Esta tese apresenta os resultados de pesquisa sobre geração de séries sintéticas de radiação solar para estudos energéticos, realizada através do uso de modelos estocásticos e com o propósito de desenvolver método para aplicações práticas no setor elétrico. Para tanto, inicialmente foi levantado o estado da arte do tema, com revisão da literatura de séries temporais e de processos estocásticos, suas particularidades e potencialidades, complementado pela contextualização do uso de cenários no setor elétrico nacional, especialmente na operação e planejamento do sistema hidrotérmico, e por experiências internacionais na modelagem do recurso solar. A modelagem das séries utilizou dados reais de localidades do nordeste brasileiro e foi desenvolvida através do método de Box-Jenkins, realizando-se estudos de alternativas para cada uma de suas etapas. O pré-tratamento dos dados foi avaliado por três estratégias de remoção da tendência das séries e na estimativa dos coeficientes dos modelos foram comparados os métodos de Yule-Walker e dos mínimos quadrados. As análises consideraram quatro opções de modelos autorregressivos e os períodos horário, diário e mensal. O modelo autorregressivo convencional com intervalo mensal, identificado como o mais adequado para aplicação em estudos energéticos, e sua variação periódica foram implementados e avaliados com maior profundidade. Este estudo complementar considerou diferentes ordens de atraso e realizou comparações dos resultados por três métodos de cálculo do erro. O modelo desenvolvido com estrutura autorregressiva periódica de primeira ordem apresentou resultados satisfatórios e significativamente superiores aos dos demais modelos. Por fim, este modelo foi empregado na geração de séries sintéticas, criando 1.000 cenários de radiação solar mensal, posteriormente aplicados em modelo de contrato de venda de energia para avaliação de estratégias de participação em leilões, em análise de riscos de suprimento e em estimativa probabilística da receita esperada por parques geradores. / This thesis presents the results of a research on the generation of solar radiation synthetic sequences for energy studies, carried out through the use of stochastic models and with the purpose of developing a method for practical applications in the electric sector. In order to do so, the state of the art was devised through a review of the literature of time series and stochastic processes, their particularities and potentialities, complemented by the contextualization of the use of scenarios in the national electricity sector, especially in the hydrothermal system operation and planning, and international experiences in modeling the solar resource. The series modeling used real data from localities in the Brazilian Northeast and was developed through the Box-Jenkins method, carrying out alternative studies for each of its stages. The data pretreatment has been evaluated by three strategies for the series trend removal and by the methods of least squares and of Yule-Walker for the estimation of the model coefficients. The analysis considered four options of autoregressive models and hourly, daily and monthly periods. The conventional autoregressive model with monthly interval, identified as the most applications in energy studies, and its periodic variation were implemented and evaluated in greater depth. This complementary study considered different orders of delay and made comparisons of the results for three error calculation methods. The model developed with periodic autoregressive structure of first order presented results that are satisfactory and significantly superior than the other models. Finally, this model was used in the generation of synthetic series, creating 1,000 scenarios of monthly solar radiation, to be later applied in a model of power purchase agreement to evaluate strategies for auctions bidding, analysis of supply risks and probabilistic estimation of the expected revenue of power plants.

