg/L) than the reduction of akaganeite (255 - 284 mg/L) within 6 days of incubation. For 21 days of incubation, souble Fe(II) concentration during akaganeite reduction (945 - 1316 mg/L) was higher than ferrihydrite reduction (120 - 738 mg/L). It may be attributed to the differences of crystallinity of the iron minerals used for microbial iron reduction. This study indicates types of the electron acceptors, ferrihydrite and akaganeite, affect Fe(II) reduction rate and types of the biotransformed minerals.

Physiology and enzymology involved in denitrification by Shewanella putrefaciens

Science.gov (United States)

Krause, B.; Nealson, K. H.

1997-01-01

Nitrate reduction to N2O was investigated in batch cultures of Shewanella putrefaciens MR-1, MR-4, and MR-7. All three strains reduced nitrate to nitrite to N2O, and this reduction was coupled to growth, whereas ammonium accumulation was very low (0 to 1 micromol liter-1). All S. putrefaciens isolates were also capable of reducing nitrate aerobically; under anaerobic conditions, nitrite levels were three- to sixfold higher than those found under oxic conditions. Nitrate reductase activities (31 to 60 micromol of nitrite min-1 mg of protein-1) detected in intact cells of S. putrefaciens were equal to or higher than those seen in Escherichia coli LE 392. Km values for nitrate reduction ranged from 12 mM for MR-1 to 1.3 mM for MR-4 with benzyl viologen as an artifical electron donor. Nitrate and nitrite reductase activities in cell-free preparations were demonstrated in native gels by using reduced benzyl viologen. Detergent treatment of crude and membrane extracts suggested that the nitrate reductases of MR-1 and MR-4 are membrane bound. When the nitrate reductase in MR-1 was partially purified, three subunits (90, 70, and 55 kDa) were detected in denaturing gels. The nitrite reductase of MR-1 is also membrane bound and appeared as a 60-kDa band in sodium dodecyl sulfate-polyacrylamide gels after partial purification.

The case for better PV forecasting

DEFF Research Database (Denmark)

Alet, Pierre-Jean; Efthymiou, Venizelos; Graditi, Giorgio

2016-01-01

Rising levels of PV penetration mean increasingly sophisticated forecasting technologies are needed to maintain grid stability and maximise the economic value of PV systems. The Grid Integration working group of the European Technology and Innovation Platform – Photovoltaics (ETIP PV) shares the ...

Development of a GIS Tool for High Precision PV Degradation Monitoring and Supervision: Feasibility Analysis in Large and Small PV Plants

Directory of Open Access Journals (Sweden)

Miguel de Simón-Martín

2017-06-01

Full Text Available It is well known that working photovoltaic (PV plants show several maintenance needs due to wiring and module degradation, mismatches, dust, and PV cell defects and faults. There are a wide range of theoretical studies as well as some laboratory tests that show how these circumstances may affect the PV production. Thus, it is mandatory to evaluate the whole PV plant performance and, then, its payback time, profitability, and environmental impact or carbon footprint. However, very few studies include a systematic procedure to quantify and supervise the real degradation effects and fault impacts on the field. In this paper, the authors first conducted a brief review of the most frequent PV faults and the degradation that can be found under real conditions of operation of PV plants. Then, they proposed and developed an innovative Geographic Information System (GIS application to locate and supervise them. The designed tool was applied to both a large PV plant of 108 kWp and a small PV plant of 9 kWp installed on a home rooftop. For the large PV plant, 24 strings of PV modules were modelized and introduced into the GIS application and every module in the power plant was studied including voltage, current, power, series and parallel resistances, fill factor, normalized PV curve to standard test conditions (STC, thermography and visual analysis. For the small PV installation three strings of PV panels were studied identically. It must be noted that PV modules in this case included power optimizers. The precision of the study enabled the researchers to locate and supervise up to a third part of every PV cell in the system, which can be adequately georeferenced. The developed tool allows both the researchers and the investors to increase control of the PV plant performance, to lead to better planning of maintenance actuations, and to evaluate several PV module replacement strategies in a preventive maintenance program. The PV faults found include hot

Adiabatic Rearrangement of Hollow PV Towers

Directory of Open Access Journals (Sweden)

Eric A Hendricks

2010-10-01

Full Text Available Diabatic heating from deep moist convection in the hurricane eyewall produces a towering annular structure of elevated potential vorticity (PV. This structure has been referred to as a hollow PV tower. The sign reversal of the radial gradient of PV satisfies the Charney-Stern necessary condition for combined barotropic-baroclinic instability. For thin enough annular structures, small perturbations grow exponentially, extract energy from the mean flow, and lead to hollow tower breakdown, with significant vortex structural and intensity change. The three-dimensional adiabatic rearrangements of two prototypical hurricane-like hollow PV towers (one thick and one thin are examined in an idealized framework. For both hollow towers, dynamic instability causes air parcels with high PV to be mixed into the eye preferentially at lower levels, where unstable PV wave growth rates are the largest. Little or no mixing is found to occur at upper levels. The mixing at lower and middle levels is most rapid for the breakdown of the thin hollow tower, consistent with previous barotropic results. For both hollow towers, this advective rearrangement of PV affects the tropical cyclone structure and intensity in a number of ways. First, the minimum central pressure and maximum azimuthal mean velocity simultaneously decrease, consistent with previous barotropic results. Secondly, isosurfaces of absolute angular momentum preferentially shift inward at low levels, implying an adiabatic mechanism by which hurricane eyewall tilt can form. Thirdly, a PV bridge, similar to that previously found in full-physics hurricane simulations, develops as a result of mixing at the isentropic levels where unstable PV waves grow most rapidly. Finally, the balanced mass field resulting from the PV rearrangement is warmer in the eye between 900 and 700 hPa. The location of this warming is consistent with observed warm anomalies in the eye, indicating that in certain instances the hurricane

Cloning of genes required for hypersensitivity and pathogenicity in Pseudomonas syringae pv. aptata.

Science.gov (United States)

Minardi, P

1995-01-01

A genomic library of Pseudomonas syringae pv. aptata strain NCPPB 2664, which causes bacterial blight of sugar beet, lettuce and other plants, was constructed in the cosmid vector pCPP31. The 13.4 kb EcoRI fragment of the cosmid pHIR11, containing the hrp (hypersensitive response and pathogenicity) gene cluster of the closely related bacterium Pseudomonas syringae pv. syringae strain 61, was used as a probe to identify a homologous hrp gene cluster in P. syringae pv. aptata. Thirty of 2500 cosmid clones, screened by colony hybridization, gave a strong hybridization signal with the probe, but none of these conferred to the non-pathogenic bacterium, Pseudomonas fluorescens, the ability to elicit the hypersensitive response (HR) in tobacco. Southern blot analysis of EcoRI-digested genomic DNA of P. syringae pv. aptata showed hybridizing bands of 12 kb and 4.4 kb. Only a 12 kb fragment hybridized in digests of the cosmids. Cosmid clone pCPP1069 was mutagenized with Tn10-minitet and marker-exchanged into the genome of P. syringae pv. aptata. Three resulting prototrophic mutant strains failed to elicit the HR in tobacco and to cause disease in lettuce. The DNA flanking the Tn10-minitet insertions from mutated derivatives of pCPP1069 hybridized with the 10.6 kb Bg/II fragment of pHIR11. These results indicate that P. syringae pv. aptata harbours hrp genes that are similar to, but arranged differently from, homologous hrp genes of P. syringae pv. syringae.

Parallel experimental study of a novel super-thin thermal absorber based photovoltaic/thermal (PV/T system against conventional photovoltaic (PV system

Directory of Open Access Journals (Sweden)

Peng Xu

2015-11-01

Full Text Available Photovoltaic (PV semiconductor degrades in performance due to temperature rise. A super thin-conductive thermal absorber is therefore developed to regulate the PV working temperature by retrofitting the existing PV panel into the photovoltaic/thermal (PV/T panel. This article presented the parallel comparative investigation of the two different systems through both laboratory and field experiments. The laboratory evaluation consisted of one PV panel and one PV/T panel respectively while the overall field system involved 15 stand-alone PV panels and 15 retrofitted PV/T panels. The laboratory testing results demonstrated the PV/T panel could achieve the electrical efficiency of about 16.8% (relatively 5% improvement comparing with the stand-alone PV panel, and yield an extra amount of heat with thermal efficiency of nearly 65%. The field testing results indicated that the hybrid PV/T panel could enhance the electrical return of PV panels by nearly 3.5%, and increase the overall energy output by nearly 324.3%. Further opportunities and challenges were then discussed from aspects of different PV/T stakeholders to accelerate the development. It is expected that such technology could become a significant solution to yield more electricity, offset heating load freely and reduce carbon footprint in contemporary energy environment.

Genome analysis of a clinical isolate of Shewanella sp. uncovered an active hybrid integrative and conjugative element carrying an integron platform inserted in a novel genomic locus.

Science.gov (United States)

Parmeciano Di Noto, Gisela; Jara, Eugenio; Iriarte, Andrés; Centrón, Daniela; Quiroga, Cecilia

2016-08-01

Shewanella spp. are currently considered to be emerging pathogens that can code for a blaOXA carbapenemase in their chromosome. Complete genome analysis of the clinical isolate Shewanella sp. Sh95 revealed that this strain is a novel species, which shares a lineage with marine isolates. Characterization of its resistome showed that it codes for genes drfA15, qacH and blaOXA-48. We propose that Shewanella sp. Sh95 acts as reservoir of blaOXA-48. Moreover, analysis of mobilome showed that it contains a novel integrative and conjugative element (ICE), named ICESh95. Comparative analysis between the close relatives ICESpuPO1 from Shewanella sp. W3-18-1 and ICE SXTMO10 from Vibrio cholerae showed that ICESh95 encompassed two new regions, a type III restriction modification system and a multidrug resistance integron. The integron platform contained a novel arrangement formed by gene cassettes drfA15 and qacH, and a class C-attC group II intron. Furthermore, insertion of ICESh95 occurred at a unique target site, which correlated with the presence of a different xis/int module. Mobility of ICESh95 was assessed and demonstrated its ability to self-transfer with high efficiency to different species of bacteria. Our results show that ICESh95 is a self-transmissible, mobile element, which can contribute to the dissemination of antimicrobial resistance; this is clearly a threat when natural bacteria from water ecosystems, such as Shewanella, act as vectors in its propagation.

The market for photovoltaic (PV) technology

International Nuclear Information System (INIS)

Frantzis, L.; Vejtasa, K.M.

1993-01-01

This paper describes a study that was intended to provide the Electric Power Research Institute (EPRI) with a market analysis for photovoltaic (PV) technologies under development by EPRI and others. The analysis was to focus on markets and factors leading to significant incremental growth for PV demand, large enough to support more efficient scale PV manufacturing capacity. EPRI anticipates that PV ultimately could provide grid-connected power, however, the 1995--2010 market dynamics are uncertain. The specific objectives of this study, therefore, were to: determine what major future domestic US markets for PV technologies will emerge and provide enough volume to support significant improvements in manufacturing costs through manufacturing economies of scale; provide insight on what is needed to gain acceptance of PV technologies for electric power generation in those major markets; provide insight on when investments in demonstration and manufacturing facilities should be made and what is needed to be successful in each element of the business that these markets could support (e.g., technology development, manufacturing, sales, installation, and service); and provide key insights on the requirements for commercial success of PV in the utility sector

Treatment Failure Due to Emergence of Resistance to Carbapenem during Therapy for Shewanella algae Bacteremia

OpenAIRE

Kim, Dong-Min; Kang, Cheol-In; Lee, Chang Seop; Kim, Hong-Bin; Kim, Eui-Chong; Kim, Nam Joong; Oh, Myoung-don; Choe, Kang-Won

2006-01-01

We describe a case of bacteremia due to imipenem-susceptible Shewanella algae. Despite treatment with imipenem, the patient developed a spinal epidural abscess, from which imipenem-resistant S. algae was isolated. The development of resistance should be monitored when S. algae infection is treated with imipenem, even though the strain is initially susceptible to imipenem.

Study on analytical modelling approaches to the performance of thin film PV modules in sunny inland climates

International Nuclear Information System (INIS)

Torres-Ramírez, M.; Nofuentes, G.; Silva, J.P.; Silvestre, S.; Muñoz, J.V.

2014-01-01

This work is aimed at verifying that analytical modelling approaches may provide an estimation of the outdoor performance of TF (thin film) PV (photovoltaic) technologies in inland sites with sunny climates with adequate accuracy for engineering purposes. Osterwald's and constant fill factor methods were tried to model the maximum power delivered and the annual energy produced by PV modules corresponding to four TF PV technologies. Only calibrated electrical parameters at STC (standard test conditions), on-plane global irradiance and module temperature are required as inputs. A 12-month experimental campaign carried out in Madrid and Jaén (Spain) provided the necessary data. Modelled maximum power and annual energy values obtained through both methods were statistically compared to the experimental ones. In power terms, the RMSE (root mean square error) stays below 3.8% and 4.5% for CdTe (cadmium telluride) and CIGS (copper indium gallium selenide sulfide) PV modules, respectively, while RMSE exceeds 5.4% for a-Si (amorphous silicon) or a-Si:H/μc-Si PV modules. Regarding energy terms, errors lie below 4.0% in all cases. Thus, the methods tried may be used to model the outdoor behaviour of the a-Si, a-Si:H/μc-Si, CIGS and CdTe PV modules tested – ordered from the lowest to the highest accuracy obtained – in sites with similar spectral characteristics to those of the two sites considered. - Highlights: • Simple analytical methods to model the outdoor behaviour of thin film PV (photovoltaic) technologies. • 8 PV modules were deployed outdoors over a 12-month period in two sunny inland sites. • RMSE (root mean square error) values stay below 3.8% and 4.5% in CdTe (cadmium telluride) and CIGS (copper indium gallium selenide sulfide) PV modules. • Errors remain below 4.0% for all the PV modules and sites in energy terms. • Simple methods: suitable estimation of PV outdoor behaviour for engineering purposes

Wind effect on PV module temperature: Analysis of different techniques for an accurate estimation.

Science.gov (United States)

Schwingshackl, Clemens; Petitta, Marcello; Ernst Wagner, Jochen; Belluardo, Giorgio; Moser, David; Castelli, Mariapina; Zebisch, Marc; Tetzlaff, Anke

2013-04-01

In this abstract a study on the influence of wind to model the PV module temperature is presented. This study is carried out in the framework of the PV-Alps INTERREG project in which the potential of different photovoltaic technologies is analysed for alpine regions. The PV module temperature depends on different parameters, such as ambient temperature, irradiance, wind speed and PV technology [1]. In most models, a very simple approach is used, where the PV module temperature is calculated from NOCT (nominal operating cell temperature), ambient temperature and irradiance alone [2]. In this study the influence of wind speed on the PV module temperature was investigated. First, different approaches suggested by various authors were tested [1], [2], [3], [4], [5]. For our analysis, temperature, irradiance and wind data from a PV test facility at the airport Bolzano (South Tyrol, Italy) from the EURAC Institute of Renewable Energies were used. The PV module temperature was calculated with different models and compared to the measured PV module temperature at the single panels. The best results were achieved with the approach suggested by Skoplaki et al. [1]. Preliminary results indicate that for all PV technologies which were tested (monocrystalline, amorphous, microcrystalline and polycrystalline silicon and cadmium telluride), modelled and measured PV module temperatures show a higher agreement (RMSE about 3-4 K) compared to standard approaches in which wind is not considered. For further investigation the in-situ measured wind velocities were replaced with wind data from numerical weather forecast models (ECMWF, reanalysis fields). Our results show that the PV module temperature calculated with wind data from ECMWF is still in very good agreement with the measured one (R² > 0.9 for all technologies). Compared to the previous analysis, we find comparable mean values and an increasing standard deviation. These results open a promising approach for PV module

Open and closed conformations of two SpoIIAA-like proteins (YP-749275.1 and YP-001095227.1) provide insights into membrane association and ligand binding

International Nuclear Information System (INIS)

Kumar, Abhinav; Lomize, Andrei; Jin, Kevin K.; Carlton, Dennis; Miller, Mitchell D.; Jaroszewski, Lukasz; Abdubek, Polat; Astakhova, Tamara; Axelrod, Herbert L.; Chiu, Hsiu-Ju; Clayton, Thomas; Das, Debanu; Deller, Marc C.; Duan, Lian; Feuerhelm, Julie; Grant, Joanna C.; Grzechnik, Anna; Han, Gye Won; Klock, Heath E.; Knuth, Mark W.; Kozbial, Piotr; Krishna, S. Sri; Marciano, David; McMullan, Daniel; Morse, Andrew T.; Nigoghossian, Edward; Okach, Linda; Reyes, Ron; Rife, Christopher L.; Sefcovic, Natasha; Tien, Henry J.; Trame, Christine B.; Bedem, Henry van den; Weekes, Dana; Xu, Qingping; Hodgson, Keith O.; Wooley, John; Elsliger, Marc-André; Deacon, Ashley M.; Godzik, Adam; Lesley, Scott A.; Wilson, Ian A.

2009-01-01

The crystal structures of two orthologous proteins from different Shewanella species have uncovered a resemblance to CRAL-TRIO carrier proteins, which suggest that they function as transporters of small nonpolar molecules. One protein adopts an open conformation, while the other adopts a closed structure that may act as a conformational switch in the transport of ligands at the membrane surface. The crystal structures of the proteins encoded by the YP-749275.1 and YP-001095227.1 genes from Shewanella frigidimarina and S. loihica, respectively, have been determined at 1.8 and 2.25 Å resolution, respectively. These proteins are members of a novel family of bacterial proteins that adopt the α/β SpoIIAA-like fold found in STAS and CRAL-TRIO domains. Despite sharing 54% sequence identity, these two proteins adopt distinct conformations arising from different dispositions of their α2 and α3 helices. In the ‘open’ conformation (YP-001095227.1), these helices are 15 Å apart, leading to the creation of a deep nonpolar cavity. In the ‘closed’ structure (YP-749275.1), the helices partially unfold and rearrange, occluding the cavity and decreasing the solvent-exposed hydrophobic surface. These two complementary structures are reminiscent of the conformational switch in CRAL-TRIO carriers of hydrophobic compounds. It is suggested that both proteins may associate with the lipid bilayer in their ‘open’ monomeric state by inserting their amphiphilic helices, α2 and α3, into the lipid bilayer. These bacterial proteins may function as carriers of nonpolar substances or as interfacially activated enzymes

Experimental investigation of PV modules recycling; PV module recycle no jikkenteki kento

Energy Technology Data Exchange (ETDEWEB)

Unagida, H; Kurokawa, K [Tokyo University of Agriculture and Technology, Tokyo (Japan); Sakuta, K; Otani, K; Murata, K [Electrotechnical Laboratory, Tsukuba (Japan)

1997-11-25

Recycling, cost/energy analysis and recovery experiment were made on crystalline silicon PV modules with EVA(ethylene vinyl acetate)-laminated structure. The life of modules is dependent not on performance deterioration of PV cells themselves but on yellowing or poor transmittance of EVA caused by ultraviolet ray, and disconnection between cells by thermal stress. Recovery is carried out in 3 stages of cell, wafer and material. Recovery in the stages of cell and wafer results in considerable reduction of energy and cost. The recovery experiment was carried out using PV module samples prepared by cutting the modules into 25times15mm pieces after removing Al frames from the used modules, peeling back sheets and cutting off EVA. Since a nitric acid process at 70-80degC can dissolve EVA effectively, it is promising for reuse of surface glass and PV cells as they are. This process is also carried out under a condition around room temperature and pressure, contributing to cost reduction and energy saving for recycling. Generation of harmful NOx is only a problem to be solved. 2 refs., 6 figs., 1 tab.

A Practical Irradiance Model for Bifacial PV Modules

Energy Technology Data Exchange (ETDEWEB)

Marion, Bill; MacAlpine, Sara; Deline, Chris; Asgharzadeh, Amir; Toor, Fatima; Riley, Daniel; Stein, Joshua; Hansen, Clifford

2017-06-21

A model, suitable for a row or multiple rows of photovoltaic (PV) modules, is presented for estimating the backside irradiance for bifacial PV modules. The model, which includes the effects of shading by the PV rows, is based on the use of configuration factors to determine the fraction of a source of irradiance that is received by the backside of the PV module. Backside irradiances are modeled along the sloped height of the PV module, but assumed not to vary along the length of the PV row. The backside irradiances are corrected for angle-of-incidence losses and may be added to the front side irradiance to determine the total irradiance resource for the PV cell. Model results are compared with the measured backside irradiances for NREL and Sandia PV systems, and with results when using ray tracing software.

Power of design - the future of building-integrated PV

International Nuclear Information System (INIS)

Abbate, Cinzia

2001-01-01

This paper discusses strategies to make building integrated photovoltaic (PV) systems more acceptable and to allow PV material to compete with conventional construction material. The history of developments in building integration and difficulties encountered by architects wishing to use PV products are explored, and the Dutch Amersfoot project in Utrecht involving a new suburb of 501 house covered with PV panels is described. Questions raised regarding architectural integration of PV systems, and PV systems and the construction market are discussed. The Italian PV programme, financial and political constraints, and the positioning of PV on existing structures are reported

PSCAD Modules Representing PV Generator

Energy Technology Data Exchange (ETDEWEB)

Muljadi, E.; Singh, M.; Gevorgian, V.

2013-08-01

Photovoltaic power plants (PVPs) have been growing in size, and the installation time is very short. With the cost of photovoltaic (PV) panels dropping in recent years, it can be predicted that in the next 10 years the contribution of PVPs to the total number of renewable energy power plants will grow significantly. In this project, the National Renewable Energy Laboratory (NREL) developed a dynamic modeling of the modules to be used as building blocks to develop simulation models of single PV arrays, expanded to include Maximum Power Point Tracker (MPPT), expanded to include PV inverter, or expanded to cover an entire PVP. The focus of the investigation and complexity of the simulation determines the components that must be included in the simulation. The development of the PV inverter was covered in detail, including the control diagrams. Both the current-regulated voltage source inverter and the current-regulated current source inverter were developed in PSCAD. Various operations of the PV inverters were simulated under normal and abnormal conditions. Symmetrical and unsymmetrical faults were simulated, presented, and discussed. Both the three-phase analysis and the symmetrical component analysis were included to clarify the understanding of unsymmetrical faults. The dynamic model validation was based on the testing data provided by SCE. Testing was conducted at SCE with the focus on the grid interface behavior of the PV inverter under different faults and disturbances. The dynamic model validation covers both the symmetrical and unsymmetrical faults.

OnToPV - a virtual guidance through the PV-plant ''Solardach New Munich Trade Fair''; OnToPV - eine virtuelle Fuehrung druch die PV-Anlage ''Solardach Neue Messe Muenchen''

Energy Technology Data Exchange (ETDEWEB)

Stich, C.; Becker, G.; Zehner, M. [Fachhochschule Muenchen (Germany). Fachbereich Elektrotechnik; Giesler, B. [Shell Solar GmbH, Muenchen (Germany); Weber, W.; Flade, F. [Solarenergiefoerderverein Bayern e.V., Muenchen (Germany)

2003-07-01

OnToPV is the project of an online tour guide through the PV-plant of the new Munich trade fair. The first focs was to provide an interactive circuit of a PV-plant. Within a virtual tour different areas of the plant should be made accessible over the internet. For this purpose a three-dimensional, multimedia guidance was developed for the PV-plant of the new Munich trade fair with informative diagrams, *.pdf-files and retrievable video-files. In such a way interested internet-users could experience with minimum system requirements, local- and time-independently the PV-plant in its structure and components and could receive different background informations in addition. From the view of the plant operators such an internet project serves on the one hand as an additional source of information where questions could be referred to and on the other hand as sort of advertisement for the technology and the PV-system. In addition the attractiveness of the internet appearance of the plant operator rises and the public awareness of such projects could increase. Seen from the user perspective - such an internet project gives private or business users the possibility to inform themselves interactively, purposefully and with the possibility to move through the plant on their own. Users could utilize the guidance through the plant without overcoming far geographical distances, saving time and money. Perhaps this source of information helps awaking a larger consciousness for renewable energies. The result OnToPV showed the various possibilities offered by projects of this kind in the internet. Ideas of possible extensions as for example the integration of current PV-plant operational data or of a virtual learning platform illustrate the perspectives of the project. Virtual guidance of this kind for various types of power plants are conceivable. (orig.)

The acid-tolerant L-arabinose isomerase from the mesophilic Shewanella sp. ANA-3 is highly active at low temperatures

Science.gov (United States)

2011-01-01

Background L-arabinose isomerases catalyse the isomerization of L-arabinose into L-ribulose at insight biological systems. At industrial scale of this enzyme is used for the bioconversion of D-galactose into D-tagatose which has many applications in pharmaceutical and agro-food industries. The isomerization reaction is thermodynamically equilibrated, and therefore the bioconversion rates is shifted towards tagatose when the temperature is increased. Moreover, to prevent secondary reactions it will be of interest to operate at low pH. The profitability of this D-tagatose production process is mainly related to the use of lactose as cheaper raw material. In many dairy products it will be interesting to produce D-tagatose during storage. This requires an efficient L-arabinose isomerase acting at low temperature and pH values. Results The gene encoding the L-arabinose isomerase from Shewanella sp. ANA-3 was cloned and overexpressed in Escherichia coli. The purified protein has a tetrameric arrangement composed by four identical 55 kDa subunits. The biochemical characterization of this enzyme showed that it was distinguishable by its maximal activity at low temperatures comprised between 15-35°C. Interestingly, this biocatalyst preserves more than 85% of its activity in a broad range of temperatures from 4.0 to 45°C. Shewanella sp. ANA-3 L-arabinose isomerase was also optimally active at pH 5.5-6.5 and maintained over 80% of its activity at large pH values from 4.0 to 8.5. Furthermore, this enzyme exhibited a weak requirement for metallic ions for its activity evaluated at 0.6 mM Mn2+. Stability studies showed that this protein is highly stable mainly at low temperature and pH values. Remarkably, T268K mutation clearly enhances the enzyme stability at low pH values. Use of this L-arabinose isomerase for D-tagatose production allows the achievement of attractive bioconversion rates of 16% at 4°C and 34% at 35°C. Conclusions Here we reported the purification and the

The acid-tolerant L-arabinose isomerase from the mesophilic Shewanella sp. ANA-3 is highly active at low temperatures

Directory of Open Access Journals (Sweden)

Rhimi Moez

2011-11-01

Full Text Available Abstract Background L-arabinose isomerases catalyse the isomerization of L-arabinose into L-ribulose at insight biological systems. At industrial scale of this enzyme is used for the bioconversion of D-galactose into D-tagatose which has many applications in pharmaceutical and agro-food industries. The isomerization reaction is thermodynamically equilibrated, and therefore the bioconversion rates is shifted towards tagatose when the temperature is increased. Moreover, to prevent secondary reactions it will be of interest to operate at low pH. The profitability of this D-tagatose production process is mainly related to the use of lactose as cheaper raw material. In many dairy products it will be interesting to produce D-tagatose during storage. This requires an efficient L-arabinose isomerase acting at low temperature and pH values. Results The gene encoding the L-arabinose isomerase from Shewanella sp. ANA-3 was cloned and overexpressed in Escherichia coli. The purified protein has a tetrameric arrangement composed by four identical 55 kDa subunits. The biochemical characterization of this enzyme showed that it was distinguishable by its maximal activity at low temperatures comprised between 15-35°C. Interestingly, this biocatalyst preserves more than 85% of its activity in a broad range of temperatures from 4.0 to 45°C. Shewanella sp. ANA-3 L-arabinose isomerase was also optimally active at pH 5.5-6.5 and maintained over 80% of its activity at large pH values from 4.0 to 8.5. Furthermore, this enzyme exhibited a weak requirement for metallic ions for its activity evaluated at 0.6 mM Mn2+. Stability studies showed that this protein is highly stable mainly at low temperature and pH values. Remarkably, T268K mutation clearly enhances the enzyme stability at low pH values. Use of this L-arabinose isomerase for D-tagatose production allows the achievement of attractive bioconversion rates of 16% at 4°C and 34% at 35°C. Conclusions Here we

PV monitoring at Jubilee Campus - Nottingham University

Energy Technology Data Exchange (ETDEWEB)

Riffat, S.B.; Gan, G.

2002-07-01

This report summarises the results of a project monitoring the efficiency of photovoltaic (PV) modules integrated in the roofs of atria to meet the energy consumption needs of ventilation fans in the academic buildings at the Jubilee Campus of the University of Nottingham. Details are given of the instrumentation of one atrium to allow the monitoring the effectiveness of the ventilation in cooling the PV arrays integrated in the atrium roof, the economic analysis of the benefit of cooling the PV system, and the use of computational fluid dynamics (CFD) modelling to predict the performance of the atrium. The design of the PV system, the calculated system efficiency, the high cost of atrium integrated PV power supplies, the periodic failure of the inverters, and the overheating of the PV array and the atrium space in the summer are discussed.

PV-DSM: Policy actions to speed commercialization

International Nuclear Information System (INIS)

Hoff, T.; Wenger, H.J.; Keane, D.M.

1993-01-01

Pacific Gas and Electric Company (PG ampersand E) recently applied Demand-Side Management (DSM) evaluation techniques to photovoltaic (PV) technology to develop the concept of photovoltaics as a Demand-Side Management option (PV-DSM). The analysis demonstrated that PV-DSM has the potential to be economically attractive. Two criticisms in response to that analysis are that the assumptions of 25 year financing and a 25 year evaluation period are unrealistic. This paper responds to those criticisms and documents the mathematical relationships to calculate the value of PV-DSM from a customer's perspective. It demonstrates how regulatory and government agencies could implement policies to resolve both issues and speed PV commercialization

The possibility of developing hybrid PV/T solar system

Science.gov (United States)

Dobrnjac, M.; Zivkovic, P.; Babic, V.

2017-05-01

An alternative and cost-effective solution to developing integrated PV system is to use hybrid photovoltaic/thermal (PV/T) solar system. The temperature of PV modules increases due to the absorbed solar radiation that is not converted into electricity, causing a decrease in their efficiency. In hybrid PV/T solar systems the reduction of PV module temperature can be combined with a useful fluid heating. In this paper we present the possibility of developing a new hybrid PV/T solar system. Hybrid PV/T system can provide electrical and thermal energy, thus achieving a higher energy conversion rate of the absorbed solar radiation. We developed PV/T prototype consisted of commercial PV module and thermal panel with our original solution of aluminium absorber with special geometric shapes. The main advantages of our combined PV/T system are: removing of heat from the PV panel; extending the lifetime of photovoltaic cells; excess of the removing heat from PV part is used to heat the fluid in the thermal part of the panel; the possibility of using on the roof and facade constructions because less weight.

PV Obelisk - Information system with photovoltaics

International Nuclear Information System (INIS)

Ruoss, D.; Rasmussen, J.

2004-01-01

This final report for the Swiss Federal Office of Energy (SFOE) describes the development of an information system powered by a photovoltaic (PV) array. As an innovative approach, the 'PV-Obelisk' project is the combination of PV with a multi-functional pillar made of natural stone in an aesthetic way. The PV modules serve both as a power supply and as a design element. Two initial prototypes led the way to a third, optimised consumer configuration that was planned to guarantee maximum user frequency. Test operation in front of the 'Heidiland' motor way restaurant confirmed the market analyses made and delivered the expected results. The product, whose three LCD displays are updated via a mobile telephony-based text-message system, proved its technical reliability and showed a high user frequency. Because of the high overall energy consumption, PV power can only partially contribute to the energy supply needed. Various compromises in the technical and aesthetic areas are discussed that were made for the sake of product acceptance in the market. The range of application areas for such a 'PV Obelisk' are discussed and the need for early co-ordination with urban planners is stressed

The new NOZ-PV: Market-oriented

International Nuclear Information System (INIS)

Ter Horst, E.

1995-01-01

In the proposal for the new National Research Program for Photovoltaics (NOZ-PV) 1995-1999 the focus is on four subjects: solar cell technology, the industrial support, the stimulation of autonomous, favorable applications and markets for PV, and the realization of a training program PV in the Built Areas. The program will be carried out as a market-oriented program. 1 tab., 2 figs

Crystallization of uridine phosphorylase from Shewanella oneidensis MR-1 in the laboratory and under microgravity and preliminary X-ray diffraction analysis

International Nuclear Information System (INIS)

Safonova, Tatyana N.; Mordkovich, Nadezhda N.; Polyakov, Konstantin M.; Manuvera, Valentin A.; Veiko, Vladimir P.; Popov, Vladimir O.

2012-01-01

High-quality crystals of uridine phosphorylase from Shewanella oneidensis were grown under microgravity conditions. X-ray diffraction data were collected to a resolution of 0.95 Å. Uridine phosphorylase (UDP, EC 2.4.2.3), a key enzyme in the pyrimidine salvage pathway, catalyses the reversible phosphorolysis of uridine to uracil and ribose 1-phosphate. The gene expression of UDP from Shewanella oneidensis MR-1 was performed in the recipient strain Escherichia coli. The UDP protein was crystallized on earth (in the free form and in complex with uridine as the substrate) by the hanging-drop vapour-diffusion method at 296 K and under microgravity conditions (in the free form) aboard the Russian Segment of the International Space Station by the capillary counter-diffusion method. The data sets were collected to a resolution of 1.9 Å from crystals of the free form grown on earth, 1.6 Å from crystals of the complex with uridine and 0.95 Å from crystals of the free form grown under microgravity. All crystals belong to the space group P2 1 and have similar unit-cell parameters. The crystal of uridine phosphorylase grown under microgravity diffracted to ultra-high resolution and gave high-quality X-ray diffraction data

Annual technical report. PV domestic field trial

Energy Technology Data Exchange (ETDEWEB)

NONE

2002-07-01

This report describes progress at the first five sites of the UK photovoltaic (PV) domestic field trial. All five sites are generating electricity, but one has not yet been commissioned and two sites are not yet monitoring performance. The BedZED development has roof-mounted PV modules and PV cells installed in sealed double-glazing. Solar slates/tiles have been installed at the Laing Homes development in Montagu Road, where the designer has sought to minimise the visual impact of the PV system on the roofs. At Hunters Moon, PV modules have been retrofitted and some unforeseen difficulties have arisen. PV is an integral part of the roof design at the state-of-the-art low energy development by Integer Houses at Greenfields. Corn Croft uses a British mounting system to facilitate integration of the modules flush with the roof. Installation issues and the progress of the trial are discussed.

Multi-heme Cytochromes in Shewanella oneidensis MR-1: Structures, functions and opportunities

Energy Technology Data Exchange (ETDEWEB)

Breuer, Marian; Rosso, Kevin M.; Blumberger, Jochen; Butt, Julea N.

2014-11-05

Multi-heme cytochromes are employed by a range of microorganisms to transport electrons over distances of up to tens of nanometers. Perhaps the most spectacular utilization of these proteins is in the reduction of extracellular solid substrates, including electrodes and insoluble mineral oxides of Fe(III) and Mn(III/IV), by species of Shewanella and Geobacter. However, multi-heme cytochromes are found in numerous and phylogenetically diverse prokaryotes where they participate in electron transfer and redox catalysis that contributes to biogeochemical cycling of N, S and Fe on the global scale. These properties of multi-heme cytochromes have attracted much interest and contributed to advances in bioenergy applications and bioremediation of contaminated soils. Looking forward there are opportunities to engage multi-heme cytochromes for biological photovoltaic cells, microbial electrosynthesis and developing bespoke molecular devices. As a consequence it is timely to review our present understanding of these proteins and we do this here with a focus on the multitude of functionally diverse multi-heme cytochromes in Shewanella oneidensis MR-1. We draw on findings from experimental and computational approaches which ideally complement each other in the study of these systems: computational methods can interpret experimentally determined properties in terms of molecular structure to cast light on the relation between structure and function. We show how this synergy has contributed to our understanding of multi-heme cytochromes and can be expected to continue to do so for greater insight into natural processes and their informed exploitation in biotechnologies.

PV in a sports arena; PV im Hexenkessel

Energy Technology Data Exchange (ETDEWEB)

Hoeche, B.

2008-05-19

The German soccer club Werder Bremen is reconstructing its stadium. Apart from higher spectator comfort and a better atmosphere, there will also be PV systems on the roof and external walls of the arena. (orig.)

Intelligent PV Power Smoothing Control Using Probabilistic Fuzzy Neural Network with Asymmetric Membership Function

Directory of Open Access Journals (Sweden)

Faa-Jeng Lin

2017-01-01

Full Text Available An intelligent PV power smoothing control using probabilistic fuzzy neural network with asymmetric membership function (PFNN-AMF is proposed in this study. First, a photovoltaic (PV power plant with a battery energy storage system (BESS is introduced. The BESS consisted of a bidirectional DC/AC 3-phase inverter and LiFePO4 batteries. Then, the difference of the actual PV power and smoothed power is supplied by the BESS. Moreover, the network structure of the PFNN-AMF and its online learning algorithms are described in detail. Furthermore, the three-phase output currents of the PV power plant are converted to the dq-axis current components. The resulted q-axis current is the input of the PFNN-AMF power smoothing control, and the output is a smoothing PV power curve to achieve the effect of PV power smoothing. Comparing to the other smoothing methods, a minimum energy capacity of the BESS with a small fluctuation of the grid power can be achieved by the PV power smoothing control using PFNN-AMF. In addition, a personal computer- (PC- based PV power plant emulator and BESS are built for the experimentation. From the experimental results of various irradiance variation conditions, the effectiveness of the proposed intelligent PV power smoothing control can be verified.

The PV market - Past, present, and future

International Nuclear Information System (INIS)

Hammond, B.

1992-01-01

This paper forecasts the photovoltaic (PV) market growth for the 1900's. Ten years of PV history are reviewed and used to establish market trends in terms of average selling price (ASP) and kilowatts shipped by market segment. The market is segmented into indoor consumer, stand-alone, and grid-connected applications. Indoor consumer presently represents a saturated market and is fairly predictable. The stand-alone market (i.e. not connected to the utility grid) is fairly stable and predictable. The utility PV market, however, is highly dependent on a number of market factors such as the cost of conventional energy, the cost of PV systems, utility acceptance of PV, and regulatory controls. Government and institutional regulations, environmental issues, OPEC and Middle East politics will have the greatest impact on the cost of conventional fuels. Private and federal investment in PV technology development could have a significant impact on the cost of PV systems. Forecasts are provided through the year 2000 for indoor consumer, stand-alone, and utility markets. PV has unique attributes which make it a desirable source of energy in specific applications. It is a renewable source of energy, non-polluting, very reliable, predictable, low maintenance, modular, and has a very low operating cost. The energy source (sunlight) is distributed around the globe. Its limitations are high initial cost, no inherent energy storage, and low energy density

Optimal Design of Modern Transformerless PV Inverter Topologies

DEFF Research Database (Denmark)

Saridakis, Stefanos; Koutroulis, Eftichios; Blaabjerg, Frede

2013-01-01

the operational lifetime period of the PV installation, is also considered in the optimization process. According to the results of the proposed design method, different optimal values of the PV inverter design variables are derived for each PV inverter topology and installation site. The H5, H6, neutral point...... clamped, active-neutral point clamped and conergy-NPC PV inverters designed using the proposed optimization process feature lower levelized cost of generated electricity and lifetime cost, longer mean time between failures and inject more PV-generated energy into the electric grid than their nonoptimized......The design optimization of H5, H6, neutral point clamped, active-neutral point clamped, and conergy-NPC transformerless photovoltaic (PV) inverters is presented in this paper. The components reliability in terms of the corresponding malfunctions, affecting the PV inverter maintenance cost during...

Programming the quorum sensing-based AND gate in Shewanella oneidensis for logic gated-microbial fuel cells.

Science.gov (United States)

Hu, Yidan; Yang, Yun; Katz, Evgeny; Song, Hao

2015-03-11

An AND logic gate based on a synthetic quorum-sensing (QS) module was constructed in a Shewanella oneidensis MR-1 mtrA knockout mutant. The presence of two input signals activated the expression of a periplasmic decaheme cytochrome MtrA to regenerate the extracellular electron transfer conduit, enabling the construction of AND-gated microbial fuel cells.

Environmental impact of PV cell waste scenario.

Science.gov (United States)

Bogacka, M; Pikoń, K; Landrat, M

2017-12-01

Rapid growth of the volume of waste from PV cells is expected in the following years. The problem of its utilization seems to be the most important issue for future waste management systems. The environmental impacts of the PV recycling scenario are presented in the manuscript. The analysis is based on the LCA approach and the average data available in specialized databases for silicon standard PV cell is used. The functional unit includes parameters like: efficiency, composition, surface area. The discussion on the environmental impact change due to the location of the PV production and waste processing plants is presented in the manuscript. Additionally, the discussion on the environmental effect of substituting different energy resources with PV cells is presented in the manuscript. The analysis of the PV cell life cycle scenario presented in the article was performed using the SIMA PRO software and data from Ecoinvent 3.0 database together with additional data obtained from other sources. Copyright © 2017 Elsevier Ltd. All rights reserved.

Novel laboratory mouse papillomavirus (MusPV) infection.

