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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.
1

Power Rating of Photovoltaic Modules: Repeatability of Measurements and Validation of Translation Procedures

January 2010 (has links)
abstract: Power rating photovoltaic modules at six irradiance and four temperature matrix levels of IEC 61853-1 draft standard is one of the most important requirements to accurately predict energy production of photovoltaic modules at different climatic conditions. Two studies were carried out in this investigation: a measurement repeatability study and a translation procedure validation study. The repeatability study was carried out to define a testing methodology that allows generating repeatable power rating results under outdoor conditions. The validation study was carried out to validate the accuracy of the four translation procedures: the first three procedures are from the IEC 60891 standard and the fourth procedure is reported by NREL. These translation procedures are needed to translate the measured data from the actual test conditions to the reporting rating conditions required by the IEC 61853-1 draft standard. All the measurements were carried out outdoors on clear days using a manual, 2-axis tracker, located in Mesa/Tempe, Arizona. Four module technologies were investigated: crystalline silicon, amorphous silicon, cadmium telluride, and copper indium gallium selenide. The modules were cooled and then allowed to naturally warm up to obtain current-voltage data at different temperatures. Several black mesh screens with a wide range of transmittance were used for varying irradiance levels. From the measurements repeatability study, it was determined that: (i) a certain minimum distance (2 inches) should be maintained between module surface and the screen surface; (ii) the reference cell should be kept outside the screen (calibrated screen) as opposed to inside the screen (uncalibrated screen); and (iii) the air mass should not exceed 2.5. From the translation procedure validation study, it was determined that the accuracy of the translation procedure depends on the irradiance and temperature range of translation. The difference between measured and translatet power at maximum power point (Pmax) is determined to be less than 3% for all the technologies, all the irradiance/ temperature ranges investigated and all the procedures except Procedure 2 of IEC 60891 standard. For the Procedure 2, the difference was found to fall between 3% and 17% depending on the irradiance range used for the translation. The difference of 17% is very large and unacceptable. This work recommends reinvestigating the cause for this large difference for Procedure 2. Finally, a complete power rating matrix for each of the four module technologies has been successfully generated as per IEC 61853-1 draft standard. / Dissertation/Thesis / M.S.Tech Technology 2010
2

Analysis of alternative energy options for buildings

Rezaie, Behnaz 01 August 2009 (has links)
The importance of utilizing different types of energy and their technical application is discussed. Awareness around the globe about the world energy crisis and its critical environmental condition has put more emphasis on the use of renewable energies in every corner of life. It is a well‐known fact that global warming, inefficient use of energy and greenhouse gases are damaging the environment, species and human life drastically. These issues will be discussed in recently conducted research. To address the crucial state of our environment, two simultaneous scenarios are considered. Initially, energy conservation and the switch to a low carbon/no carbon fuel are studied. As for energy conservation in buildings, smart methods in the use of energy in buildings are discussed. Based on different research reported, humans must change their attitude toward the use of resources, and in particular, be conscientious about energy consumption. Next, renewable energy promises a suitable alternative to energy needs in this century, and the best means to overcome the environmental issue and energy crisis is discussed. The practical methods of calculation for solar technology equipment, ground source heat pumps, and wind turbines are explained. In the application part of the study, four buildings are chosen as case studies; two of them from residential sectors, one is a commercial/institutional building, and the fourth is an industrial building. A ground source heat pump for heating and cooling, a solar water heater for heating space or hot water, and a photovoltaic panel for generating electricity are designed for the case studies. Even projects under hybrid systems combined from two technologies are designed. 36 different energy options are calculated for the four case studies. Results show that if a target is reducing CO2 emissions, what systems are the best. In contrast, when decision making is based on budget, what system is the first choice? Not only are technology, environmental protection and cost the main parameters for deciding on renewable technologies, but so are reliability, installation, maintenance and ease of use. Hence, renewable energy systems are categorized based on a broad vision.
3

Shedding (sun)light on risks : Perceived risks and access to finance on the off-grid solar market in Kenya