Os sistemas de integração lavoura-pecuária-floresta têm se apresentado promissores, e são apontados como alternativas mais sustentáveis de uso da terra, assim como ferramentas para mitigar as emissões de gases de efeito estufa e diminuir os efeitos que as mudanças climáticas possam gerar na produção agropecuária. Contudo, devido à complexidade desses sistemas, existem ainda muitas limitações técnicas que dificultam a otimização da produção de forragem. O componente arbóreo reduz a quantidade e qualidade da luz, modificando o microclima, e interferindo em processos morfofisiológicos das plantas essenciais para produção de biomassa. Visando entender essas modificações e gerar informações sobre acumulo de biomassa de plantas forrageiras e produção animal em ambientes sombreados, o objetivo geral com este estudo foi avaliar as alterações no microclima do sub-bosque florestal e seus efeitos sobre a produção de forragem, o desempenho animal, e as características morfofisiológicas e estruturais de gramíneas tropicais em diferentes arranjos florestais de sistemas ILPF.. A Brachiaria brizantha cv. Piatã avaliada em dois sistemas de integração lavoura-pecuária-floresta, com espaçamento entre linhas simples de árvores de eucalipto de 14 m (ILPF14) e de 22 m (ILPF22), comparados a um sistema de integração lavoura-pecuária (ILP, a pleno sol), com estratégia de rotação de culturas de 4 anos, sendo 1 ano de lavoura e 3 de pasto. O delineamento experimental foi de blocos casualizados, em esquema de faixas subdivididas, com 4 repetições. Avaliou-se a produção de forragem e o desempenho novilhas nelore, durante 2 ciclo de rotação, no período de 2009 a 2016, comparando as estações de cada ano. No último ano do segundo ciclo, no período de julho de 2015 a junho de 2016, com as árvores adultas e sombreamento intenso, foram realizadas avaliações das respostas morfofisiológicas e estruturais do capim-piatã, no sub-bosque florestal, conforme a distancia das árvores, e estações do ano. / The crop-livestock-forest integrated systems have been pointed out as sustainable alternatives to land use, as well as a tool to mitigate greenhouse gases emissions and to reduce the effects that climate change can generate on agricultural production. However, due the complexity of these systems, there are still many technical limitations that hamper the optimization of forage production. The arboreal component reduces the quantity and quality of light, and modifies the microclimate, interfering in morphophysiological processes essential for biomass accumulation in forage species. The objective of this study was to evaluate the shading effect of different densities of trees on microclimate, and how their interactions influence physiological and structural characteristics of forage plants, and forage production, along the seasons andcrop rotation cycle. Brachiaria brizantha cv. Piatã was evaluated in two crop-livestock-forest integration systems, with single lines of eucalyptus trees spacing by 14 m (ILPF14) and 22 m (ILPF22) (ILPF22), compared to a crop-livestock integration system (ILP; sun), with a crop rotation strategy of 4 years, with 1 year of crop cultivation and 3 years of pasture. A randomized complete blocks design, arranged in a split strips scheme, with 4 replicates was adopted. The forage production and performance of nellore heifers were evaluated during 2 rotation cycles between 2009 and 2016, comparing the seasons of each year. In the last year of the second cycle, from July 2015 to June 2016, with adult trees and intense shading, evaluations of the morphophysiological and structural responses of the piatã palisadegrass were carried out in the sub-forest, according to the distance of the trees, and seasons of the year.

Este trabalho teve como objetivo estudar a fotocatálise heterogênea com Ti'O IND.2' no tratamento de esgoto sanitário secundário, visando a oxidação da matéria orgânica e desinfecção. A luz solar foi utilizada como fonte de radiação. O reator fotocatalítico consistiu de placa de vidro (aproxidamente 0,48 'M POT.2') sobre a qual foi fixado o catalisador (10 g/'M POT.2'). Foi avaliada a influência de parâmetros operacionais (vazão e ângulo de inclinação do fotorreator) na eficiência do processo. As vazões de estudo foram 15; 22,5 e 30 L/h, e os ângulos de inclinação em relação à horizontal foram 2, 12 e 22 graus. Os experimentos foram realizados com dois tipos de efluentes. O primeiro (efluente 1) foi de reator anaeróbio compartimentado tratando esgoto doméstico e o segundo (efluente 2) de reator anaeróbio/aeróbio de leito expandido com meio suporte constituído de carvão ativado que trata o esgoto do Campus I da USP/São Carlos e de contribuições domésticas. Os ensaios foram do tipo batelada com recirculação do esgoto durante 4 horas. Também foi avaliada a fotólise (ensaio apenas com radiação solar) e adsorção do catalisador (ensaio sem luz e com Ti'O IND.2') na oxidação de matéria orgânica e na desinfecção. Foram avaliadas as remoções de matéria orgânica (DQO e COT) e de microrganismos indicadores de contaminação fecal (Clostridium perfringens, coliformes totais, E. coli e colifagos). Os resultados indicaram que a fotocatálise heterogênea foi mais eficiente como método de desinfecção que a fotólise. A resistência dos microrganismos ao processo Ti'O IND.2'/UV, em ordem decrescente, foi: