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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Design, Fabrication and Testing of a Novel Dual-Axis Automatic Solar Tracker System Using a Fresnel-Lens Solar Concentrator

Almara, Laura Mabel 08 1900 (has links)
This thesis project investigates, analyzes, designs, simulates, constructs and tests a dual-axis solar tracker system to track the sun and concentrates the heat of the sunlight, using a Fresnel lens, into a small area, which is above of an evaporator, to increase the temperature of the seawater to convert it into freshwater. The dual-axis solar tracker was designed with the main objectives that the structure was portable, dismountable, lightweight, low cost, corrosion resistant, wires inside pipes, accurate, small size, follow the sun automatically, off-grid (electrical), use green energy (solar powered), and has an empty area right below of the lens. First, a 500 mm diameter flat Fresnel lens was selected and simulated based on an algorithmic method achieved by a previous PhD student at UNT using MATLAB®, to give the optimization lens dimensions. The lens profile was drawn with AutoCAD®, then output profile lens was simulated in COMSOL Multiphysics®. The objective was to provide the high efficiency, optimum and high precision of the focal rays and heat to the receiver of the evaporator. A novel dual-axis solar tracker system was then designed that is portable, dismountable, lightweight and corrosion resistant. The solar tracker tracks the sun in two axis of rotation automatically during the day time, maximizing the angles of inclination on each axis. After testing computer simulations, the dual-axis solar tracker system was constructed and tested. Last, a detailed cost analysis was performed of the entire project. The outcome of this work can be applied for desalination seawater purposes or other any Fresnel lens application that require a focal high temperature directed by dual-axis solar tracker system.
42

[en] STOCHASTIC ANALYSIS OF ECONOMIC VIABILITY OF PHOTOVOLTAIC PANELS INSTALLATION IN LARGE CONSUMERS / [pt] ANÁLISE ESTOCÁSTICA DA VIABILIDADE ECONÔMICA DA INSTALAÇÃO DE PAINÉIS FOTOVOLTAICOS EM GRANDES CONSUMIDORES

ANDRES MAURICIO CESPEDES GARAVITO 25 May 2018 (has links)
[pt] A geração distribuída (GD) vem crescendo nos últimos anos no Brasil, particularmente a geração fotovoltaica, permitindo a pequenos e grandes consumidores ter um papel ativo no sistema elétrico, podendo investir em um sistema próprio de geração. Para os consumidores cativos, além da redução do custo de energia, o consumidor também pode ter uma redução no custo de demanda, que é calculado a partir de um contrato com a distribuidora que o atende. Assim, considerando a possibilidade de instalação de painéis fotovoltaicos, o desafio dos consumidores é estimar com maior acurácia possível sua energia, a energia gerada pelos painéis e as demandas máximas futuras de forma a determinar a quantidade ótima de painéis, bem como o contrato de demanda com a distribuidora. Nesta dissertação, propõe-se resolver este problema a partir da simulação de cenários futuros de consumo de energia, demanda máxima e correlacionando-os com cenários futuros de geração de energia. Em seguida, a partir de um modelo de otimização linear inteiro misto, calcula-se a quantidade ótima de painéis fotovoltaicos e a demanda a ser contratada. Na primeira parte da dissertação, a modelagem Box e Jenkins é utilizada para estimar os parâmetros do modelo estatístico de energia consumida e demanda combinados com a geração de energia dos painéis. Na segunda parte, é utilizado um modelo de otimização estocástica que utiliza uma combinação convexa de Valor Esperado (VE) e Conditional Value-at-Risk (CVaR) como métricas de risco para avaliar o número ótimo de painéis e a melhor contratação de demanda. Para ilustrar a abordagem proposta, é apresentado um caso de estudo real para um grande consumidor considerado na modalidade Verde A4 no Ambiente de Contratação Regulado. Os resultados obtidos mostraram que a utilização de painéis fotovoltaicos em um grande consumidor reduzem o custo anual de energia em até 20 por cento, comparado com o valor real faturado. / [en] Distributed Generation (GD) is growing up in the last years in Brazil, particularly photovoltaic generation, allowing small and large consumers play an important role in the electric system, investing in a own generation system. For the regulated consumers, besides the reduction of energy cost, they also may have a reduction in demand cost, which is computed from peak demand contract with the supply utility company. Therefore, taking into account the possibility of photovoltaic panels installation, the challenge of consumers is estimate with highest accuracy as possible its energy, the energy generation by the panels, and the future peak demand in order to estimate the optimum quantity of panels, as well as the peak demand contract with the utility. A way to solve this problem is to simulate future scenarios of energy consumption, peak demand, and correlate them with future scenarios of energy generation. After that, from a mixed integer linear stochastic optimization model, the optimum quantity of panels and peak demand to be contracted are computed. In the first part, the Box and Jenkins modelling is used to estimate the parameters of the energy consumption and peak demand by statistical model, combined with the energy generation of the panels. In the second part, a stochastic optimization model is applied using a convex combination of the Expected Value (VE) and Conditional Value-at-Risk (CVaR), which were used as risk metrics to rate the optimum number of panels and the best peak demand contract. To illustrate the proposed approach, a real case study of a large consumer presented considering the Green Tariff group A4 in the Regulated Environment. The results show that to use photovoltaic panels can reduce the annual cost by up to 20 per cent, compared with the billed real value.
43