Science.gov (United States)

Ingle, A; Ghim, S; Joh, J; Chepkoech, I; Bennett Jenson, A; Sundberg, J P

2011-03-01

Most papillomaviruses (PVs) are oncogenic. There are at least 100 different human PVs and 65 nonhuman vertebrate hosts, including wild rodents, which have species-specific PV infections. Florid papillomatosis arose in a colony of NMRI-Foxn1(nu)/Foxn1(nu) (nude) mice at the Advanced Centre for Treatment Research and Education in Cancer in India. Lesions appeared at the mucocutaneous junctions of the nose and mouth. Histologically, lesions were classical papillomas with epidermal hyperplasia on thin fibrovascular stalks in a verrucous pattern. Koilocytotic cells were observed in the stratum granulosum of the papillomatous lesions. Immunohistochemically, these abnormal cells were positive for PV group-specific antigens. With transmission electron microscopy, virus particles were observed in crystalline intranuclear inclusions within keratinocytes. The presence of a mouse PV, designated MusPV, was confirmed by amplification of PV DNA with degenerative primers specific for PVs. This report is the first of a PV and its related disease in laboratory mice.

PV Working with Industry, 2nd Quarter, 2000

Energy Technology Data Exchange (ETDEWEB)

Poole, L.; Moon, S.

2000-06-29

NREL PV Working With Industry is a quarterly newsletter devoted to the research, development, and deployment performed by NREL staff in concert with their industry and university partners. The Second Quarter, 2000, issue is titled ``Our Shared PV Future''. It contains a review of several important PV-related meetings held in the prior three months: the NCPV Program Review, the 16 European PV Conference, and year-2000 Earth Day activities in Denver, CO. The editorialist is Paul Maycock, Publisher of PV News.

Thermal modelling of PV module performance under high ambient temperatures

Energy Technology Data Exchange (ETDEWEB)

Diarra, D.C.; Harrison, S.J. [Queen' s Univ., Kingston, ON (Canada). Dept. of Mechanical and Materials Engineering Solar Calorimetry Lab; Akuffo, F.O. [Kwame Nkrumah Univ. of Science and Technology, Kumasi (Ghana). Dept. of Mechanical Engineering

2005-07-01

When predicting the performance of photovoltaic (PV) generators, the actual performance is typically lower than test results conducted under standard test conditions because the radiant energy absorbed in the module under normal operation raises the temperature of the cell and other multilayer components. The increase in temperature translates to a lower conversion efficiency of the solar cells. In order to address these discrepancies, a thermal model of a characteristic PV module was developed to assess and predict its performance under real field-conditions. The PV module consisted of monocrystalline silicon cells in EVA between a glass cover and a tedlar backing sheet. The EES program was used to compute the equilibrium temperature profile in the PV module. It was shown that heat is dissipated towards the bottom and the top of the module, and that its temperature can be much higher than the ambient temperature. Modelling results indicate that 70-75 per cent of the absorbed solar radiation is dissipated from the solar cells as heat, while 4.7 per cent of the solar energy is absorbed in the glass cover and the EVA. It was also shown that the operating temperature of the PV module decreases with increased wind speed. 2 refs.

Grid Integrated Distributed PV (GridPV) Version 2.

Energy Technology Data Exchange (ETDEWEB)

Reno, Matthew J.; Coogan, Kyle

2014-12-01

This manual provides the documentation of the MATLAB toolbox of functions for using OpenDSS to simulate the impact of solar energy on the distribution system. The majority of the functio ns are useful for interfacing OpenDSS and MATLAB, and they are of generic use for commanding OpenDSS from MATLAB and retrieving information from simulations. A set of functions is also included for modeling PV plant output and setting up the PV plant in th e OpenDSS simulation. The toolbox contains functions for modeling the OpenDSS distribution feeder on satellite images with GPS coordinates. Finally, example simulations functions are included to show potential uses of the toolbox functions. Each function i n the toolbox is documented with the function use syntax, full description, function input list, function output list, example use, and example output.

Flexible packaging for PV modules

Science.gov (United States)

Dhere, Neelkanth G.

2008-08-01

Economic, flexible packages that provide needed level of protection to organic and some other PV cells over >25-years have not yet been developed. However, flexible packaging is essential in niche large-scale applications. Typical configuration used in flexible photovoltaic (PV) module packaging is transparent frontsheet/encapsulant/PV cells/flexible substrate. Besides flexibility of various components, the solder bonds should also be flexible and resistant to fatigue due to cyclic loading. Flexible front sheets should provide optical transparency, mechanical protection, scratch resistance, dielectric isolation, water resistance, UV stability and adhesion to encapsulant. Examples are Tefzel, Tedlar and Silicone. Dirt can get embedded in soft layers such as silicone and obscure light. Water vapor transmittance rate (WVTR) of polymer films used in the food packaging industry as moisture barriers are ~0.05 g/(m2.day) under ambient conditions. In comparison, light emitting diodes employ packaging components that have WVTR of ~10-6 g/(m2.day). WVTR of polymer sheets can be improved by coating them with dense inorganic/organic multilayers. Ethylene vinyl acetate, an amorphous copolymer used predominantly by the PV industry has very high O2 and H2O diffusivity. Quaternary carbon chains (such as acetate) in a polymer lead to cleavage and loss of adhesional strength at relatively low exposures. Reactivity of PV module components increases in presence of O2 and H2O. Adhesional strength degrades due to the breakdown of structure of polymer by reactive, free radicals formed by high-energy radiation. Free radical formation in polymers is reduced when the aromatic rings are attached at regular intervals. This paper will review flexible packaging for PV modules.

Interharmonics from Grid-Connected PV Systems

DEFF Research Database (Denmark)

Sangwongwanich, Ariya; Yang, Yongheng; Sera, Dezso

2017-01-01

As the penetration level of grid-connected Photovoltaic (PV) systems increases, the power quality is one of the major concerns for system operators and the demands are becoming even stricter. The impact of interharmonics on the grid has been acknowledged in recent research when considering a large......-scale adoption of PV inverters. However, the origins of interharmonics remain unclear. Thus, this paper performs tests on a commercial PV inverter to explore interharmonic generation and more important investigates the mechanism of interharmonic emission. The investigation reveals that the perturbation...... of the solutions. Simulation results indicate that the constant-voltage MPPT method is the most suitable solution to the mitigation of interharmonics introduced by the MPPT operation, as it avoids the perturbation in the PV voltage during operation....

Optimal Solar PV Arrays Integration for Distributed Generation

Energy Technology Data Exchange (ETDEWEB)

Omitaomu, Olufemi A [ORNL; Li, Xueping [University of Tennessee, Knoxville (UTK)

2012-01-01

Solar photovoltaic (PV) systems hold great potential for distributed energy generation by installing PV panels on rooftops of residential and commercial buildings. Yet challenges arise along with the variability and non-dispatchability of the PV systems that affect the stability of the grid and the economics of the PV system. This paper investigates the integration of PV arrays for distributed generation applications by identifying a combination of buildings that will maximize solar energy output and minimize system variability. Particularly, we propose mean-variance optimization models to choose suitable rooftops for PV integration based on Markowitz mean-variance portfolio selection model. We further introduce quantity and cardinality constraints to result in a mixed integer quadratic programming problem. Case studies based on real data are presented. An efficient frontier is obtained for sample data that allows decision makers to choose a desired solar energy generation level with a comfortable variability tolerance level. Sensitivity analysis is conducted to show the tradeoffs between solar PV energy generation potential and variability.

Commercialization of PV-powered pumping systems for use in utility PV service programs. Final report

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-03-01

The project described in this report was a commercialization effort focused on cost-effective remote water pumping systems for use in utility-based photovoltaic (PV) service programs. The project combined a commercialization strategy tailored specifically for electric utilities with the development of a PV-powered pumping system that operates conventional ac pumps rather than relying on the more expensive and less reliable PV pumps on the market. By combining these two attributes, a project goal was established of creating sustained utility purchases of 250 PV-powered water pumping systems per year. The results of each of these tasks are presented in two parts contained in this Final Summary Report. The first part summarizes the results of the Photovoltaic Services Network (PSN) as a new business venture, while the second part summarizes the results of the Golden Photon system installations. Specifically, results and photographs from each of the system installations are presented in this latter part.

IEA Solar Heating and Cooling Programme Task 16: PV in Buildings

International Nuclear Information System (INIS)

Schoen, A.J.N.; Van der Weiden, T.C.J.

1993-10-01

In the title program (SHCP), initiated in 1977, twenty countries, including the European Union, participate in a broad spectrum of subjects in the field of thermal, photovoltaic (PV) and passive solar energy. Nineteen Tasks were started so far, of which eleven Tasks are finished. Task 16 deals with the architectural and electrotechnical integration of PV in buildings, aiming at a maximal contribution of solar energy to the energy supply of a building, knowledge increase and transfer with respect to the relation of PV with other components of the energy system of a building, and economic optimization. Task 16 is planned for the period 1990-1995 and is divided in Sub-Tasks A: System Design and Development; B: Building Integration; C: PV-Demonstration Buildings; and D: Technology Communication. In this report the Dutch activities of Task 16, coordinated by Ecofys, are discussed. Reports of 4 Expert Meetings and 3 Workshops are presented. A description (in English) of the first Dutch IEA Demonstration Building, the energy autonomous house in Woubrugge, is given. Finally attention is paid to the activities regarding the Ideas Competition for the design of buildings or urban areas with integrated PV systems. 6 appendices

A Practical Irradiance Model for Bifacial PV Modules: Preprint

Energy Technology Data Exchange (ETDEWEB)

Marion, Bill; MacAlpine, Sara; Deline, Chris; Asgharzadeh, Amir; Toor, Fatima; Riley, Daniel; Stein, Joshua; Hansen, Clifford

2017-06-15

A model, suitable for a row or multiple rows of photovoltaic (PV) modules, is presented for estimating the backside irradiance for bifacial PV modules. The model, which includes the effects of shading by the PV rows, is based on the use of configuration factors (CFs) to determine the fraction of a source of irradiance that is received by the backside of the PV module. Backside irradiances are modeled along the sloped height of the PV module, but assumed not to vary along the length of the PV row. The backside irradiances are corrected for angle-of-incidence losses and may be added to the front side irradiance to determine the total irradiance resource for the PV cell. Model results are compared with the measured backside irradiances for NREL and Sandia PV systems, and with results when using the RADIANCE ray tracing program.

Multifunctional a-Si PV systems

Energy Technology Data Exchange (ETDEWEB)

Peippo, K; Lund, P; Vartiainen, E [Helsinki Univ. of Technology, Otaniemi (Finland). Advanced Energy Systems

1998-10-01

The optimal use of the various forms of solar energy (passive, active, daylighting, photovoltaics) in buildings calls for an optimal integration of the technologies. As energy conservation potential in space heating may soon be exhausted, electricity efficiency and on-site generation will play an increasing role in energy-conscious building design. There, dispersed PV systems integrated into buildings show a significant market potential, due to a number of benefits: no extra land area is required, PV-array may replace conventional cladding materials and become a building element. Moreover, the produced PV-electricity is more valuable for the building owner than for an electric utility

PV installations, protection and the code

Energy Technology Data Exchange (ETDEWEB)

Silecky, L. [Mersen, Toronto, ON (Canada)

2010-12-15

This article discussed the need for improved standards in Ontario's solar industry to ensure safety for the systems and also safety for the workers. Photovoltaic cells used in solar arrays can now deliver between 50 vDC to 600 vDC. The workings of such a high voltage photocell must be understood in order to understand its protection needs. Since PVs are semiconductors and susceptible to damage from short circuits and overloads, a fast-acting overcurrent protective device (OCPD) should be used. Combiner boxes are also needed to provide a clean method of safely connecting all the wires that are needed in the system, including surge protection and a means of isolation between the PV array and the inverter. Section 50 of the Canadian Electrical Code outlines the requirements for solar PV systems, but it does not mention the protection of DC circuits, including DC fuse protectors which are manufactured to provide a high degree of protection for the PV array. As the photovoltaic (PV) market continues to grow in Ontario, the PV industry also has a responsibility to ensure it is in compliance with codes and standards related to photovoltaic systems. This author suggested that Article 690 of the National Electric Code (NEC) is a good document to use when determining the requirements for PV systems. 3 figs.

Whole genome sequence to decipher the resistome of Shewanella algae, a multidrug-resistant bacterium responsible for pneumonia, Marseille, France.

Science.gov (United States)

Cimmino, Teresa; Olaitan, Abiola Olumuyiwa; Rolain, Jean-Marc

2016-01-01

We characterize and decipher the resistome and the virulence factors of Shewanella algae MARS 14, a multidrug-resistant clinical strain using the whole genome sequencing (WGS) strategy. The bacteria were isolated from the bronchoalveolar lavage of a hospitalized patient in the Timone Hospital in Marseille, France who developed pneumonia after plunging into the Mediterranean Sea. The genome size of S. algae MARS 14 was 5,005,710 bp with 52.8% guanine cytosine content. The resistome includes members of class C and D beta-lactamases and numerous multidrug-efflux pumps. We also found the presence of several hemolysins genes, a complete flagellum system gene cluster and genes responsible for biofilm formation. Moreover, we reported for the first time in a clinical strain of Shewanella spp. the presence of a bacteriocin (marinocin). The WGS analysis of this pathogen provides insight into its virulence factors and resistance to antibiotics.

Experimental grid connected PV system power analysis

Science.gov (United States)

Semaoui, Smail; Abdeladim, Kamel; Arab, Amar Hadj; Boulahchich, Saliha; Amrouche, Said Ould; Yassaa, Noureddine

2018-05-01

Almost 80 % of Algerian territory is appropriate for the exploitation of solar energy. The Algerian energetic strategy provides a substantial injection of PV electricity to the national grid. Currently, about 344 MWp of PV arrays which corresponds approximately to 2,34 km2 of module surfaces, are connected on electricity grid over the national territory. The Algerian Northern regions are characterized by strong pollution and high humidity. These phenomena affect the energetic productivity of PV generator. The objective of our study is to analyze experimental grid connected PV system power in coastal locations. Hence, experiments have been conducted on three identical PV systems to determine the electrical performances. Transformer-less inverters are the most attractive for the ground-based photovoltaic (PV) system due to their efficiencies, reduced cost and weight. Besides, the absence of the galvanic isolation generates problems of capacitive leakage current on the AC side and the degradation of the insulation resistance on the DC side of the inverter. In this work, experimental study of the behavior of single-phase inverters without transformers is presented. The main objective of this work is to study the degradation of the insulation resistance at the input of the inverter, and the capacitive leakage current at the output of the inverter. This study was achieved at the CDER on a rainy day of 15/03/2017, on the first PV plant connected to the low voltage network in Algeria. This investigation can help forecasting the PV array energetic production by taking into account natural conditions.

Resolution of two native monomeric 90 kDa nitrate reductase active proteins from Shewanella gelidimarina and the sequence of two napA genes

International Nuclear Information System (INIS)

Simpson, Philippa J.L.; McKinzie, Audra A.; Codd, Rachel

2010-01-01

Research highlights: → Two monomeric 90 kDa nitrate reductase active proteins from Shewanella gelidimarina. → Sequence of napA from napEDABC-type operon and napA from NapDAGHB-type operon. → Isolation of NAP as NapA or NapAB correlated with NapA P47E amino acid substitution. -- Abstract: The reduction of nitrate to nitrite in the bacterial periplasm occurs in the 90 kDa NapA subunit of the periplasmic nitrate reductase (NAP) system. Most Shewanella genomes contain two nap operons: napEDABC and napDAGHB, which is an unusual feature of this genus. Two native, monomeric, 90 kDa nitrate reductase active proteins were resolved by hydrophobic interaction chromatography from aerobic cultures of Shewanella gelidimarina replete with reduced nitrogen compounds. The 90 kDa protein obtained in higher yield was characterized as NapA by electronic absorption and electron paramagnetic resonance spectroscopies and was identified by LC/MS/MS and MALDI-TOF/TOF MS as NapA from the napEDABC-type operon. The other 90 kDa protein, which was unstable and produced in low yields, was posited as NapA from the napDAGHB-type operon. Two napA genes have been sequenced from the napEDABC-type and napDAGHB-type operons of S. gelidimarina. Native NAP from S. putrefaciens was resolved as one NapA monomer and one NapAB heterodimer. Two amino acid substitutions in NapA correlated with the isolation of NAP as a NapA monomer or a NapAB heterodimer. The resolution of native, redox-active NapA isoforms in Shewanella provides new insight into the respiratory versatility of this genus, which has implications in bioremediation and the assembly of microbial fuel cells.

China PV Business and Applications Evaluation

Energy Technology Data Exchange (ETDEWEB)

Sherring, Chris (Sherring Energy Associates)

1999-08-30

This report provides an overview of photovoltaics (PV) business and applications in China. Although more than 70 million people in China are without access to grid electricity, many of the unelectrified regions benefit from considerable renewable resources, including good solar insolation. Current annual PV sales are still modest, however, and are estimated to be between 2.0 and 2.5 megawatts. This and other significant PV data, including information regarding the current status of key aspects of Chinese businesses, markets, and distribution channels, are included in the report. Detailed company profiles of Chinese business organizations and summaries of visits made to these companies (as well as to more remote sites in Inner Mongolia to examine PV usage by the end-use customer) in September-October 1998 are also presented.

Robust PV Degradation Methodology and Application

Energy Technology Data Exchange (ETDEWEB)

Jordan, Dirk [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Deline, Christopher A [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Kurtz, Sarah [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Kimball, Greg [SunPower; Anderson, Mike [SunPower

2017-11-15

The degradation rate plays an important role in predicting and assessing the long-term energy generation of PV systems. Many methods have been proposed for extracting the degradation rate from operational data of PV systems, but most of the published approaches are susceptible to bias due to inverter clipping, module soiling, temporary outages, seasonality, and sensor degradation. In this manuscript, we propose a methodology for determining PV degradation leveraging available modeled clear-sky irradiance data rather than site sensor data, and a robust year-over-year (YOY) rate calculation. We show the method to provide reliable degradation rate estimates even in the case of sensor drift, data shifts, and soiling. Compared with alternate methods, we demonstrate that the proposed method delivers the lowest uncertainty in degradation rate estimates for a fleet of 486 PV systems.

Study on an optimum ratio of PV output energy to WG output energy in PV/WG hybrid system; Taiyoko/furyoku hybrid hatsuden system no saiteki yoryohi ni kansuru kento

Energy Technology Data Exchange (ETDEWEB)

Nishikawa, S [Kandenko Co. Ltd., Tokyo (Japan)

1996-10-27

A photovoltaic power (PV) and wind generated power (WG) are an unlimited clean energy source, yet their output is unstable depending on the fluctuation of weather conditions such as solar radiation and wind velocity. Consequently, a large-scale power storage equipment is necessitated leading to a high cost especially in an independent system. As a solution, a method is available in which PV and WG are combined so that the effect may be utilized for stabilizing the output of a system as a whole, at a site where a fluctuation pattern is different between photovoltaic energy and wind energy. In building a hybrid system by PV and WG, sites with such supplementary effect existing were selected from the viewpoint of stabilizing the fluctuation of the power generation in the long run; and then, an examination was made on the optimum PV capacity ratio (%Ppo) in each site. As a result, it revealed that the %Ppo had great bearing on a ratio of PV energy fluctuation to WG, which was converted to a numerical formula. A comparatively simple examination by means of meteorological data also indicated that the share ratio was possibly optimized between the quantities of PV and WG energy. 4 refs., 2 figs., 2 tabs.

Modelling of flow and heat transfer in PV cooling channels

Energy Technology Data Exchange (ETDEWEB)

Diarra, D.C.; Harrison, S.J. [Queen' s Univ., Kingston, ON (Canada). Dept. of Mechanical and Materials Engineering Solar Calorimetry Lab; Akuffo, F.O. [Kwame Nkrumah Univ. of Science and Technology, Kumasi (Ghana). Dept. of Mechanical Engineering

2005-07-01

Under sunny conditions, the temperature of photovoltaic (PV) modules can be 20 to 30 degrees C above the ambient air temperature. This affects the performance of PV modules, particularly in regions with hot climates. For silicon solar cells, the maximum power decreases between 0.4 and 0.5 per cent for every degree C of temperature increase above a reference value. In an effort to address this issue, this experimental and numerical study examined an active PV panel evaporative cooling scheme that is typically used in hot arid climates. The cooling system circulated cool air behind the PV modules, extracting heat and lowering solar cell temperature. A fluid dynamic and thermal model of the combined system was developed using the EES program in order to study the configuration of the cooling channel and the characteristics of the cooling flow. Heat transfer and flow characteristics in the cooling channel were then calculated along with pressure drop and fan power associated with the air-circulation. The net power output was also calculated. The objective was to design a cost efficient cooling system and to optimize its flow and pressure drop in order to maximize power output. The study demonstrated how the performance of the PV panel is influenced by the geometry of the cooling channel, the inlet air temperature and the air flow rate. 2 refs.

Optimal Design of Modern Transformerless PV Inverter Topologies

OpenAIRE

Saridakis, Stefanos; Koutroulis, Eftichios; Blaabjerg, Frede

2013-01-01

The design optimization of H5, H6, neutral point clamped, active-neutral point clamped, and conergy-NPC transformerless photovoltaic (PV) inverters is presented in this paper. The components reliability in terms of the corresponding malfunctions, affecting the PV inverter maintenance cost during the operational lifetime period of the PV installation, is also considered in the optimization process. According to the results of the proposed design method, different optimal values of the PV inver...

Shewanella algae infection after surgical treatment of Haglund's heel and rupture of the Achilles tendon.] [Article in Danish

DEFF Research Database (Denmark)

Laursen, Malene

2014-01-01

This is a case report of soft tissue infection with the marine bacterium Shewanella algae that is rare in Denmark. The patient was a 43-year-old male and he was treated surgically for Haglund's heel, a bony protrusion at the calcaneus. After clinical healing the patient suffered a rupture...

Annual analysis of heat pipe PV/T systems for domestic hot water and electricity production

International Nuclear Information System (INIS)

Pei Gang; Fu Huide; Ji Jie; Chow Tintai; Zhang Tao

2012-01-01

Highlights: ► A novel heat pipe photovoltaic/thermal system with freeze protection was proposed. ► A detailed annual simulation model for the HP-PV/T system was presented. ► Annual performance of HP-PV/T was predicted and analyzed under different condition. - Abstract: Heat-pipe photovoltaic/thermal (HP-PV/T) systems can simultaneously provide electrical and thermal energy. Compared with traditional water-type photovoltaic/thermal systems, HP-PV/T systems can be used in cold regions without being frozen with the aid of a carefully selected heat-pipe working fluid. The current research presents a detailed simulation model of the HP-PV/T system. Using this model, the annual electrical and thermal behavior of the HP-PV/T system used in three typical climate areas of China, namely, Hong Kong, Lhasa, and Beijing, are predicted and analyzed. Two HP-PV/T systems, with and without auxiliary heating equipment, are studied annually under four different kinds of hot-water load per unit collecting area (64.5, 77.4, 90.3, and 103.2 kg/m 2 ).

In Situ Analysis of a Silver Nanoparticle-Precipitating Shewanella Biofilm by Surface Enhanced Confocal Raman Microscopy.

Directory of Open Access Journals (Sweden)

Gal Schkolnik

Full Text Available Shewanella oneidensis MR-1 is an electroactive bacterium, capable of reducing extracellular insoluble electron acceptors, making it important for both nutrient cycling in nature and microbial electrochemical technologies, such as microbial fuel cells and microbial electrosynthesis. When allowed to anaerobically colonize an Ag/AgCl solid interface, S. oneidensis has precipitated silver nanoparticles (AgNp, thus providing the means for a surface enhanced confocal Raman microscopy (SECRaM investigation of its biofilm. The result is the in-situ chemical mapping of the biofilm as it developed over time, where the distribution of cytochromes, reduced and oxidized flavins, polysaccharides and phosphate in the undisturbed biofilm is monitored. Utilizing AgNp bio-produced by the bacteria colonizing the Ag/AgCl interface, we could perform SECRaM while avoiding the use of a patterned or roughened support or the introduction of noble metal salts and reducing agents. This new method will allow a spatially and temporally resolved chemical investigation not only of Shewanella biofilms at an insoluble electron acceptor, but also of other noble metal nanoparticle-precipitating bacteria in laboratory cultures or in complex microbial communities in their natural habitats.

Solar cell junction temperature measurement of PV module

KAUST Repository

Huang, B.J.; Yang, P.E.; Lin, Y.P.; Lin, B.Y.; Chen, H.J.; Lai, R.C.; Cheng, J.S.

2011-01-01

The present study develops a simple non-destructive method to measure the solar cell junction temperature of PV module. The PV module was put in the environmental chamber with precise temperature control to keep the solar PV module as well

Photovoltaic (PV) Pricing Trends: Historical, Recent, and Near-Term Projections

Energy Technology Data Exchange (ETDEWEB)

Feldman, David [National Renewable Energy Lab. (NREL), Golden, CO (United States); Barbose, Galen [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Margolis, Robert [National Renewable Energy Lab. (NREL), Golden, CO (United States); Wiser, Ryan [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Darghouth, Naim [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Goodrich, Alan [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2012-11-30

The installed capacity of global and U.S. photovoltaic (PV) systems has soared in recent years, driven by declining PV prices and government incentives. The U.S. Department of Energy’s (DOE) SunShot Initiative aims to make PV cost competitive without incentives by reducing the cost of PV-generated electricity by about 75% between 2010 and 2020. This summary report—based on research at Lawrence Berkeley National Laboratory (LBNL) and the National Renewable Energy Laboratory (NREL)—examines progress in PV price reductions to help DOE and other PV stakeholders manage the transition to a market-driven PV industry, and to provide clarity surrounding the wide variety of potentially conflicting data available about PV system prices.

The Value of Transparency in Distributed Solar PV Markets

Energy Technology Data Exchange (ETDEWEB)

OShaughnessy, Eric J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Zamzam, Ahmed S [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

2017-12-01

Market transparency refers to the degree of customer awareness of product options and fair market prices for a given good. In The Value of Transparency in Distributed Solar PV Markets, we use residential solar photovoltaic (PV) quote data to study the value of transparency in distributed solar PV markets. We find that improved market transparency results in lower installation offer prices. Further, the results of this study suggest that PV customers benefit from gaining access to more PV quotes.

Cloning, expression, purification and crystallization of dihydrodipicolinate synthase from the psychrophile Shewanella benthica

International Nuclear Information System (INIS)

Wubben, Jacinta M.; Dogovski, Con; Dobson, Renwick C. J.; Codd, Rachel; Gerrard, Juliet A.; Parker, Michael W.; Perugini, Matthew A.

2010-01-01

Dihydrodipicolinate synthase (DHDPS) is an essential oligomeric enzyme of interest to antibiotic discovery research and studies probing the importance of quaternary structure to protein function, stability and dynamics. The cloning, expression, purification and crystallization of DHDPS from the psychrophilic (cold-dwelling) bacterium Shewanella benthica are described. Dihydrodipicolinate synthase (DHDPS) is an oligomeric enzyme that catalyzes the first committed step of the lysine-biosynthesis pathway in plants and bacteria, which yields essential building blocks for cell-wall and protein synthesis. DHDPS is therefore of interest to drug-discovery research as well as to studies that probe the importance of quaternary structure to protein function, stability and dynamics. Accordingly, DHDPS from the psychrophilic (cold-dwelling) organism Shewanella benthica (Sb-DHDPS) was cloned, expressed, purified and crystallized. The best crystals of Sb-DHDPS were grown in 200 mM ammonium sulfate, 100 mM bis-tris pH 5.0–6.0, 23–26%(w/v) PEG 3350, 0.02%(w/v) sodium azide and diffracted to beyond 2.5 Å resolution. Processing of diffraction data to 2.5 Å resolution resulted in a unit cell with space group P2 1 2 1 2 1 and dimensions a = 73.1, b = 84.0, c = 143.7 Å. These studies of the first DHDPS enzyme to be characterized from a bacterial psychrophile will provide insight into the molecular evolution of enzyme structure and dynamics

Optimal design of PV and HP system

DEFF Research Database (Denmark)

Nepper-Rasmussen, Bjarke Christian; Rasmussen, Theis Bo

2015-01-01

Methods of utilizing residential produced photovoltaic (PV) power by converting to thermal energy through heat pumps (HP) are present in literature, where thermal energy is dispersed as either heat or hot water at the instant moment of PV production. In this paper an alternative solution is descr...... that the thermal storage with a BT is a better investment than a PV system without HP or no investment. Furthermore, it showed that the optimization model developed in this project is capable of finding the optimal combination of component sizes based on our data.......Methods of utilizing residential produced photovoltaic (PV) power by converting to thermal energy through heat pumps (HP) are present in literature, where thermal energy is dispersed as either heat or hot water at the instant moment of PV production. In this paper an alternative solution...... is described, where the thermal energy is stored in a buffer tank (BT) capable of dispersing heat to either the heating system of a house or a hot water tank, for later use. The thermal storage solution including a BT can increase the self-consumption of residentially produced PV power and thereby shift...

Learning in PV trends and future prospects

International Nuclear Information System (INIS)

Schaeffer, G.J.; De Moor, H.H.C.

2004-06-01

For large scale application of PV cost reduction is essential. It is shown in this study that the price evolution is on track and even accelerating the last 15 years. Using an experience curve approach a learning rate of little over 20% was found consistent with other studies. As data were collected for small rooftop grid connected systems, it could be shown that this learning rate is not only found for modules, but also for BOS (all costs apart from the modules) in Germany as well as in the Netherlands. Projections of the future price of PV systems show that a learning rate of at least 20% is needed to make introduction of PV affordable. It is very effective to invest in learning, thus increasing the learning rate, as well as developing market segments were the value of PV is higher, such as residential PV systems in southern Europe

PV solar system feasibility study

International Nuclear Information System (INIS)

Ashhab, Moh’d Sami S.; Kaylani, Hazem; Abdallah, Abdallah

2013-01-01

Highlights: ► This research studies the feasibility of PV solar systems. ► The aim is to develop the theory and application of a hybrid system. ► Relevant research topics are reviewed and some of them are discussed in details. ► A prototype of the PV solar system is designed and built. - Abstract: This research studies the feasibility of PV solar systems and aims at developing the theory and application of a hybrid system that utilizes PV solar system and another supporting source of energy to provide affordable heating and air conditioning. Relevant research topics are reviewed and some of them are discussed in details. Solar heating and air conditioning research and technology exist in many developed countries. To date, the used solar energy has been proved to be inefficient. Solar energy is an abundant source of energy in Jordan and the Middle East; with increasing prices of oil this source is becoming more attractive alternative. A good candidate for the other system is absorption. The overall system is designed such that it utilizes solar energy as a main source. When the solar energy becomes insufficient, electricity or diesel source kicks in. A prototype of the PV solar system that operates an air conditioning unit is built and proper measurements are collected through a data logging system. The measured data are plotted and discussed, and conclusions regarding the system performance are extracted.

Data monitoring system for PV solar generators

International Nuclear Information System (INIS)

Stoev, M.; Katerski, A.; Williams, A.

2000-01-01

The two 1.5 kWp photovoltaic (PV) solar generators are installed and the new PC data monitoring system is developed by applying EC standards for European Solar Test Installation (ESTI). The schematic system diagram of PV generator is presented. The recording parameters for analytical and global monitoring are discussed. The meteorological data from ESTI sensors, temperature sensor and electrical data from inverter and calibrated shunt are stored via analog digital converters (ADC) on a hard disk of data storage PC. Data Logger and Monitor software for automatic data acquisition, treatment and visual distance control of all output PV data from PV solar generator has been created

Cellular Inhibition of Checkpoint Kinase 2 (Chk2) and Potentiation of Camptothecins and Radiation by the Novel Chk2 Inhibitor PV1019 [7-Nitro-1H-indole-2-carboxylic acid {4-[1-(guanidinohydrazone)-ethyl]-phenyl}-amide

Energy Technology Data Exchange (ETDEWEB)

Jobson, Andrew G.; Lountos, George T.; Lorenzi, Philip L.; Llamas, Jenny; Connelly, John; Cerna, David; Tropea, Joseph E.; Onda, Akikazu; Zoppoli, Gabriele; Kondapaka, Sudhir; Zhang, Guangtao; Caplen, Natasha J.; Cardellina, II, John H.; Yoo, Stephen S.; Monks, Anne; Self, Christopher; Waugh, David S.; Shoemaker, Robert H.; Pommier, Yves; (NIH)

2010-04-05

Chk2 is a checkpoint kinase involved in the ataxia telangiectasia mutated pathway, which is activated by genomic instability and DNA damage, leading to either cell death (apoptosis) or cell cycle arrest. Chk2 provides an unexplored therapeutic target against cancer cells. We recently reported 4,4'-diacetyldiphenylurea-bis(guanylhydrazone) (NSC 109555) as a novel chemotype Chk2 inhibitor. We have now synthesized a derivative of NSC 109555, PV1019 (NSC 744039) [7-nitro-1H-indole-2-carboxylic acid {l_brace}4-[1-(guanidinohydrazone)-ethyl]-phenyl{r_brace}-amide], which is a selective submicromolar inhibitor of Chk2 in vitro. The cocrystal structure of PV1019 bound in the ATP binding pocket of Chk2 confirmed enzymatic/biochemical observations that PV1019 acts as a competitive inhibitor of Chk2 with respect to ATP. PV1019 was found to inhibit Chk2 in cells. It inhibits Chk2 autophosphorylation (which represents the cellular kinase activation of Chk2), Cdc25C phosphorylation, and HDMX degradation in response to DNA damage. PV1019 also protects normal mouse thymocytes against ionizing radiation-induced apoptosis, and it shows synergistic antiproliferative activity with topotecan, camptothecin, and radiation in human tumor cell lines. We also show that PV1019 and Chk2 small interfering RNAs can exert antiproliferative activity themselves in the cancer cells with high Chk2 expression in the NCI-60 screen. These data indicate that PV1019 is a potent and selective inhibitor of Chk2 with chemotherapeutic and radiosensitization potential.

Economic Comparison of Two Business Models for Implementation of Small Integrated PV Systems

International Nuclear Information System (INIS)

Matak, N.; Krajacic, G.; Jerkic, E.; Duic, N.

2016-01-01

We compared two different models for the implementation of small photovoltaic solar systems in the Croatia. The new prosumer model presented in the new Croatian law on the Renewable Energy Sources and Highly Efficient Cogeneration (OG 100/15) and PV ESCO model which is similar to net metering. The PV ESCO model is developed from authors to determine possibility to raise payback period of small integrated PV systems. The comparison was done on a 15-minute basis and there were compared values of Simple Payback Period (SPP) for different locations and systems size considering electricity demand and market prices. Internal Rate of Return (IRR) and Net Present Value (NPV) were compared for 4 different cases. Conducted comparison showed that PV ESCO model is always more favourable for the owner of PV system in terms of lower SPP and higher IRR and NPV. It has been noticed that for systems higher than 5 kWp use of PV ESCO model is recommended. For smaller systems it is not always clear which model should be used, since some losses are generated in the system on the side of the electricity supply company. For smaller systems from 2 to 5 kWp, PV ESCO model has SPP from 7.5 to 13 years and SPP value for the prosumer model is 8.7 to 15 years. This difference is higher when comparing PV system from 6 to 10 kWp. SPP for PV ESCO model, in that case, is from 10 to 13 years and in the prosumer model is from 17.5 to 28 years.(author).

Simulation of Distributed PV Power Output in Oahu Hawaii

Energy Technology Data Exchange (ETDEWEB)

Lave, Matthew Samuel [Sandia National Lab. (SNL-CA), Livermore, CA (United States)

2016-08-01

Distributed solar photovoltaic (PV) power generation in Oahu has grown rapidly since 2008. For applications such as determining the value of energy storage, it is important to have PV power output timeseries. Since these timeseries of not typically measured, here we produce simulated distributed PV power output for Oahu. Simulated power output is based on (a) satellite-derived solar irradiance, (b) PV permit data by neighborhood, and (c) population data by census block. Permit and population data was used to model locations of distributed PV, and irradiance data was then used to simulate power output. PV power output simulations are presented by sub-neighborhood polygons, neighborhoods, and for the whole island of Oahu. Summary plots of annual PV energy and a sample week timeseries of power output are shown, and a the files containing the entire timeseries are described.

Analysis of concentrating PV-T systems for the commercial/industrial sector. Volume II. PV-T state-of-the-art survey and site/application pair selection and analysis

Energy Technology Data Exchange (ETDEWEB)

Schwinkendorf, W.E.

1984-09-01

As part of a project to develop feasibility assessments, design procedures, and reference designs for total energy systems that could use actively cooled concentrating photovoltaic collectors, a survey was conducted to provide an overview of available photovoltaic-thermal (PV-T) technology. General issues associated with the design and installation of a PV-T system are identified. Electrical and thermal efficiencies for the line-focus Fresnel, the linear parabolic trough, and the point-focus Fresnel collectors are specified as a function of operating temperature, ambient temperature, and insolation. For current PV-T technologies, the line-focus Fresnel collector proved to have the highest thermal and electrical efficiencies, lowest array cost, and lowest land area requirement. But a separate feasibility analysis involving 11 site/application pairs showed that for most applications, the cost of the photovoltaic portion of a PV-T system is not recovered through the displacement of an electrical load, and use of a thermal-only system to displace the thermal load would be a more economical alternative. PV-T systems are not feasible for applications that have a small thermal load, a large steam requirement, or a high load return temperature. SAND82-7157/3 identifies the technical issues involved in designing a photovoltaic-thermal system and provides guidance for resolving such issues. Detailed PV-T system designs for three selected applications and the results of a trade-off study for these applications are presented in SAND82-7157/4. A summary of the major results of this entire study and conclusions concerning PV-T systems and applications is presented in SAND82-7157/1.

Design optimization of transformerless grid-connected PV inverters including reliability

DEFF Research Database (Denmark)

Koutroulis, Eftichios; Blaabjerg, Frede

2012-01-01

Of the Electricity (LCOE) generated during the PV system lifetime period is minimized. The LCOE is calculated also considering the failure rates of the components, which affect the reliability performance and lifetime maintenance cost of the PV inverter. A design example is presented, demonstrating that compared...... to the non-optimized PV inverter structures, the PV inverters designed using the proposed optimization methodology exhibit lower total manufacturing and lifetime maintenance cost and inject more energy into the electric-grid and by that minimizing LCOE.......This paper presents a new methodology for optimal design of transformerless Photovoltaic (PV) inverters targeting a cost-effective deployment of grid-connected PV systems. The optimal values and types of the PV inverter components are calculated such that the PV inverter Levelized Cost...

Design Optimization of Transformerless Grid-Connected PV Inverters Including Reliability

DEFF Research Database (Denmark)

Koutroulis, Eftichios; Blaabjerg, Frede

2013-01-01

such that the PV inverter LCOE generated during the PV system lifetime period is minimized. The LCOE is also calculated considering the failure rates of the components, which affect the reliability performance and lifetime maintenance cost of the PV inverter. A design example is presented, demonstrating...... that compared to the nonoptimized PV inverter structures, the PV inverters designed using the proposed optimization methodology exhibit lower total manufacturing and lifetime maintenance cost and inject more energy into the electric-grid and by that minimizing LCOE.......This paper presents a new methodology for optimal design of transformerless photovoltaic (PV) inverters targeting a cost-effective deployment of grid-connected PV systems. The optimal switching frequency as well as the optimal values and types of the PV inverter components is calculated...

Effects of Cd on reductive transformation of lepidocrocite by Shewanella oneidensis MR-1

Institute of Scientific and Technical Information of China (English)

Chaolei Yuan; Fangbai Li; Rui Han; Tongxu Liu; Weimin Sun; Weilin Huang

2017-01-01

We investigated the reduction of lepidocrocite (γ-FeOOH) by Shewanella oneidensis MR-1 in the presence and absence of Cd.The results showed that Cd2+ retarded microbial reduction of γ-FeOOH and avoided formation of magnetite.The inhibitory effect on γ-FeOOH transformation may not result from Cd2+ toxicity to the bacterium;it rather was probably due to competitive adsorption between Cd2+ and Fe2+ on γ-FeOOH as its surface reduction catalyzed by adsorbed Fe2+ was eliminated by adsorption of Cd2+.

Impedance characterization of PV modules in outdoor conditions

DEFF Research Database (Denmark)

Oprea, Matei-lon; Thorsteinsson, Sune; Spataru, Sergiu

2016-01-01

Impedance spectroscopy (IS) has been used for laboratory characterizations of photovoltaic (PV) technologies under well controlled conditions. This work applies IS for outdoor characterization of PV panels, in order to observe the effect of irradiance (G) and temperature (T) on the PV module’s...

Performance of a 34 kWp grid-connected PV system in Indonesia - A comparison of tropical and European PV systems

NARCIS (Netherlands)

Veldhuis, A.J.; Reinders, Angelina H.M.E.

2014-01-01

We analysed a monitored grid-connected PV system of 34 kWp in Indonesia to investigate the performance of PV systems in tropical climates. The PV system has been installed in Jayapura, the capital of the Province of Papua, Indonesia, by the beginning of 2012. Due to the aged gensets and frequent

The Analysis of A Frequent TMPRSS3 Allele Containing P.V116M and P.V291L in A Cis Configuration among Deaf Koreans

Directory of Open Access Journals (Sweden)

Ah Reum Kim

2017-10-01

Full Text Available We performed targeted re-sequencing to identify the genetic etiology of early-onset postlingual deafness and encountered a frequent TMPRSS3 allele harboring two variants in a cis configuration. We aimed to evaluate the pathogenicity of the allele. Among 88 cochlear implantees with autosomal recessive non-syndromic hearing loss, subjects with GJB2 and SLC26A4 mutations were excluded. Thirty-one probands manifesting early-onset postlingual deafness were sorted. Through targeted re-sequencing, we detected two families with a TMPRSS3 mutant allele containing p.V116M and p.V291L in a cis configuration, p.[p.V116M; p.V291L]. A minor allele frequency was calculated and proteolytic activity was measured. A p.[p.V116M; p.V291L] allele demonstrated a significantly higher frequency compared to normal controls and merited attention due to its high frequency (4.84%, 3/62. The first family showed a novel deleterious splice site variant—c.783-1G>A—in a trans allele, while the other showed homozygosity. The progression to deafness was noted within the first decade, suggesting DFNB10. The proteolytic activity was significantly reduced, confirming the severe pathogenicity. This frequent mutant allele significantly contributes to early-onset postlingual deafness in Koreans. For clinical implication and proper auditory rehabilitation, it is important to pay attention to this allele with a severe pathogenic potential.

