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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.
21

Solar Tent : A Photovoltaic Generator Model for a Flexible Fabric with Inbuilt Cells

Manhal, Ali, M. Ali, Tammam January 2019 (has links)
Natural disasters and conflicts in many different parts of the world force thousands of people to get displaced from their homes and live in refugee camps temporarily or permanently. For refugee families, lack of energy access has great impact on their lives. Tarpon Solar Company has developed a solar tent which is a combination of laminated cloth and flexible solar cells. In addition to producing renewable electricity, it can create a comfortable outdoor shelter from sun, rain and wind.   The aims of this study were to define and size the solar system of the tent in both AC and DC systems and optimize the tent to work in different locations around the world. Besides designing a monitoring system for the solar tent to evaluate the performance. In addition, defining the social aspect and the consumer behavior for a better solar tent future design. As a case study, Tarpon AC solar tent in Glava, Sweden has been installed to cover the basic needs of the tent users. To understand the solar tent performance in different weather zones, 4 different locations were suggested. A monitor system was designed to monitor the tent solar system performance. The simulation software PVsyst was used to size the PV system in the different locations with different solar data.   The PVsyst simulation results showed that the current Tarpon solar tent with 32 photovoltaic modules is extremely oversized to cover the basic needs loads (Lighting, mobile charging and ventilation) in the emergency cases.   The current Tarpon solar tent has a standard number of photovoltaic modules integrated in the tent fabric while the photovoltaic modules number should vary from one location to another according to the weather data and solar irradiation. In this case the current Tarpon solar system used in Glava, Sweden can be optimized by decreasing the number of photovoltaic modules to only 6 photovoltaic modules instead of 32 modules.   The study also shows that the features of the off-grid system components (battery and charge controller) are different from one location to another according to the criteria of selection.   This study concludes that for the temporary short-term emergency use of the tent where only basic needs loads are needed, DC system is better than AC system in terms of energy efficiency, system size and cost in the different proposed locations. While AC system is better when using the tent for prolonged time in terms of user flexibility and ability to extend the system. Understanding the consumer behavior and the goal of the tent whether to be used for an emergency short term shelter or a permanent shelter for a prolonged time are important factors for a better solar tent design.
22

Techno Economic Analysis of Reverse Osmosis Combined with CSP + PV in Kuwait

Eriksson, Olof January 2020 (has links)
Seawater desalination plays an important role when fighting the freshwater scarcity that many places around the world are currently facing. The increasing need for desalinated water is followed by a high energy demand. It is therefore essential that an expansion of desalination capacity is accompanied by a parallel use of renewable energy sources in this process. This thesis presents a techno-economic study on a reverse osmosis (RO) desalination plant, with a nominal power consumption of 15 MW, that is powered by a concentrated solar power (CSP) plant combined with a photovoltaic (PV) power plant, in Kuwait. The main aim of this thesis was to find which system designs would give the lowest global warming potential and levelized cost of the desalinated water. In addition, it has been investigated how electricity price and emission allowance cost could make a solar power plant competitive to the grid. For this purpose, some components in the whole system were simulated using System Advisor Model and Engineering Equation Solver. With the results obtained from the simulations, a dynamic model of the whole system was developed in MATLAB, Simulink where simulations were done for a typical meteorological year in Shagaya, Kuwait. Both on-grid and off-grid systems were considered.   In the on-grid case, the lowest cost of water was obtained with only PV (ca 0.65 USD/m3) and this could reduce carbon emissions by 30 % compared to only using the grid. Combining CSP and PV could reduce the carbon emissions by 85 % but with a 35 % increase in water cost. It was found that an electricity price of 0.1 USD/kWh or an emission allowance cost of 70 USD/tCO2-eq would make a CSP + PV plant competitive to the grid. These results indicate that the choice of which system is best for powering an on-grid RO plant depends on how the environmental and economic factors are prioritised. In the case of the off-grid system, both the lowest cost of water (ca 0.9 USD/m3) and the highest capacity factor were obtained with a CSP + PV plant with 16 h of storage, a solar multiple of 3 and a PV capacity of 28 MW.
23