Autonomní dům aneb život grid-off / The Autonomous House or Living Grid-off

Chlebný, Radek January 2013 (has links)
This thesis deals with energy self-sufficiency focusing on the independence of the electric grid. Basic line emanating project form a concrete proposal for autonomous energy supply system. Emphasis is placed primarily on photovoltaic systems, electric energy accumulation and selection of individual components of such a system. Another important part of the thesis is also an economic evaluation of design variations. The thesis also deals with a market research, and thereof derived benefit assessment of each technology. The accompanying chapters are then devoted to the history of autonomous life style or classification of buildings according to their energy performance.
44

Osvětlovací systémy v ostrovních aplikacích / Lighting systems in off-grid applications

Lengyel, Ladislav January 2015 (has links)
Aim of the master's thesis is at first to explain appropriate light sources and lighting systems; secondly present suitable light sources selection for lighting a small space and design of an off-grid system. The last part consists of an overview about alternative energy transformations to light energy. The first of these three major themes focuses on the analysis of light sources suitable for use in applications with accumulation together with data on energy efficiency and the utilization efficiency associated with them, concentrating on their consumption and possible energy saving lighting within small applications. It ends with a description and calculations of electricity energy indicators for different types of rooms. The second and main part of the thesis is focusing on suitable light sources selection for off-grid systems and impacts on humans and the environment associated with it. An object representing a small application has been created in RELUX® software with suitable light sources installed in it. For this scene, appropriate parts of off-grid systems were selected, which could be used to power the proposed lighting. The last theme consists of a brief about alternative sources, most of which are still in development or existing only at a theoretical level. All of these alternative sources are having a possible application in the future.
45

Racionalizace konceptu připojení fotovoltaické elektrárny / Rationalization of the concept of photovoltaic power station connection

Svozil, Marek January 2015 (has links)
This masters thesis addresses the racionalization of the concept of photovoltaic power station connection. A way of compensation valuable components involvement standar- tizovaným inverter controlled by a microcontroller. Also includes the measurement of voltage and current using a microcontroller. The output voltage of the DC/DC con- verter is controlled by the variable duty cycle of the PWM signal generated by the microcontroller ATmega32.
46

Horský hotel / Mountain hotel

Moučka, Miroslav January 2022 (has links)
The aim of this master’s project is to develop project documentation of a new-built mountain hotel in Ostružná. This hotel is near the ski area Ramzová in Jeseníky. Foundation of my building is from ground reinforced concrete slab. My building is supported by clay block load-bearing walls and clay non-load bearing walls. Exterior building envelope is designed as an aluminum shingle ventilated facade. The slabs are from reinforced concrete. The roofs of this designed building are two, first is pitched roof with insulation over rafters and second is intensive green warm flat roof. This project contains HVAC concept, photovoltaic panel concept, heating concept in technical equipment of building part. The third part of my master’s project is energy assessment for the building.
47

Renovace budovy s ohledem na její eneregetickou náročnost / Renovation of the building with respect to energy demands

Balíková, Anna Unknown Date (has links)
The diploma thesis deals with the solutions of the renovation of a panel apartment building with regard to energy efficiency. The theoretical part deals with heat pumps. The acquired knowledge was subsequently applied in the computational part, where the energy assessment of the current state of the apartment building and the design of two possible variants of renovation are addressed. The aim of the first variant is the renovation of the building to meet classification class C using the possible funds. The second variant is focused on the technical equipment of the building and primary energy from renewable sources, so that the apartment building reaches classification class A. Both proposed variants are assessed from both an energy and financial point of view. The project part then contains certificates of energy intensity of individual variants of the building.
48

Porovnání výkonnosti fotovoltaických panelů v podmínkách ČR / Comparison of different photovoltaic panels in CR

Červinka, Pavel January 2011 (has links)
This term paper deals about history, principle and use of photovoltaic panel. It describes their stucture and constantly improving properties of these panels. It outlines their gradual generational evolution from beginning to present. Then it describes the various systems involved on – grid and off – grid. It also describes and compares the photovoltaic panels and inverters from different global manufacturer. The end of this work deals about conditions of photovoltaic in the Czech republic and about Hady photovoltaic incubator, which belongs to the company Energ servis a.s. It presents a comparison of different local and the analysis of the impact of shading for the achievement of the photovoltaic panel. It makes mathematic models for calculation of the spacing range and calculation the power loss in a specific shade.
49

Monitorovací systém vodních toků s GSM komunikací / River mionitoring system with GSM communication

Pačinek, David January 2014 (has links)
This master thesis is dedicated to system of water monitoring for use of alternative source power supply and GSM communication. The thesis carried out research on the possibilities to take measurements on watercourses, also detailed research of photovoltaic panel, available accumulators and their charging and a synopsis of similar systems. Furthermore, the master thesis also captures design and implementation datalogger device type with possibility to send measured data to the website.

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