Estudio y análisis de las necesidades computacionales de un parque eólico

[ES] La energía eólica es una de las fuentes de energía renovable más importante hoy día con un continuo crecimiento a nivel mundial. España también ha apostado por las renovables y más concretamente por la energía eólica, materializándose con importantes instalaciones en gran parte de las comunidades autónomas entre ellas, Canarias. Con la realización de este trabajo se pretende estudiar el potencial eólico disponible en la zona donde se pretenda instalar o mantener un parque eólico, empleando para ello la ayuda de un supercomputador, el cual se encargará, por medio de un software de predicción meteorológica, que ayudarán en la decisión de dónde ubicar un parque eólico y, posteriormente, en la fase de explotación, predecir la potencia que un parque eólico inyectará en la red eléctrica con la antelación suficiente para que permita planificar las centrales de reserva de generación de energía tradicional u otras acciones que se consideren de interés. Durante el desarrollo del trabajo emplearemos el software “WRF” de predicción meteorológica. Esto generará un alto coste computacional y es por lo que proponemos realizar los cálculos empleando la ayuda de un supercomputador. Para concluir el trabajo mostraremos las características del supercomputador Atlante, situado en Las Palmas de Gran Canaria, y analizaremos el coste que le supondría a una empresa, la compra o el alquiler de un supercomputador.

Estudio de eficiencia energética y estabilidad de una micro-red en La Restinga, isla de El Hierro

Máster Universitario en Eficiencia Energética (SIANI)

An adaptive solar radiation numerical model

[EN]A numerical model for the evaluation of solar radiation in different locations is presented. The solar radiation model is implemented taking into account the terrain surface using two-dimensional adaptive meshes of triangles that are constructed using a refinement/derefinement procedure in accordance with the variations of terrain surface and albedo. The selected methodology defines the terrain characteristics with a minimum number of points so that the computational cost is reduced for a given accuracy. The model can be used in atmospheric sciences as well as in other fields such as electrical engineering, since it allows the user to find the optimal location for maximum power generation in photovoltaic or solar thermal power plants...

Solar radiation estimation using a numerical model

[EN]A solar radiation numerical model is presented. It is intented to be useful for different purposes like the evaluation of the suitability of possible locations for solar power stations. This model allows the user to evaluate the radiation values in any location easily, and estimate the solar power generation taking into account not only the radiation level, but also the terrain surface conditions considering the cast shadows. The solar radiation model is implemented taking into account the terrain surface using 2-D adaptive meshes of triangles, which are constructed using a refinement/derefinement procedure in accordance with the variations of terrain surface and albedo...

Development of human visual system analysis for the implementation of a new instrument for flicker measurement

Flicker is a power quality phenomenon that applies to cycle instability of light intensity resulting from supply voltage fluctuation, which, in turn can be caused by disturbances introduced during power generation, transmission or distribution. The standard EN 61000-4-15 which has been recently adopted also by the IEEE as IEEE Standard 1453 relies on the analysis of the supply voltage which is processed according to a suitable model of the lamp – human eye – brain chain. As for the lamp, an incandescent 60 W, 230 V, 50 Hz source is assumed. As far as the human eye – brain model is concerned, it is represented by the so-called flicker curve. Such a curve was determined several years ago by statistically analyzing the results of tests where people were subjected to flicker with different combinations of magnitude and frequency. The limitations of this standard approach to flicker evaluation are essentially two. First, the provided index of annoyance Pst can be related to an actual tiredness of the human visual system only if such an incandescent lamp is used. Moreover, the implemented response to flicker is “subjective” given that it relies on the people answers about their feelings. In the last 15 years, many scientific contributions have tackled these issues by investigating the possibility to develop a novel model of the eye-brain response to flicker and overcome the strict dependence of the standard on the kind of the light source. In this light of fact, this thesis is aimed at presenting an important contribution for a new Flickermeter. An improved visual system model using a physiological parameter that is the mean value of the pupil diameter, has been presented, thus allowing to get a more “objective” representation of the response to flicker. The system used to both generate flicker and measure the pupil diameter has been illustrated along with all the results of several experiments performed on the volunteers. The intent has been to demonstrate that the measurement of that geometrical parameter can give reliable information about the feeling of the human visual system to light flicker.