FLEXIBLE FLOATING THIN FILM PHOTOVOLTAIC (PV) ARRAY CONCEPT FOR MARINE AND LACUSTRINE ENVIRONMENTS

Trapani, Kim 16 May 2014 (has links)
The focus of the research is on the development of the concept of floating flexible thin film arrays for renewable electricity generation, in marine and lacustrine application areas. This research was motivated by reliability issues from wave energy converters which are prone to large loads due to the environment which they are exposed in; a flexible system would not need to withstand these loads but simply yield to them. The solid state power take off is an advantage of photovoltaic (PV) technology which removes failure risks associated with mechanical machinery, and also potential environmental hazards such as hydraulic oil spillage. The novelty of this technology requires some development before it could even be considered feasible for large scale installation. Techno-economics are a big issue in electricity developments and need to be scoped in order to ensure that they would be cost-competitive in the market and with other technologies. Other more technical issues relate to the change in expected electrical yield due to the modulation of the PV array according to the waves and the electrical performance of the PVs when in wet conditions. Results from numerical modelling of the modulating arrays show that there is not expected variation in electrical yield at central latitudes (slightly positive), although at higher latitudes there could be considerable depreciation. With regards to the electrical performance a notable improvement was measured due to the cooling effect, slight decrease in performance was also estimated due to water absorption (of ~ 1.4%) within the panels. Overall results from both economic and technical analysis show the feasibility of the concept and that it is a possibility for future commercialisation.
24

Desenvolvimento de metodologia de detecção e identificação de fitobactérias em sementes de soja [Glycine max (L.) Merril] por primers espécie-específicos / Development of method for detection and identification of phytobacteria in soybean (Glycine max L.) seeds by species-specific primers

Goulart, Marcela Cristina, 1988 24 August 2018 (has links)
Orientador: Suzete Aparecida Lanza Destéfano / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-24T19:29:47Z (GMT). No. of bitstreams: 1 Goulart_MarcelaCristina_M.pdf: 1843141 bytes, checksum: 317126844277b642b5edc69d405b000b (MD5) Previous issue date: 2014 / Resumo: A soja é considerada uma das culturas mais importantes no Brasil, em função de seu alto valor sócio-econômico, determinado pelas inúmeras aplicações de seus produtos e subprodutos e consequente expressão no mercado interno e externo. No entanto, a cultura desta oleaginosa é frequentemente ameaçada com a ocorrência de um vasto número de doenças, que podem acarretar depreciação do produto, redução no rendimento e perdas econômicas para os produtores. Dentre as principais doenças bacterianas que afetam a cultura da soja, destacam-se a pústula bacteriana, causada por Xanthomonas axonopodis pv. glycines (Xag); o crestamento bacteriano, causado por Pseudomonas savastanoi pv. glycines (Psg); e a murcha de Curtobacterium causada por Curtobacterium flaccumfaciens pv. flaccumfaciens (Cff), ocasionando perdas na produção de até 40%. A condição sanitária das sementes é extremamente importante se considerarmos que elas são veículos desses agentes fitopatogênicos que nelas podem se alojar e serem levados ao campo, provocando redução na germinação e vigor, e originando focos primários de infecção de doenças. O presente trabalho teve por objetivo desenvolver nova metodologia de diagnóstico com o uso das técnicas moleculares que permitissem detectar e identificar a presença de Psg, Xag e Cff em sementes de soja por meio do desenvolvimento de primers espécie específicos. Os primers desenhados a partir de sequências da região espaçadora 16S-23S RNAr, mostraram-se altamente específicos e sensíveis. O par de primers Curto2f/p322anti gerou um fragmento de 675 pb e capacidade de detecção a partir de 0,01 ng de DNA genômico e aproximadamente 5x103 UFC/PCR; o par de primers Psgl/p322anti gerou um fragmento de 500 pb e o grau mínimo de sensibilidade foi de 1 pg de DNA genômico e cerca de 80 UFC/PCR; o par de primers Xanth2f/p322anti gerou um fragmento de 545 pb e capacidade de detecção a partir de 1 ng de DNA genômico e cerca de 700 UFC/PCR. Posteriormente, as sementes de soja foram infectadas artificialmente nas condições de 1; 0,5 e 0,1% de infecção. Nas amplificações com os primers espécie-específicos desenvolvidos, foi possível detectar as fitobactérias em todos os níveis de infecção testados diretamente do extrato bruto, e nas amplificações após o enriquecimento do extrato (BIO-PCR) o sinal positivo foi potencializado / Abstract: Soybean is considered one of the most important crops in Brazil, due to its high socio-economic value, determined by its several products and sub products and its significant expression on the internal and external market. However, this oleaginous plant is often affected by the occurrence of different diseases, which cause depreciation of the product, reduction in yield and substantial economic losses. Among the main bacterial diseases, the bacterial pustule, caused by Xanthomonas axonopodis pv. glycines (Xag), the bacterial blight caused by Pseudomonas savastanoi pv. glycines (Psg), and bacterial tan spot caused by Curtobacterium flaccumfaciens pv. flaccumfaciens (Cff), producing yield losses of up to 40%. The seed health is extremely important since they are considered vehicles of pathogenic agents which can be led to the field, causing germination reduction and vigor; and yielding primary infection of the diseases. This study aimed to develop a new method of diagnosis using molecular tools to detect and identify Psg, Xag or Cff in soybean seeds, through species-specific primers. The primers were designed from sequences of the 16S-23S rRNA and they were highly specific and sensitive. The pair of primers Curto2f/p322anti generated a fragment of 675 bp and was able of detecting down to 0.01 ng of genomic DNA and about 5x103 CFU/PCR; the primer set Psgl/p322anti produced a fragment of 500 bp and reached a detection limit of 1 pg of genomic DNA and about 80 CFU/PCR; and Xanth2f/p322anti yielded a fragment of 545 bp and could detect up to 1 ng of genomic DNA and about 700 CFU/PCR. Subsequently, soybean seeds were artificially infected in the following conditions: 1, 0,5% and 0,1% infection. In the amplifications using the species-specific primers, it was possible to detect the three different phytobacteria at all tested levels of infection directly of the crude extract and in the amplifications after enrichment of the extract (BIO-PCR), the positive signal was enhanced / Mestrado / Genetica de Microorganismos / Mestra em Genética e Biologia Molecular
25

