Comme de nombreux grands projets industriels, Énergie Saguenay a généré sa part de controverse. En effet, de 2014 à aujourd’hui, différents acteurs ont publiquement partagé leurs conceptions du projet. Ils l’ont défini à leur manière, s’opposant et se rejoignant parfois sur certains points. Mon objectif de recherche général est donc de décrire le processus de dispute propre à Énergie Saguenay dans ses caractéristiques rhétoriques et ses effets propres. Pour rendre compte de cet objectif, je mobilise trois littératures scientifiques. Premièrement, la littérature sur les controverses sociotechniques m’a permis de concevoir comment, d’un côté, des réseaux d’acteurs se forment et évoluent par et tout au long d’une controverse et de l’autre, comment les controverses agissent comme un lieu d’apprentissage et d’expression. Deuxièmement, je me suis inspirée de la problématisation, première étape du modèle de la traduction (Callon, 1986), pour identifier les points passages obligés (PPO) de la controverse Énergie Saguenay, soit ses principaux enjeux auxquels les acteurs doivent consentir pour sceller des alliances. Finalement, j’ai fait appel à la théorie des arguments de définition mise de l’avant par Schiappa (2003) et Zarefsky (1997) pour définir dans quel genre de controverse s’inscrit Énergie Saguenay et comment les définitions particulières d’un phénomène, en particulier le gaz en tant qu’énergie de transition, participent à la formulation de PPO. Dans l’ensemble, mon travail de recherche contribue à rendre compte des manières dont les pratiques de définition nous aident à comprendre comment, sur le plan rhétorique, se créent des points de passage obligés dans une controverse. Plus spécifiquement, par l’analyse des mémoires déposés au BAPE par les acteurs qui composent les groupes sociaux qui ont participé à la controverse, mon étude met de l’avant les différentes pratiques de définition et conceptions du gaz naturel qui existent en ce moment au Québec comme autant de PPO permettant aux acteurs de s’allier ou de s’opposer les uns aux autres, tout au long de la controverse. / Like many large industrial projects, Énergie Saguenay has generated its share of controversy. Indeed, from 2014 to today, various groups of social actors have publicly shared their conceptions of the project. They defined it in their own way, agreeing on some points and disagreeing on others. My general research objective is therefore to describe the dispute process specific to Énergie Saguenay in its rhetorical characteristics and its own effects. To account for this objective, I will mobilize three scientific literatures. First, the literature on socio-technical controversies has allowed me to conceive how on the one hand, networks of social actors are formed and evolve during a controversy and on the other, how controversies create a space for learning and expression. Second, I was inspired by problematization, the first stage of the translation model (Callon, 1986), to identify the obligatory points of passage (OPP) of the Énergie Saguenay controversy, i.e., these main issues to which the various groups of social actors must agree to seal alliances. Finally, I appealed to the theory of definition arguments put forward by Schiappa (2003) and Zarefsky (1997) to define what category of controversy Énergie Saguenay fits into and how the specific definitions of a phenomenon (in particular gas as a transition energy) participate in the formulation of OPP. Overall, my research helps capture the ways in which defining practices help us understand how, at the rhetorical level, OPPs are created in controversy. More specifically, by analyzing the briefs submitted to the BAPE by the actors who make up the social groups who had participated in the controversy, my study puts forward the different definition practices that contributed to the conceptions of natural gas that currently exist in Québec, as so many OPPs allow the actors to align or oppose each other throughout the controversy.

[pt] No Brasil, a demanda de gás natural possui um comportamento estocástico devido ao consumo das usinas termelétricas, as quais operam em regime de complementariedade ao sistema hidrelétrico. O suprimento de gás natural para estas usinas depende em grande parte do fornecimento de Gás Natural Liquefeito (GNL) spot, importado através de navios metaneiros. Em função do tempo de trânsito dos navios, as compras de GNL devem ocorrer com antecedência em relação ao despacho hidrotérmico. Este descasamento de tempo incentiva a utilização de mecanismos de compatibilização da dinâmica do setor elétrico com a dinâmica da cadeia do gás natural. Uma possibilidade de aumentar a sinergia entre estes domínios é utilizar uma estocagem de gás natural para inserir flexibilidade no sistema. A viabilidade da estocagem dependerá do preço do gás e da demanda ao longo do horizonte de análise. O objetivo deste trabalho é a construção de um modelo de programação linear para dimensionar a capacidade de uma estocagem de gás natural sob incerteza de demanda e de preço de GNL. O modelo apresentado é um híbrido de otimização estocástica, construído para considerar a incerteza do consumo de gás, com otimização robusta, construído para levar em conta a incerteza relacionada aos preços do GNL. O modelo caracteriza o perfil de risco do supridor de gás natural pela utilização do Conditional Value-at-Risk (CVaR) e utiliza um critério de segurança que reproduz um processo de suprimento avesso a risco de déficit. Ao final do trabalho é apresentado um estudo de caso hipotético, utilizando dados públicos do setor elétrico e de gás natural, para avaliar a implantação da estocagem para 2.000 cenários de demanda e patamares distintos de robustez à variação do preço do GNL. / [en] In Brazil, natural gas demand has stochastic behavior since gas-fired power plants operate in conjunction with the hydroelectric system. Natural gas supply to these plants relies upon Liquefied Natural Gas (LNG), imported through cryogenic ships. LNG acquisitions must occur before the natural gas demand is known because of the time of displacement of the ships. This lack of synchronism stimulates the use of harmonizing mechanisms between the electric sector and the natural gas sector. In this context, natural gas storage could be used to introduce flexibility into the system and increase synergy between natural gas supply and demand dynamics. However, the economic performance of the storage will depend on actual gas prices and demand behavior during the period of analysis. This study aims to construct a linear programming model to determine the size of a natural gas storage under demand and LNG price uncertainty. The model is a hybrid of a stochastic optimization algorithm – developed to consider gas demand uncertainty – and a robust optimization algorithm – built to take into account LNG price uncertainty. A convex combination between Conditional Value-at-Risk (CVaR) and expected value is also used to indicate the supplier risk profile as well as a security criterion, introduced to represent a deficit-averse supply process. At the end, a hypothetic case is presented to evaluate the implementation of a natural gas storage. The case presented uses public data from the Brazilian electric and gas natural sectors and considers 2.000 demand scenarios and various levels of robustness to LNG price variation.