Clostridium perfringens, coliformes totais, E. coli e colifagos. As melhores condições operacionais para inativação de microrganismos no efluente 1 foram: 'alfa' = 2 graus e Q = 22,5 L/h. O ângulo de inclinação da placa teve maior influência na oxidação de COT do efluente 2 do que a vazão. As características físico-químicas dos efluentes tiveram papel importante no resultado final da fotocatálise heterogênea, tanto na oxidação de matéria orgânica como na desinfecção. A concentração inicial de E. coli exerceu maior influência na desinfecção fotocatalítica do que a radiação solar, para as condições dos ensaios realizados. Os reatores de placa plana com Ti'O IND.2' imobilizado, quando expostos à luz solar, devem ser vedados para evitar evaporação excessiva / The heterogeneous photocatalysis with Ti'O IND.2' and solar radiation in secondary wastewater treatment to remove organic matter and microorganisms was investigated. A glass plate (approximate 0.48 'M POT.2') with immobilized titanium dioxide (10 g/'M POT.2') was operated in different flow rates (15; 22.5 and 30 L/h) and angles in relation to horizontal (2, 12 and 22 degrees). Two effluents were used in the assays. The first (effluent 1) was from an anaerobic reactor treating sewage and the second (effluent 2) from an anaerobic/aerobic granular activated carbon expanded bed reactor which receives the wastewater collected in the Campus of USP/São Carlos and from the surrounding neighborhood of the campus. The assays were carried out in batch with recirculation time of 4 hours. The photolysis (only solar radiation) and the catalyst adsorption (Ti'O IND.2' in the dark) in organic matter removal and disinfection were evaluated. The oxidation of organic matter (COD and TOC) and inactivation of indicators of fecal contamination (Clostridium perfringens, total coliforms, E. coli, and coliphages) were evaluated. The results shows that heterogeneous photocatalysis was more efficient in effluents disinfection than the photolysis. The resistance of the microorganisms to Ti'O IND.2'/UV process was in decreasing order: Clostridium perfringens, total coliforms, E. coli and coliphages. The best operational conditions for microorganisms inactivation in effluent 1 are: 'alfa' = 2 degrees and Q = 22.5 L/h. TOC oxidation in effluent 2 was more influenced by angle than by flow rate. The physical and chemical characteristics of the effluents had an important role in oxidation and disinfection. Initial E. coli concentration was more important than intensity of solar radiation during photocatalytic disinfection in the experimental conditions of this work. The reactors with immobilized Ti'O IND.2' open to solar radiation have to be closed to avoid excessive evaporation

The tendency to use renewable energy resources has grown continuouslyover the past few decades, be it due to fear over warnings of globalwarming or because of the depletion and short life of fossil fuels or evenas a result of the interest which has developed among researchers doingscientific research into it. This work can be considered as joining any ofthese groups with an objective of giving electric light to the poorpopulation living in one of the poorest nations in the world.The aim of the work is to investigate supplying electric energy fromsolar-wind hybrid resources to remotely located communities detachedfrom the main grid line in Ethiopia. The communities in mind are one oftwo types; the first is the majority of the poor population residing in thecountryside; and the other is people relocated by the Government fromthe over used and dry regions to relatively productive and fertile ones inline with the long-term poverty reduction plan.The work was begun by investigating wind energy and solar energypotentials at four geographically different locations in Ethiopia bycompiling data from different sources and analyzing it using a softwaretool. The locations are Addis Ababa (09:02N, 038:42E), Mekele (13:33N,39:30E), Nazret (08:32N, 039:22E), and Debrezeit (8:44N, 39:02E).The results related to wind energy potential are given in terms of themonthly Average wind speed, the wind speed probability densityfunction (PDF), the wind speed cumulative density function (CDF), thewind speed duration curve (DC), and power density plots for all fourselected sites. According to the results obtained through the analysis, thewind energy potential, even if it is not exceptional, is irrefutably highenough to be exploited for generating electric energy.The solar energy potential, based on sunshine duration data collectedover a period of 7 - 11 years and radiation data obtained from differentsources, has been calculated using regression coefficients specific to thesites in question. Based on the sunshine duration data, the monthlyaverage daily sunshine amount for each of the places has also beencomputed and given in a form of plot. Through additional work on theresults of the calculations, the solar energy potential has been given inthe form of solar radiation plots for each of the selected sites. Asexpected, the results indicated an abundance of solar energy potential.It is based on the promising findings of these two energy resourcepotentials, wind and solar, that the feasibility study for a standalonesolar-wind hybrid energy supply system has proceeded, targeting thecommunity mentioned