Tesis: "Solar energy use"

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Van, Zyl GHC. "Solar energy for domestic use". Thesis, Cape Technikon, 2000. http://hdl.handle.net/20.500.11838/884.

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Thesis (MTech(Chemical engineering))--Cape Technikon, Cape Town, 2000
The demand for pool heating has increased dramatically over the last few years. This is ascribed to the idea that a swimming pool is expensive and can only be used for four months of the year. Therefore, a need for a relatively inexpensive solar heating system, capable of heating pool water to comfortable temperatures for an extended period, does exist. The least expensive solar heating system for swimming pool heating on the market in South Africa is in the order of R 11000. This is a fixed system, usually mounted on the roof of a house. In order to ensure the safety of minors, a safety net or sail must be installed. This is an additional cost, which approximates R1500, yielding a total cost for safety and heating in the order of R 12500. Copper pipes packed in black material are utilised in these conventional heating systems, and it is the cost of this good heat conductor that makes these units expensive. In this study an alternative pool heating system constructed of PVC was investigated. The system is designed to be flexible, mobile, act as a safety mechanism and absorbs the maximum amount of solar energy available. Dark blue material as opposed to black PVC was selected for aesthetic reasons at the expense of maximum efficiency. The material strength was tested as well as the strength of adhesion. The influence of factors such as exposure to the sun and the effect of water containing chlorine and acid on the material were evaluated. Also, various means of channelling the water through the system for increased efficiency was investigated. A pilot model was constructed and its performance evaluated. It has been concluded that the alternative approach provides effective heating at a lower cost than current systems. Also, the durability of the design was found to be acceptable.

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2

Hedenberg, Ola y John Wallander. "Solar energy for domestic use in southern Brazil". Thesis, Halmstad University, School of Business and Engineering (SET), 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-1603.

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Almost all the domestic water in Brazil is heated with an electrical heater directly by the end consumer. A typical heater has an effect of 5 400 W and when the whole population takes a shower in the evening it causes big peaks in the electrical grid. This consumption peaks could be reduced by simple and cheap solar collector system.

Different system technologies and the most important parts of a solar collector system are described in the technical background. In Lajeado almost every system is a self-circulated system because of the simplicity and the lower costs.

Solar cooling as an alternative to the vapor compressor chillers has been studied. The cooling demand is biggest when the sun shines; this makes the sun perfect as a source to cooling. The ab- and adsorption chillers as a method in the future have been discussed in this paper; however it has only been studied briefly because small scale chillers using the technology can not be found on the market yet.

A number of different systems have been dimensioned after the existing conditions of Lajeado, the town where the project has been carried out in. Prizes and costs for both installation and materials come from the local solar collector supplier. With this as a background; several systems for various hot water demands has been dimensioned and costs and repayment time been calculated. A study of all the systems shows that, if the hot water demand increases and the systems get bigger, the profitability grows and the repayment time becomes shorter, down to three years. In almost every case the repayment time was under eight years, which makes solar heating attractive and the profit is good for the southern Brazil.

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3

Ek, Ludvig y Tim Ottosson. "Optimization of energy storage use for solar applications". Thesis, Linköpings universitet, Elektroniska Kretsar och System, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-149305.

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Energy storage systems is very useful to use in solar panel systems to save money, but also tobe more environment-friendly. The project was given by the solar energy companyPerpetuum Automobile (PPAM) and the project is for their customer, the condominiumcompound Ekoxen. The task is to make a energy regulation for Ekoxen's energy storage sothey can save more money. The energy storage primary task is to shave the top-peaks of theconsumption for Ekoxen. Which means that the battery will supply the household instead forthe three-phase grid. This will make the electric bill for Ekoxen cheaper. Thesimulation/analysis of the energy regulation is done in a spreadsheet tool, where one partworks as a Time-of-Use program and the other work as a modbus feature. Time-of-Use is aweb-based program for PV systems with battery storage, where time-periods can be set toaffect the battery behavior. The modbus feature simulates a system where an algorithm can beimplemented. The results will show that the time-periods for charging the battery with theTime-of-Use program needs to be changed two times per year. One time for the summermonths and a second time for the rest of the months. The results will also show that themodbus feature is better on peak shaving than the time-of-use program.

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4

Nilsson, Nina. "Increased use of solar energy in commercial buildings by integrating energy storage". Thesis, KTH, Mark- och vattenteknik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-190614.

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From a comparison of available thermal energy storage (TES) technologies it can be concluded that the most mature and suitable storage methods for modern commercial buildings in Sweden are storage tanks, either for heat or cold energy, and underground storage solutions such as borehole thermal energy storage (BTES), aquifer storage and energy piles. In this study an integrated solar energy storage system for heating purpose has been designed with BTES, hot water storage tank(s) and solar thermal collectors. The system has been constructed for three different reference buildings in Stockholm and Malmö using the simulation software Polysun, as to investigate the optimal size of BTES system from an economical and energy perspective. The results showed that the optimal storage dimension for the three reference buildings from an economic perspective for a BTES system was 50 % of a building’s peak power demand for heating and tap warm water. The specific energy demand could be lowered significantly for all three buildings, even if applying a weighting factor on the electricity used for the heat pumps. The investment return in the integrated energy storage system turned out to be positive in most cases; however the net present value (NPV) was negative for some of the storage dimensions in the sensitivity analysis. The conclusion from the study is that BTES systems have potential to increase the use of solar energy in modern commercial buildings in a cost effective way, making it easier to reach the future goals of near zero energy buildings (NZEB).

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5

Burashid, Khalid Ahmed. "Solar energy in Bahrain : prospects and potential use in desalination". Thesis, University of the West of Scotland, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.262640.

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6

Değirmencioğlu, Can İlken Zafer. "The Use Of Cell Polyurethane Foams In Air-Type Solar Collectors As The Heat Absorbing Element/". [s.l.]: [s.n.], 2006. http://library.iyte.edu.tr/tezler/master/makinamuh/T000366.pdf.

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Thesis (Master)--İzmir Institute of Technology, İzmir, 2006.
Keywords: Solar energy, solar collectors, solar energy systems, air heating, polyurethane foam. Includes bibliographical references (leaves.60-62).

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7

Wang, Jianjun. "Modelling surface solar energy by use of landsat thematic mapper data and digital elevation models". Thesis, University of Reading, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.336667.

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8

Yousif, Kamil Mansoor. "Studies of degradation modes of molybdenum black coatings in relation to their use as solar selective absorbers". Thesis, Brunel University, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.333363.

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9

Tadlock, James Eric. "A GIS analysis on possible photovoltaic cell use for energy reduction during peak hours in Huntington, West Virginia". [Huntington, WV : Marshall University Libraries], 2009. http://www.marshall.edu/etd/descript.asp?ref=962.

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10

Khan, Fahad. "Spherical Tanks for Use in Thermal Energy Storage Systems". Digital WPI, 2015. https://digitalcommons.wpi.edu/etd-dissertations/187.

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Thermal energy storage (TES) systems play a crucial part in the success of concentrated solar power as a reliable thermal energy source. The economics and operational effectiveness of TES systems are the subjects of continuous research for improvement, in order to lower the localized cost of energy (LCOE). This study investigates the use of spherical tanks and their role in sensible heat storage in liquids. In the two tank system, typical cylindrical tanks were replaced by spherical tanks of the same volume and subjected to heat loss, stress analysis, and complete tank cost evaluation. The comparison revealed that replacing cylindrical tanks by spherical tanks in two tank molten salt storage systems could result in a 30% reduction in heat loss from the wall, with a comparable reduction in total cost. For a one tank system (or thermocline system), a parametric computational fluid dynamic (CFD) study was performed in order to obtain fluid flow parameters that govern the formation and maintenance of a thermocline in a spherical tank. The parametric study involved the following dimensionless numbers: Re (500-7500), Ar (0.5-10), Fr (0.5-3), and Ri (1-100). The results showed that within the examined range of flow characteristics, the inlet Fr number is the most influential parameter in spherical tank thermocline formation and maintenance, and the largest tank thermal efficiency in a spherical tank is achieved at Fr = 0.5. Experimental results were obtained to validate the CFD model used in the parametric study. For the flow parameters within the current model, the use of an eddy viscosity turbulence model with variable turbulence intensity delivered the best agreement with experimental results. Overall, the experimental study using a spherical one tank setup validated the results of the CFD model with acceptable accuracy.

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11

Ekechukwu, O. V. "Experimental studies of integral-type natural-circulation solar-energy tropical crop dryers". Thesis, Cranfield University, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.379485.

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12

Ampatzi, Eleni. "Potential for solar thermal technologies and thermal energy storage to reduce the energy use from Welsh housing". Thesis, Cardiff University, 2010. http://orca.cf.ac.uk/55906/.

