1,720,960 research outputs found
Optimal Incentive Policy and Equilibrium Sharing Rules for Renewable Energy Communities in Deterministic and Stochastic Environments
Full text linkIl cosiddetto "Earth Overshoot Day" (EOD) è avvenuto in anticipo negli ultimi anni. Il consumo eccessivo di risorse naturali contribuisce direttamente alle emissioni di gas serra e aggrava il problema del riscaldamento globale. In questo contesto, gli esseri umani sentono l'urgenza di limitare il cambiamento climatico. Un approccio strategico è la transizione energetica. Le Comunità Energetiche Rinnovabili (CER) sono fondamentali perché incorporano i principi di collaborazione, innovazione e difesa che le rendono indispensabili nel panorama energetico globale. Per aiutare l'implementazione pratica delle CER, è essenziale approfondire il quadro legislativo emanato dall'Unione Europea (UE). Le Direttive Europee 2018/2001 (RED II) e 2019/944 (IEM) giocano un ruolo cruciale: queste direttive mirano a creare quadri regolatori di supporto, fornire incentivi finanziari e incoraggiare la collaborazione per accelerare la transizione.
Il framework virtuale delle CER è stato introdotto in Italia dal Decreto Legge n.162/2019. In tale quadro, tutta l'elettricità prodotta viene venduta alla rete e quindi acquistata quando consumata. Il coinvolgimento efficace delle parti interessate è vitale per il successo delle CER; tuttavia, favorire una collaborazione significativa può essere difficile. Un punto distintivo della normativa italiana riguarda il meccanismo di incentivo basato sull'autoconsumo, che definisce l'autoconsumo come il minimo tra l'energia prodotta e l'energia consumata in un determinato momento. All'interno del framework virtuale delle CER, è cruciale gestire l'allocazione congiunta degli incentivi all'autoconsumo e le decisioni di investimento, data la loro influenza reciproca.
La prima parte di questa tesi è dedicata all'ottimizzazione di tale decisione con una struttura a due livelli. Il livello superiore è giocato da un “policy maker” che definisce la regola di condivisione dell’incentivo sull'autoconsumo per massimizzare l'autoconsumo. Il livello inferiore comprende le CER costituite da membri eterogenei (produttori di biogas e famiglie), che ottimizzno l’investimento in capacità per massimizzare i loro profitti. La diversità degli agenti consente di studiare quanto ognuno contribuisce all'autoconsumo e mette in evidenza le interazioni tra i membri. Inoltre, l’esistenza del livello superiore garantisce una decisione neutrale. Per chiarire l'interazione tra i membri si sviluppano due modelli di iterazione. La prima versione considera un singolo membro per tipo, e le interazioni avvengono in una singola fase. Questi risultati sono influenzati dalle dimensioni dei membri e dall’ordine di iterazione, quindi caratterizzano un equilibrio di Nash non puro. Pertanto, viene sviluppato il secondo modello, dove i due membri sono aggregazioni di individui più piccoli, le interazioni sono divise in due fasi e i risultati sono un equilibrio di Nash puro.
La ricerca nei mercati dell'energia spesso richiede un approccio che gestisca in simultanea il rischio e varie fonti di incertezza, che non agiscono indipendentemente. Queste dipendenze, spesso non lineari, pongono una sfida significativa nella fase di “modelling”. Di conseguenza, le operazioni, le decisioni di investimento e la gestione del rischio diventano estremamente complesse.
La seconda parte di questa tesi introduce un metodo mirato a modellare efficacemente le dipendenze lineari, e non, tra più fonti di incertezza, basandosi sulla metodologia avanzata da Cerqueti et al. (2017a), la quale usa Catene di Markov di ordine k per bootstrappare e simulare processi stocastici multivariati; inoltre questo metodo è caratterizzato da una selezione parsimoniosa dei parametri. L'innovazione distintiva del metodo proposto in questa tesi è la capacità di gestire diverse frequenze temporali. La qualità del metodo proposto viene valutata attraverso test statistici.The so-called “Earth Overshoot Day” (EOD) has occurred earlier in the last years. The excessive consumption of natural resources directly contributes to emissions of greenhouse gases, and exacerbates the problem of global warming. In this context, humans feel the urge to limit climate change. One strategic approach is energy transition. This transition involves technical and infrastructural challenges.