earlier. The hybrid system consisted of Windturbine, Photovoltaic panel, diesel generator and a bank of batteries, witha power conditioning converter included in the system.The hybrid standalone supply system is intended to provide electricity toa model community of 200 families with five to six family members ineach. The community is equipped with a primary load, a deferrable load,a community school and a health post. An electric load which includeslighting, water pumping, a radio receiver, and some clinical equipmenthas been suggested. Hybrid Optimization Model for ElectricRenewables, HOMER, software has been used for the analysis. Theaverage wind speed and average solar radiation calculated from the datafor all of the selected sites has been used to input into the software.The hybrid system design is approached in three different ways. The firstapproach is to include within the hybrid system those components whichare locally available, without giving special attention to their efficienciesand proceed with the design work. The second approach is tothoroughly search the market for the best and most efficienttechnological products and to select the best components for theanalysis. A third approach considered in an attempt of cost minimizationis to see if a self-contained type of design can be a better solution. Whatthis means is every household will have its own supply system that mayconsist of any combination of PV and wind turbine including converter,battery and charge controller.After running the simulations, lists of power supply systems have beengenerated, sorted according to their net present cost. Sensitivity variables,such as range of wind speeds, range of radiation levels and diesel pricehave been defined as inputs into the software and the optimizationprocess has been carried out repeatedly for the sensitivity variables andthe results have been refined accordingly. / QC 20100623

Das thermische Raummodell THERAKLES berechnet das dynamische Verhalten eines Raumes und seiner Umschließungsflächen in Abhängigkeit von realistischen Klimarandbedingungen, sowie Nutzer- und Anlagenverhalten. Neben Energieverbrauchswerten werden die operative Temperatur sowie weitere Kriterien zur Beurteilung der Behaglichkeit berechnet. Schwerpunkt der Anwendung liegt auf Optimierung der thermischen Behaglichkeit im Sommerfall, sowie energetischer Optimierung der Regelung von Heizungsanlagen unter Ausnutzung der Dynamik schwerer Baukonstruktionen und Massivbauwände. Das Modell beschreibt das dynamische Verhalten der Umfassungskonstruktionen durch instationäre, räumlich aufgelöste Simulation der Wand-, Fußboden-, und Decken- bzw. Dachflächen. Dadurch werden in der Konstruktion enthaltene Phasenwechselmaterialien (PCM) berücksichtigt und die zeitliche Verfügbarkeit der zusätzlichen Wärmespeicherfähigkeit abgebildet.

Not available / text

Not available / text

Measurements by the TOMS instrument aboard the Nimbus 7 satellite, of total column ozone over polar regions have been studied to determine the effects of solar induced natural ozone modulation. Two different analysis methods were employed to ascertain short term (days to months) and long term (months to years) solar influences on polar ozone. Bursts of intense solar activity can result in solar proton events (SPE's). The high energy protons, originating in solar flares, produce secondary electrons which can generate large concentrations of odd nitrogen in the middle atmosphere. These reactive species can catalytically destroy ozone. Three case studies are presented in an attempt to quantify the effect of SPE's on ozone mass over a latitude region 90 to 70°. In order to monitor the ozone response following a SPE over both hemispheres simultaneously, the SPE must occur during the equinox period when both poles are irradiated. Fortuitously, a SPE was recorded in March 1989, the analysis of which forms a case study in this thesis. Ozone depletions of 7.4 x 10 to the power of 9 kg for the south polar cap and 8.0 x 10 to the power of 9 kg for the north polar cap indicate the degree of symmetry for this event. Longer term effects of solar variability are investigated by Fourier techniques. A Fourier transform of eleven years of total ozone mass values, over the region 90 to 70° S, was performed. Inspection of the Fourier spectrum reveals peaks associated with solar cycle, annual and semi-annual oscillations, that may be attributed directly to solar variation. Other peaks, corresponding to QBO and ENSO periodicities, may be ascribed to indirect solar influences i.e. thermally driven dynamics. Finally, a comparison between the phase of the solar cycle peak in this spectrum with that in a spectrum of daily values of solar radio flux, reveals that the austral polar ozone solar cycle periodicity lags solar forcing by 2.8 years. Portions of chapters have been reported at the 1990 South African Institute of Physics Annual Conference, University of Port Elizabeth, South Africa and as a poster at the 1992 Quadrennial Ozone Symposium, Charlottesville, United States of America, 4-13 June 1992. In addition, various parts of this work has been submitted for publication, viz: Stephenson, J. A. E. and M. W. J. Scourfield, Importance of energetic solar protons in ozone depletion, Nature, 352, 137: 1991. / Thesis (Ph.D.)-University of Natal, Durban, 1994.