Study of bypass diodes configuration on PV modules

Energy Technology Data Exchange (ETDEWEB)

Silvestre, S.; Boronat, A.; Chouder, A. [Electronics Engineering Department - UPC., C/Jordi Girona 1-3, Modul C4 Campus Nord UPC., 08034 Barcelona (Spain)

2009-09-15

A procedure of simulation and modelling solar cells and PV modules, working partially shadowed in Pspice environment, is presented. Simulation results have been contrasted with real measured data from a commercial PV module of 209 Wp from Siliken. Some cases of study are presented as application examples of this simulation methodology, showing its potential on the design of bypass diodes configuration to include in a PV module and also on the study of PV generators working in partial shading conditions. (author)

60 kW{sub p} PV-system school centre Spalterhals Barsinghausen. Synergies in energetical retrofit of school building; 60-kW{sub p}-PV-Anlage Schulzentrum Spalterhals Barsinghausen. Synergien bei der energetischen Sanierung eines Schulgebaeudes

Energy Technology Data Exchange (ETDEWEB)

Blumenscheit, R.; Hettwer, C. [Stadt Barsinghausen (Germany); Diestelmeier, C.; Wiegmann, A. [Raumplan, Hannover (Germany); Decker, B.; Hennig, C.; Mack, M. [Solar Engineering Decker and Mack GmbH, Hannover (Germany)

2004-07-01

The completely building-integrated PV plant with a nominal power of 60.54 kW{sub p} uses synergies with constructional and energetical retrofit of a school building. The PV plant is operated by the town of Barsinghausen (30 km southwest of Hannover). The federal state of Lower Saxony gave a grant of 36,61%, the Hannover region of 12,39% to the total investment of 824.190 Euro (incl. building construction). The PV plant is divided into five units. PV modules serve as the curtain wall of heat-insulated building core (blue PV cold facade: 12.67 kW{sub p}, grey PV breastwork: 8,38 kW{sub p}). Semitransparent PV modules substitute the insulating glass shed lights of a music room (4,28 kW{sub p}) and the glass roofing of an inner court (12,17 kW{sub p} - all modules: Solarnova) giving an optimum of sun-shading and daylighting. Thin-film PV modules on plastic foils (23,04 kW{sub p} - Alwitra EVALON Solar, Unisolar amorphous Si cells) are tested as flat roof standard retrofit. The PV system has 29 string inverters mostly of SMA Sunny Boy family mounted near to the PV modules in operational rooms or in crawling cellars. The PV operator gets a reimbursement of 0,481 Euro per kWh PV energy according to EEG. The PV system is monitored in detail within 'Solaroffensive' of Lower Saxony. Visualization tableaus inform the public about actual irradiance, actual power and annual energy. (orig.) [German] Schulgebaeude und insbesondere grosse Schulzentren aus den 70er Jahren haben geeignete Dachflaechen zur Errichtung von grossen PV-Anlagen (typisch >1.000 m{sup 2}). Zugleich sind Schulen ein idealer Ort, um vor breitem Publikum (Schueler, Lehrer, Eltern) Planung, Installation und Betrieb einer PV-Anlage zu demonstrieren. In Barsinghausen, am Fusse des Deisters etwa 30 km suedwestlich von Hannover, entstand zwischen August 2001 und Maerz 2003 eine innovative PV-Modellanlage am Schulzentrum 'Am Spalterhals', die verschiedene Arten der PV-Gebaeudeintegration erprobt

Latin America as new PV market opportunity

International Nuclear Information System (INIS)

Weiss, Ingrid

2015-01-01

It is important to recognize solar energy as an international and strategic opportunity for the European market to expand. The objective of this paper is to apply the methodology created during the PV Parity project for analyzing PV Competitiveness in the emerging residential PV market in Brazil, using information from the State of Rio de Janeiro. The dynamic competitiveness analysis was performed considering the price with and without taxes in order to assess the year when PV will reach grid parity in Rio de Janeiro and how the taxes impact on the results. Results are divided into 3 scenarios: Optimistic, Conservative, and Conservative Moderate. The LCOE of residential systems will likely become competitive with the residential electricity tariffs between 2020 and 2030, assuming the residential tariffs in Rio de Janeiro. This is an indicator that PV energy business opportunities are increasing in Brazil and, with the adequate policy support, its market competitiveness could be improved. We are also looking in other markets of Latin America. (full text)

Dissipation of heat from building integrated PV

Energy Technology Data Exchange (ETDEWEB)

Taylor, C.M.L.

2001-07-01

The objectives of the project were to investigate methods for improving heat transfer and the reflection of heat from PV modules in building integrated situations and to develop the design of a building integrated PV element with improved heat transfer characteristics, with the aim of reducing the operating temperature of the PV cells. The prototypes developed for improving heat transfer have only shown small reductions in the PV cell operating temperature and these results have not been fully quantified due to problems associated with experimental testing. The improvement in the overall electrical performance of PV modules operating at lower temperatures is consequently even smaller. As a result, none of the prototypes can be considered to be economically viable. Based upon the theoretical and experimental results of this work, it is the recommendation of this project that no further work be conducted in improving BIPV performance through improved heat transfer of BIPV. (Author)

The potential of solar PV in Ontario

International Nuclear Information System (INIS)

McMonagle, R.

2005-01-01

Canada has lagged behind other industrialized nations in the growth of solar energy markets. Currently, over 78 per cent of the global market for solar energy is for grid-connected applications where power is fed into the electrical distribution network. Less than 3.5 per cent of the Canadian solar market is grid-connected. This report investigated the potential size of the photovoltaic (PV) market in Ontario given adequate support from both governments and utilities. The forecast was based on sustainable growth levels that the solar industry as a whole might maintain over an extended period of time. It was suggested that it is technically feasible to install over 3000 MW of PV in single, detached homes in the province, which could generate over 3200 GWh each year. If the right policy conditions were put in place, the technical potential for PV on all buildings in Ontario is over 14,000 MW by 2025, which would generate over 13,000 GWh annually. Support mechanisms such as the Advanced Renewable Tariff (ART) or Standard Offer Contracts (SOC) will enable the PV industry to build capacity. Future markets for PV include new homes, commercial buildings and the existing housing stock. With a properly designed system, it is forecasted that the deployment of PV by 2025 could result in the involvement of 400,000 homes with over 1200 MW of installed capacity and over 290 MW installed annually by 2025. Recommendations to Ontario Power Authority's (OPA) report supply mix report focused on the use of SOCs as the appropriate support mechanism to start building solar capacity in Ontario, as projections using SOCs would see Ontario following the growth patterns of other nations. It was concluded that the OPA report does not acknowledge the current growth rates of PV globally, nor does it fully consider the potential of PV in Ontario. 9 refs., 8 figs

A detailed thermal-electrical model of three photovoltaic/thermal (PV/T) hybrid air collectors and photovoltaic (PV) module: Comparative study under Algiers climatic conditions

International Nuclear Information System (INIS)

Slimani, Mohamed El Amine; Amirat, Madjid; Kurucz, Ildikó; Bahria, Sofiane; Hamidat, Abderrahmane; Chaouch, Wafa Braham

2017-01-01

Highlights: • A detailed thermal and electrical model for PV and PV/T systems has been presented. • The developed numerical model was validated successfully with previously published experimental results. • A comparative study between four solar devices (PV and PV/T systems) was carried out. • The experimental weather conditions of Algiers site are used in the numerical model. • The glazed double-pass photovoltaic/thermal air collector shows the best overall energy efficiency. - Abstract: The thermal photovoltaic hybrid collector is a genuine cogeneration technology; it can produce electricity and heat simultaneously. In this paper, a comparative study is presented between four solar device configurations: photovoltaic module (PV-I), conventional hybrid solar air collector (PV/T-II), glazed hybrid solar air collector (PV/T-III) and glazed double-pass hybrid solar air collector (PV/T-IV). A numerical model is developed and validated through experimental results indicated in the previous literature. The numerical model takes the heat balance equations and different thermal and electrical parameters into account for each configuration included in this study, the energy performances are evaluated with a sample weather data of Algiers site. The numerical results show that the daily average of overall energy efficiency reaches: 29.63%, 51.02%, 69.47% and 74% for the first (PV-I), the second (PV/T-II), the third (PV/T-III) and the fourth (PV/T-IV) configurations respectively. These values are obtained with an air flow of 0.023 kg/s and introducing a sample of experimental weather data collected in Algiers site for a sunny day in summer.

Impact of residential PV adoption on Retail Electricity Rates

International Nuclear Information System (INIS)

Cai, Desmond W.H.; Adlakha, Sachin; Low, Steven H.; De Martini, Paul; Mani Chandy, K.

2013-01-01

The price of electricity supplied from home rooftop photo voltaic (PV) solar cells has fallen below the retail price of grid electricity in some areas. A number of residential households have an economic incentive to install rooftop PV systems and reduce their purchases of electricity from the grid. A significant portion of the costs incurred by utility companies are fixed costs which must be recovered even as consumption falls. Electricity rates must increase in order for utility companies to recover fixed costs from shrinking sales bases. Increasing rates will, in turn, result in even more economic incentives for customers to adopt rooftop PV. In this paper, we model this feedback between PV adoption and electricity rates and study its impact on future PV penetration and net-metering costs. We find that the most important parameter that determines whether this feedback has an effect is the fraction of customers who adopt PV in any year based solely on the money saved by doing so in that year, independent of the uncertainties of future years. These uncertainties include possible changes in rate structures such as the introduction of connection charges, the possibility of PV prices dropping significantly in the future, possible changes in tax incentives, and confidence in the reliability and maintainability of PV. -- Highlights: •Households who install PV reduce their electricity consumption from the grid. •Electricity rates must increase for utility companies to recover its fixed costs. •However, higher electricity rates give households more incentives to adopt PV. •We find that this feedback has significant impact on PV uptake only in later years. •Utility companies could lose a significant fraction of high consumption customers

Remote and Centralized Monitoring of PV Power Plants

DEFF Research Database (Denmark)

Kopacz, Csaba; Spataru, Sergiu; Sera, Dezso

2014-01-01

the inverters within each PV plant. The monitoring software stores the PV measurements in a data warehouse optimized for managing and data mining large amounts of data, from where it can be later visualized, analyzed and exported. By combining PV production measurements data with I-V curve measurements...

Theoretical investigation of the energy performance of a novel MPCM (Microencapsulated Phase Change Material) slurry based PV/T module

International Nuclear Information System (INIS)

Qiu, Zhongzhu; Zhao, Xudong; Li, Peng; Zhang, Xingxing; Ali, Samira; Tan, Junyi

2015-01-01

Aim of the paper is to present a theoretical investigation into the energy performance of a novel PV/T module that employs the MPCM (Micro-encapsulated Phase Change Material) slurry as the working fluid. This involved (1) development of a dedicated mathematical model and computer program; (2) validation of the model by using the published data; (3) prediction of the energy performance of the MPCM (Microencapsulated Phase Change Material) slurry based PV/T module; and (4) investigation of the impacts of the slurry flow state, concentration ratio, Reynolds number and slurry serpentine size onto the energy performance of the PV/T module. It was found that the established model, based on the Hottel–Whillier assumption, is able to predict the energy performance of the MPCM slurry based PV/T system at a very good accuracy, with 0.3–0.4% difference compared to a validated model. Analyses of the simulation results indicated that laminar flow is not a favorite flow state in terms of the energy efficiency of the PV/T module. Instead, turbulent flow is a desired flow state that has potential to enhance the energy performance of PV/T module. Under the turbulent flow condition, increasing the slurry concentration ratio led to the reduced PV cells' temperature and increased thermal, electrical and overall efficiency of the PV/T module, as well as increased flow resistance. As a result, the net efficiency of the PV/T module reached the peak level at the concentration ratio of 5% at a specified Reynolds number of 3,350. Remaining all other parameters fixed, increasing the diameter of the serpentine piping led to the increased slurry mass flow rate, decreased PV cells' temperature and consequently, increased thermal, electrical, overall and net efficiencies of the PV/T module. In overall, the MPCM slurry based PV/T module is a new, highly efficient solar thermal and power configuration, which has potential to help reduce fossil fuel consumption and carbon emission to

SunShot 2030 for Photovoltaics (PV): Envisioning a Low-cost PV Future

Energy Technology Data Exchange (ETDEWEB)

Cole, Wesley J. [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Frew, Bethany A. [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Gagnon, Pieter J. [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Richards, James [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Sun, Yinong [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Margolis, Robert M. [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Woodhouse, Michael A. [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

2017-09-12

In this report we summarize the implications, impacts, and deployment potential of reaching the SunShot 2030 targets for the electricity system in the contiguous United States. We model 25 scenarios of the U.S. power sector using the Regional Energy Deployment Systems (ReEDS) and Distributed Generation (dGen) capacity expansion models. The scenarios cover a wide range of sensitivities to capture future uncertainties relating to fuel prices, retirements, renewable energy capital costs, and load growth. We give special attention to the potential for storage costs to also rapidly decline due to its large synergies with low-cost solar. The ReEDS and dGen models project utility- and distributed-scale power sector evolution, respectively, for the United States. Both models have been designed with special emphasis on capturing the unique traits of renewable energy, including variability and grid integration requirements. Across the suite of scenarios modeled, we find that reaching the SunShot 2030 target has the potential to lead to significant capacity additions of PV in the United States. By 2050, PV penetration levels are projected to reach 28-46 percent of total generation. If storage also sees significant reductions in cost, then the 2050 solar penetration levels could reach 41-64 percent. PV deployment is projected to occur in all of the lower 48 states, though the specific deployment level is scenario dependent. The growth in PV is projected to be dominated by utility-scale systems, but the actual mix between utility and distributed systems could ultimately vary depending on how policies, system costs, and rate structures evolve.

The Value of Transparency in Distributed Solar PV Markets

Energy Technology Data Exchange (ETDEWEB)

OShaughnessy, Eric J. [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Margolis, Robert M. [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

2017-10-09

Distributed solar photovoltaic (PV) markets are relatively non-transparent: PV price and product information is not readily available, searching for this information is costly (in terms of time and effort), and customers are mostly unfamiliar with the new technology. Quote aggregation, where third-party companies collect PV quotes on behalf of customers, may be one way to increase PV market transparency. In this paper, quote aggregation data are analyzed to study the value of transparency for distributed solar PV markets. The results suggest that easier access to more quotes results in lower prices. We find that installers tend to offer lower prices in more competitive market environments. We supplement the empirical analysis with key findings from interviews of residential PV installers.

Low concentrator PV optics optimization

Science.gov (United States)

Sharp, Leonard; Chang, Ben

2008-08-01

Purpose: Cost reduction is a major focus of the solar industry. Thin film technologies and concentration systems are viable ways to reducing cost, with unique strengths and weakness for both. Most of the concentrating PV work focuses on high concentration systems for reducing energy cost. Meanwhile, many believe that low concentrators provide significant cost reduction potential while addressing the mainstream PV market with a product that acts as a flat panel replacement. This paper analyzes the relative benefit of asymmetric vs. symmetric optics for low-concentrators in light of specific PV applications. Approach: Symmetric and asymmetric concentrating PV module performance is evaluated using computer simulation to determine potential value across various geographic locations and applications. The selected optic design is modeled against standard cSi flat panels and thin film to determine application fit, system level energy density and economic value. Results: While symmetric designs may seem ideal, asymmetric designs have an advantage in energy density. Both designs are assessed for aperture, optimum concentration ratio, and ideal system array configuration. Analysis of performance across climate specific effects (diffuse, direct and circumsolar) and location specific effects (sunpath) are also presented. The energy density and energy production of low concentrators provide a compelling value proposition. More significantly, the choice of optics for a low concentrating design can affect real world performance. With the goal of maximizing energy density and return on investment, this paper presents the advantages of asymmetric optic concentration and illustrates the value of this design within specific PV applications.

Commercialization and business development of grid-connected PV at SMUD

International Nuclear Information System (INIS)

Osborn, D.E.

1998-01-01

SMUD has completed its first 5 year, 6 MW PV commercialization effort based on the sustained, orderly development of the utility PV market. SMUD has begun a 5 year, 10 MW program designed to complete a process that will result in PV being at a market competitive price by 2002 and as a sustainable business opportunity for SMUD. As part of this effort, by the end of 1997, SMUD had installed over 450 PV systems totaling 6 MW. These included over 420 residential rooftop systems as well as commercial buildings, parking lots and substation systems. Under its new Business Plan, SMUD has signed contracts for an additional 10 MW of PV systems for 1998 through 2002 with cost decreasing to less than $3/W. As part of its new competitive business strategy responding to changes the utility industry is undergoing, SMUD has incorporated PV as a key business opportunity. SMUD has established partnerships with its customers through the PV Pioneer green pricing program, with DOE and UPVG through TEAM-UP and Million Solar Roofs to advance PV commercialization and to develop rooftops as PV power plant sites and with other utilities through its PV Partnership program

Rapid disinhibition by adjustment of PV intrinsic excitability during whisker map plasticity in mouse S1.

Science.gov (United States)

Gainey, Melanie A; Aman, Joseph W; Feldman, Daniel E

2018-04-20

Rapid plasticity of layer (L) 2/3 inhibitory circuits is an early step in sensory cortical map plasticity, but its cellular basis is unclear. We show that, in mice of either sex, 1 day whisker deprivation drives rapid loss of L4-evoked feedforward inhibition and more modest loss of feedforward excitation in L2/3 pyramidal (PYR) cells, increasing E-I conductance ratio. Rapid disinhibition was due to reduced L4-evoked spiking by L2/3 parvalbumin (PV) interneurons, caused by reduced PV intrinsic excitability. This included elevated PV spike threshold, associated with an increase in low-threshold, voltage activated delayed rectifier (presumed Kv1) and A-type potassium currents. Excitatory synaptic input and unitary inhibitory output of PV cells were unaffected. Functionally, the loss of feedforward inhibition and excitation were precisely coordinated in L2/3 PYR cells, so that peak feedforward synaptic depolarization remained stable. Thus, rapid plasticity of PV intrinsic excitability offsets early weakening of excitatory circuits to homeostatically stabilize synaptic potentials in PYR cells of sensory cortex. SIGNIFICANCE STATEMENT Inhibitory circuits in cerebral cortex are highly plastic, but the cellular mechanisms and functional importance of this plasticity are incompletely understood. We show that brief (1-day) sensory deprivation rapidly weakens parvalbumin (PV) inhibitory circuits by reducing the intrinsic excitability of PV neurons. This involved a rapid increase in voltage-gated potassium conductances that control near-threshold spiking excitability. Functionally, the loss of PV-mediated feedforward inhibition in L2/3 pyramidal cells was precisely balanced with the separate loss of feedforward excitation, resulting in a net homeostatic stabilization of synaptic potentials. Thus, rapid plasticity of PV intrinsic excitability implements network-level homeostasis to stabilize synaptic potentials in sensory cortex. Copyright © 2018 the authors.

Genome-level homology and phylogeny of Shewanella (Gammaproteobacteria: lteromonadales: Shewanellaceae

Directory of Open Access Journals (Sweden)

Dikow Rebecca B

2011-05-01

Full Text Available Abstract Background The explosion in availability of whole genome data provides the opportunity to build phylogenetic hypotheses based on these data as well as the ability to learn more about the genomes themselves. The biological history of genes and genomes can be investigated based on the taxomonic history provided by the phylogeny. A phylogenetic hypothesis based on complete genome data is presented for the genus Shewanella (Gammaproteobacteria: Alteromonadales: Shewanellaceae. Nineteen taxa from Shewanella (16 species and 3 additional strains of one species as well as three outgroup species representing the genera Aeromonas (Gammaproteobacteria: Aeromonadales: Aeromonadaceae, Alteromonas (Gammaproteobacteria: Alteromonadales: Alteromonadaceae and Colwellia (Gammaproteobacteria: Alteromonadales: Colwelliaceae are included for a total of 22 taxa. Results Putatively homologous regions were found across unannotated genomes and tested with a phylogenetic analysis. Two genome-wide data-sets are considered, one including only those genomic regions for which all taxa are represented, which included 3,361,015 aligned nucleotide base-pairs (bp and a second that additionally includes those regions present in only subsets of taxa, which totaled 12,456,624 aligned bp. Alignment columns in these large data-sets were then randomly sampled to create smaller data-sets. After the phylogenetic hypothesis was generated, genome annotations were projected onto the DNA sequence alignment to compare the historical hypothesis generated by the phylogeny with the functional hypothesis posited by annotation. Conclusions Individual phylogenetic analyses of the 243 locally co-linear genome regions all failed to recover the genome topology, but the smaller data-sets that were random samplings of the large concatenated alignments all produced the genome topology. It is shown that there is not a single orthologous copy of 16S rRNA across the taxon sampling included in this

TRNSYS HYBRID wind diesel PV simulator

Energy Technology Data Exchange (ETDEWEB)

Quinlan, P.J.A.; Mitchell, J.W.; Klein, S.A.; Beckman, W.A.; Blair, N.J. [Univ. of Wisconsin, Madison, WI (United States)

1996-12-31

The Solar Energy Laboratory (SEL) has developed a wind diesel PV hybrid systems simulator, UW-HYBRID 1.0, an application of the TRNSYS 14.2 time-series simulation environment. An AC/DC bus links up to five diesels and wind turbine models, along with PV modules, a battery bank, and an AC/DC converter. Multiple units can be selected. PV system simulations include solar angle and peak power tracking options. Weather data are Typical Meteorological Year data, parametrically generated synthesized data, or external data files. PV performance simulations rely on long-standing SEL-developed algorithms. Loads data are read as scalable time series. Diesel simulations include estimated fuel-use and waste heat output, and are dispatched using a least-cost of fuel strategy. Wind system simulations include varying air density, wind shear and wake effects. Time step duration is user-selectable. UW-HYBRID 1.0 runs in Windows{reg_sign}, with TRNSED providing a customizable user interface. 12 refs., 6 figs.

Environmental and exergy benefit of nanofluid-based hybrid PV/T systems

International Nuclear Information System (INIS)

Hassani, Samir; Saidur, R.; Mekhilef, Saad; Taylor, Robert A.

2016-01-01

Highlights: • Environmental and ExPBT analysis of different PV/T configurations is presented. • The exergy payback time of nanofluid-based hybrid PV/T system is about 2 years. • Nanofluid-based hybrid PV/T system is a reliable solution for pollution prevention. • Nanofluid-based hybrid PV/T system is highly recommended at high solar concentration. - Abstract: Photovoltaic/thermal (PV/T) solar systems, which produce both electrical and thermal energy simultaneously, represent a method to achieve very high conversion rates of sunlight into useful energy. In recent years, nanofluids have been proposed as efficient coolants and optical filter for PV/T systems. Aim of this paper is to theoretically analyze the life cycle exergy of three different configurations of nanofluids-based PV/T hybrid systems, and compare their performance to a standard PV and PV/T system. Electrical and thermal performance of the analyzed solar collectors was investigated numerically. The life cycle exergy analysis revealed that the nanofluids-based PV/T system showed the best performance compared to a standard PV and PV/T systems. At the optimum value of solar concentration C, nanofluid-based PV/T configuration with optimized optical and thermal properties produces ∼1.3 MW h/m 2 of high-grade exergy annually with the lowest exergy payback time of 2 years, whereas these are ∼0.36, ∼0.79 MW h/m 2 and 3.48, 2.55 years for standard PV and PV/T systems, respectively. In addition, the nanofluids-based PV/T system can prevent the emissions of about 448 kg CO 2 eq m −2 yr −1 . Overall, it was found that the nanofluids-based PV/T with optimized optical and thermal properties has potential for further development in a high-concentration solar system.

Less CO2 by means of photovoltaic energy (PV)

International Nuclear Information System (INIS)

Alsema, E.A.; Van Brummelen, M.

1992-11-01

Regarding the title subject special attention is paid to the technical limitations of a fast introduction of the use of photovoltaic (PV) energy conversion. After a brief introduction on PV systems and the operation of a solar cell in chapter two, a state of the art is given of PV technology and possible price developments for PV modules and Balance-Of-System (BOS) components up to the year 2000 in chapters three and four. In chapter five the potential of installing grid-connected PV systems in the Netherlands is determined, taking into account the options of using existing buildings (PV systems on the roof), unexplored ground, in the verge of highways or railroads, industrial areas and airports. In chapter six non-economical bottlenecks for a large-scale introduction of grid-connected PV systems are discussed: the industrial production capacity for PV modules and other components, the fitting-in into the public electricity supply, and institutional aspects of installing PV systems on roofs. In chapter seven it is determined how much costs can be saved and CO 2 emission can be reduced when PV capacity is fitted-in into the Dutch electric power supply. The calculations are based on the Global Shift scenario. In chapter eight two scenarios (an optimistic scenario and a more realistic scenario) for the introduction of PV systems are outlined. For both scenarios the financial consequences and the contribution to the electric power supply are indicated. In chapter nine the net energy yield, being the result of the previously discussed introduction scenarios, is calculated, followed by a calculation of the avoided CO 2 emission, as well as the costs to avoid such emission. 25 figs., 15 tabs., 116 refs., 1 annex

How to stimulate the South African rooftop PV market without putting electricity distributors’ financial stability at risk [Conference presentation

CSIR Research Space (South Africa)

Bischof-Niemz, Sebastian T

2015-09-01

Full Text Available in three important ways: • Embedded Solar PV can be deployed very quickly • Favourable lifetime costs (at 5.7–6.4 €/kWh) compared to other new build options • Large amounts of capacity can be deployed. This value cannot be unlocked because...Wh Electricity bill 8,000 kWh/yr *0.09 €/kWh – ~ Residential load 12,000 kWh/yr 8,000 kWh/yr 10,000 kWh/yr 12,000 kWh/yr 4 ,0 0 0 Self-consumption Gross PV generation PV inverter PV panels 6 kWp Source: CSIR analysis Grid energy Solar energy Payments...

Accelerating residential PV expansion: supply analysis for competitive electricity markets

International Nuclear Information System (INIS)

Payne, Adam; Williams, Robert H.; Duke, Richard

2001-01-01

Photovoltaic (PV) technology is now sufficiently advanced that market support mechanisms such as net metering plus a renewable portfolio standard (RPS) could induce rapid PV market growth in grid-connected applications. With such support mechanisms, markets would be sufficiently large that manufacturers could profitably build and operate 100 MW p /yr PV module factories, and electricity costs for residential rooftop PV systems would compare favorably with residential electricity prices in certain areas (e.g., California and the greater New York region in the US). This prospect is illustrated by economic and market analyses for one promising technology (amorphous silicon thin-film PV) from the perspectives of both module manufacturers and buyers of new homes with rooftop PV systems. With public policies that reflect the distributed and environmental benefits offered by PV-and that can sustain domestic PV market demand growth at three times the historical growth rate for a period of the order of two decades - PV could provide 3% of total US electricity supply by 2025. (Author)

PV panel model based on datasheet values

DEFF Research Database (Denmark)

Sera, Dezso; Teodorescu, Remus; Rodriguez, Pedro

2007-01-01

This work presents the construction of a model for a PV panel using the single-diode five-parameters model, based exclusively on data-sheet parameters. The model takes into account the series and parallel (shunt) resistance of the panel. The equivalent circuit and the basic equations of the PV cell....... Based on these equations, a PV panel model, which is able to predict the panel behavior in different temperature and irradiance conditions, is built and tested....

Good and bad practices in pv plants

OpenAIRE

Martinez Moreno, Francisco; Helleputte, F.; Tyutyundzhiev, N.; Rabal Echeverria, Daniel; Conlon, Michael; Fartaria, Tomás; Oteiza, David

2013-01-01

The PVCROPS project (PhotoVolta ic Cost r€duction, Reliability, Operational performance, Prediction and Simulation), cofinanced by European Commission in the frame of Seventh Framework Programme, has compiled in the “Good and bad practices: Manual to improve the quality and reduce the cost of PV systems” a collection of good and bad practices in actual PV plants . All the situations it collects represent the state-of-the-art of existing PV installations all around Europe. They show how ...

Real Time Photovoltaic Array Simulator for Testing Grid-Connected PV Inverters

DEFF Research Database (Denmark)

Sera, Dezso; Valentini, Massimo; Raducu, Alin

2008-01-01

In this paper a real time flexible PV array simulator is presented. It is a system that can simulate different PV panel arrays in specific environmental conditions. To evaluate performance of the Maximum Power Point Tracking (MPPT) of grid-connected Photovoltaic (PV) inverters only measurements...... undertaken with an appropriate PV array simulator provide accurate and reproducible results. Thus the PV array simulator has been developed and implemented. MPPT efficiency tests on a commercial grid-connected PV inverter have been performed to validate the PV array simulator....

Energy metrics analysis of hybrid - photovoltaic (PV) modules

Energy Technology Data Exchange (ETDEWEB)

Tiwari, Arvind [Department of Electronics and Communication, Krishna Institute of Engineering and Technology, 13 k.m. stone, Ghaziabad - Meerut Road, Ghaziabad 201 206, UP (India); Barnwal, P.; Sandhu, G.S.; Sodha, M.S. [Centre for Energy Studies, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110 016 (India)

2009-12-15

In this paper, energy metrics (energy pay back time, electricity production factor and life cycle conversion efficiency) of hybrid photovoltaic (PV) modules have been analyzed and presented for the composite climate of New Delhi, India. For this purpose, it is necessary to calculate (1) the energy consumption in making different components of the PV modules and (2) the annual energy (electrical and thermal) available from the hybrid-PV modules. A set of mathematical relations have been reformulated for computation of the energy metrics. The manufacturing energy, material production energy, energy use and distribution energy of the system have been taken into account, to determine the embodied energy for the hybrid-PV modules. The embodied energy and annual energy outputs have been used for evaluation of the energy metrics. For hybrid PV module, it has been observed that the EPBT gets significantly reduced by taking into account the increase in annual energy availability of the thermal energy in addition to the electrical energy. The values of EPF and LCCE of hybrid PV module become higher as expected. (author)

Real time PV manufacturing diagnostic system

Energy Technology Data Exchange (ETDEWEB)

Kochergin, Vladimir [MicroXact Inc., Blacksburg, VA (United States); Crawford, Michael A. [MicroXact Inc., Blacksburg, VA (United States)

2015-09-01

The main obstacle Photovoltaic (PV) industry is facing at present is the higher cost of PV energy compared to that of fossil energy. While solar cell efficiencies continue to make incremental gains these improvements are so far insufficient to drive PV costs down to match that of fossil energy. Improved in-line diagnostics however, has the potential to significantly increase the productivity and reduce cost by improving the yield of the process. On this Phase I/Phase II SBIR project MicroXact developed and demonstrated at CIGS pilot manufacturing line a high-throughput in-line PV manufacturing diagnostic system, which was verified to provide fast and accurate data on the spatial uniformity of thickness, an composition of the thin films comprising the solar cell as the solar cell is processed reel-to-reel. In Phase II project MicroXact developed a stand-alone system prototype and demonstrated the following technical characteristics: 1) ability of real time defect/composition inconsistency detection over 60cm wide web at web speeds up to 3m/minute; 2) Better than 1mm spatial resolution on 60cm wide web; 3) an average better than 20nm spectral resolution resulting in more than sufficient sensitivity to composition imperfections (copper-rich and copper-poor regions were detected). The system was verified to be high vacuum compatible. Phase II results completely validated both technical and economic feasibility of the proposed concept. MicroXact’s solution is an enabling technique for in-line PV manufacturing diagnostics to increase the productivity of PV manufacturing lines and reduce the cost of solar energy, thus reducing the US dependency on foreign oil while simultaneously reducing emission of greenhouse gasses.

Methods for the Optimal Design of Grid-Connected PV Inverters

DEFF Research Database (Denmark)

Koutroulis, Eftichios; Blaabjerg, Frede

2011-01-01

and the efficient processing of this power by the DC/AC inverter. In this paper two new methods are presented for the optimal design of a PV inverter power section, output filter and MPPT control strategy. The influences of the electric grid regulations and standards as well as the PV array operational......The DC/AC inverters are used in grid-connected PV energy production systems as the power processing interface between the PV energy source and the electric grid. The energy injected into the electric grid by the PV installation depends on the amount of power extracted from the PV power source...

NPC Based Design Optimization for a Net Zero Office Building in Hot Climates with PV Panels as Shading Device

Directory of Open Access Journals (Sweden)

Muhammad Zubair

2018-05-01

Full Text Available Hot areas of the world receive a high amount of solar radiation. As a result, buildings in those areas consume more energy to maintain a comfortable climate for their inhabitants. In an effort to design net-zero energy building in hot climates, PV possesses the unique advantage of generating electrical energy while protecting the building from solar irradiance. In this work, to form a net-zero energy building (NZEB, renewable resources such as solar and wind available onsite for an existing building have been analyzed in a hot climate location. PV and wind turbines in various configurations are studied to form a NZEB, where PV-only systems offer better performance than Hybrid PV Wind systems, based on net present cost (NPC. The self-shading losses in PV placed on rooftop areas are analyzed by placing parallel arrays of PV modules at various distances in between them. The effect on building cooling load by rooftop PV panels as shading devices is investigated. Furthermore, self-shading losses of PV are compared by the savings in cooling loads using PV as shading. In the case study, 12.3% saving in the cooling load of the building is observed when the building rooftop is completed shaded by PV panels; annual cooling load decreased from 3.417 GWh to 2.996 GWh, while only 1.04% shaded losses are observed for fully shaded (FS buildings compared to those with no shading (NS, as PV generation decreases from 594.39 kWh/m2 to 588.21 kWh/m2. The net present cost of the project has been decreased from US$4.77 million to US$4.41 million by simply covering the rooftop completely with PV panels, for a net-zero energy building.

Design Optimization of Transformerless Grid-Connected PV Inverters Including Reliability

OpenAIRE

Koutroulis, Eftichios; Blaabjerg, Frede

2013-01-01

This paper presents a new methodology for optimal design of transformerless photovoltaic (PV) inverters targeting a cost-effective deployment of grid-connected PV systems. The optimal switching frequency as well as the optimal values and types of the PV inverter components is calculated such that the PV inverter LCOE generated during the PV system lifetime period is minimized. The LCOE is also calculated considering the failure rates of the components, which affect the reliability performance...

Terawatt Challenge for Thin-Film PV

Energy Technology Data Exchange (ETDEWEB)

Zweibel, K.

2005-08-01

The evolution of PV into one of the world's largest industries is not going to happen without major unforeseen problems. However, this study attempts to address the obvious ones, so that we can put aside the mythology of PV (for example, that it is only ''boutique power'' or that one must pave the world with it to be useful) and get on with changing the world's energy infrastructure. With the years of rapid market growth now under way in PV, the author is sure this will not be the last effort to understand the real potential and pitfalls of meeting the Challenge.

National survey report on PV power applications in Switzerland 2006

International Nuclear Information System (INIS)

Huesser, P.; Hostettler, T.

2007-01-01

This annual report was published by the Swiss Federal Office of Energy (SFOE) as part of the International Energy Agency's work on the exchange and dissemination of information on photovoltaic power systems (PVPS). The political situation in Switzerland with regard to the promotion of photovoltaics (PV) and new legislation in the energy area is discussed. The report provides information on installed PV power, costs and prices and the Swiss PV industry. Examples of PV applications are presented and data on the cumulative installed PV power in various application sectors is presented and discussed. Highlights, major projects and various demonstration and field-test programmes are dealt with, as are public budgets for market stimulation. Figures on the development, production and prices of PV cells and modules are presented. Swiss balance-of-system products are reviewed, as are PV-related services and the value of the Swiss PV business. A review of non-technical factors and new initiatives completes the report.

National survey report on PV power applications in Switzerland 2006

Energy Technology Data Exchange (ETDEWEB)

Huesser, P. [Nova Energie GmbH, Aarau (Switzerland); Hostettler, T. [Ingenieurbuero Hostettler, Berne (Switzerland)

2007-07-01

This annual report was published by the Swiss Federal Office of Energy (SFOE) as part of the International Energy Agency's work on the exchange and dissemination of information on photovoltaic power systems (PVPS). The political situation in Switzerland with regard to the promotion of photovoltaics (PV) and new legislation in the energy area is discussed. The report provides information on installed PV power, costs and prices and the Swiss PV industry. Examples of PV applications are presented and data on the cumulative installed PV power in various application sectors is presented and discussed. Highlights, major projects and various demonstration and field-test programmes are dealt with, as are public budgets for market stimulation. Figures on the development, production and prices of PV cells and modules are presented. Swiss balance-of-system products are reviewed, as are PV-related services and the value of the Swiss PV business. A review of non-technical factors and new initiatives completes the report.

Accelerating residential PV expansion: demand analysis for competitive electricity markets

International Nuclear Information System (INIS)

Duke, Richard; Williams, Robert; Payne, Adam

2005-01-01

This article quantifies the potential market for grid-connected, residential photovoltaic (PV) electricity integrated into new homes built in the US. It complements an earlier supply-side analysis by the authors that demonstrates the potential to reduce PV module prices below $1.5/W p by scaling up existing thin-film technology in 100 MW p /yr manufacturing facilities. The present article demonstrates that, at that price, PV modules may be cost effective in 125,000 new home installations per year (0.5 GW p /yr). While this market is large enough to support multiple scaled up thin-film PV factories, inefficient energy pricing and demand-side market failures will inhibit prospective PV consumers without strong public policy support. Net metering rules, already implemented in many states to encourage PV market launch, represent a crude but reasonable surrogate for efficient electricity pricing mechanisms that may ultimately emerge to internalize the externality benefits of PV. These public benefits include reduced air pollution damages (estimated costs of damage to human health from fossil fuel power plants are presented in Appendix A), deferral of transmission and distribution capital expenditures, reduced exposure to fossil fuel price risks, and increased electricity system reliability for end users. Thus, net metering for PV ought to be implemented as broadly as possible and sustained until efficient pricing is in place. Complementary PV 'buydowns' (e.g., a renewable portfolio standard with a specific PV requirement) are needed to jumpstart regional PV markets

Do feed-in tariffs drive PV cost or viceversa?

International Nuclear Information System (INIS)

Antonelli, Marco; Desideri, Umberto

2014-01-01

Highlights: • The distribution of PV installations on the territory is not a function of the solar radiation. • Cost of PV plants were adapted to the FIT framework. • The FIT for PV in Italy was considered an incentive to financial investment. • The FIT for PV in Italy did not stimulate the development of national PV industry. - Abstract: A survey of the PV market in Italy was done studying a number of installations of different sizes whose economic data were known and assessed. The Italian market has experienced a boom in the PV market after the first mechanism of feed-in tariffs was promoted in 2005. The variations of the tariff structure in the following years have caused significant changes in the market structure in terms of average size and technical characteristics of installed plants. However, an Italian PV industry was not stimulated by the incentives and only companies involved in installation and maintenance were created. At the same time, the cost of the PV plants components, design and commissioning have followed quite a particular trend, which is more determined by the tariffs than by the market development and structure. It is quite clear that the costs of PV plants component are not driven by the amount of installations but by the tariffs, with a trend that follows the decreases in the incentives and not the global installed power. It is therefore very important to study the right tariff mechanisms and benefits to avoid financial disturbances on the market and to promote a real competitive market instead of a simple financial operation under a fake façade of green economy

Solar Energy: Incentives to Promote PV in EU27

Directory of Open Access Journals (Sweden)

María del P. Pablo-Romero

2013-11-01

Full Text Available The growth in the use of renewable energies in the EU has been remarkable. Among these energies is PV. The average annual growth rate for the EU-27 countries in installed PV capacity in the period 2005-2012 was 41.2%. While the installed capacity of PV has reached almost 82 % of National Renewable Energy Action Plan (NREAP targets for the EU-27 countries for 2020, it is still far from being used at its full potential. Over recent years, several measures have been adopted in the EU to enhance and promote PV. This paper undertakes a complete review of the state of PV power in Europe and the measures taken to date to promote it in EU-27. 25 countries have adopted measures to promote PV. The most widespread measure to promote PV use is Feed- in Tariffs. Tariffs are normally adjusted, in a decreasing manner, annually. Nevertheless, currently, seven countries have decided to accelerate this decrease rate in view of cost reduction of the installations and of higher efficiencies. The second instrument used to promote PV in the EU-27 countries is the concession of subsidies. Nevertheless, subsidies have the disadvantage of being closely linked to budgetary resources and therefore to budgetary constraints. In most EU countries, subsidies for renewable energy for PV are being lowered. Twelve EU-27 countries adopted tax measures. Low-interest loans and green certificate systems were only sparingly used.

Kauai Island Utility Co-op (KIUC) PV integration study.

Energy Technology Data Exchange (ETDEWEB)

Ellis, Abraham; Mousseau, Tom (Knoxville, TN)

2011-08-01

This report investigates the effects that increased distributed photovoltaic (PV) generation would have on the Kauai Island Utility Co-op (KIUC) system operating requirements. The study focused on determining reserve requirements needed to mitigate the impact of PV variability on system frequency, and the impact on operating costs. Scenarios of 5-MW, 10-MW, and 15-MW nameplate capacity of PV generation plants distributed across the Kauai Island were considered in this study. The analysis required synthesis of the PV solar resource data and modeling of the KIUC system inertia. Based on the results, some findings and conclusions could be drawn, including that the selection of units identified as marginal resources that are used for load following will change; PV penetration will displace energy generated by existing conventional units, thus reducing overall fuel consumption; PV penetration at any deployment level is not likely to reduce system peak load; and increasing PV penetration has little effect on load-following reserves. The study was performed by EnerNex under contract from Sandia National Laboratories with cooperation from KIUC.