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This thesis deals with the potential contribution that state-of-the-art solar thermal (ST) systems enhanced by thermal energy storage (TES) technologies might have in reducing the energy use in Welsh dwellings. The focus of this work lies with the share of the overall amount of conventional energy currently consumed for thermal comfort and hot water preparation that could be replaced by solar energy harvested by active, water-based, solar systems. Twelve typical Welsh dwellings drawn from a recent survey and considered as representative of the Welsh housing stock are modelled and the solar collectors' yield for different orientations and tilts is predicted. The subject is investigated with computer simulations using the TRNSYS simulation engine. The methodology dictates at first prediction and analysis of the thermal energy demand profiles of 12x4 case studies using average (smoothed) and actual (warmer) weather conditions, continuous and intermittent comfort maintenance. Next the ST potential is estimated considering solely a maximum (0.7) and an average (0.4) overall system efficiency and no other technical part for the ST system (modelling approach), in order to investigate the mismatch of energy demand and availability and the TES contribution. The performance characteristics of some representative European ST systems (short-term TES only), as derived from the IEA SHC Task 26 FSC method, are then applied to the simulations to reveal the potential with realistic losses and parasitic energy consumption included (applied only to 5 compatible models). It is revealed that all these house types are possible candidates for effective ST applications, assuming that economies of scale would allow for large absorber areas in the near future. The modelling approach shows that ST systems could contribute to thermal savings between 9%-34% solely with direct utilisation of the collected energy. Furthermore, for most cases, if reasonable sized stores would be used (up to 300kWh TES capacity) then the solar contribution to the overall thermal energy consumption, in the most favourable conditions, would be around 42-58%. Only a couple of models appear to have a lower potential, mainly due to lack of sufficient absorber areas. However for reaching the highest end of expectations for certain house types---up to 54% with average and up to 100% with warmer weather conditions---inter-seasonal storage would be required. In this case, the justifiable storage capacities predicted correspond to very large store volumes, revealing that these are currently not feasible options, as sensible heat storage is still the state-of-the-art for TES. Use of innovative storage types identified by the literature survey, that would only be available in the future, are required in order to achieve high solar contributions, considering space limitations in Welsh dwellings. The FSC results show that for the 5 models the use of solar energy would bring thermal energy savings of around 41-47% if the best system is employed compared to a conventional system, while if parasitic (electric) energy consumption is considered the expected energy savings could be as low as 10%. The actual ST potential is analysed and is found to be in between the two approaches, as both methods have advantages and limitations and complement each other.

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13

Hoetman, Agus Rusyana. "A computational and experimental study of a solar powered Rankine cycle engine for use in Jakarta". Thesis, University of Salford, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.292902.

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14

Fiedler, Frank. "Combined solar and pellet heating systems : Study of energy use and CO-emissions". Doctoral thesis, Västerås : Department of Public Technology, Mälardalen University, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-167.

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15

Goff, Michael J. "Fat and oil derivatives for use as phase change materials /". free to MU campus, to others for purchase, 2004. http://wwwlib.umi.com/cr/mo/fullcit?p3144418.

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16

Gimeno, Furió Alexandra. "On the use of nanofluids to enhance the direct absorption of solar radiation". Doctoral thesis, Universitat Jaume I, 2019. http://hdl.handle.net/10803/666638.

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The present thesis evaluates the potential of solar nanofluids as direct absorption solar collectors and to generate steam. Nowadays, as energy consumption continues to rise while conventional energy are close to begin exhausted, there is an increasing demand for renewable energy technologies, especially solar thermal. Currently, solar thermal energy systems include numerous losses due to the heat transfer processes, thus, nanofluids have been proposed to enhance the solar collectors efficiency through the direct sunlight absorption. In this work, optical properties of different nanofluids carbon based have been characterised in order to study their suitability as direct absorption solar collectors.
La presente tesis trata de evaluar el potencial de los nanofluidos solares para absorber directamente la radiación solar e intentar generar vapor. Como el consumo de energía continúa aumentando y las fuentes de energía convencionales se están agotando, aparece como excelente alternativa, el uso de las energías renovables, concretamente, la energía solar térmica. Los sistemas actuales de energía solar térmica presentan numerosas pérdidas debido a los procesos de transferencia de calor, por ello, se han propuesto los nanofluidos solares como absorbedores de la radiación y fluidos de transferencia de calor y así, mejorar la eficiencia del proceso de generación de vapor en las centrales solares térmicas. En este trabajo, se ha realizado la caracterización de las propiedades ópticas de diferentes nanofluidos solares basados en nanopartículas de carbón para estudiar su idoneidad en la aplicación solar térmica.

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17

Caballero, Lorenzo Álvaro. "Optimization of hydrogenated amorphous silicon for its use in different photovoltaic technologies". Doctoral thesis, Universitat de Barcelona, 2016. http://hdl.handle.net/10803/400401.

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The main objective of this work is to study and optimize the amorphous silicon deposited in a PECVD reactor of recent acquisition, making it suitable for thin film and c-Si based solar cells. Optimization of intrinsic and doped a-Si:H was developed based on several optical and electrical properties. Intrinsic a-Si:H as active layer was optimized with series in three parameters: Depletion, hydrogen flow and temperature. The optimum layer was obtained at low depletion values, with a hydrogen flow ratio of 2:1 and at 200ºC. The series developed for p a- Si:H (TMB flow, temperature, pressure and CH4 flow) led to obtaining device quality material (σdark=1.1·10-5 S/cm, Ea=0.43 eV, Eg=2.02 eV). For p μc-Si:H, after four optimization series (temperature, TMB flow, power and SiH4 flow) device quality material was also obtained (σdark=1.32 S/cm, Eg=2.07 eV, Φ=0.596). In the complete device, the front doped layer thickness and the back reflector optimizations led to increments on the short circuit current of 11% and 12% respectively, and improvements in other parameters. A working PIN a-Si:H solar cell fully deposited at the UB with an efficiency of 7.08% was obtained. During the stage in the LPCIM, a study in polymorphous PIN and NIP solar cells was developed aiming to improve Voc. a-Si:H buffer layers before the pm-Si:H intrinsic material produced an increase in the Voc due to the formation of better interface with the existing μc-SiOx doped layer. Conversely, a-Si:H layers deposited over pm-Si:H and before μc-SiOx material caused the failure of the cell, due to a bad growth of μc-SiOx over amorphous material. To study the light induced degradation of a-Si:H and the associated seasonal effect, a light soaking system was designed and constructed. An optimization of the intrinsic layer thickness was developed; finding an optimal thickness of 200 nm. The role of the temperature in seasonal effect was studied in both T-Solar cells and laboratory UB cells by degradations at different temperatures. Samples going from lower to higher temperatures experienced a recovery of their properties. Conversely, samples going from higher to lower temperatures experienced a sudden drop of their properties. The final state of the parameters of the sample does not depend on the previous history of the sample, but only on the final degradation temperature. Then, a-Si:H deposited at the UB was used as part of c-Si solar cells in collaboration with the UPC. First, the role of sputtered alumina combined with a-Si:H in passivation was studied. A very thin layer of a-Si:H was deposited over the crystalline wafer to act as intermediate layer. This a-Si:H layer acts as physical barrier that protects the wafer from the ion bombardment in the sputtering and serves as hydrogen source that contributes to the saturation of surface defects. The carrier lifetimes obtained with the a-Si:H layer are more than one order of magnitude higher than those without it. Finally, i a-Si:H, p a-Si:H and p μc-Si:H deposited at the UB reactor were used to develop a p- type emitter on an n-wafer. A reoptimization of these materials for this purpose was done. The use of optimized UB’s ITO produced an absolute increment of 3% in the efficiency of devices with n-emitter. The thickness of the p-layers for the emitter was adjusted on an a-Si:H solar cell: The Voc is good (0.875 V), but the absorption has still to be reduced. First trials of p-emitters showed values of the lifetimes limited by the passivation of the a-Si:H, which has to be improved. A study on the influence of carbon concentration and deposition temperature in a- Si:H passivation revealed that including some methane and increasing the temperature help passivation.
En este trabajo se estudia y optimiza el silicio amorfo depositado en un reactor PECVD de reciente adquisición, a fin de ser empleado en células de lámina delgada y como parte de células basadas en silicio cristalino. La optimización del silicio de diferentes tipos (, i a-Si:H, p a-Si:H y p μc-Si:H) basado en varias propiedades ópticas y eléctricas han permitido obtener una célula de silicio amorfo del 7,08% de eficiencia depositada completamente en la UB. El estudio con capas buffer para aumentar el Voc, ha revelado que epositar una capa de a-Si:H intermedia antes de depositar el pm-Si:H produce un aumento del Voc. Se ha estudiado la degradación por iluminación del a-Si:H. Primero se optimizó el espesor (200 nm) y posteriormente se estudió el rol de la temperatura en el LID. Las células que pasaron de temperaturas más bajas a más altas experimentaron una recuperación en sus propiedades, mientras que las que pasaron de temperaturas más altas a más bajas sufrieron una brusca disminución de sus propiedades. El estado final no depende de la historia de la célula, sino solamente de la temperatura final de degradación. En cuanto al uso de a-Si:H combinado con otras tecnologías, se ha observado que depositar una capa muy delgada de silicio amorfo antes de pasivar una oblea de c-Si con alúmina depositada por sputtering mejora el tiempo de vida en más de un orden de magnitud, al proteger la oblea del bombardeo de iones y servir como fuente de hidrógeno para saturación de enlaces. Se ha realizado una reoptimización de ITO, i a-Si:H, p a-Si:H y p μc-Si:H depositados en la UB con el objetivo de desarrollar un emisor tipo p. El espesor de las capas del emisor tipo p se ajustó en función de su funcionamiento en células de a-Si:H. Las primeras pruebas de emisores presentaron valores de tiempo de vida bajos, limitados por la pasivación del silicio amorfo. Se ha observado que incluir metano y aumentar la temperatura en el depósito de a-Si:H es beneficioso para la pasivación, que aún debe ser mejorada.

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18

Gros, Ellinor. "Amasonen : A Design Proposal for a Mixed-Use Building with Integrated Solar Cells". Thesis, Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-69617.

