A novel incentive-based demand response model for Cournot competition in electricity markets

This paper presents an analysis of competition between generators when incentive-based demand response is employed in an electricity market. Thermal and hydropower generation are considered in the model. A smooth inverse demand function is designed using a sigmoid and two linear functions for modeling the consumer preferences under incentive-based demand response program. Generators compete to sell energy bilaterally to consumers and system operator provides transmission and arbitrage services. The profit of each agent is posed as an optimization problem, then the competition result is found by solving simultaneously Karush-Kuhn-Tucker conditions for all generators. A Nash-Cournot equilibrium is found when the system operates normally and at peak demand times when DR is required. Under this model, results show that DR diminishes the energy consumption at peak periods, shifts the power requirement to off-peak times and improves the net consumer surplus due to incentives received for participating in DR program. However, the generators decrease their profit due to the reduction of traded energy and market prices

Rational consumer decisions in a peak time rebate program

A rational behavior of a consumer is analyzed when the user participates in a Peak Time Rebate (PTR) mechanism, which is a demand response (DR) incentive program based on a baseline. A multi-stage stochastic programming is proposed from the demand side in order to understand the rational decisions. The consumer preferences are modeled as a risk-averse function under additive uncertainty. The user chooses the optimal consumption profile to maximize his economic benefits for each period. The stochastic optimization problem is solved backward in time. A particular situation is developed when the System Operator (SO) uses consumption of the previous interval as the household-specific baseline for the DR program. It is found that a rational consumer alters the baseline in order to increase the well-being when there is an economic incentive. As results, whether the incentive is lower than the retail price, the user shifts his load requirement to the baseline setting period. On the other hand, if the incentive is greater than the regular energy price, the optimal decision is that the user spends the maximum possible energy in the baseline setting period and reduces the consumption at the PTR time. This consumer behavior produces more energy consumption in total considering all periods. In addition, the user with high uncertainty level in his energy pattern should spend less energy than a predictable consumer when the incentive is lower than the retail price

New approaches to indirect demand response management in smart grids

La respuesta de la demanda ha surgido como una solución para dar forma a la curva de la demanda y balancear la red eléctrica. Particularmente, la gestión de la respuesta de la demanda indirecta se refiere a programas basados en la modificación de la carga y del comportamiento del consumidor a través de señales de precios o pagos de incentivos. En esta tesis, modelos son propuestos para analizar e integrar sistemas de respuesta de la demanda en redes eléctricas inteligentes. El trabajo es abordado en cuatro partes. Primero, el comportamiento racional de un consumidor bajo incertidumbre es cuantificado en programa de incentivos para horas picos. Segundo, un nuevo contrato de respuesta de la demanda entre un usuario y un agregador es propuesto para enfrentar problemas en los programas tradicionales. Este contracto es basado en la probabilidad de llamado, el cuál es el chance de un consumidor para ser seleccionado por un agregador, para servir como un recurso de respuesta de la demanda durante cierto periodo. Luego, otro contracto para vehículos eléctricos es presentado como una solución de respuesta de la demanda indirecta. Un modelo basado en precios es propuesto para gestionar el proceso de carga. Finalmente, a nivel de mercado, competencia entre generadores con presencia de respuesta de la demanda es propuesto. Una función inversa de demanda suave es diseñada para modelar preferencias del consumidor para respuesta de la demanda basada en incentivos.Demand response has emerged as a solution to shape the load curve and balance the grid. Particularly, indirect demand response management refers to programs based on the load modification of consumer behavior through price signals or incentive payments. In this dissertation, models are proposed to analyze and integrate DR systems in smart grids. The work is addressed in four parts. First, a rational behavior of a consumer under uncertainty is quantified in Peak Time Rebate programs. Second, a novel demand response contract between a user and an aggregator is proposed to face gaming concerns. This contract is based on the probability of call, which is the chance of a consumer to be selected by the aggregator to serve as demand response resource at a given period. Next, another contract for electric vehicles is presented as a solution in the indirect demand response management. A price-based model is proposed to schedule the charging process. Finally, at the market level, a competition between generators with the presence of demand response is proposed. A smooth inverse demand function is designed for modeling the consumer preferences under incentive-based demand response program.Doctor en IngenieríaDoctorad

Remuneration Sensitivity Analysis in Prosumer and Aggregator Strategies by Controlling Electric Vehicle Chargers

