2,390 research outputs found
The Recognition of Fires Originating from Photovoltaic (PV) Solar Systems
No full textThere has been an observable increase in the fitting of photovoltaic (PV) solar panels on the roofs
of buildings in the UK over the last decade. The origin of some fires in domestic and commercial
properties has been attributed to PV systems. This thesis examines the ability of fire examiners to
recognise and record details of fires believed to have originated from PV systems, as well as
investigating the effect of internal heating in direct current (DC) isolators to the point at which they
fail.
National fire data was examined along with the methods for collecting and collating these data.
This clarified that national fire data cannot identify the specifics of electrical fires. Validity of these
data was then tested by identifying the confidence and competence in the recognition of the origin
of fire, (especially when associated with PV systems), of some fire staff responsible for collecting
fire data. This suggests that some fire scenes examiners are not confident in their own ability to
recognise fires originating from PV systems. Evidence for fires occurring in PV systems in Kent
between 2009 and 2014 was then examined, including a cold case forensic review of the
evidence. This provided an indication that a potential common point of failure, which may lead to
fire originating from a PV system, was to be found within the DC section of the PV circuits and
probably within the DC isolator switch itself. Experimentation revealed that internal heating of a
terminal connection can lead to changes of the phase of the insulating material, causing failure of
structural integrity and therefore allowing an arc to be established. Observable post fire indicators
associated with this mechanism of failure have been identified as well as hydrocarbons evolved
from pyrolysis of isolator insulating material.
Finally, areas for further experimental research and training of fire staff are suggested as well as
the modification of recording mechanisms and building regulations
Keeping time on the plant-pathogen arms race : a role for the plant circadian clock in immune response
No full textIn this study, Arabidopsis thaliana (Arabidopsis) in the Columbia-0 (Col-0) background showed time-of-day variation in susceptibility to the plant-pathogen Pseudomonas syringae DC3000 pathovar tomato (P. syringae DC3000) when infected under constant light and temperature conditions. Wild type plants showed least susceptibility at circadian time (CT) 26 and 50, which correspond to "subjective" morning. Plants were most susceptible when infected at CT42 and CT66, "subjective" night
Solar PV hosting capacity: Grid-based vs. market-based scenarios
No full textAssessing the capability of a distribution grid to accommodate new solar PV installations, namely its hosting capacity (HC), has been a prevalent research topic. Although providing a technical limit to how much additional solar PV can be integrated into a distribution grid without trespassing operational limits, commonly used HC analysis (HCA) does not consider consumer preferences or the economic feasibility of installations. Using a market-based optimal power flow (MBOPF) and HCA, we compare the economic and technical limits of solar PV capacity integration in low voltage distribution systems (LVDS). Findings illustrate that (1) the PV HC computed using grid limits only does not give a complete picture of solar PV capacity integration potential, (2) linear, deterministic power flow is not a foolproof method for assessing the network-secure amount of PV, and (3) the number of technically feasible installation sites supersedes the economically feasible ones.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Energy and Industr
Identification of the cir1 disease resistance gene in Arabidopsis thaliana
No full textIncludes bibliographical references.Plants rely on an elaborate multi-layered defence system to perceive and effectively respond to disease causing pathogens. The defence-related cir1 (constitutively induced resistance 1) mutant was first isolated in an effort to identify components of the Arabidopsis thaliana defence system essential for resistance against pathogens. The cir1 mutant has previously been described as having increased resistance to the virulent bacterial pathogen Pseudomonas syringae pv. tomato DC3000 and oomycete pathogen Hyaloperonospora parasitica Noco2 and was shown to constitutively express salicyclic acid-, jasmonic acid/ethylene- and reactive oxygen intermediate-responsive genes. Genetic analysis and mapping studies of the mutation revealed that it is recessive and may be encoded by one of eight genes located within a 309.10 kb region on the lower arm of chromosome four
PV-boats: Design issues in the realization of PV powered boats
No full textPV integration in boats is rarely seen, but offers clean and silent transportation while on the water. In order to research the PV realization into boat design challenges, the University of Twente and the NHL hogeschool, both in the Netherlands, started a joined research into PV integration in boats. By studying 3 cases, PV boat specifications and the key design challenges are researched. The first case, the Frisian Solar Challenge 2010, offered the possibility to gather information about 44 innovative PV powered racing boats. The Frisian Solar Challenge is a 5 day 220km race for PV powered boats. Boats need to be fast, efficient and reliable to finish the race at high positions. The second case shows the NHL hogeschool\u92s PV powered racing boat design and building process which attended the Frisian Solar Challenge 2010. The third case is a study in PV powered boats found worldwide. From 105 boats, specifications are collected to learn recent developments in PV powered boats. From these 3 cases follows that light weight is one of the key parameters to build a successful PV powered boat. Especially PV modules with lower weight can bring successful PV powered boat designs. Furthermore, boats equipped with monohull designs offer high efficiency with low drag. However, catamaran designs prove to be successful as well, bringing higher stability in boat designs. Mature technology is needed to sail with reliable hardware
Comprehensive modelling and sizing of PV systems from location to load
No full textPhotovoltaic (PV) systems are progressively used for decentralized electricity generation. To obtain the maximum yield from such systems, optimisation of all components is essential. In this contribution, we provide a comprehensive modelling and sizing of PV systems for any location. Three applications are here presented providing real time monitoring of PV potential, accurate prediction of yield taking into account thermodynamic temperature effects, optimization of modules orientation addressing the effects of shading and efficient sizing of inverter for a higher yield output. When combined, these models can accurately predict the real time performance of any PV system.Accepted Author ManuscriptPhotovoltaic Materials and DevicesDC systems, Energy conversion & Storag
Isolation of three novel rat and mouse papillomaviruses and their genomic characterization.