A global strategy for the European PV industry

International Nuclear Information System (INIS)

Viaud, M.; Despotou, E.; Latour, M.; Hoffmann, W.; Macias, E.; Cameron, M.; Laborde, E.

2004-01-01

The objective was to develop a comprehensive strategy that answers to the need of today European PV industry. Namely: - Develop PV markets in Europe - Develop export markets. - Position the European PV industry within the European political environment and support the effort of national actors in their local objectives. This method lends itself to brainstorming to create actions and synergies, on order to achieve strategy objectives. The whole work is based on working groups clearly defined on the purpose, where all EPIA members are invited to participate. The overall first results are presented during the 19. EU PV Conference in Paris and EPIA will do recommendations on actions to be undertaken in the future. This strategy is co-financed by EPIA members and the 6. Framework Programme for research of the European Commission through the PV Catapult project. (authors)

A Practical Optimization Method for Designing Large PV Plants

DEFF Research Database (Denmark)

Kerekes, Tamas; Koutroulis, E.; Eyigun, S.

2011-01-01

Nowadays Photovoltaic (PV) plants have multi MW sizes, the biggest plants reaching tens of MW of capacity. Such large-scale PV plants are made up of several thousands of PV panels, each panel being in the range of 150-350W. This means that the design of a Large PV power plant is a big challenge...... and configuring such a plant should be implemented taking into consideration not only the cost of the installation, but also the Annual Energy Production, the Performance Ratio and the Levelized Cost Of Energy. In this paper, an algorithm is presented including the most important models of the PV system...

PV investment in Europe

Energy Technology Data Exchange (ETDEWEB)

Hueser, Pius [Nova Energy GmbH, (Switzerland)

2007-06-15

This presentation is mainly about how the PV market in Europe has been growing, and which elements are going to determine if this market succeed or failed not only in Europe but also in the rest of the world. In the first part of this presentation, it is mentioned how in 2005 the development of some PV technologies triggered the PV market growth without any marketing control. Then, there are explained the aspects that changed such situation out of control, therefore, it emerged the beginning of the consolidation of this market. There are briefly explained those factors that are going to determine if this market succeed or failed in the future. Finally, there are given examples of some the PV investments. [Spanish] Esta presentacion habla principalmente de la manera en como ha crecido el Mercado de sistemas fotovoltaicos en Europa, asi tambien se mencionan los elementos fundamentales que determinaran el exito o fracaso de este mercado, no solamente en Europa sino tambien en el resto del mundo, en un futuro. En la primera parte de esta presentacion, se describe como en el 2005, debido al desarrollo de algunas tecnologias fotovoltaicas se desencadeno el crecimiento desenfrenado del mercado fotovoltaico. Despues, se explican los aspectos que hicieron que dicho crecimiento tomara su curso, teniendo como resultado el inicio de un mercado mas consolidado. Se explican brevemente los factores que determinaran si este mercado encuentra el exito o el fracaso en un futuro. Finalmente, se dan ejemplos de algunas adquisiciones fotovoltaicas.

China PV Business and Applications Evaluation; TOPICAL

International Nuclear Information System (INIS)

Sherring, Chris

1999-01-01

This report provides an overview of photovoltaics (PV) business and applications in China. Although more than 70 million people in China are without access to grid electricity, many of the unelectrified regions benefit from considerable renewable resources, including good solar insolation. Current annual PV sales are still modest, however, and are estimated to be between 2.0 and 2.5 megawatts. This and other significant PV data, including information regarding the current status of key aspects of Chinese businesses, markets, and distribution channels, are included in the report. Detailed company profiles of Chinese business organizations and summaries of visits made to these companies (as well as to more remote sites in Inner Mongolia to examine PV usage by the end-use customer) in September-October 1998 are also presented

Rating PV Power and Energy: Cell, Module, and System Measurements

Energy Technology Data Exchange (ETDEWEB)

Emery, Keith

2016-06-02

A summary of key points related to research-level measurements of current vs. voltage measurement theory including basic PV operation, equivalent circuit, and concept of spectral error; PV power performance including PV irradiance sensors, simulators and commercial and generic I-V systems; PV measurement artifacts, intercomparisons, and alternative rating methods.

PV System Component Fault and Failure Compilation and Analysis.

Energy Technology Data Exchange (ETDEWEB)

Klise, Geoffrey Taylor; Lavrova, Olga; Gooding, Renee Lynne

2018-02-01

This report describes data collection and analysis of solar photovoltaic (PV) equipment events, which consist of faults and fa ilures that occur during the normal operation of a distributed PV system or PV power plant. We present summary statistics from locations w here maintenance data is being collected at various intervals, as well as reliability statistics gathered from that da ta, consisting of fault/failure distributions and repair distributions for a wide range of PV equipment types.

Examples of successful architectural integration of PV: Germany

International Nuclear Information System (INIS)

Hagemann, I.B.

2004-01-01

In Germany building-integrated photovoltaics (BIPV) are developing rapidly, and much progress has been achieved in the past five years. BIPV can be used today in different ways on both existing and new buildings. Architects and designers are discovering BIPV. With the help of custom-made products available on the German market they are beginning to explore the technical limits of an aesthetic and structural integration of PV in buildings. As a result some exciting high-profile building projects with PV have been built, for example, the small service pavilion Meereslauschen in Steinhude or the new headquarters building of the Wood Trade Association in Munich. These projects show that the use of PV is very varied and offers opportunities for creative architects. However non-technical problems still need to be solved to allow a meaningful and widespread application of PV in the built environment. To decrease costs it is essential to develop further standard BIPV components. The aim of such developments should be to replace standard PV modules by products in which PV and structural building elements are melded into one design and structural unit. (author)

PV experience curves for the Netherlands

International Nuclear Information System (INIS)

Gerwig, R.

2005-01-01

Experience curves are one of several tools used by policy makers to take a look at market development. Numerous curves have been constructed for PV but none specific to the Netherlands. The objective of this report is to take a look at the price development of grid-connected PV systems in the Netherlands using the experience curve theory. After a literature and internet search and attempts to acquire information from PV companies information on 51% of the totally installed capacity was found. Curves for the period 1991-2001 were constructed based on system price, BOS (balance-of-system) price and inverter price. The progress ratio of the locally learning BOS was similar to the globally learning module market. This indicates that the pace of development of the Dutch PV market is similar to the globally followed pace. Improvement of the detail of the data might help to get a better idea of which BOS components have declined most. The similar progress ratio also shows the importance of investing both in module and system research as is the case in the Netherlands

Cost reduction in PV manufacturing. Impact on grid-connected and building-integrated markets

International Nuclear Information System (INIS)

Maycock, Paul D.

1997-01-01

In the past three years there have been several key events or changes that can lead to fully economic, massive deployment to the grid-connected and central PV markets. The factors discussed in this report include: (1) significant cost reduction in single crystal and polycrystal silicon so that modules profitably priced at $3.10-$3.30 per peak watt and installed grid-connected systems with installed cost of $5.50 per watt are being offered; (2) several new thin film plants - amorphous silicon, cadmium telluride, and copper indium diselenide are being built for 1996, 1997 production with greatly reduced costs; (3) government subsidized volume orders for PV in grid-connected houses (Japan, Germany, Switzerland, Italy, and the United States) provide volume (2000+ units per year) that lead to reduced costs; (4) environmental benefits for PV are being applied in Europe and Japan permitting 'early adopters' to enter the market; and (5) government and commercial acceptance of PV building integrated products, especially in Europe, are expanding PV markets. The combination of these forces lead to the prediction that an 'accelerated' market mode could start in the year 2000

Optimal design of orientation of PV/T collector with reflectors

International Nuclear Information System (INIS)

Kostic, Lj.T.; Pavlovic, T.M.; Pavlovic, Z.T.

2010-01-01

Hybrid conversion of solar radiation implies simultaneous solar radiation conversion into thermal and electrical energy in the PV/Thermal collector. In order to get more thermal and electrical energy, flat solar radiation reflectors have been mounted on PV/T collector. To obtain higher solar radiation intensity on PV/T collector, position of reflectors has been changed and optimal position of reflectors has been determined by both experimental measurements and numerical calculation so as to obtain maximal concentration of solar radiation intensity. The calculated values have been found to be in good agreement with the measured ones, both yielding the optimal position of the flat reflector to be the lowest (5 o ) in December and the highest (38 o ) in June. In this paper, the thermal and electrical efficiency of PV/T collector without reflectors and with reflectors in optimal position have been calculated. Using these results, the total efficiency and energy-saving efficiency of PV/T collector have been determined. Energy-saving efficiency for PV/T collector without reflectors is 60.1%, which is above the conventional solar thermal collector, whereas the energy-saving efficiency for PV/T collector with reflectors in optimal position is 46.7%, which is almost equal to the values for conventional solar thermal collector. Though the energy-saving efficiency of PV/T collector decreases slightly with the solar radiation intensity concentration factor, i.e. the thermal and electrical efficiency of PV/T collector with reflectors are lower than those of PV/T collector without reflectors, the total thermal and electrical energy generated by PV/T collector with reflectors in optimal position are significantly higher than total thermal and electrical energy generated by PV/T collector without reflectors.

Battery storage for PV power systems: an overview

Energy Technology Data Exchange (ETDEWEB)

Chaurey, A; Deambi, S [Tata Energy Research Inst., New Delhi (India)

1992-06-01

Batteries used in photovoltaic applications are required to have particular properties in order to minimize the system cost, in addition to meeting stringent reliability requirements associated with PV system installations. The battery sizing, installations, operation and maintenance, thus, are fundamentally different from those used in several other energy storage applications. The current paper gives an overview of battery systems commonly used in PV installation, as well as several new options which are found suitable or have been modified suitably to meet PV energy storage requirements. The systems are discussed briefly with respect to their construction, performance characteristics and compatibility with PV systems. The battery sizing procedures are also reviewed. (Author).

Assessing the PV business opportunities in Greece

International Nuclear Information System (INIS)

Patlitzianas, Konstantinos D.; Skylogiannis, Georgios K.; Papastefanakis, Dimitrios

2013-01-01

Highlights: • An approach of qualitative judgments for the PV opportunities through the assessing of the licenses’ value in Greece. • It can be supplied in other countries by applying different weights to the criteria. • It can be used by everyone in order to find a suitable PV investment without the need of experts in the field. - Abstract: Greece, as a member of the European Union (EU), has undertaken the obligation to meet the expected goals for the penetration of Renewable Energy Sources (RES) in the national energy balance in compliance with “20–20–20” goals (20% of the Gross Energy Consumption and 40% of the Gross Electricity Consumption should be covered by RES). Although the development of RES, and particularly of Photovoltaic (PV), in Greece during the last years has presented a satisfactory growth, the country is still far away from the above goals. The main reason for this delay is that – except the financial crisis – many licenses are inactive and waiting funding in order to be utilized. Additionally, the latest law (L.4152/2013) has forbidden the interconnection of new PV power Plants to the grid until the end of 2013. The above fact determines the significance of the existing PV Licenses in achieving the national goals. The aim of this paper is to present an integrated approach of qualitative judgments for the PV business opportunities through the assessing of the licenses’ value in Greece. The approach, which is based on a Multi Criteria Decision Making (MCDM) theory of quantifying multiple qualitative judgments, takes into account the real factors which can affect the expected production and cost of the PV installation and therefore the RoI (Return of Investment)

Addressing firefighter safety around solar PV systems

Energy Technology Data Exchange (ETDEWEB)

Harris, B. [Sustainable Energy Technologies, Calgary, AB (Canada)

2010-11-15

The article discussed new considerations for installing photovoltaic (PV) systems that address the needs of fire service personnel. The presence of a PV system presents a multitude of dangers for firefighters, including electrical shock, the inhalation of toxic gases from being unable to cut a hole through the roof, falling debris and flying glass, and dead loading on a compromised structure and tripping on conduits. Mapping systems should be modified so that buildings with PV systems are identified for first responders, including firefighters who should learn that solar modules present an electrical hazard during the day but not at night; covering PV modules with foam or salvage covers may not shut the system down to a safe level; it takes a few moments for the power in PV modules to reduce to zero; and PV modules or conduit should never be cut, broke, chopped, or walked upon. The California Department of Forestry and Fire Protection recommends creating pathways and allowing easier access to the roof by setting the modules back from roof edges, creating a structurally sound pathway for firefighters to walk on and space to cut ventilation holes. However, the setback rule makes the economics of solar installation less viable for residential applications. The technological innovations aimed at addressing system safety all focus on limiting firefighter contact with live electrical components to within the extra-low-voltage (ELV) band. Some of the inverters on the market that support ELV system architecture were described. 1 fig.

Performance Parameters for Grid-Connected PV Systems

Energy Technology Data Exchange (ETDEWEB)

Marion, B.; Adelstein, J.; Boyle, K.; Hayden, H.; Hammond, B.; Fletcher, T.; Canada, B.; Narang, D.; Shugar, D.; Wenger, H.; Kimber, A.; Mitchell, L.; Rich, G.; Townsend, T.

2005-02-01

The use of appropriate performance parameters facilitates the comparison of grid-connected photovoltaic (PV) systems that may differ with respect to design, technology, or geographic location. Four performance parameters that define the overall system performance with respect to the energy production, solar resource, and overall effect of system losses are the following: final PV system yield, reference yield, performance ratio, and PVUSA rating. These performance parameters are discussed for their suitability in providing desired information for PV system design and performance evaluation and are demonstrated for a variety of technologies, designs, and geographic locations. Also discussed are methodologies for determining system a.c. power ratings in the design phase using multipliers developed from measured performance parameters.The use of appropriate performance parameters facilitates the comparison of grid-connected photovoltaic (PV) systems that may differ with respect to design, technology, or geographic location. Four performance parameters that define the overall system performance with respect to the energy production, solar resource, and overall effect of system losses are the following: final PV system yield, reference yield, performance ratio, and PVUSA rating. These performance parameters are discussed for their suitability in providing desired information for PV system design and performance evaluation and are demonstrated for a variety of technologies, designs, and geographic locations. Also discussed are methodologies for determining system a.c. power ratings in the design phase using multipliers developed from measured performance parameters.

A Software Tool for Optimal Sizing of PV Systems in Malaysia

Directory of Open Access Journals (Sweden)

Tamer Khatib

2012-01-01

Full Text Available This paper presents a MATLAB based user friendly software tool called as PV.MY for optimal sizing of photovoltaic (PV systems. The software has the capabilities of predicting the metrological variables such as solar energy, ambient temperature and wind speed using artificial neural network (ANN, optimizes the PV module/ array tilt angle, optimizes the inverter size and calculate optimal capacities of PV array, battery, wind turbine and diesel generator in hybrid PV systems. The ANN based model for metrological prediction uses four meteorological variables, namely, sun shine ratio, day number and location coordinates. As for PV system sizing, iterative methods are used for determining the optimal sizing of three types of PV systems, which are standalone PV system, hybrid PV/wind system and hybrid PV/diesel generator system. The loss of load probability (LLP technique is used for optimization in which the energy sources capacities are the variables to be optimized considering very low LLP. As for determining the optimal PV panels tilt angle and inverter size, the Liu and Jordan model for solar energy incident on a tilt surface is used in optimizing the monthly tilt angle, while a model for inverter efficiency curve is used in the optimization of inverter size.

Control of a Multi-Functional Inverter for Grid Integration of PV and Battery Energy Storage System

DEFF Research Database (Denmark)

Mousazadeh, Seyyed Yousef; Firoozabadi, Mehdi Savaghebi; Beirami, A.

2015-01-01

This paper presents a multi-functional control of a DC/AC inverter for Power Quality compensation of nonlinear and unequal local loads and grid integration of hybrid photovoltaic (PV) and battery energy storage systems. Multi-layer neural network estimator and a DC/DC converter are used for maximum...... is used for delivering desire power to the grid. For compensation aim, instantaneous active and reactive power theory (p-q) is used. Via the algorithm, the DC/AC inverter not only can be controlled to inject the power of battery and PV, but also it is used as shunt active filter for compensating unequal...... power point tracking (MPPT) of PV array. The power system is 3-phase 4-wires and the DC/AC inverter is chosen 4-leg three phase inverter which has good performance in presence of zero sequence components. Battery energy storage is connected to PV system in common DC bus and a power management strategy...

Emissions and encapsulation of cadmium in CdTe PV modules during fires

Energy Technology Data Exchange (ETDEWEB)

Fthenakis, V.M.; Fuhrmann, M.; Heiser, J.; Fitts, J.; Wang, W. [Brookhaven National Laboratory, Upton, NY (United States). Environmental Sciences Dept.; Lanzirotti, A. [University of Chicago, Chicago, IL (United States). Consortium for Advanced Radiation Resources

2005-12-15

Fires in residential and commercial properties are not uncommon. If such fires involve the roof, photovoltaic arrays mounted on the roof will be exposed to the flames. The amount of cadmium that can be released in fires involving CdTe PV and the magnitude of associated health risks has been debated. The current study aims in delineating this issue. Previous thermogravimetric studies of CdTe, involved pure CdTe and single-glass PV modules. The current study is based on glass-glass CdTe PV modules which are the only ones in the market. Pieces of commercial CdTe photovoltaic (PV) modules, sizes 25x3 cm, were heated to temperatures up to 1100{sup o}C to simulate exposure to residential and commercial building fires. The temperature rate and duration in these experiments were defined according to standard protocols. Four different types of analysis were performed to investigate emissions and redistribution of elements in the matrix of heated CdTe PV modules: (1) measurements of sample weight loss as a function of temperature; (2) analyses of Cd and Te in the gaseous emissions; (3) Cd distribution in the heated glass using synchrotron X-ray fluorescence microprobe analysis; and (4) chemical analysis for Cd and Te in the acid-digested glass. These experiments showed that almost all (i.e., 99.5%) of the cadmium content of CdTe PV modules was encapsulated in the molten glass matrix; a small amount of Cd escaped from the perimeter of the samples before the two sheets of glass melted together. Adjusting for this loss in full-size modules, results in 99.96% retention of Cd. Multiplying this with the probability of occurrence for residential fires in wood-frame houses in the US (e.g., 10{sup -4}), results in emissions of 0.06 mg/GWh; the probability of sustained fires and subsequent emissions in adequately designed and maintained utility systems appears to be zero. (Author)

Delta Power Control Strategy for Multistring Grid-Connected PV Inverters

DEFF Research Database (Denmark)

Sangwongwanich, Ariya; Yang, Yongheng; Blaabjerg, Frede

2017-01-01

, is required for grid support (e.g., during frequency deviation). In this paper, a cost-effective solution to realize delta power control (DPC) for grid-connected PV systems is presented, where the multistring PV inverter configuration is adopted. This control strategy is a combination of maximum power point...... tracking (MPPT) and constant power generation (CPG) modes. In this control scheme, one PV string operating in the MPPT mode estimates the available power, whereas the other PV strings regulate the total PV power by the CPG control strategy in such a way that the delta power constraint for the entire PV...... system is achieved. Simulations and experiments have been performed on a 3-kW single-phase grid-connected PV system. The results have confirmed the effectiveness of the proposed DPC strategy, where the power reserve according to the delta power constraint is achieved under several operating conditions....

The prospects for cost competitive solar PV power

International Nuclear Information System (INIS)

Reichelstein, Stefan; Yorston, Michael

2013-01-01

New solar Photovoltaic (PV) installations have grown globally at a rapid pace in recent years. We provide a comprehensive assessment of the cost competitiveness of this electric power source. Based on data available for the second half of 2011, we conclude that utility-scale PV installations are not yet cost competitive with fossil fuel power plants. In contrast, commercial-scale installations have already attained cost parity in the sense that the generating cost of power from solar PV is comparable to the retail electricity prices that commercial users pay, at least in certain parts of the U.S. This conclusion is shown to depend crucially on both the current federal tax subsidies for solar power and an ideal geographic location for the solar installation. Projecting recent industry trends into the future, we estimate that utility-scale solar PV facilities are on track to become cost competitive by the end of this decade. Furthermore, commercial-scale installations could reach “grid parity” in about ten years, if the current federal tax incentives for solar power were to expire at that point. - Highlights: ► Assessment of the cost competitiveness of new solar Photovoltaic (PV) installations. ► Utility-scale PV installations are not yet cost competitive with fossil fuel power plants. ► Commercial-scale installations have already attained cost parity in certain parts of the U.S. ► Utility-scale solar PV facilities are on track to become cost competitive by the end of this decade

Overview of Recent Grid Codes for PV Power Integration

DEFF Research Database (Denmark)

Craciun, Bogdan-Ionut; Kerekes, Tamas; Sera, Dezso

2012-01-01

The challenge to bring down the cost of produced photovoltaic (PV) power had a major impact on the PV market and in consequence the grid operators experienced higher and higher PV power penetration. The growing share of this decentralized generation plants started to affect the grid stability...

LonWorks as Fieldbus for PV-Installations; LonWorks als Feldbus fuer PV-Anlagen

Energy Technology Data Exchange (ETDEWEB)

Bergen, Ch. von

2003-07-01

The growing market for photovoltaics increasingly requires suitable quality controls covering plant operators, planners and installers, as well as the electric utilities. Additionally, the interest of the general public in the behaviour of photovoltaic (PV) plants is growing. This includes information from everyday practice. Alongside data retrieval, other themes such as the operative management of the unit and energy management become increasingly important for grid-connected PV systems. Todays measuring systems are not compatible with each other. Data communication between different PV plants with computer-aided analysis- and visualisation programmes is very complicated. LonWorks was introduced by Motorola and Toshiba in 1991. Today it leads the world market for field bus systems. With plug and play, components by several manufacturers can easily be incorporated into a LonWorks network. Today more than 3,500 companies use LonWorks technology. The goal of this project is to introduce the very popular LonWorks technology as a new standard for PV applications. The first objective was to develop a LonWorks interface for our Convert inverters and to connect them into a small network. In a second step we installed a LonWorks system at the 260 kW{sub p} PV plant 'Felsenau' in Berne, Switzerland. All 68 inverters are controlled over power line with LonWorks. The on-site PC acts as LonWorks DataServer and making remote information monitoring and data gathering possible. As soon as a functional error occurs, an alarm will be transmitted via modem to the SMSC (Short Message Service Centre). After two years of operation we can say that all expectations were fulfilled by our new system. Knowledge gained from this project has shown that LonWorks has lived up its considerable promise and can be regarded as a high-quality piece of technology. Integration into an overall system is technically very easy. To do this, however, relatively expensive software solutions have

Interconnecting PV on New York City's Secondary Network Distribution System

Energy Technology Data Exchange (ETDEWEB)

Anderson, K; Coddington, M; Burman, K; Hayter, S; Kroposki, B; Watson, and A

2009-11-01

less expensive distributed PV system interconnections. To assess ways to improve the interconnection process, NREL conducted a four-part study with support from DOE. The NREL team then compiled the final reports from each study into this report. In Section 1PV Deployment Analysis for New York City we analyze the technical potential for rooftop PV systems in the city. This analysis evaluates potential PV power production in ten Con Edison networks of various locations and building densities (ranging from high density apartments to lower density single family homes). Next, we compare the potential power production to network loads to determine where and when PV generation is most likely to exceed network load and disrupt network protection schemes. The results of this analysis may assist Con Edison in evaluating future PV interconnection applications and in planning future network protection system upgrades. This analysis may also assist other utilities interconnecting PV systems to networks by defining a method for assessing the technical potential of PV in the network and its impact on network loads. Section 2. A Briefing for Policy Makers on Connecting PV to a Network Grid presents an overview intended for nontechnical stakeholders. This section describes the issues associated with interconnecting PV systems to networks, along with possible solutions. Section 3. Technical Review of Concerns and Solutions to PV Interconnection in New York City summarizes common concerns of utility engineers and network experts about interconnecting PV systems to secondary networks. This section also contains detailed descriptions of nine solutions, including advantages and disadvantages, potential impacts, and road maps for deployment. Section 4. Utility Application Process Reviewlooks at utility interconnection application processes across the country and identifies administrative best practices for efficient PV interconnection.

Solar photovoltaic (PV) energy; latest developments in the building integrated and hybrid PV systems

International Nuclear Information System (INIS)

Zahedi, A.

2006-01-01

Environmental concerns are growing and interest in environmental issues is increasing and the idea of generating electricity with less pollution is becoming more and more attractive. Unlike conventional generation systems, fuel of the solar photovoltaic energy is available at no cost. And solar photovoltaic energy systems generate electricity pollution-free and can easily be installed on the roof of residential as well as on the wall of commercial buildings as grid-connected PV application. In addition to grid-connected rooftop PV systems, solar photovoltaic energy offers a solution for supplying electricity to remote located communities and facilities, those not accessible by electricity companies. The interest in solar photovoltaic energy is growing worldwide. Today, more than 3500MW of photovoltaic systems have been installed all over the world. Since 1970, the PV price has continuously dropped [8]. This price drop has encouraged worldwide application of small-scale residential PV systems. These recent developments have led researchers concerned with the environment to undertake extensive research projects for harnessing renewable energy sources including solar energy. The usage of solar photovoltaic as a source of energy is considered more seriously making future of this technology looks promising. The objective of this contribution is to present the latest developments in the area of solar photovoltaic energy systems. A further objective of this contribution is to discuss the long-term prospect of the solar photovoltaic energy as a sustainable energy supply. [Author

A strategic model for PV dissemination in Thailand

Energy Technology Data Exchange (ETDEWEB)

Hiranvarodom, S. [Rajamangala Inst. of Technology, Dept. of Electrical Engineering, Pathumthani (Thailand); Hill, R. [University of Northumbria, Newcastle Photovoltaics Applications Centre, Newcastle upon Tyne (United Kingdom); O' Keefe, P. [University of Northumbria, Dept. of Geography and Environmental Management, Newcastle upon Tyne (United Kingdom)

1999-07-01

The process of information dissemination is necessary for the successful implementation for photovoltaic (PV) programmes in developing countries, and it is essential to consider the strategies for implementation of a PV project to ensure that it will be successful. This paper proposes a strategic model for PV dissemination in Thailand and discusses the roles of key players in the implementation of the strategy and the responsibilities of these organisations. (Author)

The world PV market 2000: shifting from subsidy to 'fully economic'?

International Nuclear Information System (INIS)

Maycock, Paul

2000-01-01

This article presents an overview of the world grid-connected photovoltaic (PV) market concentrating on the US, Japan and Germany. The PV markets in the three countries are examined, and PV module shipments, the economics of residential PVs in the markets, and forecasts of the grid-connected market are discussed. Details are given of the German 100,000 roofs PV roof subsidy programme to stimulate the residential and commercial grid-connected market. A summary of the grid-connected PV markets in the three countries, and economic information on German grid-connected PV roofs are tabulated

Photovoltaic (PV) contribution to the primary frequency control

International Nuclear Information System (INIS)

Rafa, Adel Hamad

2012-01-01

Photovoltaic (PV) technology is among the most efficient and cost effective renewable energy kinds currently available on the market. The connection of a large number of PVs to the grid may influence the frequency and voltage stability of the power system. This paper proposes load-frequency control technique for system with high penetration of photovoltaic (PV). The proposed controller has been successfully implemented and tested using PSCAD/EMTDC. In this study, the impact of photovoltaic (PV) on frequency stability of the system is studies in detail. This study shows that large penetration of photovoltaic (PV) with load and frequency control has a significant impact on the stability and security level of electrical network.(author)

Photovoltaic-thermal (PV/T) solar collectors: Features and performance modelling

International Nuclear Information System (INIS)

Atienza-Márquez, Antonio; Bruno, Joan Carles; Coronas, Alberto; Korolija, Ivan; Greenough, Richard; Wright, Andy

2017-01-01

Currently, the electrical efficiency of photovoltaic (PV) solar cells ranges between 5–25%. One of the most important parameters that affects the electrical efficiency of a PV collector is the temperature of its cells: the higher temperature, the lower is the efficiency. Photovoltaic/thermal (PV/T) technology is a potential solution to ensure an acceptable solar energy conversion. The PV/T technology produces both electrical and thermal energy simultaneously. It is suitable for low temperature applications (25–40 o C) and overall efficiency increases compared to individual collectors. This paper describes an installation in a single-family house where PV/T collectors are coupled with a ground heat exchanger and a heat pump for domestic hot water and space heating purposes. The aim of this work is twofold. First, the features of the PV/T technology are analyzed. Second, a model of a flat-plate PV/T water collector was developed in TRNSYS in order to analyze collectors performance. (author)

S4 Grid-Connected Single-Phase Transformerless Inverter for PV Application

DEFF Research Database (Denmark)

Ardashir, Jaber Fallah; Siwakoti, Yam Prasad; Sabahi, Mehran

2016-01-01

This paper introduces a new single-phase transformerless inverter for grid-connected photovoltaic systems with low leakage current. It consists of four power switches, two diodes, two capacitors and a filter at the output stage. The neutral of the grid is directly connected to the negative terminal...... size, low cost, flexible grounding configuration and higher efficiency. The operating principle and analysis of the proposed circuit are presented in details. Experimental results of a 500 W prototype are demonstrated to validate the proposed topology and the overall concept. The results obtained...... clearly verify the performance of the proposed inverter and its practical application for grid-connected PV systems....

Impact of Rooftop Solar PV on Residential Distribution Network

DEFF Research Database (Denmark)

Bhattarai, Bishnu Prasad; Bak-Jensen, Birgitte; Pillai, Jayakrishnan Radhakrishna

Increased environmental awareness in recent years has encouraged rapid growth of renewable energy sources especially solar PV and wind. Among them, small scale solar PV has been gaining more momentum especially at residential level. Even today moderate penetration of grid tied rooftop solar PV has...... become reality in many countries. In spite of various benefits, higher penetration of rooftop PVs might come up with number of detrimental effects, with power quality and overcurrent protection being the major ones. Therefore, it is reasonable to quantify both drawback and benefits of rooftop PV...

Improving the efficiency of photovoltaic (PV) panels by oil coating

International Nuclear Information System (INIS)

Abd-Elhady, M.S.; Fouad, M.M.; Khalil, T.

2016-01-01

Highlights: • It is possible to improve the efficiency of PV panels by increasing the amount of light transmitted to the panel. • Coating PV panels by a fine layer of Labovac oil increases the amount of sun light transmitted to the panel. • Coating PV panels by a fine layer of Labovac oil increases the power output of the panel. • Coating PV panels with a layer of Labovac oil has to be applied in cold countries and not in hot regions. - Abstract: The objective of this research is to develop a new technique for improving the efficiency of Photovoltaic (PV) panels. This technique is done by coating the front surface of the PV panel by a fine layer of oil in order to increase the amount of light transmitted to the panel, and consequently its efficiency. Different types of oils are examined, including both mineral oils and natural oils. In case of mineral oils; vacuum pump oil (Labovac oil), engine oil (Mobil oil) and brake oil (Abro oil) are examined, while in case of natural oils; olive and sunflower oils are examined. An experimental setup has been developed to examine the performance of the PV panels as a function of oil coatings. The experimental setup consists of an artificial sun, the PV panel under investigation, a cooling system and a measuring system to measure the performance of the panel. It has been found that coating the PV panel with a fine layer of Labovac oil, ∼1 mm thick, improves the efficiency of the PV panel by more than 20%, and this is due to the high transmissivity of the Labovac oil compared to other oils. However, the Labovac oil has a drawback which is overheating of the panel due to its high transmissivity. Coating of PV panels with a fine layer of Labovac oil should be done only in cold regions, in order to avoid the heating effect that can decrease the power output of PV panels.

Assessing the influence of the temporal resolution of electrical load and PV generation profiles on self-consumption and sizing of PV-battery systems

International Nuclear Information System (INIS)

Beck, T.; Kondziella, H.; Huard, G.; Bruckner, T.

2016-01-01

Highlights: • MILP optimization model for operation and investment of PV-battery systems. • Use of high resolution (10 s) electrical household load and PV generation profiles. • Analysis of influence of temporal resolution on self-consumption and optimal sizing. • Electrical load profile characteristics influence required temporal resolution. - Abstract: The interest in self-consumption of electricity generated by rooftop photovoltaic systems has grown in recent years, fueled by decreasing levelized costs of electricity and feed-in tariffs as well as increasing end customer electricity prices in the residential sector. This also fostered research on grid-connected PV-battery storage systems, which are a promising technology to increase self-consumption. In this paper a mixed-integer linear optimization model of a PV-battery system that minimizes the total discounted operating and investment costs is developed. The model is employed to study the effect of the temporal resolution of electrical load and PV generation profiles on the rate of self-consumption and the optimal sizing of PV and PV-battery systems. In contrast to previous studies high resolution (10 s) measured input data for both PV generation and electrical load profiles is used for the analysis. The data was obtained by smart meter measurements in 25 different households in Germany. It is shown that the temporal resolution of load profiles is more critical for the accuracy of the determination of self-consumption rates than the resolution of the PV generation. For PV-systems without additional storage accurate results can be obtained by using 15 min solar irradiation data. The required accuracy for the electrical load profiles depends strongly on the load profile characteristics. While good results can be obtained with 60 s for all electrical load profiles, 15 min data can still be sufficient for load profiles that do not exhibit most of their electricity consumption at power levels above 2 k

Analysis of concentrating PV-T systems for the commercial/industrial sector. Volume III. Technical issues and design guidance

Energy Technology Data Exchange (ETDEWEB)

Schwinkendorf, W.E.

1984-09-01

This report provide appropriate guidance for addressing the major technical issues associated with the design and installation of a photovoltaic-thermal (PV-T) system. Nomographs are presented for developing preliminary sizing and costing, and issues associated with specific components and the overall design of the electrical and mechanical system are discussed. SAND82-7157/2 presents a review of current PV-T technology and operating systems and a study of potential PV-T applications. Detailed PV-T system designs for three selected applications and the results of a trade-off study for these applications are presented in SAND82-7157/4. A summary of the major results of this entire study and conclusions concerning PV-T systems and applications is presented in SAND82-7157/1.

Experimental and numerical performance analysis of a converging channel heat exchanger for PV cooling

International Nuclear Information System (INIS)

Baloch, Ahmer A.B.; Bahaidarah, Haitham M.S.; Gandhidasan, Palanichamy; Al-Sulaiman, Fahad A.

2015-01-01

Highlights: • Effect of varying converging angle on temperature characteristics of PV surface studied. • Optical, CFD, thermal, and electrical models developed for the analysis. • Experimental measurements carried out for two configurations for June and December. • Using this cooling technique, maximum cell temperature reduction was 57.8%. • Maximum percentage improvement in power output was 35.5%. - Abstract: An experimental and numerical investigation of a cooling technique called as converging channel cooling intended to achieve low and uniform temperature on the surface of PV panel is presented in this paper. Experimental evaluation for an uncooled PV system and a converging channel cooled PV system was carried out subjected to the hot climate of Saudi Arabia for the month of June and December. Detailed modeling was performed using numerical analysis to investigate the effect of changing the converging angle on the thermal characteristics of the PV system. Based on the developed model, two degrees angle showed the best performance in terms of temperature distribution and average cell temperature with a standard deviation of 0.91 °C. A comprehensive system model was developed to assess the performance of PV systems numerically by coupling the optical, radiation, thermal, computational fluid dynamics, and electrical model. Thermal measurements for an uncooled PV showed cell temperature as high as 71.2 °C and 48.3 °C for the month of June and December, respectively. By employing converging cooling, cell temperature was reduced significantly to 45.1 °C for June and to 36.4 °C for December. Maximum percentage improvement in power output was 35.5% whereas maximum percentage increase in the conversion efficiency was 36.1% when compared to the performance of an uncooled PV system. For cost feasibility of an uncooled and cooled PV system, levelized cost of energy (LCE) analysis was performed using the annual energy yield simulation for both systems. LCE

Design procedures of hybrid PV/SMES system

International Nuclear Information System (INIS)

Hamad, Ismail; El-Sayas, M. A.

2006-01-01

This paper presents accurate procedures to determine the design parameters of an autonomous hybrid PV/SMES system. Integrating Superconductive magnetic energy storage as a recent storage technology with photovoltaic power system enhances the PV output utilization during the solar radiation fluctuations period. this is because of SMES fast response to any PV output fluctuation. The load demand is supplied either from PV plant or through SMES or from both. Imposed to the technical and economical constrains, the optimum solar cells area and the proper capacity and rating of SMES system are assessed. Regarding solar radiation profile, clear and cloudy days are accurately considered for investigation. Three indices are suggested to express the cloudy and fluctuations conditions. These indices represent the non-utilized PV energy due to clouds (x), fluctuation period (T f ) and location of fluctuations period(t s t). The incremental changes in the design parameters are computed for any variation in these indices. Differentiation between the role of BS and SMES in affecting the results is determined and quantitatively analyzed. The results of clear day condition with SMES are the bas quantities for these changes. Complete analysis of the most effective parameters is presented. Eventually, mathematical models are deduced for each parameter which assists in predicting its behavior against the independent variable.(Author)

The Value of Transparency in Distributed Solar PV Markets | Solar Research

Science.gov (United States)

suggest that PV customers benefit from gaining access to more PV quotes. Context Prospective PV customers are relatively non-transparent; customers are largely unaware of market prices and may not obtain the lowest available price. PV customers that use quote aggregators-third-party companies that collect quotes

Review of PV Inverter Technology Cost and Performance Projections

Energy Technology Data Exchange (ETDEWEB)

Navigant Consulting Inc.

2006-01-01

The National Renewable Energy Laboratory (NREL) has a major responsibility in the implementation of the U.S. Department of Energy's (DOE's) Solar Energy Technologies Program. Sandia National Laboratories (SNL) has a major role in supporting inverter development, characterization, standards, certifications, and verifications. The Solar Energy Technologies Program recently published a Multiyear Technical Plan, which establishes a goal of reducing the Levelized Energy Cost (LEC) for photovoltaic (PV) systems to $0.06/kWh by 2020. The Multiyear Technical Plan estimates that, in order to meet the PV system goal, PV inverter prices will need to decline to $0.25-0.30 Wp by 2020. DOE determined the need to conduct a rigorous review of the PV Program's technical and economic targets, including the target set for PV inverters. NREL requested that Navigant Consulting Inc.(NCI) conduct a review of historical and projected cost and performance improvements for PV inverters, including identification of critical barriers identified and the approaches government might use to address them.

Solar Photovoltaic (PV) Distributed Generation Systems - Control and Protection

Science.gov (United States)

Yi, Zhehan

This dissertation proposes a comprehensive control, power management, and fault detection strategy for solar photovoltaic (PV) distribution generations. Battery storages are typically employed in PV systems to mitigate the power fluctuation caused by unstable solar irradiance. With AC and DC loads, a PV-battery system can be treated as a hybrid microgrid which contains both DC and AC power resources and buses. In this thesis, a control power and management system (CAPMS) for PV-battery hybrid microgrid is proposed, which provides 1) the DC and AC bus voltage and AC frequency regulating scheme and controllers designed to track set points; 2) a power flow management strategy in the hybrid microgrid to achieve system generation and demand balance in both grid-connected and islanded modes; 3) smooth transition control during grid reconnection by frequency and phase synchronization control between the main grid and microgrid. Due to the increasing demands for PV power, scales of PV systems are getting larger and fault detection in PV arrays becomes challenging. High-impedance faults, low-mismatch faults, and faults occurred in low irradiance conditions tend to be hidden due to low fault currents, particularly, when a PV maximum power point tracking (MPPT) algorithm is in-service. If remain undetected, these faults can considerably lower the output energy of solar systems, damage the panels, and potentially cause fire hazards. In this dissertation, fault detection challenges in PV arrays are analyzed in depth, considering the crossing relations among the characteristics of PV, interactions with MPPT algorithms, and the nature of solar irradiance. Two fault detection schemes are then designed as attempts to address these technical issues, which detect faults inside PV arrays accurately even under challenging circumstances, e.g., faults in low irradiance conditions or high-impedance faults. Taking advantage of multi-resolution signal decomposition (MSD), a powerful signal

Lifetime Evaluation of PV Inverters considering Panel Degradation Rates and Installation Sites

DEFF Research Database (Denmark)

Sangwongwanich, Ariya; Yang, Yongheng; Sera, Dezso

2017-01-01

The PV inverter lifetime is affected by the installed sites related to different solar irradiance and ambient temperature profiles. In fact, the installation site also affects the PV panel degradation rate, and thus the long-term power production. Prior-art lifetime analysis in PV inverters has...... not yet investigated the impact of panel degradation. This paper thus evaluates the lifetime of PV inverters considering panel degradation rates and installation sites. Evaluations have been carried out on PV systems installed in Denmark and Arizona. The results reveal that the PV panel degradation rate...... has a considerable impact on the PV inverter lifetime, especially in the hot climate (e.g., Arizona), where the panel degrades at a faster rate. In that case, the PV inverter lifetime estimation can be deviated by 54%, if the impact of PV panel degradation is not taken into account....

Associations of Eu(III) with Gram-negative bacteria, Alcaligenes faecalis, Shewanella putrefaciens, and Paracoccus denitrificans

International Nuclear Information System (INIS)

Ozaki, Takuo; Ohnuki, Toshihiko; Kimura, Takaumi; Francis, Arokiasamy J.