The efficient use of energy resources is profoundly changing power grid regulation and policy. New forms of power generation coupled with storage and the presence of new, increasingly flexible loads such as electric vehicles enable the development of multi-agent planning systems based on new forms of interaction. For instance, consumers can take advantage of flexibility by interacting directly with the grid or through aggregators that bridge the gap between these end-users and traditional centralised markets. This paper aims to provide insight into the benefits for aggregators and end-users from a financial perspective by proposing a methodology that can be applied to different scenarios. End-users may provide flexibility services related to private vehicle charging stations or battery storage systems. The paper will analyse different remuneration levels for end-users by highlighting the most beneficial scenarios for aggregators and end-users and providing evidence on potential conflict of interests. The numerical results show that some consumers may benefit more from aggregation. This is because if taken individually, consumption habits do not allow the same flexibility when considering clusters of consumers with different behaviour. It is also shown that there are cases in which consumers do not seem to benefit from the presence of intermediate parties. We provide extensive numerical results to gain insight for better decision making

Cultura de la paz desde el aula de clases formación social en valores constitucionales, la no repetición y memoria histórica, dirigidas a los estudiantes de los grados 10 y 11 de la institución educativa públicas Nicolás Buenaventura en el distrito de Santa Marta 2015

La sociedad colombiana se encuentra inmersa en la dicotomía de sumirse en una violencia prolongada o en lograr la paz a través de las vías de dialogo propuesta en la Habana- Cuba, la reconciliación, el perdón, la reparación y la no repetición, son el argumento en el que coinciden diversos expertos en la temática de los Derechos Humanos y de los escenarios de paz, dicho dilema, juega un papel fundamental y decisorio en el ámbito escolar y en sus diferentes esferas. Para entender e interpretar ese conflicto interno, a la escuela le han faltado las características de una organización como un sistema abierto, dinámico, articulado, evolutivo, e histórico y es aquí donde le cabe la responsabilidad de no haber asumido su papel protagónico en la búsqueda de salidas a la coyuntura. Esta iniciativa de intervención plantea una contextualización acerca del conflicto armado interno, sus bases históricas, su caracterización y el rol de los actores en la búsqueda de la no repetición a través de los mecanismos de resolución pacífica de conflictos, como fundamento para una paz duradera, la reconstrucción de la nación, un nuevo contrato social y la definición de un nuevo proyecto de país bajo un enfoque diferenciador, incluyente, participativo, qué admita y entienda la diferencia en aras de consolidar una cultura de paz en el escenario del postconflicto, su situación actual, sustenta la importancia de la formación en valores constitucionales la reconstrucción de la memoria histórica. En este contexto, la propuesta en su objeto plantea la formación en valores constitucionales, la no repetición y la memoria histórica desde el ámbito de la educación media vocacional, específicamente en los grados 10 y 11, como aporte significativo en la construcción de una cultura de paz desde el aula de clases, la convivencia escolar, extendida a la comunidad académica y al proyecto de vida del estudiante, de su familia y del entorno. De igual manera en el desarrollo del proyecto, se espera el conocimiento sobre las normas de Derechos Humanos, la significancia del Estado social de Derecho y la reconstrucción de la memoria histórica, para su aplicabilidad en la vida individual y social del estudiante y comunidad educativa a través de estrategias pedagógicas

Effect of Different Cytokinins on Shoot Outgrowth and Bioactive Compounds Profile of Lemograss Essential Oil

Lemongrass (Cymbopogon citratus) essential oil (EO) is a major source of bioactive compounds (BC) with anticancer activity such as α-citral, limonene, geraniol, geranyl acetate, and β-caryophyllene. Comparative studies about cytokinin effects on BC profiles in lemongrass are missing. Here, we evaluated four cytokinins (2iP, tZ, BAP, and KIN) in two different osmotic media, MS-N (3% sucrose, 3 g L−1 Gelrite™) and MS-S (5% sucrose, 5 g L−1 Gelrite™). It results in a higher multiplication rate in BAP containing medium compared to tZ, KIN, and 2iP (p ≤ 0.05). While shoots grown on MS-N/BAP, tZ, and KIN exhibited a highly branching morphology, MS-N/2iP produced a less branching architecture. BC profile analysis of established plants in pots revealed that their maxima production depends on the in vitro shoot growth conditions: i.e., highest content (80%) of α-citral in plants that were cultured in MS-S/BAP (p ≤ 0.05), limonene (41%) in MS-N/2iP, or geranyl acetate (25.79%) in MS-S/2iP. These results indicate that it is possible to increase or address the production of BC in lemongrass by manipulating the cytokinin type and osmotic pressure in culture media. The culture protocol described here is currently successfully applied for somatic embryogenesis induction and genetic transformation in lemongrass

