Development of a methodology to optimize the integration of photovoltaic plants coupled with energy storage systems in advanced electrical grids

[ES] La integración de las tecnologías de energía renovable es un gran componente para alcanzar los serios objetivos medioambientales de diferentes gobiernos e instituciones a nivel mundial. Sin embargo, hay varios desafíos a lo largo de su camino para seguir aumentando en capacidad. La mayor penetración de estas tecnologías surge la necesidad de que proporcionen la misma fiabilidad y servicios que los generadores convencionales han hecho en la red eléctrica. El almacenamiento de energía proporciona una de las soluciones. La propuesta del trabajo fin de master era desarrollar una metodología que permita modelar y simular sistemas de almacenamiento de energía acoplado a campos fotovoltaicos, para optimizar su integración en las redes eléctricas. La metodología puede modelar cualquier ubicación y cualquier condición que requiera un proyecto de este tipo y calcular su dimensionamiento óptimo. Los parámetros que se puede variar son los siguientes: potencia, ratio DC/AC, ubicación, precios de la electricidad, mecanismos de fijación de precios de tarifas (existentes y propuestos), y finalmente costes de capital. En este modelo, además, se propuso una nueva configuración para beneficiarse de los excesos fotovoltaicos producidos a partir de un campo fotovoltaico sobredimensionado, mediante la conexión del sistema de baterías a un convertidor DC/DC de relativamente alta potencia. Se analizó diferentes casos de estudio, con el fin de mostrar como este tipo de sistema puede ayudar a reemplazar los generadores convencionales y asegurar la fiabilidad y calidad de la red eléctrica. Los casos que se estudia son: (i.) almacenamiento de excesos por “clipping”, (ii.) power-shifting, (iii.) regulación primaria y secundaria, y (iv.) acoplamiento de respuesta de demanda mediante vehículos eléctricos.[CA] La integració de les tecnologies d'energia renovable és un gran component per a aconseguir els seriosos objectius mediambientals de diferents governs i institucions a nivell mundial. No obstant això, hi ha diversos desafiaments al llarg del seu camí per a continuar augmentant en capacitat. La major penetració d'estes tecnologies sorgix la necessitat que proporcionen la mateixa fiabilitat i servicis que els generadors convencionals han fet en la xarxa elèctrica. L'emmagatzemament d'energia proporciona una de les solucions. La proposta del treball fi de màster era desenrotllar una metodologia que permeta modelar i simular sistemes d'emmagatzemament d'energia acoblat a camps fotovoltaics, per a optimitzar la seua integració en les xarxes elèctriques. La metodologia pot modelar qualsevol ubicació i qualsevol condició que requerisca un projecte d'este tipus i calcular el seu dimensionamiento òptim. Els paràmetres que es pot variar són els següents: potència, ràtio DC/AC, ubicació, preus de l'electricitat, mecanismes de fixació de preus de tarifes (existents i proposats) , i finalment costos de capital. En este model, a més, es va proposar una nova configuració per a beneficiar-se dels excessos fotovoltaics produïts a partir d'un camp fotovoltaic sobredimensionat, per mitjà de la connexió del sistema de bateries a un convertidor DC/DC de relativament alta potència. Es va analitzar diferents casos d'estudi, a fi de mostrar com este tipus de sistema pot ajudar a reemplaçar els generadors convencionals i assegurar la fiabilitat i qualitat de la xarxa elèctrica. Els casos que s'estudia són: (i.) emmagatzemament d'excessos per “clipping”, (ii.) power- shifting, (iii.) regulació primària i secundària, i (iv.) adaptament de resposta de demanda per mitjà de vehicles elèctrics.[EN] The integration of renewable energy technologies is an important component to achieve the serious environmental objectives of different governments and institutions worldwide. However, there are several challenges along the way to continue increasing in capacity. The greater penetration of these technologies arises the need to provide the same reliability and services that conventional generators have made in the electricity grid. Energy storage provides one of the solutions. The purpose of the master's project was to develop a methodology that allows modeling and simulating energy storage systems coupled to photovoltaic fields, to optimize their integration in electricity networks. The methodology can model any location and any condition that a project of this type requires and calculate its optimal sizing. The parameters that can be varied are the following: power, DC / AC ratio, location, electricity prices, tariff pricing mechanisms (existing and proposed), and finally capital costs. In this model, in addition, a new configuration was proposed to benefit from the photovoltaic excesses produced from an oversized photovoltaic field, by connecting the battery system to a DC/DC converter of relatively high power. Different cases studies were analyzed, in order to show how this type of system can help to replace conventional generators and ensure the reliability and quality of the electrical network. The cases studies were: (i.) Storage of excesses by "clipping", (ii.) Power-shifting, (iii.) Primary and secondary regulation, and (iv.) Demand response coupling by electric vehicles.Ryan, KD. (2018). Development of a methodology to optimize the integration of photovoltaic plants coupled with energy storage systems in advanced electrical grids. Universitat Politècnica de València. http://hdl.handle.net/10251/108976TFG