2005-01-01

We studied the association of Eu(III) with Gram-negative bacteria, Alcaligenes faecalis, Shewanella putrefaciens, and Paracoccus denitrificans by a batch method and time-resolved laser-induced fluorescence spectroscopy (TRLFS). The kinetics study showed that the Eu(III) adsorption on the bacteria rapidly proceeded. The Eu(III) adsorption on A. faecalis and P. denitrificans at pHs 3, 4, and 5, and that on S.putrefaciens at pHs 4 and 5 reached a maximum within 5 minutes after contact. For P. denitrificans, the percent adsorption of Eu(III) decreased after the maximum percent adsorption was attained, which suggests the existence of exudates with an affinity with Eu(III). TRLFS showed that the coordination of Eu(III) on these bacteria is multidentate through an inner-spherical process. The ligand field of Eu(III) on P. denitrificans was as strong as the ones observed for halophilic microorganisms, while that of A. faecalis and S. putrefaciens was the typical one observed for non-halophilic microorganisms. The coordination environment of Eu(III) on the bacteria differed from each other, though they are categorized as Gram-negative bacteria with the similar cell wall components. (author)

Optimization of a PV/T (photovoltaic/thermal) active solar still

International Nuclear Information System (INIS)

Saeedi, F.; Sarhaddi, F.; Behzadmehr, A.

2015-01-01

In this paper, the optimization of a PV/T (photovoltaic/thermal) active solar still is carried out. Analytical expressions for glass cover temperature, basin temperature, brackish water temperature and fresh water productivity are obtained by writing energy balance for different components of PV/T active solar still. The output electrical power of PV/T active solar still is calculated by four-parameter I–V (current–voltage) model. Objective function in present study is the energy efficiency of PV/T active solar still. A computer simulation program has been developed in order to obtain thermal and electrical parameters, respectively. The simulation results of the present study are in fair agreement with the experimental data of previous literatures. Finally, the optimization of PV/T active solar still has been carried out and the optimized value of mass flow rate, number of PV/T collector and the objective function have been obtained. Furthermore, the effect of various operating parameters on energy efficiency have been investigated. - Highlights: • The comprehensive optimization of a PV/T active solar still is carried out. • Present study is based on numerical simulation. • A modified energy efficiency for PV/T active solar still is obtained. • The effect of design and operating parameters is investigated on energy efficiency

Iron Triggers λSo Prophage Induction and Release of Extracellular DNA in Shewanella oneidensis MR-1 Biofilms

OpenAIRE

Binnenkade, Lucas; Teichmann, Laura; Thormann, Kai M.

2014-01-01

Prophages are ubiquitous elements within bacterial chromosomes and affect host physiology and ecology in multiple ways. We have previously demonstrated that phage-induced lysis is required for extracellular DNA (eDNA) release and normal biofilm formation in Shewanella oneidensis MR-1. Here, we investigated the regulatory mechanisms of prophage λSo spatiotemporal induction in biofilms. To this end, we used a functional fluorescence fusion to monitor λSo activation in various mutant backgrounds...

Design of direct solar PV driven air conditioner

KAUST Repository

Huang, Bin-Juine

2015-12-05

© 2015 Elsevier Ltd. Solar air conditioning system directly driven by stand-alone solar PV is studied. The air conditioning system will suffer from loss of power if the solar PV power generation is not high enough. It requires a proper system design to match the power consumption of air conditioning system with a proper PV size. Six solar air conditioners with different sizes of PV panel and air conditioners were built and tested outdoors to experimentally investigate the running probabilities of air conditioning at various solar irradiations. It is shown that the instantaneous operation probability (OPB) and the runtime fraction (RF) of the air conditioner are mainly affected by the design parameter rpL (ratio of maximum PV power to load power). The measured OPB is found to be greater than 0.98 at instantaneous solar irradiation IT > 600 W m-2 if rpL > 1.71 RF approaches 1.0 (the air conditioner is run in 100% with solar power) at daily-total solar radiation higher than 13 MJ m-2 day-1, if rpL > 3.

PV supply chain growing pains

Energy Technology Data Exchange (ETDEWEB)

Wilkins, A. [Matrix Energy Inc., Montreal, PQ (Canada)

2010-11-15

This article discussed issues involving the supply chain for photovoltaic (PV) equipment that is emerging in Ontario as a result of the Feed-in-Tariff (FIT) program that was launched in late 2009. The rapidly developing PV supply chain may not be taking a sustainable path. The domestic-content requirement is making manufacturers outlay capital to set up manufacturing in Ontario without reliable market data. Only a small number of dealer/installers have any meaningful experience designing and installing grid-tie PV. Until recently, wholesale distributors designed and supplied most grid-tie PV systems in Canada, and solar dealers/installers or electricians or electrical contractors did the installation. Instead of selling directly to dealer/installers, solar manufacturers should develop strong relationships with wholesalers, who have system design experience and product training. This would allow manufacturers to focus on their core strength, reach more customers, and keep lower inventory levels. Wholesale distributors in turn provide dealer/installers with expertise in product and system design, training from a range of manufacturers, marketing and logistics support, and immediate access to inventory. Manufacturers generally lack appropriate accounting, engineering, marketing, and logistics services to deal with a multitude of active accounts, and they are not structured to work with architects and engineers to do complete system design. Partnering with wholesale distributors allows manufacturers to take on the residential and small-scale commercial sectors by building brand awareness and increasing market share and sales across Canada. 2 figs.

PV supply chain growing pains

International Nuclear Information System (INIS)

Wilkins, A.

2010-01-01

This article discussed issues involving the supply chain for photovoltaic (PV) equipment that is emerging in Ontario as a result of the Feed-in-Tariff (FIT) program that was launched in late 2009. The rapidly developing PV supply chain may not be taking a sustainable path. The domestic-content requirement is making manufacturers outlay capital to set up manufacturing in Ontario without reliable market data. Only a small number of dealer/installers have any meaningful experience designing and installing grid-tie PV. Until recently, wholesale distributors designed and supplied most grid-tie PV systems in Canada, and solar dealers/installers or electricians or electrical contractors did the installation. Instead of selling directly to dealer/installers, solar manufacturers should develop strong relationships with wholesalers, who have system design experience and product training. This would allow manufacturers to focus on their core strength, reach more customers, and keep lower inventory levels. Wholesale distributors in turn provide dealer/installers with expertise in product and system design, training from a range of manufacturers, marketing and logistics support, and immediate access to inventory. Manufacturers generally lack appropriate accounting, engineering, marketing, and logistics services to deal with a multitude of active accounts, and they are not structured to work with architects and engineers to do complete system design. Partnering with wholesale distributors allows manufacturers to take on the residential and small-scale commercial sectors by building brand awareness and increasing market share and sales across Canada. 2 figs.

Generation of large-scale PV scenarios using aggregated power curves

DEFF Research Database (Denmark)

Nuño Martinez, Edgar; Cutululis, Nicolaos Antonio

2017-01-01

The contribution of solar photovoltaic (PV) power to the generation is becoming more relevant in modern power system. Therefore, there is a need to model the variability large-scale PV generation accurately. This paper presents a novel methodology to generate regional PV scenarios based...... on aggregated power curves rather than traditional physical PV conversion models. Our approach is based on hourly mesoscale reanalysis irradiation data and power measurements and do not require additional variables such as ambient temperature or wind speed. It was used to simulate the PV generation...... on the German system between 2012 and 2015 showing high levels of correlation with actual measurements (93.02–97.60%) and small deviations from the expected capacity factors (0.02–1.80%). Therefore, we are confident about the ability of the proposed model to accurately generate realistic large-scale PV...

Optimal design of NPC and Active-NPC transformerless PV inverters

DEFF Research Database (Denmark)

Saridakis, Stefanos; Koutroulis, Eftichios; Blaabjerg, Frede

2012-01-01

Targeting at a cost-effective deployment of grid-connected PhotoVoltaic (PV) systems, this paper presents a new methodology for the optimal design of transformerless PV inverters, which are based on the Neutral Point Clamped (NPC) and the Active-Neutral Point Clamped (ANPC) topologies. The design...... optimization results demonstrate that a different set of optimal values of the PV inverter switching frequency and output filter components are derived for the NPC and ANPC topologies, respectively, as well as for each of the PV inverter installation sites under study. The NPC and ANPC PV inverter structures......, which are derived using the proposed design optimization methodology exhibit lower Levelized Cost Of generated Electricity (LCOE) and manufacturing cost and they are simultaneously capable to inject more energy into the electric grid than the corresponding non-optimized PV inverters. Thus, the proposed...

A Novel Frequency Restoring Strategy of Hydro-PV Hybrid Microgrid

DEFF Research Database (Denmark)

Wei, Feng; Kai, Sun; Guan, Yajuan

2014-01-01

. The existence of frequency steady-state error and the slow active power/frequency dynamic response are inevitable. Therefore, a novel frequency restoring strategy for the hydro-PV hybrid microgrid based on the improved hierarchical control of PV systems is proposed in this paper. The output active power of PV......The conventional PV systems based on the voltage inverters only inject dispatched power to the utility grid when they work at a grid-connected mode in the hydro-PV hybrid microgrid. Due to the droop method employed for load sharing between generators, as well as the enormous inertia of system...... systems is controlled by an extra frequency restoring controller resided in the tertiary control level. The frequency steady-state error is eliminated through regulating and rebalancing the power flow between the hydropower and the PV system. The proposed strategy has verified through simulations...

Wide-band gap devices in PV systems - opportunities and challenges

DEFF Research Database (Denmark)

Sintamarean, Nicolae Cristian; Eni, Emanuel-Petre; Blaabjerg, Frede

2014-01-01

have an important role in the cost reduction. To increase the efficiency of PV systems, most of solutions for PV inverters have moved to three-level (3L) structures reaching typical efficiencies of 98% due to low switching losses of 600V Si IGBT or MOSFET and reduced core losses in the filter......The recent developments in wide band-gap devices based GaN and SiC is showing a high impact on the PV-inverter technology, which is strongly influenced by efficiency, power density and cost. Besides the high efficiency of PV inverters, also the mechanical size, the compactness and simple structure......) three-phase PV-inverter topologies in terms of efficiency, thermal loading distribution and costs. Moreover the above mentioned PV-inverters are built and tested in laboratory in order to validate the obtained results....

On the Impacts of PV Array Sizing on the Inverter Reliability and Lifetime

OpenAIRE

Sangwongwanich, Ariya; Yang, Yongheng; Sera, Dezso; Blaabjerg, Frede; Zhou, Dao

2018-01-01

To enable a more wide scale utilization of PV systems, the cost of PV energy should be comparable to or even lower than other energy sources. Due to the relatively low cost of PV modules, oversizing PV arrays becomes a common approach to reduce the cost of PV energy in practice. By doing so, the total energy yield can be increased under weak solar irradiance conditions. However, oversizing the PV array will increase the loading of PV inverters, which may have undesired influence on the PV inv...

PV Module Reliability Workshop | Photovoltaic Research | NREL

Science.gov (United States)

Gok, Cara Fagerholm, David M. Burns, Timothy J. Peshek, Laura S. Bruckman, Roger H. French Backsheet Chen, C. H. Hsueh, W. J. Hsieh Accurately Measuring PV Power Loss Due to Soiling-Michael Gostein and Walters, Stephen Barkaszi Tracking PV Changes: Bridging Between Thin-Film Cells and Modules-Russell

Assessing the need for better forecasting and observability of pv

DEFF Research Database (Denmark)

Alet, Pierre-Jean; Efthymiou, Venizelos; Graditi, Giorgio

2017-01-01

In its review of the challenges and opportunities associated with massive deployment of solar PV generation, the Grid integration working group of the ETIP PV identified forecasting and observability as critical technologies for the planning and operation of the power system with large PV...... penetration. In this white paper ETIP PV set out to spell out in more details what features are needed from these technologies and what is the state of the art....

Performance enhancement of PV cells through micro-channel cooling

Directory of Open Access Journals (Sweden)

Muzaffar Ali

2015-11-01

Full Text Available Efficiency of a PV cell is strongly dependent on its surface temperature. The current study is focused to achieve maximum efficiency of PV cells even in scorching temperatures in hot climates like Pakistan where the cell surface temperatures can even rise up to around 80 ℃. The study includes both the CFD and real time experimental investigations of a solar panel using micro channel cooling. Initially, CFD analysis is performed by developing a 3D model of a Mono-Crystalline cell with micro-channels to analyze cell surface temperature distribution at different irradiance and water flow rates. Afterwards, an experimental setup is developed for performance investigations under the real conditions of an open climate of a Pakistan's city, Taxila. Two 35W panels are manufactured for the experiments; one is based on the standard manufacturing procedure while other cell is developed with 4mm thick aluminum sheet having micro-channels of cross-section of 1mm by 1mm. The whole setup also includes different sensors for the measurement of solar irradiance, cell power, surface temperature and water flow rates. The experimental results show that PV cell surface temperature drop of around 15 ℃ is achieved with power increment of around 14% at maximum applied water flow rate of 3 LPM. Additionally, a good agreement is also found between CFD and experimental results. Therefore, that study clearly shows that a significant performance improvement of PV cells can be achieved through the proposed cell cooling technique.

Sub-synchronous resonance damping using high penetration PV plant

Science.gov (United States)

Khayyatzadeh, M.; Kazemzadeh, R.

2017-02-01

The growing need to the clean and renewable energy has led to the fast development of transmission voltage-level photovoltaic (PV) plants all over the world. These large scale PV plants are going to be connected to power systems and one of the important subjects that should be investigated is the impact of these plants on the power system stability. Can large scale PV plants help to damp sub-synchronous resonance (SSR) and how? In this paper, this capability of a large scale PV plant is investigated. The IEEE Second Benchmark Model aggregated with a PV plant is utilized as the case study. A Wide Area Measurement System (WAMS) based conventional damping controller is designed and added to the main control loop of PV plant in order to damp the SSR and also investigation of the destructive effect of time delay in remote feedback signal. A new optimization algorithm called teaching-learning-based-optimization (TLBO) algorithm has been used for managing the optimization problems. Fast Furrier Transformer (FFT) analysis and also transient simulations of detailed nonlinear system are considered to investigate the performance of the controller. Robustness of the proposed system has been analyzed by facing the system with disturbances leading to significant changes in generator and power system operating point, fault duration time and PV plant generated power. All the simulations are carried out in MATLAB/SIMULINK environment.

Effect of wind speed on performance of a solar-pv array

Science.gov (United States)

Thousands of solar photovoltaic (PV) arrays have been installed over the past few years, but the effect of wind speed on the predicted performance of PV arrays is not usually considered by installers. An increase in wind speed will cool the PV array, and the electrical power of the PV modules will ...

Control of Single-Stage Single-Phase PV inverter

DEFF Research Database (Denmark)

Ciobotaru, Mihai; Teodorescu, Remus; Blaabjerg, Frede

2005-01-01

In this paper the issue of control strategies for single-stage photovoltaic (PV) inverter is addressed. Two different current controllers have been implemented and an experimental comparison between them has been made. A complete control structure for the single-phase PV system is also presented......-forward; - and the grid current controller implemented in two different ways, using the classical proportional integral (PI) and the novel proportional resonant (PR) controllers. The control strategy was tested experimentally on 1.5 kW PV inverter....

Impacts of Solar PV Arrays on Physicochemical Properties of Soil

Science.gov (United States)

Cagle, A.; Choi, C. S.; Macknick, J.; Ravi, S.; Bickhart, R.

2017-12-01

The deployment of renewable energy technologies, such as solar photovoltaics (PV), is rapidly escalating. While PV can provide clean, renewable energy, there is uncertainty regarding its potential positive and/or negative impacts on the local environment. Specifically, its effects on the physicochemical properties of the underlying soil have not been systematically quantified. This study facilitates the discussion on the effects of PV installations related to the following questions: i. How do soil moisture, infiltration rates, total organic carbon, and nitrogen contents vary spatially under a PV array? ii. How do these physicochemical properties compare to undisturbed and adjacent land covered in native vegetation? iii. Are these variations statistically significant to provide insight on whether PV installations have beneficial or detrimental impacts on soil? We address these questions through field measurements of soil moisture, infiltration, grain particle size distribution, total organic carbon, and nitrogen content at a 1-MW solar PV array located at the National Renewable Energy Laboratory in Golden, Colorado. We collect data via multiple transects underneath the PV array as as well as in an adjacent plot of undisturbed native vegetation. Measurements are taken at four positions under the solar panels; the east-facing edge, center area under the panel, west-facing edge, and interspace between panel rows to capture differences in sun exposure as well as precipitation runoff of panels. Measurements are collected before and after a precipitation event to capture differences in soil moisture and infiltration rates. Results of this work can provide insights for research fields associated with the co-location of agriculture and PV installations as well as the long term ecological impacts of solar energy development. Trends in physicochemical properties under and between solar panels can affect the viability of co-location of commercial crops in PV arrays, the

Overview of PV simulation programs. Comparison to PVSUN; Oeversikt av PV simulerings-program. Jaemfoerelse med PVSUN

Energy Technology Data Exchange (ETDEWEB)

Perers, Bengt

2007-02-15

We have found a large number of PV simulation and calculation programmes available on Internet. Many of the programmes are free ware and can still be quite sophisticated like HOMER from NREL and RETSCreen from NRCan. We have made a closer look on the programmes PVSYST, HOMER, RETSCreen and compared to the Swedish PVSUN. All programmes are quite similar in use and in application areas and very easy to use nowadays. The main advantage with PVSUN for Swedish conditions is that it is based on TRNSYS knowledge available on research level. This means that the software can be adapted to new findings from research and development at a relatively low cost. The original question for this project about the availability of easy to use PV/T (photovoltaic/thermal) simulation softwares can be answered no. The PV/T technology is still mainly in the research and development stages.

Voltage stability issues in a distribution grid with large scale PV plant

Energy Technology Data Exchange (ETDEWEB)

Perez, Alvaro Ruiz; Marinopoulos, Antonios; Reza, Muhamad; Srivastava, Kailash [ABB AB, Vaesteraas (Sweden). Corporate Research Center; Hertem, Dirk van [Katholieke Univ. Leuven, Heverlee (Belgium). ESAT-ELECTA

2011-07-01

Solar photovoltaics (PV) has become a competitive renewable energy source. The production of solar PV cells and panels has increased significantly, while the cost is reduced due to economics of scale and technological achievements in the field. At the same time, the increase in efficiency of PV power systems and high energy prices are expected to lead PV systems to grid parity in the coming decade. This is expected to boost even more the large scale implementation of PV power plants (utility scale PV) and therefore the impact of such large scale PV plants to power system needs to be studies. This paper investigates the voltage stability issues arising from the connection of a large PV power plant to the power grid. For this purpose, a 15 MW PV power plant was implemented into a distribution grid, modeled and simulated using DIgSILENT Power Factory. Two scenarios were developed: in the first scenario, active power injected into the grid by the PV power plants was varied and the resulted U-Q curve was analyzed. In the second scenario, the impact of connecting PV power plants to different points in the grid - resulting in different strength of the connection - was investigated. (orig.)

Host-parasite interaction: selective Pv-fam-a family proteins of Plasmodium vivax bind to a restricted number of human erythrocyte receptors.

Science.gov (United States)

Zeeshan, Mohammad; Tyagi, Rupesh Kumar; Tyagi, Kriti; Alam, Mohd Shoeb; Sharma, Yagya Dutta

2015-04-01

Plasmodium vivax synthesizes the largest number of 36 tryptophan-rich proteins belonging to the Pv-fam-a family. These parasite proteins need to be characterized for their biological function because tryptophan-rich proteins from other Plasmodium species have been proposed as vaccine candidates. Recombinant P. vivax tryptophan-rich antigens (PvTRAgs) were used to determine their erythrocyte-binding activity by a cell-based enzyme-linked immunosorbent assay, flow cytometry, and a rosetting assay. Only 4 (PvTRAg26.3, PvTRAg34, PvTRAg36, and PvTRAg36.6) of 21 PvTRAgs bind to host erythrocytes. The cross-competition data indicated that PvTRAg36 and PvTRAg34 share their erythrocyte receptors with previously described proteins PvTRAg38 and PvTRAg33.5, respectively. On the other hand, PvTRAg26.3 and PvTRAg36.6 cross-compete with each other and not with any other PvTRAg, indicating that these 2 proteins bind to the same but yet another set of erythrocyte receptor(s). Together, 10 of 36 PvTRAgs possess erythrocyte-binding activity in which each protein recognizes >1 erythrocyte receptor. Further, each erythrocyte receptor is shared by >1 PvTRAg. This redundancy may be useful for the parasite to invade red blood cells and cause disease pathogenesis, and it can be exploited to develop therapeutics against P. vivax malaria. © The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Modeling Single-Phase PV HB-ZVR Inverter Connected to Grid

DEFF Research Database (Denmark)

Guo, Yougui; Zeng, Ping; Zhu, Jieqiong

2011-01-01

PLECS is used to model the PV H-bridge zero voltage rectifier (HB-ZVR) inverter connected to grid and good results are obtained. First, several common topologies of PV inverters are introduced. Then the unipolar PWM control strategy is described for PV HB-ZVR inverter. Third, PLECS is briefly...... introduced. Fourth, the modeling of PV HB-ZVR inverter is presented with PLECS. Finally, a series of simulations are carried out. The simulation results tell us PLECS is very powerful tool to real power circuits and it is very easy to simulate LCL filter. They have also verified that the unipolar PWM control...... strategy is feasible to control the PV HB-ZVR inverter....

Control Strategies for the DAB Based PV Interface System.

Directory of Open Access Journals (Sweden)

Hadi M El-Helw

Full Text Available This paper presents an interface system based on the Dual Active Bridge (DAB converter for Photovoltaic (PV arrays. Two control strategies are proposed for the DAB converter to harvest the maximum power from the PV array. The first strategy is based on a simple PI controller to regulate the terminal PV voltage through the phase shift angle of the DAB converter. The Perturb and Observe (P&O Maximum Power Point Tracking (MPPT technique is utilized to set the reference of the PV terminal voltage. The second strategy presented in this paper employs the Artificial Neural Network (ANN to directly set the phase shift angle of the DAB converter that results in harvesting maximum power. This feed-forward strategy overcomes the stability issues of the feedback strategy. The proposed PV interface systems are modeled and simulated using MATLAB/SIMULINK and the EMTDC/PSCAD software packages. The simulation results reveal accurate and fast response of the proposed systems. The dynamic performance of the proposed feed-forward strategy outdoes that of the feedback strategy in terms of accuracy and response time. Moreover, an experimental prototype is built to test and validate the proposed PV interface system.

Voltage rise mitigation for solar PV integration at LV grids

DEFF Research Database (Denmark)

Yang, Guangya; Marra, Francesco; Juamperez Goñi, Miguel Angel

2015-01-01

Solar energy from photovoltaic (PV) is among the fastest developing renewable energy systems worldwide. Driven by governmental subsidies and technological development, Europe has seen a fast expansion of solar PV in the last few years. Among the installed PV plants, most of them are situated...

Mapping the value of commercial PV applications in the US -- Accounting for externalities

International Nuclear Information System (INIS)

Perez, R.; Kmiecik, M.; Herig, C.; Wenger, H.

1999-01-01

In previous publications, the authors reported on the geographical distribution of the economic feasibility of customer-owned commercial PV systems in the US. The results showed that several regions in the country were near or above economic breakeven. However, the authors noted that these results only reflected business as usual assumptions. They did not account for existing or prospective external value elements that could, depending on the application, considerably increase PV's feasibility threshold. In this paper, the authors look at the individual and combined impact of the following value elements: (1) Replacement Value, (2) enhanced load management value, (3) emergency value and (4) environmental value. They show that accounting for these elements could significantly increase the size of cost-effective niche markets for customer-owned commercial PV installation

Isolation of Shewanella algae from rectal swabs of patients with bloody diarrhoea

Directory of Open Access Journals (Sweden)

R Nath

2011-01-01

Full Text Available Shewanella algae is an emerging bacteria rarely implicated as a human pathogen. It was infrequently recovered from clinical specimens probably because of inadequate processing of non-fermenting oxidase-positive gram-negative bacilli. We report here isolation of S. algae in pure culture and mixed with E. coli from two cases of acute gastroenteritis with bloody mucous containing diarrhea occurring at the same time. As this organism is not a normal flora of the gut, the possible source of infection may be fish contaminated with the organism. Whether this bacterium can be considered an enteric pathogen needs to be evaluated. The cases were clinically diagnosed as acute bacillary dysentery. The bacterium was identified by 16S r-RNA gene sequence analysis.

Optimal Capacity Allocation of Large-Scale Wind-PV-Battery Units

Directory of Open Access Journals (Sweden)

Kehe Wu

2014-01-01

Full Text Available An optimal capacity allocation of large-scale wind-photovoltaic- (PV- battery units was proposed. First, an output power model was established according to meteorological conditions. Then, a wind-PV-battery unit was connected to the power grid as a power-generation unit with a rated capacity under a fixed coordinated operation strategy. Second, the utilization rate of renewable energy sources and maximum wind-PV complementation was considered and the objective function of full life cycle-net present cost (NPC was calculated through hybrid iteration/adaptive hybrid genetic algorithm (HIAGA. The optimal capacity ratio among wind generator, PV array, and battery device also was calculated simultaneously. A simulation was conducted based on the wind-PV-battery unit in Zhangbei, China. Results showed that a wind-PV-battery unit could effectively minimize the NPC of power-generation units under a stable grid-connected operation. Finally, the sensitivity analysis of the wind-PV-battery unit demonstrated that the optimization result was closely related to potential wind-solar resources and government support. Regions with rich wind resources and a reasonable government energy policy could improve the economic efficiency of their power-generation units.

NREL PV Working With Industry, v. 27, Third Quarter 2000

Energy Technology Data Exchange (ETDEWEB)

Poole, L.; Nahan, R.

2000-09-12

NREL PV Working With Industry is a quarterly newsletter devoted to the research, development, and deployment performed by NREL staff in concert with their industry and university partners. The third quarter, contains articles on several important PV-related conferences held in the prior three months: the REAP/HBCU Conference and the IPS-2000 Photochemistry Conference. The issue also contains a preview article of the PV Specialists conference held in Alaska in September. The editorialist is John Benner, PV Specialist Conference Program Chairman.

Evaluating the limits of solar photovoltaics (PV) in traditional electric power systems

International Nuclear Information System (INIS)

Denholm, Paul; Margolis, Robert M.

2007-01-01

In this work, we examine some of the limits to large-scale deployment of solar photovoltaics (PV) in traditional electric power systems. Specifically, we evaluate the ability of PV to provide a large fraction (up to 50%) of a utility system's energy by comparing hourly output of a simulated large PV system to the amount of electricity actually usable. The simulations use hourly recorded solar insolation and load data for Texas in the year 2000 and consider the constraints of traditional electricity generation plants to reduce output and accommodate intermittent PV generation. We find that under high penetration levels and existing grid-operation procedures and rules, the system will have excess PV generation during certain periods of the year. Several metrics are developed to examine this excess PV generation and resulting costs as a function of PV penetration at different levels of system flexibility. The limited flexibility of base load generators produces increasingly large amounts of unusable PV generation when PV provides perhaps 10-20% of a system's energy. Measures to increase PV penetration beyond this range will be discussed and quantified in a follow-up analysis

Advanced Grid-Friendly Controls Demonstration Project for Utility-Scale PV Power Plants

Energy Technology Data Exchange (ETDEWEB)

Gevorgian, Vahan; O' Neill, Barbara

2016-01-21

A typical photovoltaic (PV) power plant consists of multiple power electronic inverters and can contribute to grid stability and reliability through sophisticated 'grid-friendly' controls. The availability and dissemination of actual test data showing the viability of advanced utility-scale PV controls among all industry stakeholders can leverage PV's value from being simply an energy resource to providing additional ancillary services that range from variability smoothing and frequency regulation to power quality. Strategically partnering with a selected utility and/or PV power plant operator is a key condition for a successful demonstration project. The U.S. Department of Energy's (DOE's) Solar Energy Technologies Office selected the National Renewable Energy Laboratory (NREL) to be a principal investigator in a two-year project with goals to (1) identify a potential partner(s), (2) develop a detailed scope of work and test plan for a field project to demonstrate the gird-friendly capabilities of utility-scale PV power plants, (3) facilitate conducting actual demonstration tests, and (4) disseminate test results among industry stakeholders via a joint NREL/DOE publication and participation in relevant technical conferences. The project implementation took place in FY 2014 and FY 2015. In FY14, NREL established collaborations with AES and First Solar Electric, LLC, to conduct demonstration testing on their utility-scale PV power plants in Puerto Rico and Texas, respectively, and developed test plans for each partner. Both Puerto Rico Electric Power Authority and the Electric Reliability Council of Texas expressed interest in this project because of the importance of such advanced controls for the reliable operation of their power systems under high penetration levels of variable renewable generation. During FY15, testing was completed on both plants, and a large amount of test data was produced and analyzed that demonstrates the ability of

A Simple Approach in Estimating the Effectiveness of Adapting Mirror Concentrator and Tracking Mechanism for PV Arrays in the Tropics

Directory of Open Access Journals (Sweden)

M. E. Ya’acob

2014-01-01

Full Text Available Mirror concentrating element and tracking mechanism has been seriously investigated and widely adapted in solar PV technology. In this study, a practical in-field method is conducted in Serdang, Selangor, Malaysia, for the two technologies in comparison to the common fixed flat PV arrays. The data sampling process is measured under stochastic weather characteristics with the main target of calculating the effectiveness of PV power output. The data are monitored, recorded, and analysed in real time via GPRS online monitoring system for 10 consecutive months. The analysis is based on a simple comparison of the actual daily power generation from each PV generator with statistical analysis of multiple linear regression (MLR and analysis of variance test (ANOVA. From the analysis, it is shown that tracking mechanism generates approximately 88 Watts (9.4% compared to the mirror concentrator which generates 144 Watts (23.4% of the cumulative dc power for different array configurations at standard testing condition (STC references. The significant increase in power generation shows feasibilities of implying both mechanisms for PV generators and thus contributes to additional reference in PV array design.

Plug and Play PV Systems for American Homes

Energy Technology Data Exchange (ETDEWEB)

Hoepfner, Christian [Fraunhofer USA, Inc., Boston, MA (United States)

2016-12-22

The core objectives of the Plug & Play PV Systems Project were to develop a PV system that can be installed on a residential rooftop for less than $1.50/W in 2020, and in less than 10 hours (from point of purchase to commissioning). The Fraunhofer CSE team’s approach to this challenge involved a holistic approach to system design – hardware and software – that make Plug & Play PV systems: • Quick, easy, and safe to install • Easy to demonstrate as code compliant • Permitted, inspected, and interconnected via an electronic process Throughout the three years of work during this Department of Energy SunShot funded project, the team engaged in a substantive way with inspectional services departments and utilities, manufacturers, installers, and distributors. We received iterative feedback on the system design and on ideas for how such systems can be commercialized. This ultimately led us to conceiving of Plug & Play PV Systems as a framework, with a variety of components compatible with the Plug & Play PV approach, including string or microinverters, conventional modules or emerging lightweight modules. The framework enables a broad group of manufacturers to participate in taking Plug & Play PV Systems to market, and increases the market size for such systems. Key aspects of the development effort centered on the system hardware and associated engineering work, the development of a Plug & Play PV Server to enable the electronic permitting, inspection and interconnection process, understanding the details of code compliance and, on occasion, supporting applications for modifications to the code to allow lightweight modules, for example. We have published a number of papers on our testing and assessment of novel technologies (e.g., adhered lightweight modules) and on the electronic architecture.

Training and certification of PV installers in Europe

International Nuclear Information System (INIS)

Tsoutsos, Theocharis; Tournaki, Stavroula; Gkouskos, Zacharias; Masson, Gaetan; Holden, John; Huidobro, Ana; Stoykova, Evelina; Rata, Camelia; Bacan, Andro; Maxoulis, Christos; Charalambous, Anthi

2013-01-01

The European strategy for the coming decades sets specific targets for a sustainable growth, including reaching a 20% share of renewables in final energy consumption till 2020. To achieve this target, a number of initiatives and measures have been in force. Europe, is currently the largest market for PV systems with more than 75% of the annual worldwide installations in 2011. The favourable European policies as well as the Member States’ supporting legislations have resulted in high market growth for photovoltaics. Applying PV technologies however, requires high qualified technicians to install, repair and maintain them. Until today, national markets have been growing faster than the skilled PV installers force can satisfy. The PVTRIN, an Intelligent Energy Europe action, addresses these issues by developing a training and certification scheme for technicians active in the installation and maintenance of small scale PV systems. During the implementation of the action, a market research was conducted in the six participating countries in order to record the stakeholders’ attitudes, perceptions and considerations and to adapt the training methods, tools and materials to the national PV industry requirements and markets’ needs. Indicative results of this analysis as well as the current situation regarding relevant training and certification schemes are presented in this paper. - Highlights: ► Market research in six EU countries on PV professional Training and Certification needs. ► PVTRIN scheme integrates the national legislations and the market's needs. ► The different aspects (technical, institutional, financial) are presented

PV Reconfiguration Systems: a Technical and Economic Study

Directory of Open Access Journals (Sweden)

Caruso M.

2017-03-01

Full Text Available Dynamical electrical array reconfiguration strategies for grid-connected PV systems have been proposed as solution to improve energy production due to the mismatch effect of PV plants during partial shading conditions. Strategies are based on the use of dynamic connections between PV panels given by the employment of switches that allow for each panel the series, parallel or exclusion connections, physically changing the electrical connections between the related PV modules, consequentially modifying the layout of the plant. Usually the cost of the dynamic matrix is not taken into account. This novel work evaluates the economic advantages obtained by the use of reconfiguration strategies in PV systems, by taking into consideration the price of energy due to incentives in different European and non-European countries and correlates it with the employment of two types of reconfigurators, with different internal structures. For each of the incentives proposed by the different Countries, the main strength and weakness points of the possible investment are highlighted and critically analyzed. From this analysis, it can be stated that the adoption of reconfiguration systems, in certain cases, can be a very convenient solution.

Molecular detection of Xanthomonas oryzae pv. oryzae, Xanthomonas oryzae pv. oryzicola, and Burkholderia glumae in infected rice seeds and leaves

Science.gov (United States)

Polymerase chain reaction (PCR) is particularly useful for plant pathogen detection. In the present study, multiplex PCR and SYBR green real-time PCR were developed to facilitate simultaneous detection of three important rice pathogens, Xanthomonas oryzae pv. oryzae, X. oryzae pv. oryzicola, and Bur...

PV GRID Advisory Paper. Consultation version: key recommendations

Energy Technology Data Exchange (ETDEWEB)

Barth, Bianca; Concas, Giorgia; Cossent, Rafael; Franz, Oliver; Frias, Pablo; Hermes, Roland; Lama, Riccardo; Loew, Holger; Mateo, Carlos; Rekinger, Manoel; Sonvilla, Paolo Michele; Vandenbergh, Michel

2014-01-15

PV GRID is a transnational collaborative effort under the umbrella of the Intelligent Energy Europe programme. The main project goal is to enhance photovoltaic (PV) hosting capacity in distribution grids while overcoming regulatory and normative barriers hampering the application of available technical solutions. The European PV GRID advisory paper aims at providing an overview of the issues and barriers that need to be addressed in order to enhance the distribution grid hosting capacity for PV and other distributed generation (DG).To this purpose, barriers are classified as either cross-cutting challenges or specific barriers, depending on whether they have an overarching, system-wide character or rather focus on one single issue such as curtailment, self-consumption or storage. Finally, a set of preliminary recommendations on how to overcome these issues is presented, allowing for the implementation of the identified technical solutions.

Microbial deposition of gold nanoparticles by the metal-reducing bacterium Shewanella algae

International Nuclear Information System (INIS)

Konishi, Y.; Tsukiyama, T.; Tachimi, T.; Saitoh, N.; Nomura, T.; Nagamine, S.

2007-01-01

Microbial reduction and deposition of gold nanoparticles was achieved at 25 deg. C over the pH range 2.0-7.0 using the mesophilic bacterium Shewanella algae in the presence of H 2 as the electron donor. The reductive deposition of gold by the resting cells of S. algae was a fast process: 1 mM AuCl 4 - ions were completely reduced to elemental gold within 30 min. At a solution pH of 7, gold nanoparticles 10-20 nm in size were deposited in the periplasmic space of S. algae cells. At pH 2.8, gold nanoparticles 15-200 nm in size were deposited on the bacterial cells, and the biogenic nanoparticles exhibited a variety of shapes that included nanotriangles: in particular, single crystalline gold nanotriangles 100-200 nm in size were microbially deposited. At a solution pH of 2.0, gold nanoparticles about 20 nm in size were deposited intracellularly, and larger gold particles approximately 350 nm in size were deposited extracellularly. The solution pH was an important factor in controlling the morphology of the biogenic gold particles and the location of gold deposition. Microbial deposition of gold nanoparticles is potentially attractive as an environmentally friendly alternative to conventional methods

PV Project Finance in the United States, 2016

Energy Technology Data Exchange (ETDEWEB)

Feldman, David; Lowder, Travis; Schwabe, Paul

2016-09-01

This brief is a compilation of data points and market insights that reflect the state of the project finance market for solar photovoltaic (PV) assets in the United States as of the third quarter of 2016. This information can generally be used as a simplified benchmark of the costs associated with securing financing for solar PV as well as the cost of the financing itself (i.e., the cost of capital). Three sources of capital are considered -- tax equity, sponsor equity, and debt -- across three segments of the PV marketplace.

Cost-Reduction Roadmap for Residential Solar Photovoltaics (PV), 2017-2030

Energy Technology Data Exchange (ETDEWEB)

Cook, Jeffrey J. [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Ardani, Kristen B. [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Margolis, Robert M. [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Fu, Ran [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

2018-01-03

The installed cost of solar photovoltaics (PV) has fallen rapidly in recent years and is expected to continue declining in the future. In this report, we focus on the potential for continued PV cost reductions in the residential market. From 2010 to 2017, the levelized cost of energy (LCOE) for residential PV declined from 52 cents per kilowatt-hour (cents/kWh) to 16 cents/kWh (Fu et al. 2017). The U.S. Department of Energy's (DOE's) Solar Energy Technologies Office (SETO) recently set new LCOE targets for 2030, including a target of 5 cents/kWh for residential PV. We present a roadmap for achieving the SETO 2030 residential PV target. Because the 2030 target likely will not be achieved under business-as-usual trends (NREL 2017), we examine two key market segments that demonstrate significant opportunities for cost savings and market growth: installing PV at the time of roof replacement and installing PV as part of the new home construction process. Within both market segments, we identify four key cost-reduction opportunities: market maturation, business model integration, product innovation, and economies of scale. To assess the potential impact of these cost reductions, we compare modeled residential PV system prices in 2030 to the National Renewable Energy Laboratory's (NREL's) quarter one 2017 (Q1 2017) residential PV system price benchmark (Fu et al. 2017). We use a bottom-up accounting framework to model all component and project-development costs incurred when installing a PV system. The result is a granular accounting for 11 direct and indirect costs associated with installing a residential PV system in 2030. All four modeled pathways demonstrate significant installed-system price savings over the Q1 2017 benchmark, with the visionary pathways yielding the greatest price benefits. The largest modeled cost savings are in the supply chain, sales and marketing, overhead, and installation labor cost categories. When we translate these

Solar Plus: A Holistic Approach to Distributed Solar PV

Energy Technology Data Exchange (ETDEWEB)

O' Shaughnessy, Eric [National Renewable Energy Lab. (NREL), Golden, CO (United States); Ardani, Kristen [National Renewable Energy Lab. (NREL), Golden, CO (United States); Cutler, Dylan [National Renewable Energy Lab. (NREL), Golden, CO (United States); Margolis, Robert [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2017-05-25

Solar 'plus' refers to an emerging approach to distributed solar photovoltaic (PV) deployment that uses energy storage and controllable devices to optimize customer economics. The solar plus approach increases customer system value through technologies such as electric batteries, smart domestic water heaters, smart air-conditioner (AC) units, and electric vehicles We use an NREL optimization model to explore the customer-side economics of solar plus under various utility rate structures and net metering rates. We explore optimal solar plus applications in five case studies with different net metering rates and rate structures. The model deploys different configurations of PV, batteries, smart domestic water heaters, and smart AC units in response to different rate structures and customer load profiles. The results indicate that solar plus improves the customer economics of PV and may mitigate some of the negative impacts of evolving rate structures on PV economics. Solar plus may become an increasingly viable model for optimizing PV customer economics in an evolving rate environment.

Solar Plus: A Holistic Approach to Distributed Solar PV

Energy Technology Data Exchange (ETDEWEB)

OShaughnessy, Eric J. [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Ardani, Kristen B. [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Cutler, Dylan S. [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Margolis, Robert M. [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

2017-06-08

Solar 'plus' refers to an emerging approach to distributed solar photovoltaic (PV) deployment that uses energy storage and controllable devices to optimize customer economics. The solar plus approach increases customer system value through technologies such as electric batteries, smart domestic water heaters, smart air-conditioner (AC) units, and electric vehicles We use an NREL optimization model to explore the customer-side economics of solar plus under various utility rate structures and net metering rates. We explore optimal solar plus applications in five case studies with different net metering rates and rate structures. The model deploys different configurations of PV, batteries, smart domestic water heaters, and smart AC units in response to different rate structures and customer load profiles. The results indicate that solar plus improves the customer economics of PV and may mitigate some of the negative impacts of evolving rate structures on PV economics. Solar plus may become an increasingly viable model for optimizing PV customer economics in an evolving rate environment.