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With the growing energy consumption in the world today, the decreasing amount of fossil fuels and their negative impact on the environment, developments and greater use of renewable energy resources is crucial. One of the promising environmentally friendly energy resources is solar power. The technology for producing electricity from the use of solar cells is continuously developing and is growing on the market. The objective of this master thesis is to illustrate how solar panels can be integrated into a building’s design, and what value this gives to the building. The purpose is also to give an indication of whether an integrated solar panel installation is profitable, and what is required for more building developers to invest in solar power. A study on solar cells was conducted to gain knowledge of the different types of solar cells and systems and their possible integration into buildings. The study also included research on why solar cell installations are not more common today. Case Studies were also conducted on projects with integrated solar cells. This was done to gain an understanding of how solar panels can be used as design elements. The study was done as a systematic literature study through a qualitative method. City and site analyses were carried out as a first step in the design process. The analyses focused on the movements, green spaces, climates, functions and architectural character of the city and site. The analyses were done to attain an impression of the environment the building would be placed in, and its requisites. These analyses were followed by volume and solar studies to come up with a building design that would fulfill the requirements of the client, while creating good areas for placement of the solar panels. The master thesis resulted in a design proposal for a mixed-use building with integrated solar cells. The resulting two buildings are located in the outskirts of the city center of Linköping. The buildings are designed to interact with the surrounding buildings and the remaining city, while at the same time bringing something new and exciting to the mix. The buildings’ placement and height were decided by the combination of the movement of the sun over the plot, so as to create good areas for the solar panels, and the requisites of the site. The integrated solar panels are placed on the roofs and facades of the buildings. The possibilities of semitransparent solar cells in windows and glass railings is also examined. The solar panels on the roof consist of solar roof tiles and are placed on the east side of the north building’s roof and the west side of the south building’s roof. These tiles have matching roof tiles without solar cells inside, on the other side of the roofs, meaning that no difference can be seen between the two sides. The façade panels are placed to cover the entire protruding stairwells of the buildings. Panels are also placed on remaining parts of the south-east and south-west facing facades but are here placed in a pattern as though they are trickling down the walls. The panels are placed to avoid shade as shading of the panels reduces their effect. The solar cells are smooth, black, thin-film solar cells and the panels have matching glass panes that are placed were the design opted for panels, but the placement was not good out of a solar irradiation perspective. The results of the rough calculations on the project’s solar panel installation’s profitability shows that the investment would have a payback time of approximately 15 years. This, when counting in a government support of 1.2 million kroners and the reduced cost for the building cover material that the solar panels replace. The solar panels in the design proposal are not in standard sizes. Would they have been so the investment cost would have been lower and the payback time, according to the rough calculations, would be around 10 years. The produced electricity constitutes around 60 percent of the operational electricity for the buildings. If semitransparent solar cells are included the value goes up to 80 percent. Although the produced electricity does not cover the complete electricity needs of the buildings, it still reduces the amount of bought electricity. Electricity that would most likely not come from a renewable source. The conclusion is, therefore, that an integrated solar cell installation is economically profitable. The solar panels contribute both the aesthetics of the building and building functions, as well as electricity from a renewable source. Investing in a solar cell installation also sets a good example and will lead to more investors taking a chance on solar power. Getting more building developers to invest in solar cells systems can be done by increasing the, today lacking, knowledge of solar energy and solar cells, the process for designing and installing a solar cell system, as well as the laws regarding solar power and solar power investments. Another obstacle for solar power is the high costs of the installations. The prices on solar cells are, however, continuously dropping, because of the development in technology and the manufacturing process, as well as the growing number of manufacturers. To increase the speed of this process more building developers should invest in solar cells, as a higher demand will lead to more manufacturers, which will then lead to reduced prices. The government can also help by offering research support and for example tax subventions to make an investment in solar power seem more worthwhile.

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19

Sankelo, Paula. "Optimal production and use of solar electricity in municipal nearly Zero Energy service buildings". Thesis, KTH, Energiteknik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-200802.

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EU Energy Performance of Buildings direktivet (EPBD) kräver att alla nya byggnader skall vara närä-nollenergibyggnader från och med år 2021. Nya kommunala byggnader måste uppfylla detta nära-nollenergikrav redan från och med år 2019. Den här studien udersöker kommunala servicebyggnader, och speciellt hur egen solelproduktion kunde användas att förbättra kommunala servicebyggnader energieffektivitet, och därigenom uppnå de kommande nära-nollenergikraven.Tre kommunala servigebyggnader (daghem, en skola och ett åldringshem) från Tammerfors, Finland, valdes som fallstudier och deras energiförbrukning simulerades. Simuleringsbaserad optimering används för att hitta den optimala solpanelytan och panelinklinationen för varje fallstudiebyggnad. De kriterier som minimerades var nuvärdet av systemlivscykelkostnaden och byggnadens primärenergiförbrukning. I beräkningarna antogs en standard kommersiellt tillgänglig solpaneltyp, och elpris enligt aktuella priser i dagsläget.Resultaten visar att egen solelproduktion kan förbättra servicebyggnadens energieffektivitet avsevärt om det finns tillräckligt med takyta för solpanelinstallation. Med aktuella elpriser är egen solel ekonomiskt lönsamt endast i åldringshemmet, där det kan ge en maximal vinst på 2,7-3,6 €/m2, beroende på vilken teknik i huvudsak används för uppvärmning. Den högsta vinsten uppnås med 461 m2 solpaneler med en inklinationsvinkel på 48°, och i kombination med en luft-vattenvärmepump. Den här uppställningen sänker också byggnadens primärenergiförbrukning med 13%. Generellt är solel mer lönsamt med värmepump än med fjärrvärme.Egen solel skapar ingen nettovinst i daghemmet eller skolbyggnaden, eftersom dessa byggnader är stängda under sommaren. Den ekonomiska lönsamheten för solel beror också på huvudsaklig uppvärmning, elpriser, framtida beteende av realräntan och energipriser, och framtida prissättning av solpaneler. En känslighetsanalys visar att ekonomisk lönsamhet är nära att uppnås också för daghemmet och skolbyggnaden. Om man inkluderar elanvändningen från hela fastigheten av daghemmet, är det ekonomisk lönsamt att installera solel även vid nuvarande el- och installationspriser. Då kan de ge en maximal vinst på 1,6-1,8 €/m2.Studiens centrala rekommendation för kommuner är att planera nya vårdhem med tillräckligt söderriktad takyta för en stor solpanelinstallation. Solkraft bör främst genomföras i byggnader som är i bruk under hela året, och kan utnyttja så mycket som möjligt av den egna elproduktionen. När man överväger den ekonomiska lönsamheten av solkraft i servicebyggnader, är det nödvändigt att utreda den verkliga elförbrukningen i hela fastigheten och inte bara i byggnaden. För undervisningsbyggnader är de bästa kandidaterna för egen solelproduktion sådana byggnader som är öppna även på sommaren, t.ex. de daghem som inte stänger för sommaren. Även om de framtida nZEB-reglerna inte kräver elproduktion i kommunala servicebyggnader, kan egen solel både förbättra byggnadens energieffektivitet och vara ekonomiskt lönsamt., särskilt i vårdhem.
Like other EU countries, Finland must implement the EU Energy Performance of Buildings Directive (EPBD), requiring all new buildings to be nearly Zero Energy Buildings from the year 2021. Municipal buildings are required to be nearly Zero Energy Buildings from the year 2019. This thesis investigates municipal service buildings and the role of solar photovoltaics (PV) in improving their energy performance, in view of the future nZEB regulation.Three case study municipal service buildings from Tampere, Finland, are modelled and their energy performance is simulated. The service buildings include a day-care centre, a school and a renovated old people’s home. Simulation-based optimization is employed to find the optimal solar panel areas and panel inclinations for each case study building. The objectives to be minimized are net present value (NPV) of system life-cycle cost for 20 years and building primary energy consumption. A standard commercially available solar panel type is assumed. Electricity pricing is based on current rates.It is found that own solar PV generation can lower the service building energy performance considerably, if there is enough roof space for panel installation. With current electricity tariffs, PV generation is financially profitable in the old people’s home, where it can bring a maximum profit of 2,7–3,6 €/m2, depending on the main heating solution. The maximum profit occurs with 461 m2 of solar panels, with inclination angle of 48°, and combined with an air-to-water heat pump. With this arrangement, the primary energy use of the building is lowered by 13%. Generally solar PV production is a more profitable combination with a heat pump solution than with district heating.Solar PV generation does not create a net profit in the day-care or school building, because unlike the old people’s home, they are closed during the summer. The profitability of solar PV generation also depends on the basic heating solution, electricity tariffs, the future behaviour of real interest rate, energy price escalation and solar panel pricing. Sensitivity analysis and additional optimization cases reveal that even for the day-care and school buildings, financial profitability is not far away. If considering the measured electricity use from the whole property of the day-care centre, installing solar PV is profitable even at current electricity tariffs and installation prices, creating a maximum profit of 1,6–1,8 €/m2.Key recommendation for municipalities is to design new care housing buildings with enough south-facing roof area for a large solar PV system. Solar PV production should be first implemented in buildings that are occupied throughout the year, and can utilize as much as possible of the own generation. When considering the profitability of the solar PV installation, it is necessary to know the actual electricity consumption arising from the whole property, and not just the building. For educational buildings, solar PV is the best candidate for the buildings that are open also in the summer, e.g. those day-care centres that do not close for the summer holiday. Even if the future nZEB targets do not necessitate own solar PV generation in municipal service buildings, both the financial profitability and the energy efficiency improvements should encourage municipal solar PV installations, especially in nursing homes.

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20

Kettenis, Christos. "Electrical supply and demand in Cyprus : optimal use of renewable energy sources in electricity production". Thesis, University of Manchester, 2016. https://www.research.manchester.ac.uk/portal/en/theses/electrical-supply-and-demand-in-cyprus-optimal-use-of-renewable-energy-sources-in-electricity-production(3861cfcb-8a74-4087-a114-4e0dc9557202).html.