Svenaeus, Agaton, Rosvall, Max January 2018 (has links)
The market for off-grid solar solutions in Kenya has developed rapidly the recent years. The growth has required capital and access to finance, which has been mainly provided by foreign investors. This thesis examines the perceived risks on the market for off-grid solar solutions in Kenya through a series of interviews with actors engaged in the market. The purpose of the thesis is to investigate the access to capital and highlight the perceived risks that might constrain a continued positive development of the market in Kenya. The findings of this thesis categorize the perceived risks on the market as political, economic, social, technological, legal and environmental (see full report table 2 in section 8 for sub categories). The companies engaged in the market for off-grid solar solutions should be differentiated based on their business model. This since their different value chains entails specific in risks. This study uses two modified value chains to highlight the differences in retail and distribution between the two defined market segments: product and utility. The product segment includes small-scale solar products often referred to as PICO-products and Solar-Home-Systems (SHS), which by being sold on installment now provides basic electricity to a growing number of people in Kenya. The utility segment includes minigrids with solar energy as power supply. This segment is subject to specific regulations regarding installations and operations, which is one of the main contributing factors to the difference in risks compared to the product segment. The other main factor is the way the respective segment distributes and retails their products/electricity. The distribution for the product segment is done by regular land transportation and customer interaction through sales agents, providing basic access to electricity. While the minigrids uses a local distribution grid to provide access to electricity. This leads to specific risks within the categorizes social, technological and legal risk. This study shows that the lack of understanding of the different market segments and their context specific risks, pose a risk to the market reputation and the local actors access to finance. The absence of knowledge about the difference in risks causes generalizations to be done, both from financiers who might place their funding elsewhere, and the customers who might choose other solutions than solar to fulfill their energy needs. The uncertainty of the future development and the position of the national regulations on the market together with the two segments creates barriers for future access to finance. Access that is required to build and boost the market even further.
4

A Study on the Effectiveness of Passive Solar Housing in Ladakh

Björkman, Leo, Nordström, Rita January 2020 (has links)
Energy use in buildings account for 32% of total global final energy consumption, and consequently, a large portion of energy - related greenhouse gas emissions. Passive Solar Designs are sustainable building techniques that use solar energy to heat or coo l living spaces without the aid of mechanical or electrical devices. This paper aims to evaluate the effectiveness of Passive Solar Housing as a possible solution to the heating challenges currently faced in Ladakh, India, from the environmental, social, and economic sustainability perspectives. Two types of Passive Solar Techniques are studied: Trombe Walls and Direct Gain. This is to be achieved by a dualistic approach, combining quantitative and qualitative data to gain a holistic view of the situation. Quantitative data were collected from rooms built with the two different approaches. This information was used to determine the energy efficiency of each Passive Solar Design, and as a basis for building a numerical model that simulates the behaviour of Trombe Walls in conditions not observed during the data collection. Qualitative data were obtained through interviews with the residents of Passive Solar Houses in the villages of Palam and Khardong. The results show that Trombe Walls are significantly more effective at keeping a stable temperature than the Direct Gain technology. The interview responses verify and validate these findings whilst describing many positive effects of living in houses with Trombe Walls. Using the numerical model, it becomes apparent that increasing room size reduces the effectiveness of the Trombe Wall room. In conclusion, Passive Solar Housing can be, both from a social and economic perspective, a very effective method to maintain comfortable living conditions while reducing the environmental impact compared to traditional construction methods. / 32% av den globala energikonsumtionen kommer från energianvändning i byggnader. Det innebär att en betydande andel utsläpp av växthusgaser kommer från dem. Passivhus är en samling hållbara byggtekniker som använder solens energi för att värma upp eller kyla ner en levnadsyta utan att förlita sig på mekaniska eller elektriska medel. Denna studie ämnar utvärdera lämpligheten av Passivhus som en lösning på de uppvärmningsutmaningar som Ladakh, Indien ställs inför, vilket görs ur de miljömässiga, sociala, och ekonomiska hållbarhetsperspektiven. Två typer av Passivhus undersöks: Trombeväggar och Direct Gain. Metoden innefattar en kvantitativ och en kvalitativ datainsamling för att ge en heltäckande bild av situationen. Kvantitativa data insamlades i rum byggda med de två olika teknikerna – denna data användes sedan i en numerisk modell som simulerar hur en Trombevägg beter sig under omständigheter som inte direkt observerats inom ramen för denna studie. Kvalitativa data erhölls från intervjuer med invånarna av Passivhus i de två byarna Palam och Khardong. Resultaten påvisar att Trombeväggar är märkbart mer effektiva på att hålla en stabil inomhustemperatur jämfört med Direct Gain. Intervjusvaren verifierar och validerar resultaten samtidigt som de beskriver flertalet positiva följder av att bo i ett Passivhus. Genom att använda den numeriska modellen blir det tydligt att en ökning av storleken på rummen minskar Trombevägg - rummens förmåga att bibehålla en adekvat inomhustemperatur. Sammanfattningsvis kan Passivhus, från sociala och ekonomiska perspektiven, vara en mycket effektiv metod för att säkerställa tillfredställande levnadsvillkor, samtidigt som de har en mindre negativ påverkan på miljön än traditionella byggnadsmetoder.
5