Renewable Energy Communities (RECs) are fundamental to energy transition because they embody the principles of empowerment, collaboration, innovation, and advocacy that make them indispensable in the global energy landscape.
To help the practical implementation of RECs, it is essential to delve into the legislative framework enacted by the European Union (EU). The European Directives 2018/2001 (RED II) and 2019/944 (IEM) play a crucial role in shaping the scope of RECs. Together, these directives aim to create supportive regulatory frameworks, provide financial incentives, and encourage collaboration among stakeholders to accelerate the transition.
The virtual framework of RECs was introduced by Italian Law decree No.162/2019. In such a framework, all the electricity produced by RECs’ plants is sold to the grid and then purchased from it when consumed. The framework confronts various challenges. Effective stakeholder engagement, is vital for RECs success; however, fostering meaningful collaboration may be challenging. A distinctive point of the Italian regulation is concerned with the incentive mechanism based on self-consumption, which defines self-consumption as the minimum between the energy produced and the energy consumed at a given time.
Within the virtual framework of RECs, it is crucial to manage the joint allocation of self-consumption incentives and investment decisions, due to their mutual influence.
The first part of this thesis is devoted to optimizing such a decision with a bi-level structure. The upper level is played by a policy maker. The agent defines the self-consumption incentive sharing rule to maximize energy self-consumption. The lower level comprises RECs consisting of heterogeneous members (biogas producers and households), that optimally size their investments in capacity plants to maximize their profits. The agent diversity allows for the examination of each member’s contribution to self-consumption and highlights the interactions among the members. Furthermore, the upper level ensures a neutral decision. To elucidate the interaction among RECs’ members two iteration models are developed. The first version considers a single member per type, and interactions occur in a single round. While the results of this model characterize a Nash equilibrium, they are influenced by the iteration order and the size of the members, precluding the attainment of a pure Nash equilibrium. Therefore, the second model is developed: it has two members that are aggregations of smaller individuals, the interactions are divided into two rounds, and the results are a pure Nash equilibrium.
Research in energy markets often requires an approach to manage risk that simultaneously considers various sources of uncertainty. Supply costs, weather conditions, sale prices, and demand levels do not act independently. These dependencies, often non-linear, pose a significant challenge in modelling. Consequently, operations, investment decisions, and risk management become exceedingly complex.
The second part of this thesis introduces a method aimed at effectively modelling linear and non-linear dependencies among multiple sources of uncertainty, building upon the methodology advanced by Cerqueti et al. (2017a), which bootstraps and simulates multivariate stochastic using Markov Chains of order k. A distinguishing innovation is the ability to deal with different temporal frequencies. Furthermore, it leverages a parsimonious selection of parameters. The quality of the method is assessed through statistical tests
Net-zero emissions: main technological, geopolitical, and economic consequences of the new energy scenario
Full text linkThis paper discusses possible technical, economical and geopolitical consequences of the new energy scenario. We analyze the net zero emissions global race with an emphasis on the role renewable energies will play in this phenomenon and COP26’s recent decisions on climate and energy transition. Using the semi-quantitative analysis method, the technological driving forces for future energy scenarios have been extrapolated. The technological developments and future scenarios regarding renewable energies are discussed by comparing two different driving forces. Furthermore, there will be a discussion of possible geopolitical consequences due to fossil fuels trade depletion during the energetic transition. Possible related consequences for MENA countries are investigated. In the last part, there will be a legal background analysis for electricity demand and renewable sources shift combined with techno-economical examples. Finally, considering all the contents, we drive our conclusions
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
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
- …