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As fossil fuel usage has been proven to have a negative impact on human health and the environment, the world has embraced the usage of renewable energy sources, mainly for energy production. In Cyprus, solar energy is the most potent renewable source and this can be seen by the vast majority of the population using solar water heaters in their households. This thesis explores the usage of solar energy for electricity and domestic hot water production at a residential level by presenting the designs of three solar-thermal concept systems for achieving this task; the first being the basic design of all three without any form of storage, the second is fitted with thermal latent heat storage and the third is fitted with a natural gas boiler instead. The optimal solution is the second concept system that is capable of storing thermal energy around the year thus having a nearly uninterrupted operation, reducing the dependency on fossil fuel produced electricity and emissions. The thesis also explored the usage of siloxane organic compounds as working fluids for a low temperature Rankine cycle, which had a significant impact in the increase of the thermal-to-electrical efficiency of the cycle, raising it to nearly 25%, greater than the efficiency of best acclaimed photovoltaic collector currently available. Lastly, taking into account a typical household’s demand profile and by allowing the optimal system to operate as part of the national electrical network continuously, the size of the system’s components could be reduced significantly making it more feasible for installing in a typical household’s premises. However, due to the non-existence of these components in the within the project’s specifications, the thesis could not include a useful economic analysis for a more realistic comparison with a similar sized photovoltaic system.

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21

Qiu, Tianyu. "Desalination of brackish water by a batch reverse osmosis desalink system for use with solar thermal energy". Thesis, Aston University, 2014. http://publications.aston.ac.uk/24333/.

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For remote, semi-arid areas, brackish groundwater (BW) desalination powered by solar energy may serve as the most technically and economically viable means to alleviate the water stresses. For such systems, high recovery ratio is desired because of the technical and economical difficulties of concentrate management. It has been demonstrated that the current, conventional solar reverse osmosis (RO) desalination can be improved by 40–200 times by eliminating unnecessary energy losses. In this work, a batch-RO system that can be powered by a thermal Rankine cycle has been developed. By directly recycling high pressure concentrates and by using a linkage connection to provide increasing feed pressures, the batch-RO has been shown to achieve a 70% saving in energy consumption compared to a continuous single-stage RO system. Theoretical investigations on the mass transfer phenomena, including dispersion and concentration polarization, have been carried out to complement and to guide experimental efforts. The performance evaluation of the batch-RO system, named DesaLink, has been based on extensive experimental tests performed upon it. Operating DesaLink using compressed air as power supply under laboratory conditions, a freshwater production of approximately 300 litres per day was recorded with a concentration of around 350 ppm, whilst the feed water had a concentration range of 2500–4500 ppm; the corresponding linkage efficiency was around 40%. In the computational aspect, simulation models have been developed and validated for each of the subsystems of DesaLink, upon which an integrated model has been realised for the whole system. The models, both the subsystem ones and the integrated one, have been demonstrated to predict accurately the system performance under specific operational conditions. A simulation case study has been performed using the developed model. Simulation results indicate that the system can be expected to achieve a water production of 200 m3 per year by using a widely available evacuated tube solar collector having an area of only 2 m2. This freshwater production would satisfy the drinking water needs of 163 habitants in the Rajasthan region, the area for which the case study was performed.

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22

Jones, Sumner Weston Jr. "The Synthesis and Photophysical Properties of New Polymetallic Complexes Designed for Use in Photoinitiated Electron Collection". Diss., Virginia Tech, 1998. http://hdl.handle.net/10919/30459.

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The goal of this research was to develop stereochemically defined multimetallic systems for use as light absorbers and electron donor / light absorber dyads in photoinitiated electron transfer and electron collection. The basis for the stereochemical control was provided by the symmetric bridging ligands 2,3,5,6-tetra(pyridyl)pyrazine (tpp) and 2,2'-bipyrimidine (bpm). The symmetric bidentate ligand 4N-perylene was designed and the majority of the synthesis was completed. The bimetallic complexes [(tpy)M(tpp)Ru(LLL)]²⁺, where M = Ru or Os and LLL = Cl₃, (CH₃CN)₃, tpp, or (dpq)Cl, and the model monometallic complexes [(tpy)M(tpp)]²⁺, where M = Ru or Os, and [(tpy)Ru(CH₃CN)₃]²⁺ were synthesized and characterized using electrochemistry, UV-vis spectroscopy, and UV-vis spectroelectrochemistry. The bimetallic complexes were investigated as potential light-absorber / electron-donor complexes to be used in larger supramolecular devices for photoinitiated electron collection and electron transfer. The electrochemistry showed that the relative energy of the metal orbitals is suitable for the metal in the (tpy)M(tpp) coordination environment to act as an electron donor. These bimetallic complexes possess extremely complicated UV-vis spectroscopy due to the number of possible transitions. The assignment of the UV-vis spectroscopy and the electrochemistry of these complexes was greatly facilitated by the UV-vis spectroelectrochemistry. The metal-to-metal charge transfer spectra of the mixed-valence species of the bimetallic complexes were obtained using NIR spectroelectrochemistry and indicate a significant degree of metal-metal communication through the bridging tpp. The bimetallic complexes [(tpy)Ru(tpp)Ru(tpy)]⁴⁺, [(tpy)Ru(tpp)Ru(tpp)]⁴⁺ [(tpy)Os(tpp)Ru(tpp)]⁴⁺, and [(tpy)Ru(tpp)Ru(CH₃CN)₃]⁴⁺ were found to have emission lifetimes on the order of 100 ns. The complexes [(bpy)₂Ru(bpm)]²⁺, [(bpy)₂Ru(bpm)Ru(bpy)₂]⁴⁺, [(bpm)₂IrCl₂]⁺, and {[(bpy)₂Ru(bpm)]₂IrCl₂}⁵⁺ were synthesized and characterized using electrochemistry, UV-vis spectroscopy, and UV-vis spectroelectrochemistry. The complex {[(bpy)₂Ru(bpm)]₂IrCl₂}⁵⁺ is a LA-EC-LA device for photoinitiated electron collection. The UV-vis spectroelectrochemistry of these complexes facilitated the assignment of the UV-vis spectroscopy as well as the electrochemistry. The UV-vis spectrum of the electrochemically generated two electron reduced form of {[(bpy)₂Ru(bpm)]₂IrCl₂}⁵⁺ was obtained. This spectrum is critical in the understanding of future studies of the photochemically generated two electron reduced species. The symmetric, planar, bidentate bridging ligand 4N-perylene was designed. This ligand would eliminate some of the isomers associated with multimetallic complexes bridged by unsymmetric bidentate bridging ligands. The large π system of 4N-perylene would likely result in a low energy π* orbital compared to dpp, dpq, or bpm. The ligand 4N-perylene would hold bridged metals at a greater distance than 2,2'-bipyrimidine and should facilitate the formation of multimetallic complexes. The synthesis of 1,8-dichloro-2,7-naphthyridine has been completed. 1,8-dichloro-2,7-naphthyridine is a possible reactant in the homo-coupling reaction of a substituted 2,7-naphthyridine to form 4N-perylene. The stereochemically defined molecular systems developed in this work show great promise for use in larger supramolecular complexes designed for photoinitiated electron transfer and electron collection.
Ph. D.

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23

Jones, Brian. "Investigating a servicisation model for the use and instillation of solar water heaters in Cape Town, South Africa". Thesis, Stellenbosch : Stellenbosch University, 2015. http://hdl.handle.net/10019.1/97343.

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Thesis (MBA)--Stellenbosch University, 2015.
ENGLISH ABSTRACT: South Africa is experiencing an energy shortage and volatile supply of electricity. This situation is placing pressure on businesses and citizens and is opening avenues into the renewable sector. This study investigates servicisation as a potential means to assist in the alleviation of energy consumption on the national power grid, and answers whether servicisation in the solar water heating sector could pose as a viable business venture. The main research goal was to investigate whether servicisation within a housing estate could be favourably received. The majority of residents in this high-income bracket were more willing to invest their own capital in renewables rather than being provided with a solar water heater through servicisation. Knowledge of solar water heating is extremely poor amongst consumers, and this contributes to the lack of penetration of solar water heaters in the industry to date. To further exacerbate the situation, installations are often poorly executed, leading to negative experiences by consumers. Initially it was assumed that post 2012, all homes built would be installed with solar geysers or heat pumps, due to legislation. However, surprisingly this was not the case, as a large portion of homes built between 2012 & 2013 have not complied with this legislation.

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24

Ma, Chenwen. "Retrofitting a Single-family Home with Increased Use of Renewable Energy". Thesis, KTH, Installations- och energisystem, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-215962.

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Buildings account for up to 40% of the total energy use in the world. Directives from the European Union have pointed out the significance of increasing the energy efficiency in buildings. New regulation in countries like Sweden has established that new buildings should fulfil regulations of Nearly Zero Energy Buildings (NZEB), providing the opportunity for renewable energy technologies to achieve these goals. In this paper, the retrofitting potential of renewable energy technologies for a single-family home in Sweden was investigated.The present work studied the characteristics of several renewable energy technologies and their applications for a single-family home in Sweden, including biomass, solar photovoltaics, solar thermal, heat pump, and small-scale wind turbine. Three renewable energy technologies (solar thermal, heat pump and small-scale wind turbine) and one renovation method (window) were selected to investigate. The analysis was made of the current energy use and the potential energy (and cost) savings from each retrofitting of these facilities by means of simulation models using IDA ICE software. The study results show that the proposed renewable energy technologies are technically feasible and economically viable as a source of alternative renewable energy in order to produce clean energy and reduce electricity bills for an electric-heated single-family home located in Sweden. Moreover, the combined retrofitting scheme consist of solar thermal system and window renovation was also proposed and explored. As a result the energy performance of the single-family home would satisfy the nearly-zero energy building requirements and thermal comfort could be maintained at an acceptable level.

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25

Choi, Chong Seok Seok. "COMBINED LAND USE OF SOLAR INFRASTRUCTURE AND AGRICULTURE FOR SOCIOECONOMIC AND ENVIRONMENTAL CO-BENEFITS IN THE TROPICS". Master's thesis, Temple University Libraries, 2019. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/546811.