Household Changes in Electricity Consumption Behavior Post Solar PV-Adoption

Blackburn, Griselda 18 September 2014 (has links)
I combine quantitative data on minute-resolved electricity-consumption profiles and survey data with qualitative interviews of PV adopters to create a holistic understanding of how PV adoption influences behavioral change of electricity use. In particular, I examine the information and heuristics consumers use to make energy-related choices and evaluate how consumption behavior affects the total amount and timing of electricity use. Consumption behavior post adoption can significantly alter the environmental benefits of solar PV. Post-adoption changes such as decreases in energy consumption or load shifting from times of high peak demand to times of lower peak demand increase the amount of solar PV generation that is exported to the grid. Higher outflows may reduce the need for less efficient peaking generation units during peak demand, particularly in the summer when solar PV is at its highest generation capacity and electricity demand is greatest. I find that PV adoption does trigger increases in awareness of electricity use. However, while adopters report small or insignificant decreases in household consumption post-adoption, examination of actual records shows both significant increases and decreases in consumption post-PV adoption at the household level. I explain this seeming discrepancy by noting that these households were already energy-conscious prior to PV adoption and had newer, more energy efficient homes, which could offset effects of increased awareness. Supporting this, a majority of respondents considered PV adoption as one action within a larger electricity conservation campaign initiated prior to system adoption. Because they had already implemented several energy efficiency measures, respondents could not easily identify additional ways to reduce electricity use. Most respondents have a method of monitoring consumption, but their attentiveness to monitoring declines after installation-- which could explain the awareness gap as well as the consumption increase. In addition, exogenous factors such as the purchase of an electric vehicle and changes in household size may explain increases in consumption. While I find changes in total consumption after adoption of solar PV at the individual household level, the aggregate mean consumption for all households is just 1.0% but the change in means is insignificant. / text
26

The design and simulation of an efficient photovoltaic inverter

Durrant, A. R. January 1997 (has links)
No description available.
27

THE DEVELOPMENT AND APPLICATION OF A SIMPLIFIED THERMAL PERFORMANCE EQUATION FOR A SHEET-AND-TUBE PHOTOVOLTAIC THERMAL COMBI-PANEL

Carriere, JARRETT 22 January 2013 (has links)
PV/Thermal technology is the combination of solar thermal and photovoltaics - two mature and widely understood technologies. Combining the two technologies complicates existing standardized rating procedures and performance modeling methods. Currently a standardized performance test method does not exist for PV/Thermal (PV/T) panels. Existing and developing PV/T panels are commonly tested using separate standardized solar thermal and photovoltaic test procedures. Solar thermal performance is rated in terms of temperature difference whereas photovoltaic performance is dependent on absolute temperature level. The thermal and electrical performance of a PV/T panel is, however, coupled so performance equations derived using traditional test methods may not accurately reflect the performance of a combined PV/T panel over a wide range of conditions. The purpose of this work was to develop an efficiency equation for a PV/T panel which can be derived from a minimal amount of empirical test data and still accurately predict its thermal and electrical performance over a wide range of conditions. To accomplish this, a quasi- 3-dimensional steady-state model of a sheet-and-tube PV/T collector was developed and used to generate a broad data set from which a simplified PV/T performance equation was developed. Using this numerically generated data set, and introducing additional coefficients into the traditional solar thermal performance characteristic, a modified PV/T efficiency equation was derived which expressed the electrical and thermal efficiency in terms of ambient temperature, incident solar irradiation and the temperature difference between the inlet fluid and the ambient. It was also shown, for the case studied, that the efficiency equation can be produced from as few as 6 data points and still accurately predicts the performance at a wide range of operating conditions. A TRNSYS [1] model was developed to demonstrate how the performance equation can be used to simulate the annual performance of a PV/T collector in a domestic hot water system. It was shown that a performance equation, derived from 6 data points, performed as well as a performance map which used over 1000 data points. The annual thermal and electrical production predicted by both models was within 1.5% of each other. The PV/T efficiency equations were also shown to perform well for a range of electrical parameters, thermal properties and substrate thermal conductivity values. Future work is recommended to validate the PV/T performance equation using real empirically derived data for a range of collector designs. / Thesis (Master, Mechanical and Materials Engineering) -- Queen's University, 2013-01-22 15:40:03.337
28