Ireta: a model of political and spatial organization of P'urépecha cities, The

Includes bibliographical references.2015 Summer.This thesis uses the published historical literature to build a theoretical model of the political organization of P’urépecha cities. Ancient P’urépecha cities were the urban component of a larger polity known as an Ireta. These were territorial polities that were similar to the Aztec altepetl, and might be considered analogous to a “city-state.” Each Ireta could be divided into a series of nested territorial units. Larger units, the uapátzequecha, consisted of neighborhoods within cities and towns or villages in the countryside. Beneath these were smaller groupings of households that formed the basis of the ocámbecha tax system used by the Kingdom of Tzintzuntzan, the empire which dominated the region during the Late Postclassic Period (c. 1350 – 1530 AD). Small architectural complexes (complejos) at the archaeological site of Angamuco, Michoacan, Mexico approximately match the size of the unit that the ocámbecha administered. This study maps these units using Object-Based Image Analysis (OBIA). The results of this modeling produce a map of complejos that approximately matches hypothesized territorial divisions at the site. While more research is needed, the current evidence suggests that the territorial divisions which formed the basis of the ocámbecha tax system may predate the Late Postclassic empire. This could indicate that the empire simply co-opted existing territorial divisions for tax collection rather than creating new ones

Brief Sheets: Examining an Intervention that Increases Academic Reinforcement

This study is designed to extend research on the Brief Sheets intervention. The Brief Sheets intervention involves taking a full-page assignment that is given to students to complete independently and breaking up this assignment into multiple, smaller assignments that still contain the same total number of problems cumulatively. An experiment was designed to see if students would complete more total problems when they were given Brief Sheets compared to a control assignment containing the same total number of problems, if the percentage of accurate responding would be higher for the Brief Sheets assignment, and if students would rate the Brief Sheets intervention as preferable to the control assignment. Our participants were 39 fourth-grade students in an elementary school in the southeastern United States. The experiment was conducted in one day with students completing a packet containing 2 of 3 possible assignments within it. One of these assignments was always a control 10-problem assignment presented on one sheet of paper. The other assignment was counter-balanced to be a 12-problem assignment on one sheet of paper, or a 12-problem assignment presented on 4 slips of paper with 3 problems per slip. A between-subjects design was chosen to answer our research questions. The results of this study did not support the hypothesis that the students who completed the Brief Sheets intervention would complete more work, as the number of problems completed and number of problems completed correctly were both not statistically significant between the Brief Sheets assignment and an alternative assignment of the same length. Likewise, the Brief Sheets intervention was not rated as statistically more favorable than the alternative assignment when comparing effort, time, difficulty, or preference for homework. A limitation of this study was that students did not complete as many problems as anticipated with the problems not being completed automatically, and that data collection took place in one day with a limited subject pool of 39 students. Future research on the Brief Sheets intervention should work with a larger subject pool and consider working with older students to see if the Brief Sheets intervention would cause more meaningful differences

Field and Numerical Investigation of Wave Power and Shoreline Retreat in Terrebonne Bay, Southern Louisiana

The marshland in southern Louisiana is a vital resource that many people and wildlife depend on. Terrebonne Bay was chosen for this research because it has experienced one of the largest wetland loss rates among Louisiana estuaries. Investigations of wave power and shoreline retreat rate could provide decision makers with a better understanding of the contributing wave force responsible for local shoreline retreat. A strong relationship has been shown to exist between wave power and shoreline retreat [Schwimmer (2001) and Marani et al. (2011)]. Whether or not this strong relationship exists in Terrebonne Bay is the subject of this research. In situ measurements over a period of 12 months are presented. Shoreline surveys were completed along with the deployment of wave gauges to determine the wave power directly in front of the marsh edge. The shoreline surveys were carried out roughly every three months and a continuous wave record was obtained between two consecutive surveys. These results are then directly compared to historical records as well as predictive models. Following the in-situ measurements, large-scale retreat rate and wave power are examined. Aerial photographs of Terrebonne Bay are used to obtain long-term retreat rates at selected sites between the years of 1998 and 2010. Numerical models were then utilized to obtain hindcasts of wave power at these sites. Historic wind and bathymetry data were used to obtain the water level in the bay (Delft3D). Next a wave model (SWAN) was implemented to obtain the wave power. These results are presented along with the in-situ measurements in Terrebonne Bay. A simple linear relationship between wave power and shoreline retreat was not observed in Terrebonne Bay. Although retreat rates increase as the wave power increases in general, large scatter in the data suggests that the spatial variability of parameters such as scarp height, marshland elevation, and soil properties should be included in future analysis. The temporal variability in yearly wave power also suggests that different formulations other than a yearly average wave power should be used when comparing to retreat rate values

Feasibility of restoring the Louisiana black bear (Ursus americanus luteolus) to portions of their former range

Black bears (Ursus americanus) historically occurred throughout much of North America’s forested landscapes, but loss of critical habitat and overharvest significantly reduced abundance and distribution. In the southeastern United States, black bear conservation has become a high priority and restoration has been suggested y to recolonize suitable habitat. My study focused on evaluating restoration of the Louisiana black bear (U. americanus luteolus) to the Red River Complex (RRC) in east-central Louisiana. This involved translocating female bears with new born cubs from source populations within Louisiana and monitoring their movements, habitat use, and social acceptance of the restoration program to determine if restoration attempts should be continued. Females relocated using this method had restricted home ranges and movements during the initial 30-days following release, and established home ranges at the release site within 7 months. Females continued to den in the area they established home ranges through the following 2 winters. Vegetation measurements at used locations suggest that habitat suitability in the RRC similar to other areas considered highly suitable for bears in the Southeast. A survey of hunters within the RRC indicates that support for the project was high (\u3e 70%) but knowledge about the restoration was low (\u3c 60%), although public meetings were held prior to the release of bears to the area. This data indicates that restoration of the Louisiana black bear to the RRC is feasible and should be continued in an effort to establish a new breeding sub-population of bears in the region