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Geology
M.S.
Solar photovoltaic (PV) generation has been gaining popularity as low carbon energy technology in the face of the global climate change. However, conventional utility-scale PV requires large swaths of land to be occupied for decades which prevents the land from producing food or performing vital ecosystem services. Co-location of PV with crop cultivation is an emerging strategy for mitigating the land use of PV. In order to optimize this strategy, the impact of the plant growth-related soil properties need to be quantified. To this end, the first portion of the thesis investigated the impacts on the soil properties in a re-vegetated solar PV facility in Boulder, Colorado, which was the oldest vegetation-PV co-location site in the world. The second portion of the thesis uses a life cycle analysis (LCA) approach to test the feasibility of co-location of model crop cultivation and solar PV electricity generation in rural Indonesia, and it is the first study to use the LCA study of the co-located solar in the tropics. The first approach revealed that the soil hydrology, grain size distribution, and total carbon and nitrogen are significantly altered from their original state by the construction and presence of photovoltaic arrays, and that those properties had not been restored to their pre-construction levels despite the fact that ten years had passed since re-vegetation of the PV array. The persistence of the altered soil properties meant that the designs regarding re-vegetation or co-location of PV with crops would have to be considered at the beginning of the construction of the PV to minimize the impact on the soil and the existing vegetation. Furthermore, soil moisture was the highest in the soil underneath the western edge of the PV panels, where the western tilt of the PV panel had concentrated the rainfall. The heterogeneity in soil hydrology created by the panels could be manipulated to benefit the growth of vegetation within the PV array. The LCA approach revealed that a hectare of PV arrays with full module density would carbon offsets against diesel electricity generation and the grid, and that the annual supply of electricity from the PV could satisfy the demand of a typical rural Indonesian village several times over. However, the high capital expenditure of solar mean that co-location with full PV module density would not be economically feasible, even with the income stream from the co-located crop cultivation. In order to reduce the capital expenditure, the PV module density for co-location was reduced to half. The combination of reduced capital expenditure and the income stream from the crop made the co-located land use significantly less costly. Additionally, the rural electrification would be able to provide secondary socioeconomic benefits such as avoidance of health costs through operation of public health infrastructures, increased standard of living, and secondary income opportunities from processing of raw materials. However, better subsidies for renewables, specialized loan structures for small-scale renewable systems, and a culture of co-operation between small landholders would need to be implemented before the co-located system becomes affordable to the inhabitants in rural Indonesian villages.
Temple University--Theses

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26

Ritter, Kenneth August III. "Virtual Solar Energy Center| A Case Study of the Use of Advanced Visualization Techniques for the Comprehension of Complex Engineering Products and Processes". Thesis, University of Louisiana at Lafayette, 2016. http://pqdtopen.proquest.com/#viewpdf?dispub=10163357.

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Industry has a continuing need to train its workforce on recent engineering developments, but many engineering products and processes are hard to explain because of limitations of size, visibility, time scale, cost, and safety. The product or process might be difficult to see because it is either very large or very small, because it is enclosed within an opaque container, or because it happens very fast or very slowly. Some engineering products and processes are also costly or unsafe to use for training purposes, and sometimes the domain expert is not physically available at the training location. All these limitations can potentially be addressed using advanced visualization techniques such as virtual reality. This dissertation describes the development of an immersive virtual reality application using the Six Sigma DMADV process to explain the main equipment and processes used in a concentrating solar power plant. The virtual solar energy center (VEC) application was initially developed and tested in a Cave Automatic Virtual Environment (CAVE) during 2013 and 2014. The software programs used for development were SolidWorks, 3ds Max Design, and Unity 3D. Current hardware and software technologies that could complement this research were analyzed. The NVIDA GRID Visual Computing Appliance (VCA) was chosen as the rendering solution for animating complex CAD models in this application. The MiddleVR software toolkit was selected as the toolkit for VR interactions and CAVE display. A non-immersive 3D version of the VEC application was tested and shown to be an effective training tool in late 2015. An immersive networked version of the VEC allows the user to receive live instruction from a trainer being projected via depth camera imagery from a remote location. Four comparative analysis studies were performed. These studies used the average normalized gain from pre-test scores to determine the effectiveness of the various training methods. With the DMADV approach, solutions were identified and verified during each iteration of the development, which saved valuable time and resulted in better results being achieved in each revision of the application, with the final version having 88% positive responses and same effectiveness as other methods assessed.

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27

Ricci, Kimberley Ann. "The implications of planning techniques for protecting solar access : a survey of state and local legislation". Virtual Press, 1988. http://liblink.bsu.edu/uhtbin/catkey/546120.

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The purpose of this paper was to compile a nationwide survey by state, on legislation designed to protect access to solar energy. Brief summaries of the information received are included. Land use planning techniques and tools such as zoning and subdivision regulations, as well as special solar zones and planned unit developments have been discussed as they relate to protection of solar access and solar energy use. This paper has distinguished between two types of solar energy systems, active and passive, and associated problems with each.Primary concerns for the users of solar energy systems have been the availability of solar energy and its access to the collector's surface. Solar energy is environmentally safe, however, access to solar energy can be a limiting factor to its use. Solar access protection methods vary with location. The differences in needs between rural and urban areas have been discussed.Increasing solar technologies indicate the need for communities to regulate solar access through innovative legislation. This paper with brief introductions to solar energy access protection techniques, and the state-by-state survey was prepared so as to provide the reader with a basic understanding of solar access protection and act as a guide to access protection methods.
Department of Urban Planning

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28

Dahmén, Viktor, Martin Holgersson, Aron Larsson y Joel Norman. "How bright does the sun shine over Storvreta IK? : Mapping the energy use of a local Swedish sports club". Thesis, Uppsala universitet, Institutionen för teknikvetenskaper, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-295100.

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In 2011 Storvreta IK installed two solar collector systems in order to reduce the club’s electricity demand for domestic hot water. However, electricity use from 2012 to 2015 shows that the expected reduction in the electricity demand has not occurred. This project investigates the solar collector systems and the heat demand of Storvreta IK’s buildings in order to explain the “failure” in electricity savings. The results of the simulations show that the heat production of the solar collectors is lower than Storvreta IK’s expectations. This could be explained by that the domestic hot water is not used as much as Storvreta IK thought and the system is therefore over-dimensioned for their need. The rebound effect could be another reason to why the electricity saving is lower than expected.

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29

Auråen, Ida Karin. "Modeling of heat exchange with the ground and analyses of energy use for a frost proof leisure building with active solar heating". Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for energi- og prosessteknikk, 2013. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-22332.

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Requirements regarding efficient energy use and reduction in CO2 emissions are becoming increasingly strict. The building sector accounts for a large part of CO2 emissions and the potential for reductions within this sector should be considerable.This thesis is a continuation of the author's project thesis. The main focus is to improve the earlier model emphasizing the modeling of the interactions between the leisure home building and the ground. The goal is to develop a prototype of a leisure home where sanitary installations are kept frost proof throughout the year without the use of primary energy sources or electricity, minimizing net CO2 emissions. The building envelope is constructed of poorly insulated log walls. The sanitary installations are placed in a thermally insulated internal zone, and an active solar heating system is developed to transfer heat into the ground in this internal zone. The intention is to store the heat, transferred to the internal zone during sunny periods, in a thermal mass under the cabin. This would then passively arise during cold periods, maintaining frost proof conditions. The leisure home is planned to be located in the southern mountain regions of Norway. Different simulation tools were considered for modeling the leisure home and its energy system. The dynamic simulation tool ESP-r was chosen, and an improved model from the project thesis was developed. Different methods and theories concerning how the solar heating system and the ground could be modeled have been studied. The interactions between the building and the ground were modeled by implementing a new basement zone for the leisure home, and defining a BASESIMP configuration as boundary conditions for the surfaces adjacent to the ground. BASESIMP performs quasi 3-dimensional calculations for the heat transfer between the building and the ground. Since the heat storage is not taken into account in the BASESIMP configuration, the storage is represented in the ground construction; the basement floor of the inner zone. The solar heating system is represented in a control loop. The control loop injects electric heat into the basement floor for a given period each day. The electric data is based on solar radiation data, and the time intervals for when heat is injected into the floor are determined from when solar radiation is available in the day. Climate data from Östersund, Sweden has been used as an approximation as there was no available climate file for the southern mountain regions of Norway. Different system parameters have been changed to investigate the influence they have on the temperature conditions in the internal zones throughout the year. The internal zones maintain much more stable temperatures throughout the year than the outer zones. This shows that isolating the frost proof zones in the leisure home, represent a major advantage in the design process. The ground construction in the basement floor of the inner zone has been modeled as a thermal mass with high density and high specific heat capacity. This dense thermal mass is modeled to account for the whole area under the cabin. A south facing solar collector with an area of 4 m2 and an inclination of 70 ° indicates that the temperature in the internal zones stays above 4.2 °C throughout the year, subject to the given ground conditions and without collecting heat during May until August. The delivered energy to the ground construction in the basement floor of the inner zone for a year under the given conditions and with a collector efficiency of 45 % turned out to be 878 kWh.Heat transfer from the ground into the internal zone turned out to have a significant heat contribution in cold periods. Results also showed a noticeable potential for seasonal storage of the energy extracted from the solar heating system.For further studies, the interactions between the heat storage and the surrounding ground should be studied in a 3-dimensional conduction program. Insulation regarding snow should also be implemented in a future model to study the effect of extra insulation on the ground surface.

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30

Vaz, Joaquim. "Estudo experimental e numérico sobre o uso do solo como reservatório de energia para o aquecimento e resfriamento de ambientes edificados". reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2011. http://hdl.handle.net/10183/28814.

