1,720,999 research outputs found
Energy storage scenarios and design of a new Italian innovation infrastructure for energy transition
No full textImpact of different regulatory approaches in renewable energy communities: A quantitative comparison of european implementations
Full text linkRecently, the uptake of renewable energy has surged in distribution networks, particularly due to the costeffectiveness and modular nature of photovoltaic systems. This has paved the way to a new era of user engagement, embodied by individual and collective self-consumption, and promoted by the EU Directive 2018/ 2001, which advocates for the establishment of Renewable Energy Communities. However, the transposition of this directive varies across Member States, resulting in specific rules for each country. In this work, the impact that different energy sharing models have on the same community is quantitatively assessed. The policy analysis focuses on the regulation of two countries, Italy and Portugal, chosen for the specular ways in which their models operate, respectively virtually and physically. The analysis is supported by a suite of tools which includes two optimization problems for community's operations, one for each analysed regulation, and a set of consumer protection mechanisms, to ensure no member is losing money while in community. Results demonstrate that the sharing model impacts community's optimal operations, optimal battery size and configuration, and members' benefit. As these models are sensitive to different variables, personalized interventions at national level are required
Techno-Economic Optimization of Services Stacking for a Battery Participating to Electricity Spot Markets
Full text linkAn optimization model for the provision of flexibility and dispatching resources by multi-vector smart energy districts
Full text linkThe Clean Energy Package expects a fundamental contribute for the decarbonisation of European energy system from Distributed Energy Resources (DERs), pushing Member States to favour the diffusion of energy production plants for individual and collective self-consumption. At the same time, DERs are required to contribute to system security mainly providing dispatching resources. The model developed includes the possibility to provide real-time balancing flexibility in a generic architecture where different energy vectors can be integrated through energy production, consumption and storage facilities. The optimization problem is built over a weekly time horizon with a stepwise approach where internal and external energy exchanges are defined updating meteorological forecasts, energy demands and markets results while approaching real-time operations. According to the Italian Authority consultation document 322/2019, both energy-only and capacity remunerated services are included in the model. The aim of the model is both to estimate the economic opportunities coming from energy markets participation for smart energy districts in the future energy framework, and to assess the actual capability and reliability of diverse DERs aggregates to provide flexibility to the external electric grid. These evaluations are carried out applying the presented model to a university campus case study where different energy conversion and storage plants are integrated at a Distribution Network level
Development, validation, and testing of advanced mathematical models for the optimization of BESS operation
Full text linkCurrent decarbonization strategies are driven by the fast-paced diffusion of non-programmable renewable energy sources (NP-RESs), mainly through solar and wind power generation. Energy storage technologies are emerging as key solutions for coping with the variability and low-inertia characteristics of NP-RESs. Particularly, battery energy storage systems (BESS) are diffusing more widely for both behind-the-meter (BTM) and utility-scale applications. In this context, we still lack a shared solution on how to proceed from the on-field data collected about the performance of BESS to reliable and fast mathematical formulations for operational optimization. This study provides a validated modeling framework that can be exploited during or after BESS commissioning to (i) identify and derive the useful parameters to characterize BESS performances, (ii) formalize them in a mathematical formulation while being aware of its specific trade-off between accuracy and computational effort, and (iii) exploit the selected BESS model within a multi-energy system optimization problem. We discuss three different modeling approaches that we developed for optimizing BESS operation, with each providing a different balance between modeling accuracy and computational effort. These three mathematical models were validated against a numerical simulation model based on on-field performance data, and they were eventually tested on a reference case study. The results indicate that it is possible to restrict the average error in estimating BESS efficiency while simultaneously limiting the computational effort of the model. Regarding the operation of BESS, the conducted simulations demonstrate that an approximate BESS model may result in an overestimation of the expected revenues
A three-stage stochastic optimization model for the design of smart energy districts under uncertainty
No full textWe propose a three-stage stochastic integer programming model to tackle the design of smart energy districts, including electricity and heat storage, conversion and distribution systems, under uncertainty. The model allows to account for the uncertainty in the short-term forecasts, the day-ahead electricity bidding, the day ahead scheduling of large power plants and the possibility of real-time scheduling adjustments of flexible energy systems (integer recourse). The application to a case study shows the complexity of the associated mixed integer linear program (MILP) and the need for ad hoc decomposition techniques
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
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
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