1,720,971 research outputs found
Energy Autarky of Households by Sufficiency Measures
No full textAbstractA consciousness about being independent from energy suppliers is spreading due to several reasons. Many authors already analyzed PV battery systems with a focus on the grade of autarky and self-consumption. But what if someone wants to be autarkic? With what does the person have to cope with and how can it be influenced? To quantify these questions the sufficiency indicator is introduced. It describes the qualitative rate of self-sufficiency and involves personal ratings of devices. With its help the effect of the sufficiency measures “shifting” and “prioritized shutdown” on the contentment of households is quantified
Smart Microgrids
No full textPublic support and feed-in tariff as a nonvariable compensation for the electric power production of energy have suppressed the risky investment of distributed generators (DGs) in smart distribution systems (SDSs). Although the using renewable energy technologies and the incorporation of plug-in DGs into SDS may have positive effects on congestion management, power loss reduction, and sustainability, they may create some difficulties relating to manage the system optimally by considering the intermittency of renewable resources in power production and uncertainties. Many researches have been carried out to deliver the high-quality power to the end-users with acceptable reliability. This book aims to present the recent materials related to the smart microgrids and the management of intermittent renewable energy sources that organized into seven chapters
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Solar Cells
No full textThis edited volume Solar Cells is a collection of reviewed and relevant research chapters offering a comprehensive overview of recent developments in the field of renewable energy. The book comprises single chapters authored by various researchers and is edited by a group of experts active in the physical sciences, engineering, and technology research areas. All chapters are complete in themselves but united under a common research study topic. This publication aims at providing a thorough overview of the latest research efforts by international authors on physical sciences, engineering, and technology, and opens new possible research paths for further novel developments
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Solar Cells
Full text linkThis edited volume Solar Cells is a collection of reviewed and relevant research chapters offering a comprehensive overview of recent developments in the field of renewable energy. The book comprises single chapters authored by various researchers and is edited by a group of experts active in the physical sciences, engineering, and technology research areas. All chapters are complete in themselves but united under a common research study topic. This publication aims at providing a thorough overview of the latest research efforts by international authors on physical sciences, engineering, and technology, and opens new possible research paths for further novel developments
Dimensioning of Decentralized Photovoltaic Storages with Limited Feed-in Power and their Impact on the Distribution Grid
No full textAbstractThe growth of photovoltaic (PV) in Germany frequently reaches its limit due to constraints in the distribution grid. In addition, we soon face an excess of renewable energy at certain day times. For both, distributed storages are a good solution.Here, at first limitations in the distribution grid are analyzed in typical residential areas, which are rural region, suburbs, town center and multistory building areas. As limiting parameters the rated power of the transformer and cables as well as voltage limits are considered. The possible feed-in power is related to the potential of PV in the corresponding area. As a result in suburb and rural areas only a fraction of the PV potential can be used. The same analysis was also performed assuming PV storages and a feed-in power limitation of 30% of the related PV peak power. A significant improvement of the use of the PV potential results.Next, the consequences of a feed-in power limitation are investigated. Depending on the limit height, without storage a certain amount of energy is lost. With 30% peak power limit, 2/3 of the PV energy is fed in, while with a “large” storage, more than 90% is fed-in (orange). The variation of the storage size reveals a reasonable size of 4 kWh, scaled to a PV system of 1 kWpk.Another criterion for the storage size is the optimization of self-consumption. A full autarky needs a very large storage covering seasonal storage. A plateau is visible for 2 kWh, scaled to a self-consumption of 1000 kWh/a, which relates to a daily storage and is independent of the PV size
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