Development of a microgrid with renewable energy sources and electrochemical storage system integration

Beside the traditional paradigm of "centralized" power generation, a new concept of "distributed" generation is emerging, in which the same user becomes pro-sumer. During this transition, the Energy Storage Systems (ESS) can provide multiple services and features, which are necessary for a higher quality of the electrical system and for the optimization of non-programmable Renewable Energy Source (RES) power plants. A ESS prototype was designed, developed and integrated into a renewable energy production system in order to create a smart microgrid and consequently manage in an efficient and intelligent way the energy flow as a function of the power demand. The produced energy can be introduced into the grid, supplied to the load directly or stored in batteries. The microgrid is composed by a 7 kW wind turbine (WT) and a 17 kW photovoltaic (PV) plant are part of. The load is given by electrical utilities of a cheese factory. The ESS is composed by the following two subsystems, a Battery Energy Storage System (BESS) and a Power Control System (PCS). With the aim of sizing the ESS, a Remote Grid Analyzer (RGA) was designed, realized and connected to the wind turbine, photovoltaic plant and the switchboard. Afterwards, different electrochemical storage technologies were studied, and taking into account the load requirements present in the cheese factory, the most suitable solution was identified in the high temperatures salt Na-NiCl2 battery technology. The data acquisition from all electrical utilities provided a detailed load analysis, indicating the optimal storage size equal to a 30 kW battery system. Moreover a container was designed and realized to locate the BESS and PCS, meeting all the requirements and safety conditions. Furthermore, a smart control system was implemented in order to handle the different applications of the ESS, such as peak shaving or load levelling.

Design and Preliminary Results of an Atmospheric-Pressure Model Gas Turbine Combustor Utilizing Varying CO2 Doping Concentration in CH4 to Emulate Biogas Combustion

Utilization of biogas can provide a source of renewable energy in both heat and power generation. Combustion of biogas in land-based gas turbines for power generation is a promising approach to reducing greenhouse gases and US dependence on foreign-source fossil fuels. Biogas is a byproduct from the decomposition of organic matter and consists primarily of CH4 and large amounts of CO2. The focus of this research was to design a combustion device and investigate the effects of increasing levels of CO2 addition to the combustion of pure CH4 with air. Using an atmospheric-pressure, swirl-stabilized dump combustor, emissions data and flame stability limitations were measured and analyzed. In particular, CO2, CO, and NOx emissions were the main focus of the combustion products. Additionally, the occurrence of lean blowout and combustion pressure oscillations, which impose significant limitations in operation ranges for actual gas turbines, was observed. Preliminary kinetic and equilibrium modeling was performed using Cantera and CEA for the CH4/CO2/Air combustion systems to analyze the effect of CO2 upon adiabatic flame temperature and emission levels. The numerical and experimental results show similar dependence of emissions on equivalence ratio, CO2 addition, inlet air temperature, and combustor residence time. (C) 2014 Elsevier Ltd. All rights reserved.

Local degradation of structural, mechanical, electrical and chemical properties of membrane electrode assembly in polymer electrolyte fuel cell

Polymer electrolyte fuel cell (PEMFC) is promising source of clean power in many applications ranging from portable electronics to automotive and land-based power generation. However, widespread commercialization of PEMFC is primarily challenged by degradation. The mechanisms of fuel cell degradation are not well understood. Even though the numbers of installed units around the world continue to increase and dominate the pre-markets, the present lifetime requirements for fuel cells cannot be guarantee, creating the need for a more comprehensive knowledge of material’s ageing mechanism. The objective of this project is to conduct experiments on membrane electrode assembly (MEA) components of PEMFC to study structural, mechanical, electrical and chemical changes during ageing and understanding failure/degradation mechanism. The first part of this project was devoted to surface roughness analysis on catalyst layer (CL) and gas diffusion layer (GDL) using surface mapping microscopy. This study was motivated by the need to have a quantitative understanding of the GDL and CL surface morphology at the submicron level to predict interfacial contact resistance. Nanoindentation studies using atomic force microscope (AFM) were introduced to investigate the effect of degradation on mechanical properties of CL. The elastic modulus was decreased by 45 % in end of life (EOL) CL as compare to beginning of life (BOL) CL. In another set of experiment, conductive AFM (cAFM) was used to probe the local electric current in CL. The conductivity drops by 62 % in EOL CL. The future task will include characterization of MEA degradation using Raman and Fourier transform infrared (FTIR) spectroscopy. Raman spectroscopy will help to detect degree of structural disorder in CL during degradation. FTIR will help to study the effect of CO in CL. XRD will be used to determine Pt particle size and its crystallinity. In-situ conductive AFM studies using electrochemical cell on CL to correlate its structure with oxygen reduction reaction (ORR) reactivity

Diesel spray mixing limited vaporization with non-ideal and multi-component fuel thermophysical property effects