Self-control system in storage unit of PV plants

Energy Technology Data Exchange (ETDEWEB)

Al-Shaban, Saad; Mohmoud, Ali [Hadhramout Univ. of Science and Technology, Faculty of Engineering, Mukalla (Yemen)

2000-04-01

A new system for self-controlling of storage batteries being charged by PV plants has been developed. This provides enhanced system reliability, lower system cost, and simpler operation for the user. In this system, the only requirement is to design and select PV panels so that their voltage-sensitive region (on the I-V curve) coincides with that required for a simpler remote PV plant and for long periods. (Author)

Design of A Grid Integrated PV System with MPPT Control and Voltage Oriented Controller using MATLAB/PLECES

Science.gov (United States)

Soreng, Bineeta; Behera, Pradyumna; Pradhan, Raseswari

2017-08-01

This paper presents model of a grid-integrated photovoltaic array with Maximum Power Point Tracker (MPPT) and voltage oriented controller. The MPPT of the PV array is usually an essential part of PV system as MPPT helps the operating point of the solar array to align its maximum power point. In this model, the MPPT along with a DC-DC converter lets a PV generator to produce continuous power, despite of the measurement conditions. The neutral-point-clamped converter (NPC) with a boost converter raises the voltage from the panels to the DC-link. An LCL-filter smoothens the current ripple caused by the PWM modulation of the grid-side inverter. In addition to the MPPT, the system has two more two controllers, such as voltage controller and a current controller. The voltage control has a PI controller to regulate the PV voltage to optimal level by controlling the amount of current injected into the boost stage. Here, the grid-side converter transfers the power from the DC-link into the grid and maintains the DC-link voltage. Three-phase PV inverters are used for off-grid or designed to create utility frequency AC. The PV system can be connected in series or parallel to get the desired output power. To justify the working of this model, the grid-integrated PV system has been designed in MATLAB/PLECS. The simulation shows the P-V curve of implemented PV Array consisting 4 X 20 modules, reactive, real power, grid voltage and current.

PV O&M Cost Model and Cost Reduction

Energy Technology Data Exchange (ETDEWEB)

Walker, Andy

2017-03-15

This is a presentation on PV O&M cost model and cost reduction for the annual Photovoltaic Reliability Workshop (2017), covering estimating PV O&M costs, polynomial expansion, and implementation of Net Present Value (NPV) and reserve account in cost models.

R and D into stand-alone PV systems for export

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-09-01

The current status of photovoltaic (PV) technology is reviewed for systems to provide electricity where mains supplies are unavailable, known as stand-alone PV systems. Typical applications and experiences with installed stand-alone systems are described. Economic issues and barriers to the wide use of PV systems are also examined. (UK)

Sizing procedures for sun-tracking PV system with batteries

Directory of Open Access Journals (Sweden)

Gerek Ömer Nezih

2017-01-01

Full Text Available Deciding optimum number of PV panels, wind turbines and batteries (i.e. a complete renewable energy system for minimum cost and complete energy balance is a challenging and interesting problem. In the literature, some rough data models or limited recorded data together with low resolution hourly averaged meteorological values are used to test the sizing strategies. In this study, active sun tracking and fixed PV solar power generation values of ready-to-serve commercial products are recorded throughout 2015–2016. Simultaneously several outdoor parameters (solar radiation, temperature, humidity, wind speed/direction, pressure are recorded with high resolution. The hourly energy consumption values of a standard 4-person household, which is constructed in our campus in Eskisehir, Turkey, are also recorded for the same period. During sizing, novel parametric random process models for wind speed, temperature, solar radiation, energy demand and electricity generation curves are achieved and it is observed that these models provide sizing results with lower LLP through Monte Carlo experiments that consider average and minimum performance cases. Furthermore, another novel cost optimization strategy is adopted to show that solar tracking PV panels provide lower costs by enabling reduced number of installed batteries. Results are verified over real recorded data.

Sizing procedures for sun-tracking PV system with batteries

Science.gov (United States)

Nezih Gerek, Ömer; Başaran Filik, Ümmühan; Filik, Tansu

2017-11-01

Deciding optimum number of PV panels, wind turbines and batteries (i.e. a complete renewable energy system) for minimum cost and complete energy balance is a challenging and interesting problem. In the literature, some rough data models or limited recorded data together with low resolution hourly averaged meteorological values are used to test the sizing strategies. In this study, active sun tracking and fixed PV solar power generation values of ready-to-serve commercial products are recorded throughout 2015-2016. Simultaneously several outdoor parameters (solar radiation, temperature, humidity, wind speed/direction, pressure) are recorded with high resolution. The hourly energy consumption values of a standard 4-person household, which is constructed in our campus in Eskisehir, Turkey, are also recorded for the same period. During sizing, novel parametric random process models for wind speed, temperature, solar radiation, energy demand and electricity generation curves are achieved and it is observed that these models provide sizing results with lower LLP through Monte Carlo experiments that consider average and minimum performance cases. Furthermore, another novel cost optimization strategy is adopted to show that solar tracking PV panels provide lower costs by enabling reduced number of installed batteries. Results are verified over real recorded data.

Performance of a directly-coupled PV water pumping system

International Nuclear Information System (INIS)

Mokeddem, Abdelmalek; Midoun, Abdelhamid; Kadri, D.; Hiadsi, Said; Raja, Iftikhar A.

2011-01-01

Highlights: → Directly coupled PV water pumping system installed and performance studied. → Configured for two static heads, operate without electronic control and auxiliary power. → The system attains steady state soon after any abrupt change. → Cost effective and useful for low head communicating wells system. - Abstract: This paper describes the experimental study carried out to investigate the performance of a simple, directly coupled dc photovoltaic (PV) powered water pumping system. The system comprises of a 1.5 kWp PV array, dc motor and a centrifugal pump. The experiment was conducted over a period of 4 months and the system performance was monitored under different climatic conditions and varying solar irradiance with two static head configurations. Although the motor-pump efficiency did not exceed 30%, which is typical for directly-coupled photovoltaic pumping systems, such a system is clearly suitable for low head irrigation in the remote areas, not connected to the national grid and where access to water comes as first priority issue than access to technology. The system operates without battery and complex electronic control, therefore not only the initial cost is low but also maintenance, repairing and replacement cost can be saved. The study showed that directly coupled system attains steady state soon after any abrupt change.

Retaining the Value of PV at High Penetration Workshop

Energy Technology Data Exchange (ETDEWEB)

Kurtz, Sarah; Bolen, Michael

2017-01-19

PV prices have dropped and are now attractive without incentives for peaking applications in some locations. Modeling suggests and, empirically, some regions demonstrate that as PV penetration increases its value decreases, predominantly due to a decrease in energy and capacity value. It is not apparent what technologies and price may be needed for PV to supply tens of percent of electricity in the most economically efficient manner. A 1-day workshop was co-sponsored by EPRI and NREL with support from ASU. A dozen presentations and discussions introduced how the interplay of various technologies impact the value of PV, identified technical challenges and gaps impeding implementation, and discussed future R&D needs and opportunities.

PV Systems Reliability Final Technical Report.

Energy Technology Data Exchange (ETDEWEB)

Lavrova, Olga [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Flicker, Jack David [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Johnson, Jay [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Armijo, Kenneth Miguel [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Gonzalez, Sigifredo [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Schindelholz, Eric John [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Sorensen, Neil R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Yang, Benjamin Bing-Yeh [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2015-12-01

The continued exponential growth of photovoltaic technologies paves a path to a solar-powered world, but requires continued progress toward low-cost, high-reliability, high-performance photovoltaic (PV) systems. High reliability is an essential element in achieving low-cost solar electricity by reducing operation and maintenance (O&M) costs and extending system lifetime and availability, but these attributes are difficult to verify at the time of installation. Utilities, financiers, homeowners, and planners are demanding this information in order to evaluate their financial risk as a prerequisite to large investments. Reliability research and development (R&D) is needed to build market confidence by improving product reliability and by improving predictions of system availability, O&M cost, and lifetime. This project is focused on understanding, predicting, and improving the reliability of PV systems. The two areas being pursued include PV arc-fault and ground fault issues, and inverter reliability.

Issues and prospects vis a vis Indian PV commercialization programme

International Nuclear Information System (INIS)

Deambi, Suneel

1994-01-01

Following a large scale demonstration of photovoltaic systems attending to the important requirements of lighting, water pumping, television and battery charging etc. in the remote surroundings of India, serious efforts are being made to promote the commercial use of these systems. A recently launched World Bank-supported project on PV market development has provided the much needed boost to the Indian PV programme. This paper tries to analyse the issues and prospects with respect to the National PV Commercialization Programme in view of the changing PV scenario in the country. (author)

Dynamic Characteristics Analysis and Stabilization of PV-Based Multiple Microgrid Clusters

DEFF Research Database (Denmark)

Zhao, Zhuoli; Yang, Ping; Wang, Yuewu

2018-01-01

-based multiple microgrid clusters. A detailed small-signal model for PV-based microgrid clusters considering local adaptive dynamic droop control mechanism of the voltage-source PV system is developed. The complete dynamic model is then used to access and compare the dynamic characteristics of the single...... microgrid and interconnected microgrids. In order to enhance system stability of the PV microgrid clusters, a tie-line flow and stabilization strategy is proposed to suppress the introduced interarea and local oscillations. Robustly selecting of the key control parameters is transformed to a multiobjective......As the penetration of PV generation increases, there is a growing operational demand on PV systems to participate in microgrid frequency regulation. It is expected that future distribution systems will consist of multiple microgrid clusters. However, interconnecting PV microgrids may lead to system...

An Improved Matlab-Simulink Model of PV Module considering Ambient Conditions

Directory of Open Access Journals (Sweden)

R. Ayaz

2014-01-01

Full Text Available A photovoltaic (PV model is proposed on Matlab/Simulink environment considering the real atmospheric conditions and this PV model is tested with different PV panels technologies (monocrystalline silicon, polycrystalline silicon, and thin film. The meteorological data of Istanbul—the location of the study—such as irradiance, cell temperature, and wind speed are taken into account in the proposed model for each technology. Eventually, the power outputs of the PV module under real atmospheric conditions are measured for resistive loading and these powers are compared with the results of proposed PV model. As a result of the comparison, it is shown that the proposed model is more compatible for monocrystal silicon and thin-film modules; however, it does not show a good correlation with polycrystalline silicon PV module.

Fuzzy Logic Based MPPT Controller for a PV System

Directory of Open Access Journals (Sweden)

Carlos Robles Algarín

2017-12-01

Full Text Available The output power of a photovoltaic (PV module depends on the solar irradiance and the operating temperature; therefore, it is necessary to implement maximum power point tracking controllers (MPPT to obtain the maximum power of a PV system regardless of variations in climatic conditions. The traditional solution for MPPT controllers is the perturbation and observation (P&O algorithm, which presents oscillation problems around the operating point; the reason why improving the results obtained with this algorithm has become an important goal to reach for researchers. This paper presents the design and modeling of a fuzzy controller for tracking the maximum power point of a PV System. Matlab/Simulink (MathWorks, Natick, MA, USA was used for the modeling of the components of a 65 W PV system: PV module, buck converter and fuzzy controller; highlighting as main novelty the use of a mathematical model for the PV module, which, unlike diode based models, only needs to calculate the curve fitting parameter. A P&O controller to compare the results obtained with the fuzzy control was designed. The simulation results demonstrated the superiority of the fuzzy controller in terms of settling time, power loss and oscillations at the operating point.

On the Impacts of PV Array Sizing on the Inverter Reliability and Lifetime

DEFF Research Database (Denmark)

Sangwongwanich, Ariya; Yang, Yongheng; Sera, Dezso

2018-01-01

, the total energy yield can be increased under weak solar irradiance conditions. However, oversizing the PV array will increase the loading of PV inverters, which may have undesired influence on the PV inverter reliability and lifetime. In that case, it may result in a negative impact on the overall PV...... energy cost, due to the increased maintenance for the PV inverters. With the above concern, this paper evaluates the reliability and lifetime of PV inverters considering the PV array sizing. The evaluation is based on the mission profile of the installation sites in Denmark and Arizona, where...... the reliability-critical components such as power devices and capacitors are considered. The results reveal that the variation in the PV array sizing can considerably deviate the reliability performance and lifetime expectation of PV inverters, especially for those installed in Denmark, where the average solar...

Homogentisic acid is the product of MelA, which mediates melanogenesis in the marine bacterium Shewanella colwelliana D.

OpenAIRE

Coon, S L; Kotob, S; Jarvis, B B; Wang, S; Fuqua, W C; Weiner, R M

1994-01-01

Shewanella colwelliana D is a marine procaryote which produces a diffusible brown pigment that correlates with melA gene expression. Previously, melA had been cloned, sequenced, and expressed in Escherichia coli; however, the reaction product of MelA had not been identified. This report identifies that product as homogentisic acid, provides evidence that the pigment is homogentisic acid-melanin (pyomelanin), and suggests that MelA is p-hydroxyphenylpyruvate hydroxylase. This is the first repo...

Development of outdoor luminescence imaging for drone-based PV array inspection

DEFF Research Database (Denmark)

Benatto, Gisele Alves dos Reis; Riedel, Nicholas; Thorsteinsson, Sune

2017-01-01

This work has the goal to examined experimentally PV module imaging methods under natural light conditions, that will be used in a fast, accurate and automatic drone-based inspection system for PV power plants.......This work has the goal to examined experimentally PV module imaging methods under natural light conditions, that will be used in a fast, accurate and automatic drone-based inspection system for PV power plants....

Is rooftop solar PV at socket parity without subsidies?

International Nuclear Information System (INIS)

Hagerman, Shelly; Jaramillo, Paulina; Morgan, M. Granger

2016-01-01

Installations of rooftop solar photovoltaic (PV) technology in the United States have increased dramatically in recent years, in large part because of state and federal subsidies. In the future, such subsidies may be reduced or eliminated. From the homeowner's perspective, solar PV is competitive when it can produce electricity at a cost equivalent to the retail electricity rate, a condition sometimes referred to as “socket parity”. In assessing the economic viability of residential solar PV, most existing literature considers only a few locations and fails to consider the differences in PV system cost and electricity prices that exist across the U.S. We combined insolation data from more than 1000 locations, installation costs by region, and county-level utility rates to provide a more complete economic assessment of rooftop solar PV across the U.S. We calculated the break-even electricity prices and evaluated the reductions in installed costs needed to reach socket parity. Among the scenarios considered, we estimate that only Hawaii has achieved socket parity without the use of subsidies. With subsidies, six states reach socket parity, yet widespread parity is still not achieved. We find that high installation costs and financing rates are two of the largest barriers to socket parity. - Highlights: • We evaluate the economic viability of residential rooftop solar PV across the U.S. • Widespread socket parity has not been achieved in the U.S. without subsidies. • Net metering may be critical for the economic viability of rooftop solar PV.

Cooled solar PV panels for output energy efficiency optimisation

International Nuclear Information System (INIS)

Peng, Zhijun; Herfatmanesh, Mohammad R.; Liu, Yiming

2017-01-01

Highlights: • Effects of cooling on solar PV performance have been experimentally investigated. • As a solar panel is cooled down, the electric output can have significant increase. • A cooled solar PV system has been proposed for resident application. • Life cycle assessment suggests the cost payback time of cooled PV can be reduced. - Abstract: As working temperature plays a critical role in influencing solar PV’s electrical output and efficacy, it is necessary to examine possible way for maintaining the appropriate temperature for solar panels. This research is aiming to investigate practical effects of solar PV surface temperature on output performance, in particular efficiency. Experimental works were carried out under different radiation condition for exploring the variation of the output voltage, current, output power and efficiency. After that, the cooling test was conducted to find how much efficiency improvement can be achieved with the cooling condition. As test results show the efficiency of solar PV can have an increasing rate of 47% with the cooled condition, a cooling system is proposed for possible system setup of residential solar PV application. The system performance and life cycle assessment suggest that the annual PV electric output efficiencies can increase up to 35%, and the annual total system energy efficiency including electric output and hot water energy output can increase up to 107%. The cost payback time can be reduced to 12.1 years, compared to 15 years of the baseline of a similar system without cooling sub-system.

PV solar electricity industry: Market growth and perspective

International Nuclear Information System (INIS)

Hoffmann, Winfried

2006-01-01

The photovoltaic (PV) solar electricity market has shown an impressive 33% growth per year since 1997 until today with market support programs as the main driving force. The rationales for this development and the future projections towards a 100 billion | industry in the 2020s, by then only driven by serving cost-competitively customer needs are described. The PV market, likely to have reached about 600MW in the year 2003, is discussed according to its four major segments: consumer applications, remote industrial electrification, developing countries, and grid-connected systems. While in the past, consumer products and remote industrial applications used to be the main cause for turnover in PV, in recent years the driving forces are more pronounced in the grid-connected systems and by installations in developing countries. Examples illustrating the clear advantage of systems using PV over conventional systems based, e.g., on diesel generators in the rural and remote electrification sector are discussed. For the promotion of rural electrification combined with the creation of local business and employment, suitable measures are proposed in the context of the PV product value chain. The competitiveness of grid-connected systems is addressed, where electricity generating costs for PV are projected to start to compete with conventional utility peak power quite early between 2010 and 2020 if time-dependent electricity tariffs different for bulk and peak power are assumed. The most effective current-pulling force for grid-connected systems is found to be the German Renewable Energy (EEG) Feed-in Law where the customers are focusing on yield, performance, and long-life availability. The future growth in the above-defined four market segments are discussed and the importance of industry political actions in order to stimulate the markets either in grid-connected systems by feed-in tariff programs as well as for off-grid rural developing country applications by long

PV solar electricity industry: Market growth and perspective

Energy Technology Data Exchange (ETDEWEB)

Hoffmann, Winfried [RWE SCHOTT Solar GmbH, Carl-Zeiss-Str. 4, 63755 Alzenau (Germany)

2006-11-23

The photovoltaic (PV) solar electricity market has shown an impressive 33% growth per year since 1997 until today with market support programs as the main driving force. The rationales for this development and the future projections towards a 100 billion | industry in the 2020s, by then only driven by serving cost-competitively customer needs are described. The PV market, likely to have reached about 600MW in the year 2003, is discussed according to its four major segments: consumer applications, remote industrial electrification, developing countries, and grid-connected systems. While in the past, consumer products and remote industrial applications used to be the main cause for turnover in PV, in recent years the driving forces are more pronounced in the grid-connected systems and by installations in developing countries. Examples illustrating the clear advantage of systems using PV over conventional systems based, e.g., on diesel generators in the rural and remote electrification sector are discussed. For the promotion of rural electrification combined with the creation of local business and employment, suitable measures are proposed in the context of the PV product value chain. The competitiveness of grid-connected systems is addressed, where electricity generating costs for PV are projected to start to compete with conventional utility peak power quite early between 2010 and 2020 if time-dependent electricity tariffs different for bulk and peak power are assumed. The most effective current-pulling force for grid-connected systems is found to be the German Renewable Energy (EEG) Feed-in Law where the customers are focusing on yield, performance, and long-life availability. The future growth in the above-defined four market segments are discussed and the importance of industry political actions in order to stimulate the markets either in grid-connected systems by feed-in tariff programs as well as for off-grid rural developing country applications by long

A wide-gap a-SiC:H PV-powered electrochromic window coating

Energy Technology Data Exchange (ETDEWEB)

Gao, W.; Lee, S.H.; Xu, Y.; Benson, D.K.; Deb, S.K.; Branz, H.M. [National Renewable Energy Lab., Golden, CO (United States)

1998-09-01

The authors report on the first monolithic, amorphous-silicon-based, photovoltaic-powered electrochromic window coating. The coating employs a wide bandgap a-Si{sub 1{minus}x}C{sub x}:H n-i-p photovoltaic (PV) cell as a semitransparent power supply, and a Li{sub y}WO{sub 3}/LiAlF{sub 4}/V{sub 2}O{sub 5} electrochromic (EC) device as an optical-transmittance modulator. The EC device is deposited directly on top of a PV cell that coats a glass substrate. The a-Si{sub 1{minus}x}C{sub x}:H PV cell has a Tauc gap of 2.2 eV and a transmittance of 60--80% over a large portion of the visible light spectrum. The authors reduced the thickness of the device to about 600 {angstrom} while maintaining a 1-sun open-circuit voltage of 0.9 V and short-circuit current of 2 mA/cm{sup 2}. The prototype 16 cm{sup 2} PV/EC device modulates the transmittance by more than 60% over a large portion of the visible spectrum. The coloring and bleaching times of the EC device are approximately 1 minute under normal operating conditions ({+-} 1 volt). A brief description of photoelectrochromic windows study is also given.

CFD Simulation of Turbulent Wind Effect on an Array of Ground-Mounted Solar PV Panels

Science.gov (United States)

Irtaza, Hassan; Agarwal, Ashish

2018-02-01

Aim of the present study is to determine the wind loads on the PV panels in a solar array since panels are vulnerable to high winds. Extensive damages of PV panels, arrays and mounting modules have been reported the world over due to high winds. Solar array of dimension 6 m × 4 m having 12 PV panels of size 1 m × 2 m on 3D 1:50 scaled models have been simulated using unsteady solver with Reynolds-Averaged Navier-Stokes equations of computational fluid dynamics techniques to study the turbulent wind effects on PV panels. A standalone solar array with 30° tilt angle in atmospheric surface layer with the Renormalized Group (RNG) turbulence closure subjected to incident wind varied from - 90° to 90°. The net pressure, drag and lift coefficients are found to be maximum when the wind is flowing normally to the PV panel either 90° or - 90°. The tilt angle of solar arrays the world over not vary on the latitude but also on the seasons. Keeping this in mind the ground mounted PV panels in array with varying tilt angle from 10° to 60° at an interval of 10° have been analyzed for normal wind incident i.e. 90° and - 90° using unsteady RNG turbulence model. Net pressure coefficients have been calculated and found to be increasing with increase in array tilting angle. Maximum net pressure coefficient was observed for the 60° tilted PV array for 90° and - 90° wind incident having value of 0.938 and 0.904 respectively. The results can be concluded that the PV panels are subjected to significant lift and drag forces under wind loading, which needs to be quantified with sufficient factor of safety to avoid damages.

CFD Simulation of Turbulent Wind Effect on an Array of Ground-Mounted Solar PV Panels

Science.gov (United States)

Irtaza, Hassan; Agarwal, Ashish

2018-06-01

Aim of the present study is to determine the wind loads on the PV panels in a solar array since panels are vulnerable to high winds. Extensive damages of PV panels, arrays and mounting modules have been reported the world over due to high winds. Solar array of dimension 6 m × 4 m having 12 PV panels of size 1 m × 2 m on 3D 1:50 scaled models have been simulated using unsteady solver with Reynolds-Averaged Navier-Stokes equations of computational fluid dynamics techniques to study the turbulent wind effects on PV panels. A standalone solar array with 30° tilt angle in atmospheric surface layer with the Renormalized Group (RNG) turbulence closure subjected to incident wind varied from - 90° to 90°. The net pressure, drag and lift coefficients are found to be maximum when the wind is flowing normally to the PV panel either 90° or - 90°. The tilt angle of solar arrays the world over not vary on the latitude but also on the seasons. Keeping this in mind the ground mounted PV panels in array with varying tilt angle from 10° to 60° at an interval of 10° have been analyzed for normal wind incident i.e. 90° and - 90° using unsteady RNG turbulence model. Net pressure coefficients have been calculated and found to be increasing with increase in array tilting angle. Maximum net pressure coefficient was observed for the 60° tilted PV array for 90° and - 90° wind incident having value of 0.938 and 0.904 respectively. The results can be concluded that the PV panels are subjected to significant lift and drag forces under wind loading, which needs to be quantified with sufficient factor of safety to avoid damages.

Assessment of MPPT Techniques During the Faulty Conditions of PV System

Directory of Open Access Journals (Sweden)

Bhukya Krishna Naick

2018-01-01

Full Text Available The contribution of Distributed Generation (DG systems like wind energy systems and solar Photovoltaic (PV systems on the generation of electricity has increased. Out of these DG systems, the PV systems have gained wide popularity, because of the availability of solar energy throughout the day. Depending on the size of PV installations, a large number of PV modules can be interconnected in the form of series and parallel connection. Since a large number of modules are interconnected, it is possible for the faults in a PV array to occur due to the failure of protection system, which can cause damage to the PV module and also the decrease in the output power. This paper presents the tracking of a maximum power point under the faulty conditions of 12x5 PV array. The fault conditions that have been considered in the PV array are open circuit fault, line to ground, line to line and failure of bypass diodes. Perturb and observe, incremental conductance and fuzzy logic controller are the maximum power point tracking techniques that have been implemented. For each of the fault conditions, the results have been presented in terms of the maximum power tracked, tracking time and tracking efficiency.

A Non-Modeling Exploration of Residential Solar Photovoltaic (PV) Adoption and Non-Adoption

Energy Technology Data Exchange (ETDEWEB)

Moezzi, Mithra [Portland State Univ., Portland, OR (United States); Ingle, Aaron [Portland State Univ., Portland, OR (United States); Lutzenhiser, Loren [Portland State Univ., Portland, OR (United States); Sigrin, Benjamin O. [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

2017-09-01

Although U.S. deployment of residential rooftop solar photovoltaic (PV) systems has accelerated in recent years, PV is still installed on less than 1 percent of single-family homes. Most research on household PV adoption focuses on scaling initial markets and modeling predicted growth rather than considering more broadly why adoption occurs. Among the studies that have investigated the characteristics of PV adoption, most collected data from adopters, sometimes with additional non-adopter data, and rarely from people who considered but did not adopt PV. Yet the vast majority of Americans are non-adopters, and they are a diverse group - understanding their ways of evaluating PV adoption is important. Similarly, PV is a unique consumer product, which makes it difficult to apply findings from studies of other technologies to PV. In addition, little research addresses the experience of households after they install PV. This report helps fill some of these gaps in the existing literature. The results inform a more detailed understanding of residential PV adoption, while helping ensure that adoption is sufficiently beneficial to adopters and even non-adopters.

Comparison and selection of off-grid PV systems

Science.gov (United States)

Izmailov, Andrey Yu.; Lobachevsky, Yakov P.; Shepovalova, Olga V.

2018-05-01

This work deals with comparison, evaluation and selection of PV systems of the same type based on their technical parameters either indicated in their technical specifications or calculated ones. Stand-alone and grid backed up photoelectric systems have been considered. General requirements for photoelectric system selection and evaluation have been presented that ensure system operability and required efficiency in operation conditions. Generic principles and definition of photoelectric systems characteristics have been considered. The described method is mainly targeted at PV engineering personnel and private customers purchasing PV systems. It can be also applied in the course of project contests, tenders, etc.

Robustness analysis of the efficiency in PV inverters

DEFF Research Database (Denmark)

Pigazo, Alberto; Liserre, Marco; Blaabjerg, Frede

2013-01-01

topology and control strategy but also on the characteristics of the employed components. The aim of this paper is evaluate the effect of physical variations associated to the main components on the overall efficiency of PV inverters. It is concluded that a statistical evaluation of the power converter......During last years an increasing attention has been paid to the efficiency of grid-connected PV inverters. They are manufactured from a number of discrete components and by using a certain topology and control strategy. Hence, the performance of a certain PV inverter not only depends on the selected...

Building PV markets: customers and prices

International Nuclear Information System (INIS)

Haas, Reinhard

2002-01-01

What makes market deployment strategies for PV successful? A group of specialists (from IEA Task 7) has been looking at the progress made so far. Here, in the first of two articles based on their report, the author presents some of their findings, including benefits and barriers for defined groups of customers; how customers for PV systems are identified, and what they are willing to pay. It also looks at current prices in different countries, and their possible trends. (Author)

Industry consultation on grid connection of small PV systems

Energy Technology Data Exchange (ETDEWEB)

Knight, J.; Thorneycroft, J.; Cotterell, M.; Gambro, S.

2000-07-01

This report presents the results of consultation within the PV industry and the electricity supply industry concerning guidelines for the connection of small PV systems to the electricity network. (author)

Delta Power Control Strategy for Multi-String Grid-Connected PV Inverters

DEFF Research Database (Denmark)

Sangwongwanich, Ariya; Yang, Yongheng; Blaabjerg, Frede

2016-01-01

With a still increasing penetration level of grid-connected PV systems, more advanced active power control functionalities have been introduced in certain grid regulations. A delta power constraint, where a portion of the active power from the PV panels is reserved during operation, is required...... for grid support (e.g., during frequency deviation). In this paper, a cost-effective solution to realize delta power control for grid-connected PV systems is presented, where the residential/commercial multi-string PV inverter configuration is adopted. This control strategy is a combination of Maximum...... for the entire PV system is achieved. Simulations and experiments have been performed on a 3-kW single-phase grid-connected PV system. The results have confirmed the effectiveness of the delta power control strategy, where the power reserve according to the delta power constraint is achieved under several...

Regressing Multiple Viral Plaques and Skin Fragility Syndrome in a Cat Coinfected with FcaPV2 and FcaPV3

Directory of Open Access Journals (Sweden)

Alberto Alberti

2015-01-01

Full Text Available Feline viral plaques are uncommon skin lesions clinically characterized by multiple, often pigmented, and slightly raised lesions. Numerous reports suggest that papillomaviruses (PVs are involved in their development. Immunosuppressed and immunocompetent cats are both affected, the biological behavior is variable, and the regression is possible but rarely documented. Here we report a case of a FIV-positive cat with skin fragility syndrome and regressing multiple viral plaques in which the contemporary presence of two PV types (FcaPV2 and FcaPV3 was demonstrated by combining a quantitative molecular approach to histopathology. The cat, under glucocorticoid therapy for stomatitis and pruritus, developed skin fragility and numerous grouped slightly raised nonulcerated pigmented macules and plaques with histological features of epidermal thickness, mild dysplasia, and presence of koilocytes. Absolute quantification of the viral DNA copies (4555 copies/microliter of FcaPV2 and 8655 copies/microliter of FcaPV3 was obtained. Eighteen months after discontinuation of glucocorticoid therapy skin fragility and viral plaques had resolved. The role of the two viruses cannot be established and it remains undetermined how each of the viruses has contributed to the onset of VP; the spontaneous remission of skin lesions might have been induced by FIV status change over time due to glucocorticoid withdraw and by glucocorticoids withdraw itself.

PV Life Cycle Analysis

OpenAIRE

Karsten Wambach

2017-01-01

This presentation was part of the Workshop: Recycling, reuse and resource efficiency: New solutions for a PV circular economy - Results from the projects CABRISS and ECOSOLAR. The workshop was organized within Freiberg Silicon Days 2017.

Energy rating procedure for PV-modules; Energy rating procedure voor PV-modules

Energy Technology Data Exchange (ETDEWEB)

Van der Borg, N.J.C.M.; Jansen, M.J. [ECN Zon, Petten (Netherlands)

2005-10-15

The performance of PV-modules is usually characterized by the nominal power at standard test conditions. However more relevant for the end-user is the energy production. To arrive at a so-called energy rating procedure the P(G{sub i},T{sub m}) matrix is defined, which makes it possible to calculate the expected annual energy production of a PV-module at any given location with known frequency distribution of horizontal irradiation and ambient temperature. In order to make the de P(G{sub i},T{sub m}) independent of the time and location of the tests the effective irradiation (G{sub i}) is measured with a device with the same characteristics as the module under test. Such a device can be a suitable reference cell or, even better, the module under test itself. The latter, however, is only possible in case the module under test is stable in time. Measurements were performed to test the applicability of the so-called self-reference for a-Si modules. Furthermore the difference between the effective irradiance and the real irradiance (measured with a pyranometer) was quantified for the test location Petten, the Netherlands. The conclusions are: Self-reference is not applicable for a-Si modules because of the time instability, even after 1 full year of degradation; Self-reference signals (the short circuit current of the module under test) can be calibrated outdoor by comparison with a pyranometer at irradiance levels above 800 W/m{sup 2}. The uncertainty of such a calibration is within 3%; The difference between the effective irradiance and the real irradiance on annual basis at Petten is virtually zero for x-Si modules and about 1% for a-Si modules. [Dutch] Het is gebruikelijk om de prestatie van PV-modules te karakteriseren met het nominale vermogen onder standaard testcondities (STC). Echter dit nominaal vermogen geeft geen directe indicatie voor de energieopbrengst. Om tot een karakteristiek voor de energie-opbrengst (energy rating) te komen wordt de prestatie van de

How PV system ownership can impact the market value of residential homes

Energy Technology Data Exchange (ETDEWEB)

Klise, Geoffrey Taylor [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Johnson, Jamie L. [Energy Sense Finance, LLC, Punta Gorda, FL (United States)

2014-01-01

There are multiple ways for a homeowner to obtain the electricity generating and savings benefits offered by a photovoltaic (PV) system. These include purchasing a PV system through various financing mechanisms, or by leasing the PV system from a third party with multiple options that may include purchase, lease renewal or PV system removal. The different ownership options available to homeowners presents a challenge to appraisal and real estate professionals during a home sale or refinance in terms of how to develop a value that is reflective of the PV systems operational characteristics, local market conditions, and lender and underwriter requirements. This paper presents these many PV system ownership options with a discussion of what considerations an appraiser must make when developing the contributory value of a PV system to a residential property.

Analysis of Long-Term Performance of PV Systems

NARCIS (Netherlands)

Nordmann, T.; Clavadetscher, L.; van Sark, Wilfried; Green, M.

This report describes the activities, conclusions and continued efforts undertaken in Subtask 1 by the participating countries in IEA-PVPS Task 13. Subtask 1 examines the PV power plant as a system. It collects and studies the data supplied from installed operating PV plants from different countries

Reliability evaluation of an impedance-source PV microconverter

DEFF Research Database (Denmark)

Shen, Yanfeng; Liivik, Elizaveta; Blaabjerg, Frede

2018-01-01

The reliability of an impedance-source PV microconverter is evaluated based on the real-field mission profile. As part of a PV microinverter, the dc-dc microconverter is firstly described. Then the electro-thermal and lifetime models are built for the most reliability-critical components, i...

Estimation of PV energy production based on satellite data

Science.gov (United States)

Mazurek, G.

2015-09-01

Photovoltaic (PV) technology is an attractive source of power for systems without connection to power grid. Because of seasonal variations of solar radiation, design of such a power system requires careful analysis in order to provide required reliability. In this paper we present results of three-year measurements of experimental PV system located in Poland and based on polycrystalline silicon module. Irradiation values calculated from results of ground measurements have been compared with data from solar radiation databases employ calculations from of satellite observations. Good convergence level of both data sources has been shown, especially during summer. When satellite data from the same time period is available, yearly and monthly production of PV energy can be calculated with 2% and 5% accuracy, respectively. However, monthly production during winter seems to be overestimated, especially in January. Results of this work may be helpful in forecasting performance of similar PV systems in Central Europe and allow to make more precise forecasts of PV system performance than based only on tables with long time averaged values.

Highlight of Grid-connected PV systems in administrative buildings in Egypt

Directory of Open Access Journals (Sweden)

Dina Said

2017-03-01

Full Text Available Solar energy applications are becoming increasingly common in Egypt. The abundant sunshine in Egypt, as well as the increasing competitiveness of solar energy systems including- but not limited to photovoltaic (PV, – predicts that these technologies could be weighed to be raised in Egypt.PV systems are installed on roof tiles or other parts of building structures to supplement grid utility, reduce electric bills, and provide emergency back–up energy. Moreover, they simultaneously reduce significant amounts of CO2 emissions. It is foreseen, a number of residential and public buildings in Egypt are using solar power to cut electric utility bills significantly. The approximately payback period to recover the investment costs for PV systems is up to about 5 years.  In addition, it is more economical to use PV system than grid utility systems. The two components that determine the total initial price of a grid- connected PV system are the modules and the balance of systems (BOS. The BOS includes different components such as mounting frames, inverters and site- specific installation hardware.The Government of Egypt (GOE has endorsed the deployment of PV systems through three approaches. It started with a prime minister decree to install PV projects on one-thousand of the governmental buildings. This was followed by as an initiative called "Shamsk ya Masr", and finally the Feed-in Tariff (FiT projects.Following the prime minster decree the Egyptian Electricity Holding Company (EEHC and its affiliated companies took the lead to install PV systems at the top roof of their administrative buildings and interconnect these systems to the electricity network where the suitable locations have been selected for mounting them. About 90 PV systems have been already mounted with about a capacity of 9 MW. On the other hand, "Shamsk ya Masr" has considered energy efficiency (EE so as to complement the PV systems, which will be installed on administrative

Bio-reduction of plutonyl and neptunyl by Shewanella alga

International Nuclear Information System (INIS)

Reed, D.T.; Lucchini, J.F; Rittmann, B.E.; Songkasiri, W.

2005-01-01

Full text of publication follows: The results of a concurrent experimental and modeling study to investigate the bio-reduction of higher-valent plutonium and neptunium by Shewanella alga strain BrY are presented. S. Alga, as a facultative metal reducer, is representative of bacteria that will be important in defining the mobility of plutonium and neptunium species as they migrate from oxic to anoxic zones. This is also an important consideration in defining the long-term stability of bio-precipitated 'immobilized' plutonium phases under changing redox conditions in biologically active systems and subsequently the effectiveness of remediation/containment approaches used for bio-remediation. Neptunium (VI) is readily reduced in groundwaters by many organics. In biologically active systems, it is unlikely, for this reason, that this oxidation state of neptunium will be important. Under all conditions investigated, neptunium (V) was reduced to neptunium (IV) when anaerobic conditions were established for a wide variety of electron donors. This was evidences by 3-4 orders of magnitude reduction in solution concentration and confirmed by XANES analysis. This led to high bio-association and/or precipitation of the neptunium. Plutonium (VI), as was the case with neptunium (VI) was reduced by the organics typically present in biologically active systems. Analogous bio-reduction experiments with plutonium (V) and plutonium (VI) are in progress and are expected to show that bio-reduction will predominate under anaerobic conditions, as was the case with neptunium. These results for neptunium and plutonium show S. Alga to be an effective microbe for the bio-reduction, and consequently the immobilization, of these important actinide contaminants. (authors)

Performance evaluation of stand alone hybrid PV-wind generator

Energy Technology Data Exchange (ETDEWEB)

Nasir, M. N. M.; Saharuddin, N. Z.; Sulaima, M. F.; Jali, Mohd Hafiz; Bukhari, W. M.; Bohari, Z. H. [Faculty of Electrical Engineering, Universiti Teknikal Malaysia Melaka (UTeM), Hang Tuah Jaya, 76100 Melaka (Malaysia); Yahaya, M. S. [Faculty of Engineering Technology, Universiti Teknikal Malaysia Melaka (UTeM), Hang Tuah Jaya, 76100 Melaka (Malaysia)

2015-05-15

This paper presents the performance evaluation of standalone hybrid system on Photovoltaic (PV)-Wind generator at Faculty of Electrical Engineering (FKE), UTeM. The hybrid PV-Wind in UTeM system is combining wind turbine system with the solar system and the energy capacity of this hybrid system can generate up to charge the battery and supply the LED street lighting load. The purpose of this project is to evaluate the performance of PV-Wind hybrid generator. Solar radiation meter has been used to measure the solar radiation and anemometer has been used to measure the wind speed. The effectiveness of the PV-Wind system is based on the various data that has been collected and compared between them. The result shows that hybrid system has greater reliability. Based on the solar result, the correlation coefficient shows strong relationship between the two variables of radiation and current. The reading output current followed by fluctuate of solar radiation. However, the correlation coefficient is shows moderate relationship between the two variables of wind speed and voltage. Hence, the wind turbine system in FKE show does not operate consistently to produce energy source for this hybrid system compare to PV system. When the wind system does not fully operate due to inconsistent energy source, the other system which is PV will operate and supply the load for equilibrate the extra load demand.

Performance evaluation of stand alone hybrid PV-wind generator

Science.gov (United States)

Nasir, M. N. M.; Saharuddin, N. Z.; Sulaima, M. F.; Jali, Mohd Hafiz; Bukhari, W. M.; Bohari, Z. H.; Yahaya, M. S.

2015-05-01

This paper presents the performance evaluation of standalone hybrid system on Photovoltaic (PV)-Wind generator at Faculty of Electrical Engineering (FKE), UTeM. The hybrid PV-Wind in UTeM system is combining wind turbine system with the solar system and the energy capacity of this hybrid system can generate up to charge the battery and supply the LED street lighting load. The purpose of this project is to evaluate the performance of PV-Wind hybrid generator. Solar radiation meter has been used to measure the solar radiation and anemometer has been used to measure the wind speed. The effectiveness of the PV-Wind system is based on the various data that has been collected and compared between them. The result shows that hybrid system has greater reliability. Based on the solar result, the correlation coefficient shows strong relationship between the two variables of radiation and current. The reading output current followed by fluctuate of solar radiation. However, the correlation coefficient is shows moderate relationship between the two variables of wind speed and voltage. Hence, the wind turbine system in FKE show does not operate consistently to produce energy source for this hybrid system compare to PV system. When the wind system does not fully operate due to inconsistent energy source, the other system which is PV will operate and supply the load for equilibrate the extra load demand.

Performance evaluation of stand alone hybrid PV-wind generator

International Nuclear Information System (INIS)

Nasir, M. N. M.; Saharuddin, N. Z.; Sulaima, M. F.; Jali, Mohd Hafiz; Bukhari, W. M.; Bohari, Z. H.; Yahaya, M. S.