Αντικείμενο της παρούσας διπλωματικής εργασίας, είναι η μελέτη της συμπεριφοράς φωτοβολταϊκού πλαισίου λεπτής ταινίας CIS, σε πραγματικές συνθήκες λειτουργίας. Μελετάται η επίδραση διάφορων εξωτερικών παραγόντων και κυρίως της θερμοκρασίας, της ηλιακής ακτινοβολίας και της σκίασης. Με στόχο την εκτίμηση της παραγόμενης DC ισχύος σε διάφορες συνθήκες λειτουργίας., έχουν πραγματοποιηθεί μετρήσεις ρεύματος-τάσης στο χώρο του Πανεπιστημίου Πατρών, σε φωτοβολταϊκό πλαίσιο CIS ονομαστικής ισχύος 75W. Οι μετρήσεις ήταν συνήθως ημερήσιες και καταγράφονταν οι τιμές για διάφορες συνθήκες λειτουργίας και σε διαφορετικές εποχές του έτους. Με ένα μεταβλητό φορτίο συνδεδεμένο με το εν λόγω φωτοβολταϊκό πλαίσιο, ήταν δυνατός ο προσδιορισμός της χαρακτηριστικής I-V καμπύλης σε κάθε μέτρηση και ως εκ τούτου, ο υπολογισμός του σημείου μέγιστης ισχύος. Για κάθε μέτρηση καταγράφονταν, εκτός του ρεύματος και της τάσης, η λαμβανόμενη ηλιακή ακτινοβολία, η θερμοκρασία αέρα καθώς και οι θερμοκρασίες στις δύο όψεις του συλλέκτη. Αρχικά, υπολογίζεται η απόδοση του πλαισίου σε διαφορετικές θερμοκρασίες λειτουργίας ενώ σε αυτό προσπίπτουν ίδια ποσά της ηλιακής ακτινοβολίας. Επίσης, μελετάται ποιες χαρακτηριστικές παράμετροι επηρεάζονται περισσότερο όπου διαπιστώνεται πως η αύξηση της θερμοκρασίας προκαλεί μείωση της τάσης και μία μικρή αύξηση του ρεύματος η οποία όμως, δεν είναι ικανή να αντισταθμίσει την μείωση της τάσης, με αποτέλεσμα η αύξηση της θερμοκρασίας να επιδρά αρνητικά στην απόκριση ισχύος. Στη συνέχεια, γίνεται αντίστοιχος υπολογισμός και για την ηλιακή ακτινοβολία όπου παρουσιάζεται η θετική της επίδραση στην απόδοση του πλαισίου, ενώ ταυτόχρονα μελετάται η συμπεριφορά του CIS σε συνθήκες ηλιοφάνειας αλλά και συννεφιάς. Κατά την επεξεργασία των αποτελεσμάτων αυτών, ήταν δυνατός ο υπολογισμός μίας μέσης τιμής της αποδιδόμενης ισχύος τόσο για τη θερινή όσο και για τη χειμερινή περίοδο. Τέλος, προκαλώντας τεχνητή σκίαση στο 30% περίπου της επιφάνειας του φωτοβολταϊκού πλαισίου κατά τη διάρκεια κάποιων μετρήσεων, υπολογίζεται το ποσοστό μείωσης της παραγόμενης DC ισχύος, συγκριτικά με τις περιπτώσεις όπου κάτω από τις ίδιες εξωτερικές συνθήκες, το πλαίσιο δεν σκιάζεται. / The objective of this diploma thesis, is to study the behavior of a thin film photovoltaic module CIS, under real conditions of operation. The effect of various exterior factors is studied and mainly the factors of temperature, solar radiation and shading. To estimate the produced DC Power in various conditions, measurements has been took place at the University of Patras using a CIS photovoltaic module, of 75W Maximum Power. Measurements were usually daily and were taken in all seasons of year. With a variable load connected to the photovoltaic module, the determination of the I-V curve was possible for each measurement and consequently, the calculation of the Maximum Power Point could be made. At each measurement, were noted the current, the voltage and also the received solar radiation, the air temperature as well as the temperatures at the two sides of the module. At first, the output and the efficiency of the module in different temperatures of operation are calculated , while the received solar radiation is the same in every case. Also, it is studied witch parameters are more influenced by increasing temperature and it is proved that voltage is decreased and current is a little increased. However, the increasing current is not capable to