Anti‑inflammatory drugs and uterine cervical cancer cells: Antineoplastic effect of meclofenamic acid

Uterine cervical cancer (UCC) is one of the main causes of cancer-associated mortality in women. Inflammation has been identified as an important component of this neoplasia; in this context, anti-inflammatory drugs represent possible prophylactic and/or therapeutic alternatives that require further investigation. Anti-inflammatory drugs are common and each one may exhibit a different antineoplastic effect. As a result, the present study investigated different anti-inflammatory models of UCC in vitro and in vivo. Celecoxib, sulindac, nimesulide, dexamethasone, meclofenamic acid, flufenamic acid and mefenamic acid were tested in UCC HeLa, VIPA, INBL and SiHa cell lines. The cytotoxicity of the drugs was evaluated in vitro. Celecoxib, sulindac, nimesulide, mefenamic acid and flufenamic acid presented with slight to moderate toxicity (10–40% of cell death corresponding to 100 µM) in certain cell lines, while meclofenamic acid exhibited significant cytotoxicity in all essayed cell lines (50–90% of cell death corresponding to 100 µM). The meclofenamic acid was tested in murine models (immunodeficient and immunocompetent) of UCC, which manifested a significant reduction in tumor growth and increased mouse survival. It was demonstrated that of the evaluated anti-inflammatory drugs, meclofenamic acid was the most cytotoxic, with a significant antitumor effect in murine models. Subsequent studies are necessary to evaluate the clinical utility of this drug

Flower Greenhouse Energy Management to Offer Local Flexibility Markets

Electricity access is strongly linked to human growth. Despite this, a portion of the world’s population remains without access to energy. In Colombia, rural communities have energy challenges due to the National Interconnected System’s (NIS) lack of quality and stability. It is common to find that energy services in such locations are twice as costly as in cities and are only accessible for a few hours every day due to grid overload. Implementing market mechanisms that enable handling imbalances through the flexible load management of main loads within the grid is vital for improving the rural power grid’s quality. In this research, the energy from the rural grid is primarily employed to power a heating, ventilation, and air-conditioning (HVAC) system that chills flowers for future commerce. This load has significant consumption within the rural grid, so handling HVAC consumption in a suitable form can support the grid to avoid imbalances and improve the end-user access to energy. The primary responsibilities of the flower greenhouse operator are to reduce energy costs, maximize flexibility, and maintain a proper indoor temperature. Accordingly, this research proposes a flexible energy market based on the bi-level mixed-integer linear programming problem (Bi-MILP), involving the Agricultural Demand Response Aggregator (ADRA) and the flower greenhouse. ADRA is responsible for assuring the grid’s stability and quality and developing pricing plans that promote flexibility. A flower greenhouse in Colombia’s Boyacá department is used as an application for this research. This study looked at the HVAC’s flexibility under three different pricing schemes (fixed, time-of-use, and hourly) and graded the flower greenhouse’s flexibility as a reliable system

Optimal Portfolio Selection Methodology for a Demand Response Aggregator

This paper presents a methodology for determining the optimal portfolio allocation for a demand response aggregator. The formulation is based on Day-Ahead electricity prices, in which the aggregator coordinates a set of residential consumers that are recruited through contracts. Four types of contracts are analyzed, considering both direct and indirect demand response programs. The objective is to compare different scenarios for contract portfolios in order to establish the benefits of each market agent. An optimization problem is formulated to capture the interactions between the aggregator and end consumers. The model is formulated as a mathematical program with equilibrium constraints: At the upper level, the aggregator maximizes its benefits, whereas the lower level represents the consumers’ contracts. By applying the developed methodology, the characterization of the consumers’ behavior is established in order to forecast their responses to the generation of punctual incentives, both for usual scenarios and peak events, as well as to evaluate the impact that direct and indirect control contracts have on the performance of the aggregator as the energy price varies