2015-01-01

This paper presents the performance evaluation of standalone hybrid system on Photovoltaic (PV)-Wind generator at Faculty of Electrical Engineering (FKE), UTeM. The hybrid PV-Wind in UTeM system is combining wind turbine system with the solar system and the energy capacity of this hybrid system can generate up to charge the battery and supply the LED street lighting load. The purpose of this project is to evaluate the performance of PV-Wind hybrid generator. Solar radiation meter has been used to measure the solar radiation and anemometer has been used to measure the wind speed. The effectiveness of the PV-Wind system is based on the various data that has been collected and compared between them. The result shows that hybrid system has greater reliability. Based on the solar result, the correlation coefficient shows strong relationship between the two variables of radiation and current. The reading output current followed by fluctuate of solar radiation. However, the correlation coefficient is shows moderate relationship between the two variables of wind speed and voltage. Hence, the wind turbine system in FKE show does not operate consistently to produce energy source for this hybrid system compare to PV system. When the wind system does not fully operate due to inconsistent energy source, the other system which is PV will operate and supply the load for equilibrate the extra load demand

Designing PV Incentive Programs to Promote Performance: A Reviewof Current Practice

Energy Technology Data Exchange (ETDEWEB)

Barbose, Galen; Wiser, Ryan; Bolinger, Mark

2007-06-01

Increasing levels of financial support for customer-sited photovoltaic (PV) systems, provided through publicly-funded incentive programs, has heightened concerns about the long-term performance of these systems. Given the barriers that customers face to ensuring that their PV systems perform well, and the responsibility that PV incentive programs bear to ensure that public funds are prudently spent, these programs should, and often do, play a critical role in ensuring that PV systems receiving incentives perform well. To provide a point of reference for assessing the current state of the art, and to inform program design efforts going forward, we examine the approaches to encouraging PV system performance used by 32 prominent PV incentive programs in the U.S. We identify eight general strategies or groups of related strategies that these programs have used to address performance issues, and highlight important differences in the implementation of these strategies among programs.

Analysis on the MPPT control of PV generation system using SPRW

Energy Technology Data Exchange (ETDEWEB)

Park, Min Won [Osaka University (Japan); Kim, Bong Tae; Lee, Jae Deuk; Yu, In Keun [Changwon National University (Korea)

2001-07-01

Photovoltaic (PV) system has been studied and watch with keen interest due to a clean and renewable power source. But, because the output power of PV system is not only unstable but also uncontrollable, the MPPT control of PV power system is still hard to be optimized with the tracking failure under the sudden fluctuation of irradiance. Authors proposed a novel transient phenomenon simulation method for PV power generation system under the real field weather condition(SPRW), and the research and development of PV power generation system is expected to be able to analyze easily and cheaply under various conditions with considering the sort of cell, the capacity of system and the used converter system. In this paper, a PV array was simulated to confirm the availability of SPRW. And, several real weather conditions were used with various MPPT controls. (author). 6 refs., 9 figs., 3 tabs.

An insight on advantage of hybrid sun–wind-tracking over sun-tracking PV system

International Nuclear Information System (INIS)

Rahimi, Masoud; Banybayat, Meisam; Tagheie, Yaghoub; Valeh-e-Sheyda, Peyvand

2015-01-01

Graphical abstract: Real photograph of hybrid sun–wind-tracking system. - Highlights: • Novel hybrid sun–wind-tracking system proposed to enhance PV cell performance. • The wind tracker can cool down the PV cell as sun-tracking system work. • The hybrid tracker achieved 7.4% increase in energy gain over the sun tracker. • The overall daily output energy gain was increased by 49.83% by using this system. - Abstract: This paper introduces the design and application of a novel hybrid sun–wind-tracking system. This hybrid system employs cooling effect of wind, besides the advantages of tracking sun for enhancing power output from examined hybrid photovoltaic cell. The principal experiment focuses on comparison between dual-axes sun-tracking and hybrid sun–wind-tracking photovoltaic (PV) panels. The deductions based on the research tests confirm that the overall daily output energy gain was increased by 49.83% compared with that of a fixed system. Moreover, an overall increase of about 7.4% in the output power was found for the hybrid sun–wind-tracking over the two-axis sun tracking system.

Consequences of Reducing the Cost of PV Modules on a PV Wind Diesel Hybrid System with Limited Sizing Components

Directory of Open Access Journals (Sweden)

Jones S. Silva

2012-01-01

Full Text Available The use of renewable resources for power supply in family homes has passed the stage of utopia to became a reality, with limits set by technical and economic parameters. This paper presents the results of a project originated from the initiative of a middle-class family to achieve energy independence at home. The starting point was the concept of home with “zero energy” in which the total energy available is equal to the energy consumed. The solution devised to meet the energy demand of the residence in question is a PV wind diesel hybrid system connected to the grid, with the possibility of energy storage in batteries and in the form of heating water and the environment of the house. As a restriction, the family requested that the system would represent little impact to the lifestyle and landscape. This paper aims to assess the consequences of reductions in the cost of the PV modules on the optimization space, as conceived by the software Homer. The results show that for this system, a 50% reduction in the cost of PV modules allows all viable solutions including PV modules.

Cost-Reduction Roadmap for Residential Solar Photovoltaics (PV),

Science.gov (United States)

Office (SETO) residential 2030 photovoltaics (PV) cost target of $0.05 per kilowatt-hour by identifying could influence system costs in key market segments. This report examines two key market segments that demonstrate significant opportunities for cost savings and market growth: installing PV at the time of roof

Recent developments in ASSERT-PV code for subchannel thermalhydraulics

International Nuclear Information System (INIS)

Rao, Y.F.; Hammouda, N.

2003-01-01

This paper summarises recent development of ASSERT-PV, and provides examples of applications to CANDU fuel bundles in predicting flow, heat transfer and sheath temperatures. The development work is intended to improve computational and phenomenological modelling capabilities of ASSERT-PV in simulating various flow scenarios in CANDU fuel bundles. The latest version of ASSERT-PV can be used for simulations of steady state or transient, subchannel thermalhydraulics in CANDU bundles under conditions up to and including post-dryout heat transfer. (author)

Industrial application of PV/T solar energy systems

International Nuclear Information System (INIS)

Kalogirou, S.A.; Tripanagnostopoulos, Y.

2007-01-01

Hybrid photovoltaic/thermal (PV/T) systems consist of PV modules and heat extraction units mounted together. These systems can simultaneously provide electrical and thermal energy, thus achieving a higher energy conversion rate of the absorbed solar radiation than plain photovoltaics. Industries show high demand of energy for both heat and electricity and the hybrid PV/T systems could be used in order to meet this requirement. In this paper the application aspects in the industry of PV/T systems with water heat extraction is presented. The systems are analyzed with TRNSYS program for three locations Nicosia, Athens and Madison that are located at different latitudes. The system comprises 300 m 2 of hybrid PV/T collectors producing both electricity and thermal energy and a 10 m 3 water storage tank. The work includes the study of an industrial process heat system operated at two load supply temperatures of 60 deg. C and 80 deg. C. The results show that the electrical production of the system, employing polycrystalline solar cells, is more than the amorphous ones but the solar thermal contribution is slightly lower. A non-hybrid PV system produces about 25% more electrical energy but the present system covers also, depending on the location, a large percentage of the thermal energy requirement of the industry considered. The economic viability of the systems is proven, as positive life cycle savings are obtained in the case of hybrid systems and the savings are increased for higher load temperature applications. Additionally, although amorphous silicon panels are much less efficient than the polycrystalline ones, better economic figures are obtained due to their lower initial cost, i.e., they have better cost/benefit ratio

Molecular Phylogenetic Exploration of Bacterial Diversity in a Bakreshwar (India) Hot Spring and Culture of Shewanella-Related Thermophiles

Science.gov (United States)

Ghosh, Dhritiman; Bal, Bijay; Kashyap, V. K.; Pal, Subrata

2003-01-01

The bacterial diversity of a hot spring in Bakreshwar, India, was investigated by a culture-independent approach. 16S ribosomal DNA clones derived from the sediment samples were found to be associated with gamma-Proteobacteria, cyanobacteria, and green nonsulfur and low-GC gram-positive bacteria. The first of the above phylotypes cobranches with Shewanella, a well-known iron reducer. This phylogenetic correlation has been exploited to develop culture conditions for thermophilic iron-reducing microorganisms. PMID:12839826

Grid Integration of PV Power based on PHIL testing using different Interface Algorithms

DEFF Research Database (Denmark)

Craciun, Bogdan-Ionut; Kerekes, Tamas; Sera, Dezso

2013-01-01

to be more active in grid support. Therefore, a better understanding and detailed analysis of the PV systems interaction with the grid is needed; hence power hardware in the loop (PHIL) testing involving PV power became an interesting subject to look into. To test PV systems for grid code (GC) compliance......Photovoltaic (PV) power among all renewable energies had the most accelerated growth rate in terms of installed capacity in recent years. Transmission System Operators (TSOs) changed their perspective about PV power and started to include it into their planning and operation, imposing PV systems...

Lifetime Evaluation of Grid-Connected PV Inverters Considering Panel Degradation Rates and Installation Sites

DEFF Research Database (Denmark)

Sangwongwanich, Ariya; Yang, Yongheng; Sera, Dezso

2018-01-01

Lifetime of PV inverters is affected by the installation sites related to different solar irradiance and ambient temperature profiles (also referred to as mission profiles). In fact, the installation site also affects the degradation rate of the PV panels, and thus long-term energy production...... and reliability. Prior-art lifetime analysis in PV inverters has not yet investigated the impact of PV panel degradations. This paper thus evaluates the lifetime of PV inverters considering panel degradation rates and mission profiles. Evaluations have been carried out on PV systems installed in Denmark...... and Arizona. The results reveal that the PV panel degradation rate has a considerable impact on the PV inverter lifetime, especially in the hot climate (e.g., Arizona), where the panel degrades at a faster rate. In that case, the PV inverter lifetime prediction can be deviated by 54%, if the impact of PV...

Solar Plus: A Holistic Approach to Distributed Solar PV | Solar Research |

Science.gov (United States)

customer economics. Illustration titled "The Solar Plus Home," showing depicting the relationship rate structures that affect the customer value of PV generation. At the same time, increasing PV . These issues have prompted the PV industry to consider new ways to optimize the customer value of

Maximum power point tracking controller for PV systems using neural networks

Energy Technology Data Exchange (ETDEWEB)

Bahgat, A.B.G. [Cairo Univ. (Egypt). Faculty of Engineering; Helwa, N.H.; Ahmad, G.E.; El Shenawy, E.T. [National Research Center, Dokki, Cairo (Egypt). Solar Energy Dept.

2005-07-01

This paper presents a development and implementation of a PC-based maximum power point tracker (MPPT) for PV system using neural networks (NN). The system consists of a PV module via a MPPT supplying a dc motor that drives an air fan. The control algorithm is developed to use the artificial NN for detecting the optimal operating point under different operating conditions, then the control action gives the driving signals to the MPPT. A PC is used for data acquisition, running the control algorithm, data storage, as well as data display and analysis. The system has been implemented and tested under various operating conditions. The experimental results showed that the PV system with MPPT always tracks the peak power point of the PV module under various operating conditions. The MPPT transmits about 97% of the actual maximum power generated by the PV module. The MPPT not only increases the power from the PV module to the load, but also maintains longer operating periods for the PV system. The air velocity and the air mass flow rate of the mechanical load are increased considerably, due to the increase of the PV system power. It is also found that the increase in the output energy due to using the MPPT is about 45.2% for a clear sunny day. (Author)

Large scale PV plants - also in Denmark. Project report

Energy Technology Data Exchange (ETDEWEB)

Ahm, P [PA Energy, Malling (Denmark); Vedde, J [SiCon. Silicon and PV consulting, Birkeroed (Denmark)

2011-04-15

Large scale PV (LPV) plants, plants with a capacity of more than 200 kW, has since 2007 constituted an increasing share of the global PV installations. In 2009 large scale PV plants with cumulative power more that 1,3 GWp were connected to the grid. The necessary design data for LPV plants in Denmark are available or can be found, although irradiance data could be improved. There seems to be very few institutional barriers for LPV projects, but as so far no real LPV projects have been processed, these findings have to be regarded as preliminary. The fast growing number of very large scale solar thermal plants for district heating applications supports these findings. It has further been investigated, how to optimize the lay-out of LPV plants. Under the Danish irradiance conditions with several winter months with very low solar height PV installations on flat surfaces will have to balance the requirements of physical space - and cost, and the loss of electricity production due to shadowing effects. The potential for LPV plants in Denmark are found in three main categories: PV installations on flat roof of large commercial buildings, PV installations on other large scale infrastructure such as noise barriers and ground mounted PV installations. The technical potential for all three categories is found to be significant and in the range of 50 - 250 km2. In terms of energy harvest PV plants will under Danish conditions exhibit an overall efficiency of about 10 % in conversion of the energy content of the light compared to about 0,3 % for biomass. The theoretical ground area needed to produce the present annual electricity consumption of Denmark at 33-35 TWh is about 300 km2 The Danish grid codes and the electricity safety regulations mention very little about PV and nothing about LPV plants. It is expected that LPV plants will be treated similarly to big wind turbines. A number of LPV plant scenarios have been investigated in detail based on real commercial offers and

Angle Resolved Performance Measurements on PV Glass and Modules

DEFF Research Database (Denmark)

Juutilainen, Line Tollund; Thorsteinsson, Sune; Poulsen, Peter Behrensdorff

2016-01-01

The angular response of PV-modules has significant impact on the energy production. This is especially pronounced in BIPV where installation angles often are far from optimal. Nevertheless, a gain in energy yield may be obtained by choosing a proper glass as superstrate. In this work we present...... the concept of PV balconies as cost efficient and easy way of integrating PV into buildings. The experimental work consists of the fabrication of single cell mini modules with different glass covering, and characterizing their angular response in a custom made setup, where only the direct sunlight is used...... as a light source. As a special case we estimate the annual yield for each glass in the case of PV balconies for a specific geographical location and orientation of the module....

Metabolic Characteristics of a Glucose-Utilizing Shewanella oneidensis Strain Grown under Electrode-Respiring Conditions.

Directory of Open Access Journals (Sweden)

Gen Nakagawa

Full Text Available In bioelectrochemical systems, the electrode potential is an important parameter affecting the electron flow between electrodes and microbes and microbial metabolic activities. Here, we investigated the metabolic characteristics of a glucose-utilizing strain of engineered Shewanella oneidensis under electrode-respiring conditions in electrochemical reactors for gaining insight into how metabolic pathways in electrochemically active bacteria are affected by the electrode potential. When an electrochemical reactor was operated with its working electrode poised at +0.4 V (vs. an Ag/AgCl reference electrode, the engineered S. oneidensis strain, carrying a plasmid encoding a sugar permease and glucose kinase of Escherichia coli, generated current by oxidizing glucose to acetate and produced D-lactate as an intermediate metabolite. However, D-lactate accumulation was not observed when the engineered strain was grown with a working electrode poised at 0 V. We also found that transcription of genes involved in pyruvate and D-lactate metabolisms was upregulated at a high electrode potential compared with their transcription at a low electrode potential. These results suggest that the carbon catabolic pathway of S. oneidensis can be modified by controlling the potential of a working electrode in an electrochemical bioreactor.

Economic and policy analysis for solar PV systems in Indiana

International Nuclear Information System (INIS)

Jung, Jinho; Tyner, Wallace E.

2014-01-01

In recent years, the energy market in the US and globally is expanding the production of renewable energy. Solar energy for electricity is also expanding in the US. Indiana is one of the states expanding solar energy with solar photovoltaic (PV) systems. Therefore, we conduct benefit cost analysis with several uncertain input variables to determine the economics of adopting solar PV systems in Indiana based on policy instruments that could increase adoption of solar PV systems. The specific objectives are analyses of the cost distribution of solar PV systems compared with grid electricity in homes and estimating the probability that solar can be cheaper than electricity from grids under different policy combinations. We first do the analysis under current policy and then the analysis under potential policy options for a variety of scenarios. Also, the results inform government policy makers on how effective the alternative policies for encouraging solar PV systems are. The results show that current policies are important in reducing the cost of solar PV systems. However, with current policies, there is only 50–50 chance of solar being cheaper than electricity from grids. If potential policies are implemented, solar PV systems can be more economical than grid electricity. - Highlights: • We investigate the economics of solar PV systems based on policy instruments. • We do scenario analyses under different combinations of policies. • We examine the probability of solar being cheaper than grid electricity for each scenario. • With current policies, there is 50–50 chance of solar being cheaper than the grid. • With depreciation and carbon tax, solar is much more economical than the grid

Continuing Developments in PV Risk Management: Strategies, Solutions, and Implications

Energy Technology Data Exchange (ETDEWEB)

Lowder, T.; Mendelsohn, M.; Speer, B.; Hill, R.

2013-02-01

As the PV industry matures, successful risk management practices will become more imperative to ensure investor confidence, control costs, and facilitate further growth. This report discusses several key aspects of risk management during the commercial- and utility-scale project life cycle, from identification of risks, to the process of mitigating and allocating those risks among project parties, to transferring those risks through insurance. The report also explores novel techniques in PV risk management, options to offload risks onto the capital markets, and innovative insurance policies (namely warranty policies) that address risks unique to the PV sector. One of the major justifications for robust risk management in the PV industry is the cost-reduction opportunities it affords. If the PV industry can demonstrate the capability to successfully manage its risks, thereby inspiring confidence in financiers, it may be able to obtain a lower cost of capital in future transactions. A lower cost of capital translates to a lower cost of energy, which will in turn enhance PV?s competitiveness at a time when it will have to rely less on subsidies to support its market penetration.

Validation of PV-RPM Code in the System Advisor Model.

Energy Technology Data Exchange (ETDEWEB)

Klise, Geoffrey Taylor [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Lavrova, Olga [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Freeman, Janine [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2017-04-01

This paper describes efforts made by Sandia National Laboratories (SNL) and the National Renewable Energy Laboratory (NREL) to validate the SNL developed PV Reliability Performance Model (PV - RPM) algorithm as implemented in the NREL System Advisor Model (SAM). The PV - RPM model is a library of functions that estimates component failure and repair in a photovoltaic system over a desired simulation period. The failure and repair distributions in this paper are probabilistic representations of component failure and repair based on data collected by SNL for a PV power plant operating in Arizona. The validation effort focuses on whether the failure and repair dist ributions used in the SAM implementation result in estimated failures that match the expected failures developed in the proof - of - concept implementation. Results indicate that the SAM implementation of PV - RPM provides the same results as the proof - of - concep t implementation, indicating the algorithms were reproduced successfully.

Innovation and technology transfer through global value chains: Evidence from China's PV industry

International Nuclear Information System (INIS)

Zhang, Fang; Gallagher, Kelly Sims

2016-01-01

China's success as a rapid innovation follower in the infant Photovoltaic (PV) industry surprised many observers. This paper explores how China inserted itself into global clean energy innovation systems by examining the case of the solar PV industry. The paper decomposes the global PV industrial value chain, and determines the main factors shaping PV technology transfer and diffusion. Chinese firms first entered PV module manufacturing through technology acquisition, and then gradually built their global competitiveness by utilizing a vertical integration strategy within segments of the industry as well as the broader PV value chain. The main drivers for PV technology transfer from the global innovation system to China are global market formation policy, international mobilization of talent, the flexibility of manufacturing in China, and belated policy incentives from China's government. The development trajectory of the PV industry in China indicates that innovation in cleaner energy technologies can occur through both global and national innovation processes, and knowledge exchange along the global PV value chain. - Highlights: •The value chain analytical approach is synergized with the theories of technology transfer and innovation systems. •A detailed review of how China integrated itself into the global solar PV innovation system is provided. •Four main factors shape PV technology transfer to China across various value chain segments. •Innovation in cleaner energy technologies is a combination of global and national innovation processes.

Power Generation Potential and Cost of a Roof Top Solar PV System in Kathmandu, Nepal

Science.gov (United States)

Sanjel, N.; Zhand, A.

2017-12-01

The paper presents a comparative study of the 3 most used solar PV module technologies in Nepal, which are Si-mono-crystalline, Si-poly-crystalline and Si-amorphous. The aim of the paper is to present and discuss the recorded Global Solar Radiation, received in the Kathmandu valley by three different, Si-mono-crystalline, Si-poly-crystalline and Si-amorphous calibrated solar cell pyranometers and to propose the best-suited solar PV module technology for roof top solar PV systems inside the Kathmandu valley. Data recorded over the course of seven months, thus covering most of the seasonal meteorological conditions determining Kathmandu valley's global solar radiation reception are presented. The results indicate that the Si-amorphous pyranometer captured 1.56% more global solar radiation than the Si-mono-crystalline and 18.4% more than Si-poly-crystalline pyranometer over the course of seven months. Among the three pyranometer technologies the maximum and minimum cell temperature was measured by the Si-mono-crystalline pyranometer. Following the technical data and discussion, an economical analysis, using the versatile software tool PVSYST V5.01is used to calculate the life cycle costs of a 1kW roof top solar PV RAPS system, with battery storage, and a 1kW roof top solar PV grid connected system with no energy storage facility, through simulations, using average recorded global solar radiation data for the KTM valley and investigated market values for each solar PV module and peripheral equipment costs.

Fault Analysis and Detection in Microgrids with High PV Penetration

Energy Technology Data Exchange (ETDEWEB)

El Khatib, Mohamed [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hernandez Alvidrez, Javier [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Ellis, Abraham [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2017-05-01

In this report we focus on analyzing current-controlled PV inverters behaviour under faults in order to develop fault detection schemes for microgrids with high PV penetration. Inverter model suitable for steady state fault studies is presented and the impact of PV inverters on two protection elements is analyzed. The studied protection elements are superimposed quantities based directional element and negative sequence directional element. Additionally, several non-overcurrent fault detection schemes are discussed in this report for microgrids with high PV penetration. A detailed time-domain simulation study is presented to assess the performance of the presented fault detection schemes under different microgrid modes of operation.

Photovoltaic (PV) energy in the Netherlands and Switzerland. A comparison

International Nuclear Information System (INIS)

Van der Loo, F.; Spiessens, P.

1995-01-01

The development of photovoltaic (PV) energy in Switzerland and the Netherlands is compared for a number of aspects. The Swiss have realized more PV capacity. Also the economic conditions to develop PV are better in Switzerland than in the Netherlands. In Switzerland the public support is mobilized for solar energy while in the Netherlands a social basis is created for wind energy. 3 ills., 3 tabs

Tools for PV (photovoltaic) plant operators: Nowcasting of passing clouds

Czech Academy of Sciences Publication Activity Database

Paulescu, M.; Badescu, V.; Brabec, Marek

2013-01-01

Roč. 54, č. 1 (2013), s. 104-112 ISSN 0360-5442 R&D Projects: GA MŠk LD12009 Institutional support: RVO:67985807 Keywords : PV (photovoltaic) plants * Sunshine number * Nowcasting * ARIMA (Autoregressive Integrated Moving Average ) modeling Subject RIV: JE - Non-nuclear Energetics, Energy Consumption ; Use Impact factor: 4.159, year: 2013

Shewanella putrefaciens Adhesion and Biofilm Formation on Food Processing Surfaces

Science.gov (United States)

Bagge, Dorthe; Hjelm, Mette; Johansen, Charlotte; Huber, Ingrid; Gram, Lone

2001-01-01

Laboratory model systems were developed for studying Shewanella putrefaciens adhesion and biofilm formation under batch and flow conditions. S. putrefaciens plays a major role in food spoilage and may cause microbially induced corrosion on steel surfaces. S. putrefaciens bacteria suspended in buffer adhered readily to stainless steel surfaces. Maximum numbers of adherent bacteria per square centimeter were reached in 8 h at 25°C and reflected the cell density in suspension. Numbers of adhering bacteria from a suspension containing 108 CFU/ml were much lower in a laminar flow system (modified Robbins device) (reaching 102 CFU/cm2) than in a batch system (reaching 107 CFU/cm2), and maximum numbers were reached after 24 h. When nutrients were supplied, S. putrefaciens grew in biofilms with layers of bacteria. The rate of biofilm formation and the thickness of the film were not dependent on the availability of carbohydrate (lactate or glucose) or on iron starvation. The number of S. putrefaciens bacteria on the surface was partly influenced by the presence of other bacteria (Pseudomonas fluorescens) which reduced the numbers of S. putrefaciens bacteria in the biofilm. Numbers of bacteria on the surface must be quantified to evaluate the influence of environmental factors on adhesion and biofilm formation. We used a combination of fluorescence microscopy (4′,6′-diamidino-2-phenylindole staining and in situ hybridization, for mixed-culture studies), ultrasonic removal of bacteria from surfaces, and indirect conductometry and found this combination sufficient to quantify bacteria on surfaces. PMID:11319118

Synthetic Klebsiella pneumoniae-Shewanella oneidensis Consortium Enables Glycerol-Fed High-Performance Microbial Fuel Cells.

Science.gov (United States)

Li, Feng; Yin, Changji; Sun, Liming; Li, Yuanxiu; Guo, Xuewu; Song, Hao

2018-05-01

Microbial fuel cell (MFC) is an eco-friendly bio-electrochemical sys-tem that uses microorganism as biocatalyst to convert biomass into electricity. Glycerol, as a waste in the biodiesel refinery processes, is an appealing substrate for MFC. Nevertheless, glycerol cannot be utilized as carbon source by well-known exoelectrogens such as Shewanella oneidensis. Herein, to generate electricity by rapidly harnessing glycerol, the authors rationally constructed a Klebsiella pneumoniae-Shewanella oneidensis microbial consortium to efficiently harvest electricity from glyc-erol, in which K. pneumoniae converted glycerol into lactate, fed to S. oneidensis as carbon source and electron donor. To improve electricity output, the authors systematically engineered the consortium in terms of carbon flux distribution and efficiency of extracellular electron transfer (EET). To direct more carbon flux to lactate biosynthesis in K. pneumoniae, the authors eliminated the ethanol pathway by knocking out the alcohol dehydrogenase gene (adhE), and enhanced lactate biosynthesis by heterologously expressing a lactate dehydrogen-ase gene (ldhD) from Lactobacillus bulgaricus and a lactate transporter gene (lldP) from Escherichia coli. To facilitate EET between S. oneidensis and anode surfaces, a biosynthetic flavins pathway from Bacillus subtilis is introduced into S. oneidensis. The author further optimized the glycerol concentration, thus S. oneidensis could be continuously fed with lactate synthesized from K. pneumoniae at a constant rate. Our glycerol-fed MFC generated a maximum power density of 19.9 mW/m 2 , significantly higher than that of the wild-type consor-tium. This work suggested that engineering microbial consortia is an effi-cient strategy to expand the spectrum of usable carbon sources and promote electricity power production in MFCs. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Developing High PV Penetration Cases for Frequency Response Study of U.S. Western Interconnection: Preprint

Energy Technology Data Exchange (ETDEWEB)

Tan, Jin; Zhang, Yingchen; Veda, Santosh; Elgindy, Tarek; Liu, Yilu

2017-04-11

Recent large penetrations of solar photovoltaic (PV) generation and the inertial characteristics of inverter-based generation technologies have caught the attention of those in the electric power industry in the United States. This paper presents a systematic approach to developing test cases of high penetrations of PV for the Western Interconnection. First, to examine the accuracy of the base case model, the Western Electricity Coordinating Council (WECC) model is validated by using measurement data from synchronized phasor measurement units. Based on the 2022 Light Spring case, we developed four high PV penetration cases for the WECC system that are of interest to the industry: 5% PV+15 % wind, 25% PV+15% wind, 45% PV+15% wind, 65% PV+15% wind). Additionally, a method to project PV is proposed that is based on collected, realistic PV distribution information, including the current and future PV power plant locations and penetrations in the WECC system. Both the utility-scale PV plant and residential rooftop PV are included in this study.

Effect of PV module output power on module temperature; Taiyo denchi no shutsuryoku henka ga module hyomen ondo ni oyobosu eikyo

Energy Technology Data Exchange (ETDEWEB)

Hongo, T; Kitamura, A [Kansai Electric Power Co. Inc., Osaka (Japan); Igaki, K; Mizumoto, T [Kanden Kako Co. Inc., Osaka (Japan)

1996-10-27

Effect of the photovoltaic (PV) module output power variation on the module surface temperature has been investigated by field measurements. PV modules with capacity of 54 W were used for the temperature measurements. Three 2 kW-class PV systems were operated. T-type thermocouples were used for measuring temperatures. Measurement time intervals were 15 minutes, 30 minutes, 60 minutes, and 24 hours. Measurement period was between May 25, 1995 and June 25, 1996. The surface temperature increased during non-loaded PV output, and decreased during load-carrying PV output. Difference of the surface temperature between non-loaded PV output and load-carrying PV output was 3.5{degree}C at maximum through a year. The surface temperature was saturated within 30 minutes. When PV output was changed in 30 or 60 minutes interval, the variation of surface temperature was distinctly observed. When PV output was changed in 15 minutes interval, it was not observed distinctly. There was no difference of the surface temperatures during the time zones with less solar radiation, such as in the morning and evening, and at night. Except these time zones, difference of the surface temperatures was 3.5{degree}C at maximum. 4 figs.

Methodology for the optimal design of tansformerless grid-connected PV interters

DEFF Research Database (Denmark)

Koutroulis, E.; Blaabjerg, Frede

2012-01-01

inverter, such that the PV inverter levelised cost of the generated electricity is minimised. The proposed method constitutes a systematic design process, which is capable to explore the impact of the PV inverter configuration on the trade-off between the PV inverter manufacturing cost and the power losses...

DOE Request for Information (RFI) DE-FOA-0000153 PV Manufacturing Initiative

Energy Technology Data Exchange (ETDEWEB)

none,

2010-02-01

This draft report summarizes the results of the U.S. Department of Energy PV Manufacturing Request for Information (RFI), DE-FOA-0000153, that was released in September 2009. The PV Manufacturing Initiative is intended to help facilitate the development of a strong PV manufacturing industry in the United States.

Task 9. PV deployment in developing countries. Institutional framework and financial instruments for PV deployment in developing countries

Energy Technology Data Exchange (ETDEWEB)

NONE

2003-09-15

This report for the International Energy Agency (IEA) made by Task 9 of the Photovoltaic Power Systems (PVPS) programme takes a look at the institutional framework and financial instruments necessary for PV deployment in developing countries. This guide describes the institutional and financial aspects that need to be addressed to ensure that a long term sustainable (and profitable) PV market is established in developing countries. The guide details main fundamental functions that need to be performed such as the agents needed to perform the functions and their differing roles within the framework, the relationships between these agents and the financial instruments available. It is stated that the majority of the aspects recommended in this guide can be adopted to two main PV deployment models: direct sales and rural electrification and development programmes. It is noted that both approaches will have to be tailored and adapted to local conditions.

Household photovoltaic market in Xining, Qingha province, China: the role of local PV business

International Nuclear Information System (INIS)

Ling, S.; Boardman, B.

2002-01-01

This paper assesses the present and future market for household photovoltaic (PV) systems in rural Northwest China, especially from the PV commerce at Xining, Qinghai Province. This unsubsidised free market is now met by the emerging PV industry in China, which includes cell and module manufacturers, and PV system distributors and assemblers. For widespread deployment of such a renewable energy technology, the development of a local free market seems more successful than donor- or 'government subsidy'-driven programmes. Presently, there is a thriving infant PV industry in Northwest China, mostly centred in Xining. Xining-based PV sales companies have extensive networks for selling, marketing and servicing household PV systems for rural farmers and nomads. Small systems are now ordinary items on sale in local shops. Based on interviews and fieldwork observations with seven major PV sales companies in Xining, the household PV market is assessed from the present business operations of these companies. Detail of primary sources is given with the aim of archiving seminal progress in the history of photovoltaic power. The results suggest that although the household PV market will continue to grow, current government and international sponsored PV programmes can create both opportunities and barriers for the infant PV market an industry in China. (author)

The impact of high PV penetration levels on electrical distribution networks

Energy Technology Data Exchange (ETDEWEB)

Collinson, A; Beddoes, A; Thornycroft, J [Halcrow (United Kingdom); Strbac, G; Jenkins, N [UMIST, Manchester (United Kingdom); Verhoeven, B [KEMA (Netherlands)

2002-07-01

This report describes the results of a collaborative study by EA Technology, UMIST and Halcrow into the effects of large-scale connection of dispersed photovoltaic (PV) power systems on the national electricity supply network. The report is intended to help manufacturers and installers of PV systems and electricity companies to understand the issues associated with grid connection of PV power systems. The increased use of PV systems is expected to have a significant impact on the design, operation and management of electricity supply networks. The study examined three main areas: probability and risk analysis of islanding; PV and network voltage control (including analysis of voltage control in a commercial, domestic retrofit and domestic new build scenarios); and future low voltage network design and operational policies.

Room-temperature synthesis of gold nanoparticles and nanoplates using Shewanella algae cell extract

International Nuclear Information System (INIS)

Ogi, Takashi; Saitoh, Norizoh; Nomura, Toshiyuki; Konishi, Yasuhiro

2010-01-01

Biosynthesis of spherical gold nanoparticles and gold nanoplates was achieved at room temperature and pH 2.8 when cell extract from the metal-reducing bacterium Shewanella algae was used as both a reducing and shape-controlling agent. Cell extract, prepared by sonicating a suspension of S. algae cells, was capable of reducing 1 mol/m 3 aqueous AuCl 4 - ions into elemental gold within 10 min when H 2 gas was provided as an electron donor. The time interval lapsed since the beginning of the bioreductive reaction was found to be an important factor in controlling the morphology of biogenic gold nanoparticles. After 1 h, there was a large population of well-dispersed, spherical gold nanoparticles with a mean size of 9.6 nm. Gold nanoplates with an edge length of 100 nm appeared after 6 h, and 60% of the total nanoparticle population was due to gold nanoplates with an edge length of 100-200 nm after 24 h. The yield of gold nanoplates prepared with S. algae extract was four times higher than that prepared with resting cells of S. algae. The resulting biogenic gold nanoparticle suspensions showed a large variation in color, ranging from pale pink to purple due to changes in nanoparticle morphology.

Room-temperature synthesis of gold nanoparticles and nanoplates using Shewanella algae cell extract

Energy Technology Data Exchange (ETDEWEB)

Ogi, Takashi; Saitoh, Norizoh; Nomura, Toshiyuki; Konishi, Yasuhiro, E-mail: yasuhiro@chemeng.osakafu-u.ac.j [Osaka Prefecture University, Department of Chemical Engineering (Japan)

2010-09-15

Biosynthesis of spherical gold nanoparticles and gold nanoplates was achieved at room temperature and pH 2.8 when cell extract from the metal-reducing bacterium Shewanella algae was used as both a reducing and shape-controlling agent. Cell extract, prepared by sonicating a suspension of S. algae cells, was capable of reducing 1 mol/m{sup 3} aqueous AuCl{sub 4}{sup -} ions into elemental gold within 10 min when H{sub 2} gas was provided as an electron donor. The time interval lapsed since the beginning of the bioreductive reaction was found to be an important factor in controlling the morphology of biogenic gold nanoparticles. After 1 h, there was a large population of well-dispersed, spherical gold nanoparticles with a mean size of 9.6 nm. Gold nanoplates with an edge length of 100 nm appeared after 6 h, and 60% of the total nanoparticle population was due to gold nanoplates with an edge length of 100-200 nm after 24 h. The yield of gold nanoplates prepared with S. algae extract was four times higher than that prepared with resting cells of S. algae. The resulting biogenic gold nanoparticle suspensions showed a large variation in color, ranging from pale pink to purple due to changes in nanoparticle morphology.

Automatic fault diagnosis in PV systems with distributed MPPT

International Nuclear Information System (INIS)

Solórzano, J.; Egido, M.A.

2013-01-01

Highlights: • An automatic failure diagnosis procedure for PV systems with DMPPT is presented. • The different failures diagnosed and their effects on the PV systems are described. • No use of irradiance and temperature sensors decreasing the cost of the system. • Voltage and current analysis to diagnose different failures. • Hot-spots, localized dirt, shading, module degradation and cable losses diagnosis. - Abstract: This work presents a novel procedure for fault diagnosis in PV systems with distributed maximum power point tracking at module level—power optimizers (DC/DC) or micro-inverters (DC/AC). Apart from the power benefits obtained when an irregular irradiance distribution is present, this type of systems permit the monitoring of the PV plant parameters at the module level: voltage and current at the working power point. With these parameters, a prototype diagnosis tool has been developed in Matlab and it has been experimentally verified in a real rooftop PV generator by applying different failures. The tool can diagnose the following failures: fixed object shading (with distance estimation), localized dirt, generalized dirt, possible hot-spots, module degradation and excessive losses in DC cables. In addition, it alerts the user of the power losses produced by each failure and classifies the failures by their severity. This system does not require the use of irradiance or temperature sensors, except for the generalized dirt failure, reducing the cost of installation, especially important in small PV systems

Exploring the Economic Value of EPAct 2005's PV Tax Credits

Energy Technology Data Exchange (ETDEWEB)

Bolinger, Mark; Wiser, Ryan; Ing, Edwin

2006-03-28

The market for grid-connected photovoltaics (PV) in the US has grown dramatically in recent years, driven in large part by PV grant or ''buy-down'' programs in California, New Jersey, and many other states. The recent announcement of a new 11-year, $3.2 billion PV program in California suggests that state policy will continue to drive even faster growth over the next decade. Federal policy has also played a role, primarily by providing commercial PV systems access to tax benefits, including accelerated depreciation (5-year MACRS schedule) and a business energy investment tax credit (ITC). With the signing of the Energy Policy Act of 2005 (EPAct) on August 8, the federal government is poised to play a much more significant future role in supporting both commercial and residential PV systems. Specifically, EPAct increased the federal ITC for commercial PV systems from 10% to 30% of system costs, and also created a new 30% ITC (capped at $2000) for residential solar systems. Both changes went into effect on January 1, 2006, and--absent an extension (for which the solar industry has already begun lobbying)--will last for a period of two years: the new residential ITC will expire, and the 30% commercial ITC will revert back to 10%, on January 1, 2008. How much economic value do these new and expanded federal tax credits really provide to PV system purchasers? And what implications might they hold for state/utility PV grant programs? Using a generic (i.e., non-state-specific) cash flow model, this report explores these questions. We begin with a discussion of the taxability of PV grants and their interaction with federal credits, as this issue significantly affects the analysis that follows. We then calculate the incremental value of EPAct's new and expanded credits for PV systems of different sizes, and owned by different types of entities. We conclude with a discussion of potential implications for purchasers of PV systems, as well as for

The Moroccan solar plan. A comparative analysis of CSP and PV utilization until 2020

International Nuclear Information System (INIS)

Richts, Christoph

2012-01-01

The present master thesis conducts technical and economic simulations of large-scale Photovoltaic (PV) and Concentrated Solar Power (CSP) plants for the Moroccan Solar Plan. It provides a database of performance indicators such as energy yields, capacity factors, typical efficiencies and losses of technical components, LCOE, and difference costs (DC: LCOE minus avoided costs of the conventional power system) for fixed tilted, 1-axis horizontal, 1-axis vertical and 2-axis tracking PV and CSP with no, 6, 12 and 18 full load hours of thermal storage. HelioClim irradiation data of 2005 for the sites in Ouarzazate, Ain Ben Mathar, Boujdour, Laayoune and Tarfaya is used ranging between 1,927 - 2,428 kWh/m 2 /y (DNI) and 1,968 - 2,154 kWh/m 2 /y (GHI). In the base scenario minimum LCOE are 9.6 - 5.4 EURct/kWh for PV (2012 - 2020) varying between 0.90 - 1.55 EURct/kWh among sites and technologies. CSP reaches 12.8 - 9.2 EURct/kWh and a bandwidth of 2.3 - 1.6 EURct/kWh. Average DC are lowest for horizontal 1-axis tracking (0.4 and -7.7 EURct/kWh for plants built in 2012 and 2020 respectively) and CSP with 6 hours of storage (1.3 and -3.5 EURct/kWh). PV is cheaper for all sites and technologies due to higher learning curves and less initial investment, but cannot contribute to coverage of the daily evening peak in Morocco. Four different MSP-scenarios with 2000 MW of solar energy require total investments of 3.7 - 7.5 billion EUR and yield 7.9% - 12.8% of the electricity demand in 2020 (given a growth 7%/y) depending on the ratio of PV and CSP utilization. The average LCOE are 8.3 - 11.7 EURct/kWh and the total discounted DC (10%/y) are -254 - 391 million EUR. Thus, solar energy is partly less expensive than a business-as-usual scenario. An extensive sensitivity analysis for WACC and price escalation of conventional energy shows that for only PV and only CSP scenarios in 55 and 22 out of 72 cases the DC are negative - although no environmental costs for conventional

Heritage plaza parking lots improvement project- Solar PV installation

Energy Technology Data Exchange (ETDEWEB)

Hooks, Todd [Agua Caliente Indian Reservation, Palm Springs, CA (United States)

2017-03-31

The Agua Caliente Band of Cahuilla Indians (ACBCI or the “Tribe”) installed a 79.95 kW solar photovoltaic (PV) system to offset the energy usage costs of the Tribal Education and Family Services offices located at the Tribe's Heritage Plaza office building, 90I Tahquitz Way, Palm Springs, CA, 92262 (the "Project"). The installation of the Solar PV system was part of the larger Heritage Plaza Parking Lot Improvements Project and mounted on the two southern carport shade structures. The solar PV system will offset 99% of the approximately 115,000 kWh in electricity delivered annually by Southern California Edison (SCE) to the Tribal Education and Family Services offices at Heritage Plaza, reducing their annual energy costs from approximately $22,000 annually to approximately $200. The total cost of the proposed solar PV system is $240,000.