Internal combustion engines are, and will continue to be, a primary mode of power generation for ground transportation. Challenges exist in meeting fuel consumption regulations and emission standards while upholding performance, as fuel prices rise, and resource depletion and environmental impacts are of increasing concern. Diesel engines are advantageous due to their inherent efficiency advantage over spark ignition engines; however, their NOx and soot emissions can be difficult to control and reduce due to an inherent tradeoff. Diesel combustion is spray and mixing controlled providing an intrinsic link between spray and emissions, motivating detailed, fundamental studies on spray, vaporization, mixing, and combustion characteristics under engine relevant conditions. An optical combustion vessel facility has been developed at Michigan Technological University for these studies, with detailed tests and analysis being conducted. In this combustion vessel facility a preburn procedure for thermodynamic state generation is used, and validated using chemical kinetics modeling both for the MTU vessel, and institutions comprising the Engine Combustion Network international collaborative research initiative. It is shown that minor species produced are representative of modern diesel engines running exhaust gas recirculation and do not impact the autoignition of n-heptane. Diesel spray testing of a high-pressure (2000 bar) multi-hole injector is undertaken including non-vaporizing, vaporizing, and combusting tests, with sprays characterized using Mie back scatter imaging diagnostics. Liquid phase spray parameter trends agree with literature. Fluctuations in liquid length about a quasi-steady value are quantified, along with plume to plume variations. Hypotheses are developed for their causes including fuel pressure fluctuations, nozzle cavitation, internal injector flow and geometry, chamber temperature gradients, and turbulence. These are explored using a mixing limited vaporization model with an equation of state approach for thermopyhysical properties. This model is also applied to single and multi-component surrogates. Results include the development of the combustion research facility and validated thermodynamic state generation procedure. The developed equation of state approach provides application for improving surrogate fuels, both single and multi-component, in terms of diesel spray liquid length, with knowledge of only critical fuel properties. Experimental studies are coupled with modeling incorporating improved thermodynamic non-ideal gas and fuel

Integrated solar energy and absorption cooling model for HVAC (heating, ventilating, and air conditioning) applications in buildings

The demands in production and associate costs at power generation through non renewable resources are increasing at an alarming rate. Solar energy is one of the renewable resource that has the potential to minimize this increase. Utilization of solar energy have been concentrated mainly on heating application. The use of solar energy in cooling systems in building would benefit greatly achieving the goal of non-renewable energy minimization. The approaches of solar energy heating system research done by initiation such as University of Wisconsin at Madison and building heat flow model research conducted by Oklahoma State University can be used to develop and optimize solar cooling building system. The research uses two approaches to develop a Graphical User Interface (GUI) software for an integrated solar absorption cooling building model, which is capable of simulating and optimizing the absorption cooling system using solar energy as the main energy source to drive the cycle. The software was then put through a number of litmus test to verify its integrity. The litmus test was conducted on various building cooling system data sets of similar applications around the world. The output obtained from the software developed were identical with established experimental results from the data sets used. Software developed by other research are catered for advanced users. The software developed by this research is not only reliable in its code integrity but also through its integrated approach which is catered for new entry users. Hence, this dissertation aims to correctly model a complete building with the absorption cooling system in appropriate climate as a cost effective alternative to conventional vapor compression system.

Processing and characterization of PbSnTe-based thermoelectric materials made by mechanical alloying

The research reported in this dissertation investigates the processes required to mechanically alloy Pb1-xSnxTe and AgSbTe2 and a method of combining these two end compounds to result in (y)(AgSbTe2)–(1 - y)(Pb1-xSnxTe) thermoelectric materials for power generation applications. In general, traditional melt processing of these alloys has employed high purity materials that are subjected to time and energy intensive processes that result in highly functional material that is not easily reproducible. This research reports the development of mechanical alloying processes using commercially available 99.9% pure elemental powders in order to provide a basis for the economical production of highly functional thermoelectric materials. Though there have been reports of high and low ZT materials fabricated by both melt alloying and mechanical alloying, the processing-structure-properties-performance relationship connecting how the material is made to its resulting functionality is poorly understood. This is particularly true for mechanically alloyed material, motivating an effort to investigate bulk material within the (y)(AgSbTe2)–(1 - y)(Pb1-xSnx- Te) system using the mechanical alloying method. This research adds to the body of knowledge concerning the way in which mechanical alloying can be used to efficiently produce high ZT thermoelectric materials. The processes required to mechanically alloy elemental powders to form Pb1-xSnxTe and AgSbTe2 and to subsequently consolidate the alloyed powder is described. The composition, phases present in the alloy, volume percent, size and spacing of the phases are reported. The room temperature electronic transport properties of electrical conductivity, carrier concentration and carrier mobility are reported for each alloy and the effect of the presence of any secondary phase on the electronic transport properties is described. An mechanical mixing approach for incorporating the end compounds to result in (y)(AgSbTe2)–(1-y)(Pb1-xSnxTe) is described and when 5 vol.% AgSbTe2 was incorporated was found to form a solid solution with the Pb1-xSnxTe phase. An initial attempt to change the carrier concentration of the Pb1-xSnxTe phase was made by adding excess Te and found that the carrier density of the alloys in this work are not sensitive to excess Te. It has been demonstrated using the processing techniques reported in this research that this material system, when appropriately doped, has the potential to perform as highly functional thermoelectric material.