compensate the decreasing voltage, so the increase of temperature affects negatively the output power and the efficiency. Afterwards, a similar calculation has been made, studying the influence of solar radiation at the characteristic parameters of the CIS photovoltaic module. During these calculations, except the positive effect of solar radiation it is presented the behavior of CIS in sunlight and also cloudy conditions. As a result, an average output power of the module has calculated for the aestival and the wintry period. Finally, causing artificial shading in about the 30% of the module's surface, it is determined the rate of reduction of produced DC power, comparatively the case where the module is not shading under the same exterior conditions.

Resumo: A pesquisa vem testar duas tecnologias conhecidas, mas no Brasil nunca utilizada em conjunto. O processo de oxidação com utilização de radiação solar seguida pelo processo de filtração lenta pode ser muito promissor no tratamento de água para pequenas comunidades ou comunidades rurais. A praticidade em conjunto com uma nova tecnologia vem mostrar a eficiência de uma energia que não é aproveitada ou até pouco aproveitada no mundo todo. A incidência de raios Ultra Violeta presente na radiação solar quebrou as moléculas de ácido húmico e de fármacos facilitando sua remoção pela camada biológica dos filtros lento. As moléculas restantes poderão ser retiradas por adsorção pelo carvão ativado granular presente em uma coluna. Tanto o ácido húmico quanto os fármacos são moléculas difíceis de serem retiradas da água em um processo convencional de tratamento de água, estes são micro poluentes que tem causado preocupação entre os estudiosos. Devido a esta dificuldade pensou-se em desenvolver um método que é mais eficaz e tornar-se a água mais potável e financeiramente mais acessível pela classe baixa. No tratamento da água obteve-se uma remoção de ácido húmico em torno de 55% e de fármacos na média de 60%, variando de acordo com os compostos utilizados que foram diclofenaco, dipirona, ibuprofeno e naproxeno / Abstract: The study is to test two known technologies, but never used in Brazil together. The oxidation process using solar radiation followed by slow filtration process can be very promising in the treatment of water for small communities or rural communities. The practice together with a new technology comes along to show the efficiency of energy that is wasted or even little advantage worldwide. The breaking of the molecule by the impact of UV rays present in sunlight broke the molecules of humic acid and drugs facilitating its removal by biological layer of slow filters. The remaining molecules may be removed by adsorption by granular activated carbon present in a column. Both the humic acid molecules as drugs are difficult to be removed from the water in a conventional process water treatment, these are micro pollutants that has caused concern among scholars. This difficulty incentived the developing of the method that is more efficient and become more potable water and more financially accessible for the lower class. In water treatment obtained a removal of humic acid and about 55% of drugs on average 60%, varying according to the compounds used were diclofenac, dipyrone, ibuprofen and naproxen / Orientador: Milton Dall'Aglio Sobrinho / Coorientador: Edson Pereira Tangerino / Banca: Alessandro Minillo / Banca: Mauricio Luiz Sens / Mestre