8 research outputs found

    Strategic storage use in a hydro-thermal power system with carbon constraints

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    Several interconnected power systems worldwide have largely thermal and hydro production along with CO_{2} cap-and-trade (C&T) systems and variable renewable energy sources (VRES). C&T policies increase VRES generation, and socially optimal storage deployment could integrate VRES output. However, hydro reservoirs may be used strategically due to market power. We investigate these distortions and assess measures for their mitigation via a bottom-up equilibrium model of New York and Québec. In particular, we find evidence that hydro producers shift water between seasons to manipulate electricity prices even under a net-hydro production constraint. Alternative regulation covering net imports as well as net-hydro production limits such temporal arbitrage but enables firms with both thermal generation and pumped-hydro storage to exercise spatial arbitrage. We demonstrate that these distortions will be exacerbated under more stringent C&T policies because price-taking thermal producers are less able to respond to price signals

    Understanding How University Students Use Perceptions of Consent, Wantedness, and Pleasure in Labeling Rape.

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    While the lack of consent is the only determining factor in considering whether a situation is rape or not, there is sufficient evidence that participants conflate wantedness with consent and pleasurableness with wantedness. Understanding how people appraise sexual scenarios may form the basis to develop appropriate educational packages. We conducted two large-scale qualitative studies in two UK universities in which participants read vignettes describing sexual encounters that were consensual or not, wanted or unwanted and pleasurable or not pleasurable. Participants provided free-text responses as to whether they perceived the scenarios to be rape or not and why they made these judgments. The second study replicated the results of the first and included a condition where participants imagined themselves as either the subject or initiator of the sexual encounter. The results indicate that a significant portion of our participants held attitudes reflecting rape myths and tended to blame the victim. Participants used distancing language when imagining themselves in the initiator condition. Participants indicated that they felt there were degrees of how much a scenario reflected rape rather than it simply being a dichotomy (rape or not). Such results indicate a lack of understanding of consent and rape and highlight avenues of potential educational materials for schools, universities or jurors

    Large-scale unit commitment under uncertainty: an updated literature survey

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    The Unit Commitment problem in energy management aims at finding the optimal production schedule of a set of generation units, while meeting various system-wide constraints. It has always been a large-scale, non-convex, difficult problem, especially in view of the fact that, due to operational requirements, it has to be solved in an unreasonably small time for its size. Recently, growing renewable energy shares have strongly increased the level of uncertainty in the system, making the (ideal) Unit Commitment model a large-scale, non-convex and uncertain (stochastic, robust, chance-constrained) program. We provide a survey of the literature on methods for the Uncertain Unit Commitment problem, in all its variants. We start with a review of the main contributions on solution methods for the deterministic versions of the problem, focussing on those based on mathematical programming techniques that are more relevant for the uncertain versions of the problem. We then present and categorize the approaches to the latter, while providing entry points to the relevant literature on optimization under uncertainty. This is an updated version of the paper "Large-scale Unit Commitment under uncertainty: a literature survey" that appeared in 4OR 13(2), 115--171 (2015); this version has over 170 more citations, most of which appeared in the last three years, proving how fast the literature on uncertain Unit Commitment evolves, and therefore the interest in this subject

    Large-scale unit commitment under uncertainty: an updated literature survey

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