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Objetivos: Este trabalho, abrangendo a área da transferência de calor e da mecânica dos fluidos, em seu desenvolvimento envolveu métodos analíticos, numéricos computacionais e experimentais (em ambiente de campo), com a finalidade de analisar o uso de trocadores de calor solo-ar, como estratégia para diminuir o consumo de energia convencional, no aquecimento ou resfriamento de ambientes construídos. Assim, um dos objetivos do estudo foi avaliar, com base em resultados experimentais, a performance do solo como um reservatório de energia, derivada da radiação solar. Buscou-se, pois, identificar parâmetros, procedimentos e condições favoráveis envolvendo esta estratégia. O outro objetivo do estudo foi, usando os softwares GAMBIT e FLUENT, modelar computacionalmente o escoamento do ar no trocador de calor solo-ar. Método: O estudo experimental e numérico foi precedido pela construção de uma edificação, especificamente concebida para a pesquisa, identificada como Casa Ventura. Em continuidade, foram enterrados dutos no solo, que conduziriam ar exterior e água (esta última por um período limitado) ao ambiente interno. No caso da condução de ar, o solo funcionaria como um reservatório de energia, aquecendo ou resfriando a ar. Já, no caso da condução de água, prevista com duto de baixa condutividade térmica, o solo funcionaria apenas como um protetor à radiação solar, para preservar as características térmicas da água, desde um reservatório, de onde a mesma era bombeada, até o interior da casa. Na Casa Ventura foram construídos dois ambientes centrais com características dimensionais e de envolvente equivalentes, constituindo os ambientes monitorados no processo, sendo um, na condição natural, referencial, sem renovação de ar, e o outro, com renovação de ar. Na parte experimental, o ar foi captado do ambiente externo e insuflado por um ventilador nos dutos enterrados, renovou o ar no interior deste último ambiente. Com ajuda de um fan-coil, colocado neste ambiente, o ar renovado trocou calor com a água. Por questões de dificuldades operacionais, o bombeamento de água funcionou por um período muito curto. Durante o experimento, que se desenvolveu por todo o ano de 2007, foram monitoradas e registradas, além da temperatura do solo e da água, a temperatura e a umidade: do ar externo, do ar nos ambientes internos e do ar em escoamento nos dutos enterrados, bem como a velocidade de escoamento nos mesmos. Resultados: De forma geral, o potencial do solo para aquecer foi maior do que o de resfriamento do ar injetado nos dutos enterrados. O potencial de aquecimento foi mais destacado nos meses de maio, junho, julho e agosto, e se mostrou maior que 3K. Para profundidades entre 2 e 3m, estima-se que o potencial possa ser superior a 8K. Por outro lado, o potencial de resfriamento foi maior nos meses de janeiro, fevereiro e dezembro, mas foi baixo para pequenas profundidades (menos de um metro). Para resfriamento, este potencial pode chegar a 4K. Contribuições da pesquisa: Face aos resultados da pesquisa, diversas foram as suas contribuições, dentre as quais se destacam: a construção de um banco de dados experimentais sobre as propriedades e características do solo (índices físicos, difusividade térmica, capacidade térmica volumétrica, condutividade térmica, temperatura e umidade) e do ar ambiente (temperatura e umidade) para o município de Viamão, localizado na região sul do Brasil, e que pode ser usado para a continuidade desta pesquisa ou para a elaboração de novas pesquisas e projetos; e o desenvolvimento de uma metodologia para a modelagem computacional de trocadores de calor solo-ar, validada através dos dados experimentais citados acima, possibilitando, assim, o emprego deste procedimento numérico, para a elaboração de projetos ou novas pesquisas nesta área.
Purpose: The development of the present work, comprising the area of heat transfer and fluids mechanics involved analytical, numerical computational and experimental (in field environment) methods, with the purpose of analyzing the use of earth-to-air heat exchanger, as a strategy to reduce conventional energy consumption, for the heating or cooling of built environments. Thus, one of the study purposes was to evaluate, based on experimental results, the earth performance as an energy reservoir, derived from solar radiation incidence on the surface of the ground. We aimed, then, at identifying favorable parameters, procedures and conditions involving this strategy. The other study purpose was, using the GAMBIT and FLUENT softwares, computationally modeling the air flow in the earth-to-air heat exchanger. Method: The experimental and numerical study was preceded by the construction of a building, specially planned for the research, called Casa Ventura. As a follow-up, ducts were buried on the ground, to conduct external air and water (the latter one for a limited period) to the internal environment of the house. In terms of air conduction, the earth would work as an energy reservoir, heating or cooling the air. Concerning the water conduction, planned to use a duct of low thermal conductivity, the earth would only work as a protector from solar radiation, to preserve the water thermal characteristics, when flowing from the water reservoir, where it would be taken from, to the inside of the house. At Casa Ventura two central environments were built with similar dimensional and envelope characteristics, constituting the environments monitored in the process, in which, one in the natural and referential condition, without air renovation, and the other, with air renovation. In the experimental part, the air was captured from the external environment and inflated by a fan in the buried ducts, and it renovated the air inside this latter environment. With the help of a fan-coil, placed in this environment, the renovated air exchanged heat with the water flowing through the ducts. Due to some operational difficulties, the pumping of water lasted for a very short period. During the experiment, which lasted through the whole year of 2007, besides the water and earth temperature, the temperature and humidity of the following were also monitored and registered: the external air, the air in the internal environments and the air flowing in the buried ducts, as well as the flowing speed of the different fluids. Results: In a general way, the earth potential to heat was higher than the cooling of air injected in the buried ducts. The heating potential was higher in the months of May, June, July and August, doing so by more 3K. For depths between 2 and 3m, it is estimated that the potential might be over 8K. On the other hand, the potential for cooling was higher in the months of January, February and December, but it was low for low depths (less than a meter). For cooling, this potential may reach 4K. Research contributions: Considering the research results, several were the contributions, among which we highlight: the construction of an experimental database on the earth properties and characteristics (physical indexes, thermal diffusivity, volumetric heat capacity, thermal conductivity, temperature and humidity) and the environmental characteristics of the air (temperature and humidity) for the city of Viamão, located in Southern Brazil, and that may be used for the continuation of this research or for the elaboration of new researches and projects; and the development of a methodology for computational modeling of earth-to-air heat exchangers, validated through the experimental data mentioned before, enabling, therefore, the use of this numerical procedure for the elaboration of projects or new researches in this area.

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Holyk, O., R. Zhesan, M. Miroshnichenko, I. Berezyuk, О. П. Голик, Р. В. Жесан, М. С. Мірошніченко y І. А. Березюк. "Conditions for the effective use of stand-alone power sources". Thesis, Baltija Publishing, 2017. http://dspace.kntu.kr.ua/jspui/handle/123456789/7665.

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The terms of effective use of autonomous energy sources proposed in the work can be used for various combinations of RES and any consumers. The use of the proposed criterion makes it possible to determine the conditions for efficient use of autonomous energy sources and the sequence of switching on power plants, while taking into account the operating conditions of APSS autonomous consumers. The criterion of the priority of the sequence of switching on power plants in the APSS allows the efficient use of energy from RES in accordance with the energy needs of the autonomous consumer Запропоновані в роботі умови ефективного використання автономних джерел енергії можна використовувати для різних комбінацій ВДЕ та будь-яких споживачів. Використання запропонованого критерію дає змогу визначити умови ефективного використання автономних джерел енергії та послідовності вмикання енергоустановок, при цьому враховуються умови експлуатації СЕП автономних споживачів. Критерій пріоритетів послідовності вмикання енергоустановок в СЕП дає можливість ефективно використовувати енергію від ВДЕ у відповідності до енергетичних потреб автономного споживача

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32

OLAUSSON, HANNA y EMMA WERNIUS. "Development of a Simulation Model for Combined PVT and Ground Source Heat Pump Systems : A TRNSYS Model Created for Commercial Use". Thesis, KTH, Skolan för industriell teknik och management (ITM), 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-299352.

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The Swedish government has set a target of a 100% renewable electricity system by 2040. To reach this goal, many actions have to be undertaken. Electrification of buildings is one action to be undertaken as the residential sector accounts for a large share of greenhouse gas emissions, where the most energy efficient method is to use heat pumps. Ground Source Heat Pumps typically have the highest efficiency out of the different heat pumps. These types of heat pumps are most commonly used in single family houses, as multi-family houses often are located in highly densely areas. However, when adding hybrid PV/thermal collectors to ground source heat pump systems, studies have shown that the borehole drilling area can be reduced, which increases the potential for combined PV/thermal collectors and ground source heat pump systems in multi-family areas. In this project, a time-efficient, flexible and user- friendly model was developed to increase the potential for designing combined PV/thermal collectors and ground source heat pump systems. The model is based on the research model by Sommerfeldt and Madani (2019), where the flexibility and time step of the model was investigated and adjusted. The finished model was verified to the model by Sommerfelt and Madani (2019). Overall, the results show that the new model gives similar results to the original model, despite all adjustments. The heaviest adjustments were made in the heat pump where the quantitative results show a mean bias error of -0.51 kWh and a total yearly difference of -5.18% for the compressor power. The corresponding values for the condenser heating rate are -1.05 kWh and -2.86%. The user is able to change boundary conditions such as location, PVT array, building size, and borehole field size. The model takes approximately 2 minutes to run for a 20 years simulation on a business grade desktop computer, which is a five-hour twenty minute reduction from the original research model and assumed to be an acceptable time range for a commercial applications.
Regeringen har satt ett mål om att nå ett 100% förnybart energisystem till 2040. För att nå målet måste många insatser göras. Bostadssektorn står för höga halter av växthusgasutsläpp och elektrifiering av sektorn är en lovande väg att gå. Värmepumpar tillhör de mer energieffektiva tillvägagångssätten, av vilka bergvärmepumpar oftast erhåller den högsta effektiviteten. Bergvärmepumpar är idag mestadels installerat i enfamiljshus där det finns utrymme för att borra borrhål. Flerfamiljshus finns ofta i tätbebyggda områden där ytan tillgänglig för borrhål är begränsad. Emellertid har studier har visat att kombinerade PVT och bergvärmesystem kan minska borrhålsytorna, vilket ökar möjligheten för dessa typ av system även till flerfamiljshus. Detta projekt syftar till att utveckla en kommersiell modell för design av PVT och bergvärmesystem för att underlätta design av dessa system. Att modellen är kommersiell antyder på att den är användarvänlig, flexibel och tidseffektiv. Modellen är baserad på en forskningsmodell av Sommerfeldt och Madani (2019) men justerades för att möta kraven för en kommersiell modell. Den färdiga modellen jämfördes och verifierades med modellen av Sommerfeldt och Madani (2019). Övergripande visades resultat som är jämförbara med forskningsmodellen, trots alla justeringar. De största justeringarna gjordes i värmepumpen där de kvantitativa resultaten visar ett mean bias error på -0.51 kWh och en årlig skillnad på -5.18% för elbehovet i kompressorn. Motsvarande värden för värmeutbytet i kondensorn är -1.05 kWh och -2.86%. Användaren har möjlighet att ändra gränsvillkor så som geografisk plats, PVT system, byggnadsstorlek och storleken på borrhålsfältet. Den färdiga modellen tar cirka två minuter att köra för en 20-års simulering på en typisk arbetsdator, vilket motsvarar en minskning på 5 timmar och 20 minuter jämfört med originalmodellen. Detta kan anses vara inom tidsramen för kommersiella appliceringar.