Optimizing The DSSC Fabrication Process Using Lean Six Sigma

January 2012 (has links)
abstract: Alternative energy technologies must become more cost effective to achieve grid parity with fossil fuels. Dye sensitized solar cells (DSSCs) are an innovative third generation photovoltaic technology, which is demonstrating tremendous potential to become a revolutionary technology due to recent breakthroughs in cost of fabrication. The study here focused on quality improvement measures undertaken to improve fabrication of DSSCs and enhance process efficiency and effectiveness. Several quality improvement methods were implemented to optimize the seven step individual DSSC fabrication processes. Lean Manufacturing's 5S method successfully increased efficiency in all of the processes. Six Sigma's DMAIC methodology was used to identify and eliminate each of the root causes of defects in the critical titanium dioxide deposition process. These optimizations resulted with the following significant improvements in the production process: 1. fabrication time of the DSSCs was reduced by 54 %; 2. fabrication procedures were improved to the extent that all critical defects in the process were eliminated; 3. the quantity of functioning DSSCs fabricated was increased from 17 % to 90 %. / Dissertation/Thesis / M.S.Tech Technology 2012
6

Tecnologia solar residencial : inserção de aquecedores solares de agua no Distrito de Barão Geraldo - Campinas / Residential solar technology : insertion of solar water heaters in Barão Geraldo, district of Campinas

Varella, Fabiana Karla de Oliveira Martins 30 July 2004 (has links)
Orientador: Jose Tomaz Vieira Pereira / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica / Made available in DSpace on 2018-08-06T10:01:41Z (GMT). No. of bitstreams: 1 Varella_FabianaKarladeOliveiraMartins_M.pdf: 1832499 bytes, checksum: 1908f1a8e922a649668feeb398910006 (MD5) Previous issue date: 2004 / Resumo: O mercado de aquecimento solar de água vem crescendo desde a década de 90, porém há falta de informações sobre estudos de caso que avaliem a inserção de aquecedores solares de água nos domicílios brasileiros. Visando contribuir para reduzir essa carência o presente trabalho tem como objetivo avaliar a inserção de aquecedores solares de água no distrito de Barão Geraldo, Campinas-SP. A avaliação foi efetuada através de um plano amostral aleatório estratificado, pois essa metodologia permite conhecer melhor as características próprias de cada segmento da região estudada. Foi necessária a construção de um cadastro para a população pertencente ao distrito de Barão Geraldo, a realização de uma amostra piloto, e por fim, uma amostra final. Após a elaboração do cadastro foram desenvolvidos três questionários para revendedores autorizados, fabricantes e consumidores. O resultado dos questionários aplicados aos consumidores mostra que 19% (com margem de erro máximo de ±5%) dos domicílios do distrito de Barão Geraldo possuem aquecedor solar, ou seja, 1.800 domicílios. Foi realizada a análise do perfil de consumo de energia elétrica dos domicílios por posse de aquecedor solar de água, no período de 1999 a 2003. Verificou-se que os domicílios com aquecedor solar estão consumindo mais energia elétrica do que aqueles que não o tem. Porém, não foi avaliado se esses domicílios consomem mais energia elétrica após a instalação do aquecedor solar / Abstract: The market of solar water heating is growing since the decade of 1990, however there is a lack of information on case studies that evaluate the insertion of solar water heaters in Brazilian dwellings. In order to supply that lack, the present work aims at evaluating the insertion of solar water heaters in Barão Geraldo, district of Campinas-SP. The evaluation was made through a stratified aleatory sample plan, which allows to know the characteristics of each segment of the studied area. It was necessary to create a database of Barão Geraldo population, to accomplish a pilot sample and a final sample. After the elaboration of the database three questionnaires were developed for resellers, manufacturers and consumers. The result of the applied questionnaires to the consumers shows that 19% (with maximum error margin of ±5%) of the dwellings of Barão Geraldo district possesses solar heaters, i.e. , 1.800 dwellings. The analysis of electric power consumption of the dwellings was realized by ownership of solar water heater, in the period from 1999 to 2003. It was verified that the dwellings with solar heaters consume more electric power than the ones that don't possess it. However, it wasn¿t evaluated if those dwellings consume more electric power after the installation of the solar heaters / Mestrado / Planejamento de Sistemas Energeticos / Mestre em Engenharia Mecânica
7

Vliv malých domácích spotřebičů na ekonomiku kombinovaných systémů / Influence of small household appliances on economy of combined solar systems

Hosová, Žaneta January 2013 (has links)
This Master’s thesis deals with the problems of small domestic appliances in solar systems. The theoretical part provides a description of solar thermal systems and solar photovoltaic systems, including the possibility of their combination. It adds options connecting the small household appliances in system of solar technology and economics of the washing process. The practical part evaluates the economy of operation small household appliances connected to the solar system.
8

Vzduchový kolektor v tepelné bilanci budovy / Air-collector in heat balance of building

Dosedlová, Anna January 2013 (has links)
The subject of the thesis is the use of solar thermal technology for the production of low-potential heat. The theoretical part is focus in the solar technology, variants of passive use of solar energy. Describes in detail the solar facades, it's classification in terms of basic criteria. Applications on the project forced ventilation in administrative buildings, installation of solar facade. The work also includes an experiment that deals with the thermal behavior of the air collector.

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