No full textDespite a growing knowledge about the biological diversity of papillomaviruses (PV), only little is known about non-human PV in general and about PV mice models in particular. We cloned and sequenced the complete genomes of two novel PV types from the Norway rat (Rattus norvegicus; RnPV2) and the wood mouse (Apodemus sylvaticus; AsPV1) as well as a novel variant of the recently described MmuPV1 (originally designated as MusPV) from a house mouse (Mus musculus; MmuPV1 variant). In addition, we conducted phylogenetic analyses using a systematically representative set of 79 PV types, including the novel sequences. As inferred from concatenated amino acid sequences of six proteins, MmuPV1 variant and AsPV1 nested within the Beta+Xi-PV super taxon as members of the Pi-PV. RnPV2 is a member of the Iota-PV that has a distant phylogenetic position from Pi-PV. The phylogenetic results support a complex scenario of PV diversification driven by different evolutionary forces including co-divergence with hosts and adaptive radiations to new environments. PV types particularly isolated from mice and rats are the basis for new animal models, which are valuable to study PV induced tumors and new treatment options
PV Module Integrated Converter for Distributed MPPT PV Systems
No full textDriven by constant advances and cost reductions in photovoltaic (PV) technology,together with incentive government policies toward cleaner environment, the PV energy became one of the fastest growing market in the world. In many countries the amount of installed PV power is increasing at an exponential rate, in all sectors from large utility scale power plants to small residential PV systems.DC systems, Energy conversion & Storag
Approaching nearly zero energy of PV direct air conditioners by integrating building design, load flexibility and PCM
No full textThe energy matching of PV driven air conditioners is influenced by building load demand and PV generation. Merely increasing energy performance of building or PV capacity separately may improve the energy balance on a large time resolution, the real-time energy mismatching problem is still serious. In this study, a coordinated optimization method of PV capacity, building design, and load flexibility is proposed for improving the real-time energy matching of PVAC system. Then, a methodology integrating data mining method (XG Boost) and parametric simulation was developed to identify the determinant parameters of PV system and building design, exploring feature importance and correlations. The results of XG Boost indicate that the PV capacity, shape factor, and SHGC are the most critical factors. Finally, based on the optimized building design, the PCM layer was applied to improve the real time energy matching. To achieve a goal of 90 % ZEP, the PCM capacity can be decreased by 50.4 % and 62.8 % in Guangzhou and Shanghai in the optimized building. Moreover, the PV capacity can be reduced by 23 % in Guangzhou. The findings of this study provide practical guidance for designing PVAC system coupling with building design and energy storage devices.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Environmental & Climate Desig
Highly Compact Partial Power Converter for a Highly Efficient PV-BESS Stacked Generation System
No full textThe inherently intermittent nature of photovoltaic (PV) energy has brought increasing interest towards the integration between PV sources and Battery Energy Storage Systems (BESS). In this paper, a Series Partial Power Processing (PPP) converter based on Capacitive Power Transfer (CPT) is proposed to integrate PV and BESS in a grid-connected inverter system. The proposed converter has been simulated according to a PV string capable to provide 1430 W under full irradiance conditions, a BESS nominal voltage equal to 215 V and a solar inverter assumed to operate with a minimum voltage of 150 V and a maximum current of 10 A. Simulation tests carried out at different conditions of solar radiation and required load power aim at demonstrating the correct operation of the proposed system.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.DC systems, Energy conversion & Storag
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