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33

Abbassi, Monjezi Alireza. "Development of a comprehensive transient model of energy capture and storage in solar ponds for use in thermal regeneration of draw solutes in forward osmosis". Thesis, University of Surrey, 2017. http://epubs.surrey.ac.uk/813996/.

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Salinity gradient solar ponds can be used to store heat by trapping solar radiation. The heat can then be employed to drive various industrial applications that require low-grade heat. In this study, a comprehensive finite difference transient model has been developed incorporating many processes that affect the performance of a solar pond to predict the hourly temperature distribution. A novel heat extraction method for salinity gradient solar ponds is then proposed. This method can be operated in batch or continuous modes. A comparison between the performance of two solar ponds of the same size (10,000 m2) in Adana (Turkey) and Ahvaz (Iran) is also presented. The heat extraction method entails brine removal from the Non-Convective Zone (NCZ) as well as the HSZ. The presented model incorporates the heat losses from the bottom and surface of the pond as well as the cooling effect imposed as a consequence of the replacement of extracted brine from each layer, and the supply of freshwater to the surface of the pond to maintain its inventory. The model can be employed to predict the performance of solar ponds of various dimensions for any given location. In the final part of this study, utilisation of solar thermal energy from salinity gradient solar ponds in forward osmosis (FO) is investigated. This study will present two novel processes for the regeneration of dimethyl ether (DME) and ammonium bicarbonate as a draw solutes in FO using thermal energy provided from a solar pond. The average daily volume of desalinated water produced using these processes and a solar pond of 10,000 m2 was determined. It is indicated that, a solar pond of such moderate size can drive a forward osmosis plant to provide a total of 5,210 m3 of potable water in the first two years of operation in the location considered in this study (Chabahar) if DME is used as the draw solute. The proposed process can provide freshwater at varying rates throughout the year and benefits from a very low electricity consumption rate of 0.46 kWh per cubic metre of desalinated water presenting a viable option for solar desalination. In case of ammonium bicarbonate, the product water contains small quantities of ammonia ions making it unsuitable for drinking purposes. Given that there are vast uninhabited coastal areas in many countries, particularly in the MENA region where there are high solar radiation rates, this method can contribute towards addressing the growing water scarcity.

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Tamura, Cintia Akemi. "Análise da influência dos parâmetros edilícios na obtenção de acesso solar nas zonas residenciais de Curitiba". Universidade Tecnológica Federal do Paraná, 2010. http://repositorio.utfpr.edu.br/jspui/handle/1/359.

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Edificações construídas conforme os parâmetros permitidos pela legislação de uso do solo nem sempre garantem bons resultados em relação ao acesso solar. Obras com limites em divisas de terrenos, super utilização dos limites de ocupação e de altura legalmente permitidos no município de Curitiba para edificações em zonas residenciais comumente bloqueiam o acesso solar no interior das edificações, causando frequentemente sombreamento, aumento da umidade e frio no período de inverno, condições agravadas pela tendência atual de adensamento e verticalização urbanos. Considerando que Curitiba é a capital mais fria do Brasil, este fato torna-se preocupante sob a análise do conforto ambiental destes edifícios. O trabalho visa contribuir para a melhoria do conforto ambiental em construções residenciais de Curitiba, a partir da elaboração de modelos para verificação da eficácia da legislação vigente, e a proposição de parâmetros obtidos através do conceito de envelope solar que propiciem o ganho efetivo de insolação e luz natural. Para isto, foram realizadas simulações de ocupação de acordo com o permitido por lei no município com os programas Google SketchUp 7.0.657 Pro, AutoCAD 2007 e através de maquete física no equipamento Heliodon. Foram realizadas também simulações com o programa Relux Professional 2007, que forneceu dados em lux para cada implantação avaliada. Os dados obtidos com a simulação de ocupação permitida por lei foram comparados com os obtidos pela simulação desta mesma ocupação com o uso do envelope solar para dimensionamento dos limites máximos construtivos, que demonstrou um acréscimo significativo no ganho de insolação no interior da edificação. Por fim, foram sugeridas as orientações com o melhor potencial de acesso solar para cada Zona residencial avaliada.
Buildings constructed according to the parameters allowed by the law of soil use and occupation do not always yield satisfactory results with regard to solar access. Buildings erected on the plot limits, overuse of the limits of height and occupancy legally permitted in the city of Curitiba for buildings in residential areas commonly block solar access within the buildings, often causing shading, increased humidity and cold in winter conditions, together with the current trend of urban densification and verticalization. Considering that Curitiba is the coldest capital of Brazil, this fact becomes alarming with regard to indoor comfort analyses in such buildings. The thesis aims to contribute for the improvement of environmental comfort in residential buildings in Curitiba, presenting models to check the effectiveness of the current legislation in providing solar gains and daylight, next to the use of the solar envelope concept. For this, simulations were carried out regarding maximum plot occupation permitted by law with Google SketchUp 7.0.657 Pro, AutoCAD 2007 and by means of a physical model in the Heliodon device. Were also carried out simulations with the software Relux Professional 2007, which provided data in lux evaluated for each deployment The similarity of the results confirmed the reliability of the method. The data obtained from the simulation of maximum occupancy were compared to those obtained considering the use of the solar envelope concept, the latter showing a significant increase in daylight inside the building. Finally, guidelines have been suggested with the best potential for solar access for each residential area evaluated. Keywords: Soil use and occupation. Insolation. Daylight. Simulation. Solar envelope.

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35

Новак, К. С. "Перспективи розвитку сонячної енергетики в Україні". Thesis, Сумський державний університет, 2015. http://essuir.sumdu.edu.ua/handle/123456789/44099.

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З кожним роком в Україні зростають обсяги споживання енергетичних ресурсів, які спрямовані на задоволення потреб промислового комплексу, житлового сектора та транспортної системи. В той же час кількість корисних копалин, необхідних для забезпечення зростаючих потреб людства у енергоносіях, зменшується, спричиняючи підвищення рівня цін на енергоносії. Одним з шляхів вирішення існуючих суперечностей полягає у поширенні використання альтернативних джерел енергії, зокрема сонячної енергії.

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36

Palla, Martin. "Simulátory solárního záření pro testování solárních článků". Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2013. http://www.nusl.cz/ntk/nusl-220120.

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The first part deals with an introduction to the basic fundamentals and presentation of theory from the assignment. The fundamentals are presented and described in detail. This part is followed by chapter describing possibilities of using solar energy. The paper presents possibilities of using both direct and diffuse solar radiation. The last chapter of the theoretical part is devoted to the basic description of the IEC 60904 and IEC 60904-9 standards. The practical part presents selected solar simulators and their measurement. Classification class according to IEC 60904-9 is determined from this measurement. The last part of the work is devoted to the construction of a solar simulator composed of LEDs. The simulator is then measured and its class is determined by emitted spectrum.

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37

Widén, Joakim. "System Studies and Simulations of Distributed Photovoltaics in Sweden". Doctoral thesis, Uppsala universitet, Fasta tillståndets fysik, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-132907.

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Grid-connected photovoltaic (PV) capacity is increasing worldwide, mainly due to extensive subsidy schemes for renewable electricity generation. A majority of newly installed systems are distributed small-scale systems located in distribution grids, often at residential customers. Recent developments suggest that such distributed PV generation (PV-DG) could gain more interest in Sweden in the near future. With prospects of decreasing system prices, an extensive integration does not seem impossible. In this PhD thesis the opportunities for utilisation of on-site PV generation and the consequences of a widespread introduction are studied. The specific aims are to improve modelling of residential electricity demand to provide a basis for simulations, to study load matching and grid interaction of on-site PV and to add to the understanding of power system impacts. Time-use data (TUD) provided a realistic basis for residential load modelling. Both a deterministic and a stochastic approach for generating different types of end-use profiles were developed. The models are capable of realistically reproducing important electric load properties such as diurnal and seasonal variations, short time-scale fluctuations and random load coincidence. The load matching capability of residential on-site PV was found to be low by default but possible to improve to some extent by different measures. Net metering reduces the economic effects of the mismatch and has a decisive impact on the production value and on the system sizes that are reasonable to install for a small-scale producer. Impacts of large-scale PV-DG on low-voltage (LV) grids and on the national power system were studied. Power flow studies showed that voltage rise in LV grids is not a limiting factor for integration of PV-DG. Variability and correlations with large-scale wind power were determined using a scenario for large-scale building-mounted PV. Profound impacts on the power system were found only for the most extreme scenarios.
Felaktigt tryckt som Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology 711

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38

Zein, Waël. "Etude d'un capteur absorbant l'energie solaire par le fluide caloporteur : application au chauffage des piscines de plein-air". Poitiers, 1986. http://www.theses.fr/1986POIT2289.