Investigation of the reliability of the encapsulation system of photovoltaic modules

Wu, Dan January 2015 (has links)
Good reliability of the encapsulation system of Photovoltaic (PV) modules is crucial to ensure the long-term performance of PV modules. A carefully controlled lamination process is required to produce a reliable encapsulation system. To date, the influences of different lamination conditions on the reliability of the encapsulation system are poorly understood. To predict the performance of the encapsulation system, the correlation of the reliability of the encapsulation system with various stress levels is required, which is poorly developed. This thesis improves the understanding of these issues by investigating the correlation of different lamination conditions with the reliability of the encapsulation system and the degradation of adhesion strength under variable damp-heat conditions. The influence of the curing temperature and curing time on the long-term reliability of the encapsulation system is investigated from various viewpoints such as curing level of EVA, chemical and optical stability of EVA and adhesion strength within the encapsulation system. The correlation of curing level and lamination quality has been identified. The effects of over-curing are demonstrated. Results show that the chemical stability, optical stability and the adhesion strength between encapsulant and backsheet increases with the increasing curing level. However, the best long-term adhesion performance at the glass-encapsulant interface is obtained at lower gel content. Too high curing can cause problems of bubble generation, discoloration and unstable interfaces. Among those identified degradation phenomena, interfacial adhesion strength demonstrates the fastest and the largest degradation. The reliability of the adhesion strength is further examined under different stress levels. Among different environmental stress factors, moisture is considered to cause the greatest problems of adhesive interfacial stability. Therefore, the adhesion strength is investigated under different damp-heat conditions. A methodology is developed that can be used to model the adhesion degradation induced by moisture at different humidity and temperature conditions. To do so, a stress model is established which enables quantitative description of the moisture related stresses on PV modules. Based on this model, an exponential correlation is established between the adhesion strength and the humidity and temperature levels. This enables the comparison of adhesion strength of PV modules operating at different humid environments.
29

AESCU-BIKE design, implementation and testing

Romero Suarez, Ivan Jesus January 2019 (has links)
The AESCU-BIKE project is a cargo bike which has an inbuilt off-grid photovoltaic and a monitoring system. The off-grid photovoltaic system consists of a PV module, a lithium-ion battery, a lead acid battery, a charge controller and an electrical fridge. The PV module produces electrical energy which is used to cover the demand of an electrical fridge to supply enough cooling to store and transport pharmaceutical at temperature ranges between 0 °C and 8 °C within the city of Ulm. The monitoring system acquires, saves and plot information regarding the performance of the AESCU-BIKE such as voltages, currents, irradiance, temperatures, location and speed.  The first aim is to theoretically estimate the performance of the off-grid photovoltaic system during summertime and verify that the off-grid photovoltaics system components match. The second aim is to experimentally verify the theoretical estimation of the off-grid photovoltaic system performance during summertime by designing and implementing a monitoring system. The third aim is to visualize in real time information regarding the performance of the AESCU-BIKE. This information is used for an instant analysis of both transportation quality and correct functionality of the off-grid photovoltaic system. A user interface is programmed by using the software Nodered which can be installed in any smart device such as a computer, a smartphone or a Raspberry Pi.  Three different tests are performed to experimentally verify the theorical estimation of the off-grid photovoltaic system performance during summertime. Information such as PV module electrical energy production, fridge electrical energy demand, fridge temperature, ambient temperature, location and speed are plotted and analyzed using the software Excel.  After the results analysis, it is concluded that the monitoring system provides essential information to validate theoretical estimations and to deeply understand the behavior of the off-grid photovoltaic system. Regarding the PV module electrical energy production, losses related to the lack of a MPPT, not optimal PV module inclination angle and shading effect are clearly understood. Regarding the fridge electrical power demand, it is shown that the energy demand is highly related with the ambient temperature. The user interface makes the entire system more friendly. The instant visualization of the measurements helps the user to relate the physical phenomena with the system behavior.
30

ELECTRIC POWER SYSTEM OF AN EMERGENCY ENERGY MODULE

RANAWEERA, CHAMINDA January 2012 (has links)
No description available.

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