Cladophialophora bantiana: a rare cause of fungal brain abscess. Clinical aspects and new therapeutic options

Black molds or dematiaceous fungi are rare etiologic agents of intracerebral abscesses and such infections carry a high mortality of up to 70% despite combined surgical and antifungal therapy. While the growing use of immunosuppressive therapies and organ transplantation have caused an increase in the incidence of rare fungal cerebral infections, occurrence in immunocompetent hosts is also possible. We describe a 60-year-old female patient with a cerebral abscess caused by Cladophialophora bantiana. The case illustrates the clinical and radiological similarities between glioblastomas and brain abscesses and emphasizes the need to perform histological and microbiological studies prior to the initiation of any form of therapy. Long-term survival from cerebral black mold abscesses has been reported only when complete surgical resection was possible. The recommended antifungal treatment involves the use of amphotericin B combined with a triazole and, if possible, flucytosine. Highly-active new generation triazole antifungal compounds (voriconazole or posaconazole) are likely to offer improved survival rates for patients with rare mold infections. In particular, posaconazole could be a new therapeutic option given its better tolerance, lower toxicity and fewer drug-drug interactions. We discuss clinical, microbiological and practical pharmacological aspects and review current and evolving treatment options.

AGENT BASED, DISTRIBUTED CONTROL STRATEGIES AND OPTIMIZATION OF PLUG-IN ELECTRIC VEHICLES ON SMART/MICROGRID ARCHITECTURES

This thesis will present strategies for the use of plug-in electric vehicles on smart and microgrids. MATLAB is used as the design tool for all models and simulations. First, a scenario will be explored using the dispatchable loads of electric vehicles to stabilize a microgrid with a high penetration of renewable power generation. Grid components for a microgrid with 50% photovoltaic solar production will be sized through an optimization routine to maintain storage system, load, and vehicle states over a 24-hour period. The findings of this portion are that the dispatchable loads can be used to guard against unpredictable losses in renewable generation output. Second, the use of distributed control strategies for the charging of electric vehicles utilizing an agent-based approach on a smart grid will be studied. The vehicles are regarded as additional loads to a primary forecasted load and use information transfer with the grid to make their charging decisions. Three lightweight control strategies and their effects on the power grid will be presented. The findings are that the charging behavior and peak loads on the grid can be reduced through the use of distributed control strategies.

Game Theoretic Bidding Strategies for Auctions in Green Electricity Markets

Electricity markets in the United States presently employ an auction mechanism to determine the dispatch of power generation units. In this market design, generators submit bid prices to a regulation agency for review, and the regulator conducts an auction selection in such a way that satisfies electricity demand. Most regulators currently use an auction selection method that minimizes total offer costs ["bid cost minimization" (BCM)] to determine electric dispatch. However, recent literature has shown that this method may not minimize consumer payments, and it has been shown that an alternative selection method that directly minimizes total consumer payments ["payment cost minimization" (PCM)] may benefit social welfare in the long term. The objective of this project is to further investigate the long term benefit of PCM implementation and determine whether it can provide lower costs to consumers. The two auction selection methods are expressed as linear constraint programs and are implemented in an optimization software package. Methodology for game theoretic bidding simulation is developed using EMCAS, a real-time market simulator. Results of a 30-day simulation showed that PCM reduced energy costs for consumers by 12%. However, this result will be cross-checked in the future with two other methods of bid simulation as proposed in this paper.

Para que no pase con Potrerillos lo que pasó con El Carrizal

El embalse Carrizal es una obra realizada sobre el río Tunuyán, que nace a la vida del oasis en el año 1971, acompañada de importantes proyectos de desarrollo económico e integración territorial. La inexistencia de una legislación adecuada a las necesidades generadas por esta infraestructura, la ineficiencia en su administración y la desconexión puesta de manifiesto entre el embalse y su zona de influencia, son las causas que provocan la falta de equipamiento turístico-recreativo adecuado y el aprovechamiento óptimo del recurso agua. En el caso de Potrerillos , se diferencian 3 zonas en donde el impacto de la presa puede producir cambios importantes, potenciando su desarrollo o provocando la aparición de externalidades negativas y mayores gastos de los previstos. Estas son : la márgenes del embalse, en donde se espera, al igual que en El Carrizal, el desarrollo de una serie de proyectos turísticos y recreativos; la zona de influencia de la Villa Potrerillos y la del Alto Potrerillos y la zona de riego del río Mendoza. La inserción de este tipo de obra debe ser planificada, y las políticas y acciones a implementar deben surgir de un análisis profundo de su realidad, de las limitaciones y potencialidades naturales como también de las necesidades y requerimientos de todos los agentes que participan en la construcción del nuevo ecosistema.