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Modelisation des transferts radiatifs pour les differents composants du capteur. Resolution numerique des equations permettant d'obtenir les lois d'evolution des performances du capteur en fonction de ces caracteristiques geometriques, des conditions radiatives et meteorologiques d'un site. Verification experimentale a l'aide d'un simulateur de rayonnement. Application envisagee, au chauffage d'une piscine en plein-air. Optimisation des conditions de fonctionnement et analyse economique du systeme de chauffage

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39

MAYER, ERIC RENE. "Contribution au developpement des ecotechniques en amerique latine et au venezuela". Paris 7, 1987. http://www.theses.fr/1987PA077224.

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Bilan des differentes actions en genie solaire menee dans le cadre d'une mission de cooperation scientifique et technique effectuee au venezuela:deshumidification de l'air dans une installation qui utilise le potentiel thermique du sous-sol et l'energie solaire. Concentrateur solaire constitue de deux portions de spirales logarithmiques destine a servir de recepteur secondaire dans une installation de production de vapeur industrielle; amelioration des conditions de confort de l'environnement construit et elaboration des criteres de dessin d'un habitat climatique pour les conditions specifiques de chaque site; methode de dimensionnement d'un generateur solaire autonome avec stockage saisonnier

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40

Ladipo, Alexandre. "Conception et mise au point d'un sechoir solaire polyvalent modulaire à vocation industrielle adapté au benin". Poitiers, 1988. http://www.theses.fr/1988POIT2271.

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L'auteur etudie deux sechoirs a chauffage partiellement solaire: le premier est un "insolateur-sechoir" ayant la forme d'une boite parallelepipedique et le second, modulaire, est constitue d'un insolateur a air relie par un conduit souple isole a une armoire de sechage. Un modele de fonctionnement est etabli pour chacun de ces sechoirs et une simulation de leurs comportements est faite sur ordinateur. Une etude experimentale permet a l'auteur de comparer entre eux les deux sechoirs, de valider les modeles de fonctionnement et de montrer qu'un insolateur a simple passe est preferable a un insolateur a double passe

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41

Pál, Tamás. "Nízkoenergetický GSM/GPRS modul pro senzorické aplikace". Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2014. http://www.nusl.cz/ntk/nusl-220607.

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This project deals with the problematics of self-powered universal GSM/GPRS module which is used for sensorical applications. The first part analyzes features of mobile networks and applying energy from the environment. The second section expalins the various parts and characteristic of their associated components together with some fundamental functions of the technology for possible realization of sensoric module. The third part describes plan for system realisation and fourth parth illustrates achiaved results.

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42

Dakyo, Brayima. "Étude et réalisation de dispositifs à commande numérique pour l'alimentation d'une machine synchrone à aimants permanents par générateur photovoltaïque : stratégies de commande pour le pompage au fil du soleil". Le Havre, 1988. http://www.theses.fr/1988LEHA0003.

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La notion de degré de liberté pour l'optimisation de la conversion d'énergie est introduite et reliée aux différents dispositifs utilisables pour associer la machine synchrone au générateur. La réalisation de ces dispositifs associés à une commande numérique par microordinateur flexible et conviviale est décrite. Les fonctionnements et stratégies de commande sont étudies pour deux types de systèmes : alimentation par onduleur de courant a thyristor, a commutation naturelle avec un ou deux degrés de liberté; l'alimentation en tension ou en courant par un onduleur de tension MLI en technologie Mosfet.

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43

Mamontoff, Andres. "Incorporating solar technology to design in humid subtropical climates". [Tampa, Fla] : University of South Florida, 2009. http://purl.fcla.edu/usf/dc/et/SFE0003170.

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Guenther, Clinton, Robert Mertens y Adam Lewis. "Telemetry System for the Solar Miner VII". International Foundation for Telemetering, 2010. http://hdl.handle.net/10150/605981.

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ITC/USA 2010 Conference Proceedings / The Forty-Sixth Annual International Telemetering Conference and Technical Exhibition / October 25-28, 2010 / Town and Country Resort & Convention Center, San Diego, California
This paper describes a telemetry system used in the Missouri S&T solar car, which competed in the American Solar Challenge. The system monitors parameters of a number of the on-board electronic and mechanical systems, and also the activities of the vehicle driver. This data is transmitted to a lead vehicle, where the support team analyzes the performance in real-time to optimize the vehicle's performance. In previous vehicles the data was displayed using a LabVIEW based user interface. In this work we will describe a custom software solution, which provides the team with additional flexibility to display and analyze the data.

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45

Ho, Hin-Ming. "User-performance sensitivity of small sunspaces in a Scottish housing context". Thesis, Glasgow School of Art, 1995. http://radar.gsa.ac.uk/4025/.

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The performance of unheated solar buffer zones (SBZs) or sunspaces in relatively high latitudes' locations has become increasingly controversial. Conceived as simultaneously saving energy and providing amenity, the latter characteristic has provided the user with the opportunity and/or aspiration to negate the former - by heating a sunspace during winter either directly, or by opening it up as an extended heated part of the dwelling. Scotland has been host to passive solar projects promoting the use of small sunspaces where 'opening up' is a greater risk than directly heating. 'Opening-up' signals a change from 'indirect' to 'direct' solar gain with the heated volume partially extended. Within this context, this work examines the relevant aspects of a small sunspace as a passive solar technique by posing three questions from which answers are to be sought. 1. How useful and usable are the sunspaces ? 2. To what extent are occupants' interventions affecting energy saving ? 3. What is the energy 'worth' of the two sunspaces? The vehicle for this work is the CEC Solar Energy Demonstration Project at Easthall, Glasgow, where 36 thermally sub-standard flats built in the 1960s have been retrofitted with each flat having two sunspaces on opposite facades to tackle the issue of random orientation, and a common stairwell functioning as a shared thermal buffer space. The author's close acquaintanceship with a relatively large sample of occupants over a monitoring period of two years, taken in conjunction with data from questionnaires, interviews, diaries and personal observations, has enabled a substantive 'cause and effect' analysis. The findings confirm the likelihood of user intervention negating optimum performance, especially in spring and autumn, and in association with particular household types and characteristics. Nevertheless, the mean space heating load was approximately 30% lower than it would have been for the equivalent dwelling adjusted to the same internal temperature and ventilation rate, but without the front and rear sunspaces; and winter performance vindicates the role of sunspaces in providing good air quality at a relatively low running cost. The work sets aside the issue of life-cycle, pay-back analysis since, in general terms, this is dependent firstly on how much of the cost of sunspaces is written off as necessary floor area or improved amenity, and secondly on variable costs of a complementary energy-efficient package. However, on the assumption that these factors may be favourable, the work concludes with broad design recommendations based on the research findings; in particular recognising the dominance of the 'heat recovery' rather than 'solar' mode of operation of sunspaces.

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Dallas, William. "Resonance ultrasonic vibrations (RUV) for crack detection in silicon wafers for solar cells". [Tampa, Fla] : University of South Florida, 2006. http://purl.fcla.edu/usf/dc/et/SFE0001848.

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Monastyrskyi, Andrii. "Resonance ultrasonic vibrations and photoluminescence mapping for crack detection in crystalline silicon wafers and solar cells". [Tampa, Fla] : University of South Florida, 2008. http://purl.fcla.edu/usf/dc/et/SFE0002779.

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Weaver, Eric P. "Low voltage electrochemical hydrogen production". [Tampa, Fla] : University of South Florida, 2006. http://purl.fcla.edu/usf/dc/et/SFE0001849.

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49

Blazer, Mark A. "Architectural strategies in reducing heat gain in the sub-tropical urban heat island". [Tampa, Fla] : University of South Florida, 2008. http://purl.fcla.edu/usf/dc/et/SFE0002781.

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Mustaffa, Muhammad Ubaidah Syafiq. "Alternative Uses of CZTS Thin Films for Energy Harvesting". Doctoral thesis, Università degli studi di Trento, 2021. http://hdl.handle.net/11572/315176.

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The search for renewable energy resources and ways to harvest them has become a global mainstream topic among researchers nowadays, with solar cells and thermoelectric generators among the energy harvesting technologies currently being researched in vast. CZTS (Cu2ZnSnS4), a p-type semiconducting material initially researched to replace copper indium gallium selenide (CIGS) as the light absorbing layer in thin film solar cells, was studied in this doctoral work for alternative uses in energy harvesting. This work aims to systemically investigate the prospects of CZTS to be used as hole transport layers and thermoelectric generators. CZTS thin film was successfully fabricated using a versatile approach involving hot-injection synthesis of CZTS nanoparticles ink followed by spin coating and thermal treatment. Results obtained revealed the possibility to fine control CZTS thin film fabrication based on ink concentration and spin. Besides that, thermal treatment temperature was found to affect the film’s overall properties, where an increase in thermal treatment temperature improved the degree of crystallinity and electrical properties. In addition, a phase change going from less stable cubic and wurtzite structures to a more stable tetragonal structure was also observed. Furthermore, CZTS was found to be a good candidate to replace the commonly used organic hole transport layer in perovskite solar cells, with potentials in improving performance and stability. In addition, CZTS also possessed good transport properties to be a potential p-type material in a thermoelectric generator, with the preliminary performance of fabricated CZTS/AZO thermoelectric generator showing a maximum power output of ~350 nW at ~170 KΔT. These findings provide new perspectives for CZTS in energy harvesting applications, despite the struggle in its development as the absorber layer in thin film solar cells. Besides providing a deeper understanding of CZTS and its vast possibilities in energy harvesting applications, promising future research stemming from this work is also limitless, reinventing ways in material studies, in search of alternative applications which may be of benefit.

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Tesis sobre el tema "Solar energy use"

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