Optimum Design Of On Grid Pv System Using Tracking System

Directory of Open Access Journals (Sweden)

Saeed Mansour

2015-05-01

Full Text Available Abstract The fossil fuel is a main issue in the world due to the increase of fossil fuel cost and the depletion of the fossil fuel with continuous increasing demand on electricity. With continuous decrease of PV panels cost it is interesting to consider generation of electricity from PV system. To provide electric energy to a load in a remote area where electric grid utility is not available or connection with grid utility is available there are two approaches of photovoltaic system PV without tracking system Fixed System and PV with tracking systems. The result shows that the energy production by using PV with tracking system generates more energy in comparison with fixed panels system. However the cost per produced KWH is less in case of using fixed panels. This is the backbone in choice between two approaches of photovoltaic system. In this work a system design and cost analysis for two approaches of photovoltaic system are considered.

Evolution of Cell Size Homeostasis and Growth Rate Diversity during Initial Surface Colonization of Shewanella oneidensis.

Science.gov (United States)

Lee, Calvin K; Kim, Alexander J; Santos, Giancarlo S; Lai, Peter Y; Lee, Stella Y; Qiao, David F; Anda, Jaime De; Young, Thomas D; Chen, Yujie; Rowe, Annette R; Nealson, Kenneth H; Weiss, Paul S; Wong, Gerard C L

2016-09-06

Cell size control and homeostasis are fundamental features of bacterial metabolism. Recent work suggests that cells add a constant size between birth and division ("adder" model). However, it is not known how cell size homeostasis is influenced by the existence of heterogeneous microenvironments, such as those during biofilm formation. Shewanella oneidensis MR-1 can use diverse energy sources on a range of surfaces via extracellular electron transport (EET), which can impact growth, metabolism, and size diversity. Here, we track bacterial surface communities at single-cell resolution to show that not only do bacterial motility appendages influence the transition from two- to three-dimensional biofilm growth and control postdivisional cell fates, they strongly impact cell size homeostasis. For every generation, we find that the average growth rate for cells that stay on the surface and continue to divide (nondetaching population) and that for cells that detach before their next division (detaching population) are roughly constant. However, the growth rate distribution is narrow for the nondetaching population, but broad for the detaching population in each generation. Interestingly, the appendage deletion mutants (ΔpilA, ΔmshA-D, Δflg) have significantly broader growth rate distributions than that of the wild type for both detaching and nondetaching populations, which suggests that Shewanella appendages are important for sensing and integrating environmental inputs that contribute to size homeostasis. Moreover, our results suggest multiplexing of appendages for sensing and motility functions contributes to cell size dysregulation. These results can potentially provide a framework for generating metabolic diversity in S. oneidensis populations to optimize EET in heterogeneous environments.

Estimation of Maximum Allowable PV Connection to LV Residential Power Networks

DEFF Research Database (Denmark)

Demirok, Erhan; Sera, Dezso; Teodorescu, Remus

2011-01-01

Maximum photovoltaic (PV) hosting capacity of low voltage (LV) power networks is mainly restricted by either thermal limits of network components or grid voltage quality resulted from high penetration of distributed PV systems. This maximum hosting capacity may be lower than the available solar...... potential of geographic area due to power network limitations even though all rooftops are fully occupied with PV modules. Therefore, it becomes more of an issue to know what exactly limits higher PV penetration level and which solutions should be engaged efficiently such as over sizing distribution...

Size optimization of stand-alone photovoltaic (PV) room air conditioners

International Nuclear Information System (INIS)

Chen, Chien-Wei; Zahedi, A.

2006-01-01

Sizing of a stand-alone PV system determines the main cost of the system. PV electricity cost is determined by the amount of solar energy received, hence the actual climate and weather conditions such as solar irradiance and ambient temperature affect the size required and cost of the system. Air conditioning demand also depends on the weather conditions. Therefore, sizing a PV powered air conditioner must consider the characteristics of local climate and temperature. In this paper, sizing procedures and special considerations for air conditioning under Melbourne's climatic conditions is presented. The reliability of various PV-battery size combinations is simulated by MATLAB. As a result, excellent system performance can be predicated.(Author)

Integrating Solar PV in Utility System Operations

Energy Technology Data Exchange (ETDEWEB)

Mills, A.; Botterud, A.; Wu, J.; Zhou, Z.; Hodge, B-M.; Heany, M.

2013-10-31

This study develops a systematic framework for estimating the increase in operating costs due to uncertainty and variability in renewable resources, uses the framework to quantify the integration costs associated with sub-hourly solar power variability and uncertainty, and shows how changes in system operations may affect these costs. Toward this end, we present a statistical method for estimating the required balancing reserves to maintain system reliability along with a model for commitment and dispatch of the portfolio of thermal and renewable resources at different stages of system operations. We estimate the costs of sub-hourly solar variability, short-term forecast errors, and day-ahead (DA) forecast errors as the difference in production costs between a case with “realistic” PV (i.e., subhourly solar variability and uncertainty are fully included in the modeling) and a case with “well behaved” PV (i.e., PV is assumed to have no sub-hourly variability and can be perfectly forecasted). In addition, we highlight current practices that allow utilities to compensate for the issues encountered at the sub-hourly time frame with increased levels of PV penetration. In this analysis we use the analytical framework to simulate utility operations with increasing deployment of PV in a case study of Arizona Public Service Company (APS), a utility in the southwestern United States. In our analysis, we focus on three processes that are important in understanding the management of PV variability and uncertainty in power system operations. First, we represent the decisions made the day before the operating day through a DA commitment model that relies on imperfect DA forecasts of load and wind as well as PV generation. Second, we represent the decisions made by schedulers in the operating day through hour-ahead (HA) scheduling. Peaking units can be committed or decommitted in the HA schedules and online units can be redispatched using forecasts that are improved

Energy performance of water hybrid PV/T collectors applied to combisystems of Direct Solar Floor type

Energy Technology Data Exchange (ETDEWEB)

Fraisse, G.; Johannes, K. [Laboratoire Optimisation de la Conception et Ingenierie de l' Environnement, Ecole Superieure d' Ingenieurs de Chambery, Campus Scientifique Savoie Technolac, 73376 Le Bourget du Lac Cedex (France); Menezo, C. [Centre de Thermique de Lyon, Domaine Scientifique de La Doua, Bat. Freyssinet, 20, Avenue A. Einstein, 69621 Villeurbanne Cedex (France)

2007-11-15

The integration of photovoltaic (PV) modules in buildings allows one to consider a multifunctional frame and then to reduce the cost by substitution of components. In order to limit the rise of the cell operating temperature, a photovoltaics/thermal (PV/T) collector combines a solar water heating collector and PV cells. The recovered heat energy can be used for heating systems and domestic hot water. A combination with a Direct Solar Floor is studied. Its low operating temperature level is appropriate for the operating conditions of the mono- or poly-crystalline photovoltaic modules which are selected in that study. However, for a system including a glass covered collector and localised in Macon area in France, we show that the annual photovoltaic cell efficiency is 6.8% which represents a decrease of 28% in comparison with a conventional non-integrated PV module of 9.4% annual efficiency. This is obviously due to a temperature increase related to the cover. On the other hand, we show that without a glass cover, the efficiency is 10% which is 6% better than a standard module due to the cooling effect. Moreover, in the case of a glazed PV/T collector with a conventional control system for Direct Solar Floor, the maximum temperature reached at the level of the PV modules is higher than 100{sup o}C. This is due to the oversize of the collectors during the summer when the heating needs are null, i.e. without a heated swimming pool for example. This temperature level does not allow the use of EVA resin (ethylene vinyl acetate) in PV modules due to strong risks of degradation. The current solution consists of using amorphous cells or, if we do not enhance the thermal production, uncovered PV/T collector. Further research led to water hybrid PV/T solar collectors as a one-piece component, both reliable and efficient, and including the thermal absorber, the heat exchanger and the photovoltaic functions. (author)

Is solar PV generated electricity cheap in South Africa?

CSIR Research Space (South Africa)

Roro, Kittessa T

2015-07-01

Full Text Available This presentation reflects on photovoltaic (PV) generated electricity in South Africa, and whether it is a cheaper alternative to current generated electricity in the country. It is projected that by 2019 the installed capacity of PV could...

Designing PV powered LED products - Integration of PV technology in innovative products

NARCIS (Netherlands)

Reinders, Angelina H.M.E.; de Boer, Andries; de Winter, Arjan; Haverlag, Marco; Ossenbrink Sinke, W.; Helm, P.

2009-01-01

This study covers the design of innovative product concepts based on a combination of PV and LED technology. The products were developed in a project that took place in 2008 and 2009 during a cooperation of the University of Twente with Philips Lighting. It is shown that surprisingly unpredictable -

Life cycle cost analysis of single slope hybrid (PV/T) active solar still

International Nuclear Information System (INIS)

Kumar, Shiv; Tiwari, G.N.

2009-01-01

This paper presents the life cycle cost analysis of the single slope passive and hybrid photovoltaic (PV/T) active solar stills, based on the annual performance at 0.05 m water depth. Effects of various parameters, namely interest rate, life of the system and the maintenance cost have been taken into account. The comparative cost of distilled water produced from passive solar still (Rs. 0.70/kg) is found to be less than hybrid (PV/T) active solar still (Rs. 1.93/kg) for 30 years life time of the systems. The payback periods of the passive and hybrid (PV/T) active solar still are estimated to be in the range of 1.1-6.2 years and 3.3-23.9 years, respectively, based on selling price of distilled water in the range of Rs. 10/kg to Rs. 2/kg. The energy payback time (EPBT) has been estimated as 2.9 and 4.7 years, respectively. (author)

Oil field and freshwater isolates of Shewanella putrefaciens have lipopolysaccharide polyacrylamide gel profiles characteristic of marine bacteria

International Nuclear Information System (INIS)

Pickard, C.; Foght, J.M.; Pickard, M.A.; Westlake, D.W.S.

1993-01-01

The lipopolysaccharide structure of oil field and freshwater isolates of bacteria that reduce ferric iron, recently classified as strains of Shewanella putrefaciens, was analyzed using polyacrylamide gel electrophoresis and a lipopolysaccharide-specific silver-staining procedure. The results demonstrate that all the oil field and freshwater isolates examined exhibited the more hydrophobic R-type lipopolysaccharide, which has been found to be characteristic of Gram-negative marine bacteria. This hydrophobic lipopolysaccharide would confer an advantage on bacteria involved in hydrocarbon degradation by assisting their association with the surface of oil droplets. 15 refs., 1 fig

On-line monitoring system of PV array based on internet of things technology

Science.gov (United States)

Li, Y. F.; Lin, P. J.; Zhou, H. F.; Chen, Z. C.; Wu, L. J.; Cheng, S. Y.; Su, F. P.

2017-11-01

The Internet of Things (IoT) Technology is used to inspect photovoltaic (PV) array which can greatly improve the monitoring, performance and maintenance of the PV array. In order to efficiently realize the remote monitoring of PV operating environment, an on-line monitoring system of PV array based on IoT is designed in this paper. The system includes data acquisition, data gateway and PV monitoring centre (PVMC) website. Firstly, the DSP-TMS320F28335 is applied to collect indicators of PV array using sensors, then the data are transmitted to data gateway through ZigBee network. Secondly, the data gateway receives the data from data acquisition part, obtains geographic information via GPS module, and captures the scenes around PV array via USB camera, then uploads them to PVMC website. Finally, the PVMC website based on Laravel framework receives all data from data gateway and displays them with abundant charts. Moreover, a fault diagnosis approach for PV array based on Extreme Learning Machine (ELM) is applied in PVMC. Once fault occurs, a user alert can be sent via E-mail. The designed system enables users to browse the operating conditions of PV array on PVMC website, including electrical, environmental parameters and video. Experimental results show that the presented monitoring system can efficiently real-time monitor the PV array, and the fault diagnosis approach reaches a high accuracy of 97.5%.

Reconciling Consumer and Utility Objectives in the Residential Solar PV Market

Science.gov (United States)

Arnold, Michael R.

Today's energy market is facing large-scale changes that will affect all market players. Near the top of that list is the rapid deployment of residential solar photovoltaic (PV) systems. Yet that growing trend will be influenced multiple competing interests between various stakeholders, namely the utility, consumers and technology provides. This study provides a series of analyses---utility-side, consumer-side, and combined analyses---to understand and evaluate the effect of increases in residential solar PV market penetration. Three urban regions have been selected as study locations---Chicago, Phoenix, Seattle---with simulated load data and solar insolation data at each locality. Various time-of-use pricing schedules are investigated, and the effect of net metering is evaluated to determine the optimal capacity of solar PV and battery storage in a typical residential home. The net residential load profile is scaled to assess system-wide technical and economic figures of merit for the utility with an emphasis on intraday load profiles, ramp rates and electricity sales with increasing solar PV penetration. The combined analysis evaluates the least-cost solar PV system for the consumer and models the associated system-wide effects on the electric grid. Utility revenue was found to drop by 1.2% for every percent PV penetration increase, net metering on a monthly or annual basis improved the cost-effectiveness of solar PV but not battery storage, the removal of net metering policy and usage of an improved the cost-effectiveness of battery storage and increases in solar PV penetration reduced the system load factor. As expected, Phoenix had the most favorable economic scenario for residential solar PV, primarily due to high solar insolation. The study location---solar insolation and load profile---was also found to affect the time of year at which the largest net negative system load was realized.

Valley of Death analysis for polymer PV technology; Valley of Death analyse voor polymere PV technologie

Energy Technology Data Exchange (ETDEWEB)

Schoots, K. [ECN Beleidsstudies, Petten (Netherlands)

2013-12-15

This report describes the results of a qualitative study of the barriers that actors involved in the development and commercialization of polymer solar cells, may encounter. The purpose of this socio-economic research is to identify these barriers for the (market) development of thin film polymeric PV technology and to develop strategies for them in order to overcome the constraints. The necessary data are collected from interviews with actors who are active in the development and deployment of conventional solar cells. Based on the results from this study, it is conclude that it is important for the Organic PV industry to carry out many market experiments beyond the built environment. The report provides recommendations with regard to the markets in which these experiments are most likely to succeed and which drivers should be taken into account [Dutch] Dit rapport beschrijft de resultaten van een kwalitatief onderzoek naar de barrieres die actoren, betrokken bij de ontwikkeling en marktintroductie van polymere zonnecellen, kunnen tegenkomen. Het doel van dit sociaal-economische onderzoek is deze barrieres voor de (markt)ontwikkeling van dunne film polymere PV technologie te identificeren en strategieen te ontwikkelen om ze voor te zijn of ze te overbruggen. De benodigde gegevens worden verzameld uit interviews met actoren die actief zijn in de ontwikkeling en uitrol van conventionele zonnecellen. Op basis van de resultaten uit dit onderzoek komen we tot de conclusie dat het voor de Organische PV sector belangrijk is veel marktexperimenten aan te gaan buiten de gebouwde omgeving. Het rapport geeft aanbevelingen in welke soort markten deze experimenten de meeste kans van slagen hebben en met welke drivers van marktpartijen rekening moet worden gehouden.

PV-wind hybrid system performance. A new approach and a case study

International Nuclear Information System (INIS)

Arribas, Luis; Cano, Luis; Cruz, Ignacio; Mata, Montserrat; Llobet, Ermen

2010-01-01

Until now, there is no internationally accepted guideline for the measurement, data exchange and analysis of PV-Wind Hybrid Systems. As there is a need for such a tool, so as to overcome the barrier that the lack of confidence due to the absence of reliability means for the development of the market of Hybrid Systems, an effort has been made to suggest one tool for PV-Wind Hybrid Systems. The suggested guidelines presented in this work are based on the existing guidelines for PV Systems, as a PV-Wind Hybrid system can be roughly thought of as a PV System to which wind generation has been added. So, the guidelines for PV Systems are valid for the PV-Wind System, and only the part referred to wind generation should be included. This has been the process followed in this work. The proposed method is applied to a case study, the CICLOPS Project, a 5 kW PV, 7.5 kW Wind Hybrid system installed at the Isolated Wind Systems Test Site that CIEMAT owns in CEDER (Soria, Spain). This system has been fully monitored through a year and the results of the monitoring activity, characterizing the long-term performance of the system are shown in this work. (author)

PV-wind hybrid system performance. A new approach and a case study

Energy Technology Data Exchange (ETDEWEB)

Arribas, Luis; Cano, Luis; Cruz, Ignacio [Departamento de Energias Renovables, CIEMAT, Avda. Complutense 22, 28040 Madrid (Spain); Mata, Montserrat; Llobet, Ermen [Ecotecnia, Roc Boronat 78, 08005 Barcelona (Spain)

2010-01-15

Until now, there is no internationally accepted guideline for the measurement, data exchange and analysis of PV-Wind Hybrid Systems. As there is a need for such a tool, so as to overcome the barrier that the lack of confidence due to the absence of reliability means for the development of the market of Hybrid Systems, an effort has been made to suggest one tool for PV-Wind Hybrid Systems. The suggested guidelines presented in this work are based on the existing guidelines for PV Systems, as a PV-Wind Hybrid system can be roughly thought of as a PV System to which wind generation has been added. So, the guidelines for PV Systems are valid for the PV-Wind System, and only the part referred to wind generation should be included. This has been the process followed in this work. The proposed method is applied to a case study, the CICLOPS Project, a 5 kW PV, 7.5 kW Wind Hybrid system installed at the Isolated Wind Systems Test Site that CIEMAT owns in CEDER (Soria, Spain). This system has been fully monitored through a year and the results of the monitoring activity, characterizing the long-term performance of the system are shown in this work. (author)

Comparative Analysis and Considerations for PV Interconnection Standards in the United States and China

Energy Technology Data Exchange (ETDEWEB)

None

2017-01-01

The main objectives of this report are to evaluate China's photovoltaic (PV) interconnection standards and the U.S. counterparts and to propose recommendations for future revisions to these standards. This report references the 2013 report Comparative Study of Standards for Grid-Connected PV System in China, the U.S. and European Countries, which compares U.S., European, and China's PV grid interconnection standards; reviews various metrics for the characterization of distribution network with PV; and suggests modifications to China's PV interconnection standards and requirements. The recommendations are accompanied by assessments of four high-penetration PV grid interconnection cases in the United States to illustrate solutions implemented to resolve issues encountered at different sites. PV penetration in China and in the United States has significantly increased during the past several years, presenting comparable challenges depending on the conditions of the grid at the point of interconnection; solutions are generally unique to each interconnected PV installation or PV plant.

Residential Solar PV Planning in Santiago, Chile: Incorporating the PM10 Parameter

Directory of Open Access Journals (Sweden)

Gustavo Cáceres

2014-12-01

Full Text Available This paper addresses an economic study of the installation of photovoltaic (PV solar panels for residential power generation in Santiago, Chile, based on the different parameters of a PV system, such as efficiency. As a performance indicator, the Levelized Cost of Energy (LCOE was used, which indicates the benefit of the facility vs. the current cost of electrical energy. In addition, due to a high level of airborne dusts typically associated with PM10, the effect of the dust deposition on PV panels’ surfaces and the effect on panel performance are examined. Two different scenarios are analyzed: on-grid PV plants and off-grid PV plants.

Modeling of a VMJ PV array under Gaussian high intensity laser power beam condition

Science.gov (United States)

Eom, Jeongsook; Kim, Gunzung; Park, Yongwan

2018-02-01

The high intensity laser power beaming (HILPB) system is one of the most promising systems in the long-rang wireless power transfer field. The vertical multi-junction photovoltaic (VMJ PV) array converts the HILPB into electricity to power the load or charges a battery. The output power of a VMJ PV array depends mainly on irradiance values of each VMJ PV cells. For simulating an entire VMJ PV array, the irradiance profile of the Gaussian HILPB and the irradiance level of the VMJ PV cell are mathematically modeled first. The VMJ PV array is modeled as a network with dimension m*n, where m represents the number of VMJ PV cells in a column, and n represents the number of VMJ PV cells in a row. In order to validate the results obtained in modeling and simulation, a laboratory setup was developed using 55 VMJ PV array. By using the output power model of VMJ PV array, we can establish an optimal power transmission path by the receiver based on the received signal strength. When the laser beam from multiple transmitters aimed at a VMJ PV array at the same time, the received power is the sum of all energy at a VMJ PV array. The transmitter sends its power characteristics as optically coded laser pulses and powers as HILPB. Using the attenuated power model and output power model of VMJ PV array, the receiver can estimate the maximum receivable powers from the transmitters and select optimal transmitters.

Polymicrobial bacteremia caused by Escherichia coli, Edwardsiella tarda, and Shewanella putrefaciens.

Science.gov (United States)

Wang, I-Kuan; Lee, Ming-Hsun; Chen, Yu-Ming; Huang, Chiu-Ching

2004-09-01

Edwardsiella tarda, a member of Enterobacteriaceae, is found in freshwater and marine environments and in animals living in these environments. This bacterium is primarily associated with gastrointestinal diseases, and has been isolated from stool specimens obtained from persons with or without clinical infectious diseases. Shewanella putrefaciens, a saprophytic gram-negative rod, is rarely responsible for clinical syndromes in humans. Debilitated status and exposure to aquatic environments are the major predisposing factors for E. tarda or S. putrefaciens infection. A 61-year-old woman was febrile with diarrhea 8 hours after ingesting shark meat, and two sets of blood cultures grew Escherichia coli, E. tarda and S. putrefaciens at the same time. She was successfully treated with antibiotics. We present this rare case of polymicrobial bacteremia caused by E. coli, E. tarda and S. putrefaciens without underlying disease, which is the first found in Taiwan. This rare case of febrile diarrhea with consequent polymicrobial bacteremia emphasizes that attention should always be extended to these unusual pathogens.

Seasonal energy storage - PV-hydrogen systems

Energy Technology Data Exchange (ETDEWEB)

Leppaenen, J. [Neste Oy/NAPS (Finland)

1998-10-01

PV systems are widely used in remote areas e.g. in telecommunication systems. Typically lead acid batteries are used as energy storage. In northern locations seasonal storage is needed, which however is too expensive and difficult to realise with batteries. Therefore, a PV- battery system with a diesel backup is sometimes used. The disadvantages of this kind of system for very remote applications are the need of maintenance and the need to supply the fuel. To overcome these problems, it has been suggested to use hydrogen technologies to make a closed loop autonomous energy storage system

Solar PV O&M Standards and Best Practices - Existing Gaps and Improvement Efforts

Energy Technology Data Exchange (ETDEWEB)

Klise, Geoffrey Taylor [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Balfour, John R. [High Performance PV, Phoenix, AZ (United States); Keating, T. J. [SunSpec Alliance, San Jose, CA (United States)

2014-11-01

As greater numbers of photovoltaic (PV) systems are being installed, operations & maintenance (O&M) activities will need to be performed to ensure the PV system is operating as designed over its useful lifetime. To mitigate risks to PV system availability and performance, standardized procedures for O&M activities are needed to ensure high reliability and long-term system bankability. Efforts are just getting underway to address the need for standard O&M procedures as PV gains a larger share of U.S. generation capacity. Due to the existing landscape of how and where PV is installed, including distributed generation from small and medium PV systems, as well as large, centralized utility-scale PV, O&M activities will require different levels of expertise and reporting, making standards even more important. This report summarizes recent efforts made by solar industry stakeholders to identify the existing standards and best practices applied to solar PV O&M activities, and determine the gaps that have yet to be, or are currently being addressed by industry.

Performance of a PV module augmented by a plane reflector

Energy Technology Data Exchange (ETDEWEB)

Ahmad, G. E; Hussein, H. M. S; Mohamad, M. A [Dokki, Giza (Egypt)

2000-07-01

This paper presents a comparative experimental study on the performance of a PV module augmented by a south facing titled plane reflector and another identical one without reflector. The tilt angles of the two PV modules and reflector overhang are selected to be according to a previous theoretical study by the authors. The reflector tilt angle has been changed once a month so that the reflected beams from the plane reflector cover the total surface area of the PV module all days of every month during the high solar radiation period (i.e. three hours before and after solar noon). The study has been carried out on the two PV modules for a complete year under the actual atmospheric conditions of Cairo, Egypt. The measuring system used in the study comprises a data acquisition system, a computer, an electronic load and weather station. The experimental results indicate that the plane reflector enhances the yearly output energy of the PV module y about 22%. [Spanish] Este articulo presenta un estudio comparativo experimental sobre el rendimiento de un modulo de PV aumentado por un reflector plano inclinado mirando hacia el sur y otro identico sin reflector. Los angulos de inclinacion de los dos modulos y el reflector sobresaliente se seleccionan para que esten de acuerdo con un estudio teorico previo hecho por los autores. El angulo de inclinacion del reflector se cambio una vez al mes de manera que los rayos reflejados por el reflector plano cubrieran el area total de la superficie del modulo de PV todos los dias de cada mes durante el periodo de radiacion alto (o sea tres horas antes y despues del medio dia solar). El estudio ha sido llevado a cabo en dos modulos de PV durante un ano completo bajo condiciones atmosfericas reales de El Cairo, Egipto. El sistema de medicion usado en el estudio comprende un sistema de adquisicion de datos, una computadora, una memoria electronica y una estacion climatologica. Los resultados experimentales indican que el reflector plano

Xanthomonas citri pv. citri pathotypes

DEFF Research Database (Denmark)

Di Lorenzo, Flaviana; Silipo, Alba; Gersby, Lotte Bettina Andersen

2017-01-01

Xanthomonas citri pv. citri is the pathogen responsible for Asiatic citrus canker, one of the most serious citrus diseases worldwide. The lipopolysaccharide (LPS) molecule has been demonstrated to be involved in X. citri pv. citri virulence. Despite enormous progress in investigations of the mole...

The Historical Evolution of South Korea's Solar PV Policies since the 1970's

International Nuclear Information System (INIS)

Hyun Jin Yu, Julie; Popiolek, Nathalie

2013-01-01

The study aims at analyzing the historical evolution of South Korea's solar PV policies from the 1970's until today. An in-depth analysis of different policy instruments has been conducted to understand the PV policy context and the consequences of public policies in the PV sector in terms of patents, manufacturing capacity, PV installations, and impacts on the national economy and energy transition. Also, the key success factors and barriers in South Korea's past PV policies have been identified to make recommendations for future development

PV inverter test setup for European efficiency, static and dynamic MPPT efficiency evaluation

DEFF Research Database (Denmark)

Sera, Dezso; Teodorescu, Remus; Valentini, Massimo

2008-01-01

This paper concerns the evaluation of performance of grid-connected PV inverters in terms of conversion efficiency, European efficiency, static and dynamic MPP efficiency. Semi-automated tests were performed in the PV laboratory of the Institute of Energy Technology at the Aalborg University...... (Denmark) on a commercial transformerless PV inverter. Thanks to the available experimental test setups, that provide the required high measuring accuracy, and the developed PV simulator, which is required for MPPT performance evaluation, PV Inverters can be pretested before being tested by accredited...

What's stopping a huge expansion of the PV market?

International Nuclear Information System (INIS)

Varadi, P.F.

1998-01-01

Over the past 25 years the terrestrial PV industry has turned into a billion-dollar global business. The necessary technology is available and substantial market growth is continuing. It has often been said that the cost of PV must come down further before the technology really takes off. However the author argues here that the dominant segments of the market are not price-sensitive and that the future explosive expansion of PV markets will need financing on a global basis, assured quality in the products, and the institution of an extensive public-awareness programme of advertising, promotion and education. (author)

Performance Study of Photovoltaic-Thermal (Pv/T) Solar Collector with ·-Grooved Absorber Plate

International Nuclear Information System (INIS)

Mohd Yusof Othman; Hafidz Ruslan; Kamaruzzaman Sopian; Jin, G.L.

2009-01-01

A hybrid photovoltaic-thermal solar collector has been designed, built and its performance has been studied. The advantage of the collector is that it can generate electricity and heat simultaneously. Photovoltaic module SHARP NE-80E2EA with maximum output power of 80 W was used to generate electricity. The module also acts as heat absorber of the collector. Single pass ·-groove collector made of aluminium sheet with 0.7 mm thickness has been used to collect heat generated. Study was conducted under a designed halogen lamps solar simulator with intensities set at 386 ± 8 Wm -2 and 817 ± 8 Wm -2 . The speed of air passing through the collector was set between (69.6 ± 2.2) x 10 -4 kg/s to (695.8 ± 2.2) x 10 -4 kg/s. The objective of the study is to compare the performance of PV/T collector with and without ·-groove absorber. The study found that the PV/T collector with ·-groove absorber plate has higher efficiency than the PV/T without ·-groove absorber. The electrical and thermal efficiencies are also increased when radiation intensity and speed of air increase. (author)

Assessment of subchannel code ASSERT-PV for flow-distribution predictions

International Nuclear Information System (INIS)

Nava-Dominguez, A.; Rao, Y.F.; Waddington, G.M.

2014-01-01

Highlights: • Assessment of the subchannel code ASSERT-PV 3.2 for the prediction of flow distribution. • Open literature and in-house experimental data to quantify ASSERT-PV predictions. • Model changes assessed against vertical and horizontal flow experiments. • Improvement of flow-distribution predictions under CANDU-relevant conditions. - Abstract: This paper reports an assessment of the recently released subchannel code ASSERT-PV 3.2 for the prediction of flow-distribution in fuel bundles, including subchannel void fraction, quality and mass fluxes. Experimental data from open literature and from in-house tests are used to assess the flow-distribution models in ASSERT-PV 3.2. The prediction statistics using the recommended model set of ASSERT-PV 3.2 are compared to those from previous code versions. Separate-effects sensitivity studies are performed to quantify the contribution of each flow-distribution model change or enhancement to the improvement in flow-distribution prediction. The assessment demonstrates significant improvement in the prediction of flow-distribution in horizontal fuel channels containing CANDU bundles

Assessment of subchannel code ASSERT-PV for flow-distribution predictions

Energy Technology Data Exchange (ETDEWEB)

Nava-Dominguez, A., E-mail: navadoma@aecl.ca; Rao, Y.F., E-mail: raoy@aecl.ca; Waddington, G.M., E-mail: waddingg@aecl.ca

2014-08-15

Highlights: • Assessment of the subchannel code ASSERT-PV 3.2 for the prediction of flow distribution. • Open literature and in-house experimental data to quantify ASSERT-PV predictions. • Model changes assessed against vertical and horizontal flow experiments. • Improvement of flow-distribution predictions under CANDU-relevant conditions. - Abstract: This paper reports an assessment of the recently released subchannel code ASSERT-PV 3.2 for the prediction of flow-distribution in fuel bundles, including subchannel void fraction, quality and mass fluxes. Experimental data from open literature and from in-house tests are used to assess the flow-distribution models in ASSERT-PV 3.2. The prediction statistics using the recommended model set of ASSERT-PV 3.2 are compared to those from previous code versions. Separate-effects sensitivity studies are performed to quantify the contribution of each flow-distribution model change or enhancement to the improvement in flow-distribution prediction. The assessment demonstrates significant improvement in the prediction of flow-distribution in horizontal fuel channels containing CANDU bundles.

Numerical investigation of heat pipe-based photovoltaic–thermoelectric generator (HP-PV/TEG) hybrid system

International Nuclear Information System (INIS)

Makki, Adham; Omer, Siddig; Su, Yuehong; Sabir, Hisham

2016-01-01

Highlights: • Integration of TE generators with a heat pipe-based PV module as a hybrid system is proposed. • Numerical transient modeling based on the energy balance equations of the system was performed. • Integration of TE generators with PV module aid operating the solar cells at a steady level in harsh conditions. - Abstract: Photovoltaic (PV) cells are able to absorb about 80% of the solar spectral irradiance, however, certain percentage accounts for electricity conversion depending on the cell technology employed. The remainder energy however, can elevate the silicon junction temperature in the PV encapsulation perilously, resulting in deteriorated performance. Temperature rise at the PV cell level is addressed as one of the most critical issues that can seriously degrade and shortens the life-time of the PV cells, hence thermal management of the PV module during operation is considered essential. Hybrid PV designs which are able to simultaneously generate electrical energy and utilize the waste heat have been proven to be the most promising solution. In this study, theoretical investigation of a hybrid system comprising of thermoelectric generator integration with a heat pipe-based Photovoltaic/Thermal (PV/T) absorber is proposed and evaluated. The system presented incorporates a PV panel for direct electricity generation, a heat pipe for excessive heat absorption from the PV cells and a thermoelectric generator (TEG) performing direct heat-to-electricity conversion. A mathematical model based on the energy balance within the system is developed to evaluate the performance of the hybrid integration and the improvements associated with the thermal management of PV cells. Results are presented in terms of the overall system efficiency compared to a conventional PV panel under identical operating conditions. The integration of TEG modules with PV cells in such way aid improving the performance of the PV cells in addition to utilizing the waste

Final Technical Report: Advanced Measurement and Analysis of PV Derate Factors.

Energy Technology Data Exchange (ETDEWEB)

King, Bruce Hardison [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Burton, Patrick D. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hansen, Clifford [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Jones, Christian Birk [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2015-12-01

The Advanced Measurement and Analysis of PV Derate Factors project focuses on improving the accuracy and reducing the uncertainty of PV performance model predictions by addressing a common element of all PV performance models referred to as “derates”. Widespread use of “rules of thumb”, combined with significant uncertainty regarding appropriate values for these factors contribute to uncertainty in projected energy production.

Review of Artificial Abrasion Test Methods for PV Module Technology

Energy Technology Data Exchange (ETDEWEB)

Miller, David C. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Muller, Matt T. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Simpson, Lin J. [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2016-08-01

This review is intended to identify the method or methods--and the basic details of those methods--that might be used to develop an artificial abrasion test. Methods used in the PV literature were compared with their closest implementation in existing standards. Also, meetings of the International PV Quality Assurance Task Force Task Group 12-3 (TG12-3, which is concerned with coated glass) were used to identify established test methods. Feedback from the group, which included many of the authors from the PV literature, included insights not explored within the literature itself. The combined experience and examples from the literature are intended to provide an assessment of the present industry practices and an informed path forward. Recommendations toward artificial abrasion test methods are then identified based on the experiences in the literature and feedback from the PV community. The review here is strictly focused on abrasion. Assessment methods, including optical performance (e.g., transmittance or reflectance), surface energy, and verification of chemical composition were not examined. Methods of artificially soiling PV modules or other specimens were not examined. The weathering of artificial or naturally soiled specimens (which may ultimately include combined temperature and humidity, thermal cycling and ultraviolet light) were also not examined. A sense of the purpose or application of an abrasion test method within the PV industry should, however, be evident from the literature.

On-Grid Solar PV versus Diesel Electricity Generation in Sub-Saharan Africa: Economics and GHG Emissions

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Saule Baurzhan

2017-03-01

Full Text Available Many power utilities in sub-Saharan Africa (SSA have inadequate generation capacity, unreliable services, and high costs. They also face capital constraints that restrict them from making the investments necessary for capacity expansion. Capacity shortages have compelled power utilities to use leased emergency power-generating units, mainly oil-fired diesel generators, as a short-term solution. An economic analysis is carried out to compare the economic net present value (ENPV of fuel savings, as well as the greenhouse gas (GHG savings, from investing capital in a solar PV power-generation plant with those from investing the same amount of funds into a diesel power plant. The results show that ENPV is negative for the solar PV plant, whereas it has a large positive value for the diesel plant. In addition, the diesel plant would be almost three times as effective in reducing GHG emissions as the same value of investment in the solar PV plant. Even with solar investment costs falling, it will take 12 to 24 years of continuous decline before solar PV becomes cost-effective for SSA. The capital cost of solar PV would need to drop to US$1058.4 per kW to yield the same level of ENPV as the diesel plant.

Dynamic response evaluation of sensorless MPPT method for hybrid PV-DFIG wind turbine system

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Danvu Nguyen

2016-01-01

Full Text Available This research proposes a sensorless Maximum Power Point Tracking (MPPT method for a hybrid Photovoltaic-Wind system, which consists of Photovoltaic (PV system and Doubly-Fed Induction Generator (DFIG Wind Turbine. In the hybrid system, the DC/DC converter output of the PV system is directly connected to the DC-link of DFIG’s back-to-back converter. Therefore, the PV inverter and its associated circuit can be removed in this structure. Typically, the PV power is monitored by using PV current sensor and PV voltage sensor for MPPT. In this paper, the powers of converters on grid side and rotor side of DFIG are used to estimate the PV power without the PV current sensor. That can efficiently reduce the cost of the hybrid system. The detailed analysis of the sensorless MPPT method, which includes derived equations and operation response, is also presented in this paper. In addition, an overview of PV-DFIG research in literature is stated to supply comprehensive knowledge of related research.

Life cycle assessment of a medium sized PV facility in Scotland

International Nuclear Information System (INIS)

Muneer, T; Younes, S.; Kubie, J.

2006-01-01

Napier University's School of Engineering has been involved in education and research in renewable energy for the past 35 years. With the aim demonstration of the viability of production of solar electricity at a high latitude location such as Edinburgh (56 degree north)the school undertook to commission a medium-sized PV electricity generation project. The installation of 32 rows of BP solar silicon panels covering a total area of 160 square metres ensures generation of 17.6kW peak (AC) power. Figure 1 presents a photograph of the facility under discussion. The project has been part (60%) financed by UK Government's PV electricity demonstration programme through the office of Energy Saving Trust. The University has plans to generate hydrogen from solar electricity that will be stored for noctumal production of electricity using fuel-cell technology, thus completing the complete cycle of generation, storage and reproduction of sustainable energy. The project that is part of Napier University's Merchiton Campus was completed on 6 April 2005 and since that date AC power has been fed into the University grid with the peak power being enough to operate up to 80 of the 500 computers at the University's Jack Kilby Computing Centre. DC power is produced from the BP solar high efficincy (17%) monocrystalline panels, each of which produces 90W of power at 22 Volts. This DC electricity is then fed into a total of four inverters hence converting to a stable AC supply. Two of the larger inverters receive current from 12 rows (4 strings x 3 rows) each, while the smaller inverters take power in from 4 rows (2 strings x 2 rows) each. The PV facility is fully instrumented with both input (incident solar energy) and PV electrical energy output recorded at a frequency of 15 minutes. This article will present the energetic, environmental and monetary life cycle assessment (LCA) of the above facility.(Author)

Annual Prediction Output of an RADTIRC-PV Module

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Daria Freier

2018-03-01

Full Text Available The number of solar photovoltaic (PV installations has been increasing worldwide but the high capital cost of installation continues to be the main challenge, particularly in many developing countries. The solar concentrator, a device that focuses the sunlight onto a small area, has the potential to minimize the use of expensive PV material while maintaining the system’s performance, ultimately bringing down its overall cost. This study aims to predict the annual electrical output of a specific concentrator design called the rotationally asymmetrical dielectric totally internally reflecting concentrator (RADTIRC. The aforementioned design is assumed to be installed in Berlin/Brandenburg, Germany. First, a short review of concentrators is provided. Next, a description of the RADTIRC and the previous research that revolved around it are provided. Afterwards, the key parameters that are needed to determine the annual electrical output of the RADTIRC are explained before presenting the results of the simulations. It was found that the yearly energy yield was increased by a factor of 2.29 when the RADTIRC-PV module was used when compared with the non-concentrating PV module.

The German experience with grid-connected PV-systems

International Nuclear Information System (INIS)

Erge, T.; Hoffmann, V.U.; Kiefer, K.

2001-01-01

Grid-connected photovoltaics experienced increasing attention in Germany in recent years and are expected to face a major boost at the beginning of the new millennium. Highlights like the German 100,000-Roofs-Solar-Programme, PV programmes at schools financed by utilities and governments (e.g. 'SONNEonline' by PreussenElektra, 'Sonne in der Schule' by BMWi and 'Sonne in der Schule' by Bayernwerk) and large centralised installations of MW size ('Neue Messe Munchen' by Bayernwerk and 'Energiepark Mont-Cenis' by state Nordrhein-Westfalen, Stadtwerke Herne and European Union) count for the potential of grid-connected PV. Today in Germany a typical grid-connected PV installation of 1 kW nominal power produces average annual energy yields of 700 kWh (dependent on location and system components) and shows a high operating availability. The price per kWh from PV installations is still significantly higher than the price for conventional energy, but new funding schemes and cost models (like the large increase of feed-in tariff in Germany due to the Act on Granting Priority to Renewable Energy Sources in 2000) give optimism about the future. (Author)

Prioritized rule based load management technique for residential building powered by PV/battery system

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T.R. Ayodele

2017-06-01

Full Text Available In recent years, Solar Photovoltaic (PV system has presented itself as one of the main solutions to the electricity poverty plaguing the majority of buildings in rural communities with solar energy potential. However, the stochasticity associated with solar PV power output owing to vagaries in weather conditions is a major challenge in the deployment of the systems. This study investigates approach for maximizing the benefits of a Stand-Alone Photovoltaic-Battery (SAPVB system via techniques that provide for optimum energy gleaning and management. A rule-based load management scheme is developed and tested for a residential building. The approach allows load prioritizing and shifting based on certain rules. To achieve this, the residential loads are classified into Critical Loads (CLs and Uncritical Loads (ULs. The CLs are given higher priority and therefore are allowed to operate at their scheduled time while the ULs are of less priority, hence can be shifted to a time where there is enough electric power generation from the PV arrays rather than the loads being operated at the time period set by the user. Four scenarios were created to give insight into the applicability of the proposed rule based load management scheme. The result revealed that when the load management technique is not utilized as in the case of scenario 1 (Base case, the percentage satisfaction of the critical and uncritical loads by the PV system are 49.8% and 23.7%. However with the implementation of the load management scheme in scenarios 2, 3 and 4, the percentage satisfaction of the loads (CLs, ULs are (93.8%, 74.2%, (90.9%, 70.1% and (87.2%, 65.4% for scenarios 2, 3 and 4, respectively.